43 results on '"Rivka Hadar"'
Search Results
2. Endocannabinoid Levels in Ulcerative Colitis Patients Correlate With Clinical Parameters and Are Affected by Cannabis Consumption
- Author
-
Shelly Tartakover Matalon, Shahar Azar, David Meiri, Rivka Hadar, Alina Nemirovski, Narjes Abu Jabal, Fred Meir Konikoff, Liat Drucker, Joseph Tam, and Timna Naftali
- Subjects
cannabis ,ulcerative colitis ,Crohn’s disease ,inflammatory bowel disease ,endocannabinoids ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
BackgroundInflammatory bowel diseases (IBDs) are chronic, idiopathic, inflammatory, gastrointestinal disorders. The endocannabinoid system may have a role in the pathogenesis of IBD. We aimed to assess whether cannabis treatment influences endocannabinoids (eCBs) level and clinical symptoms of IBD patients.MethodsBlood samples and biopsies were taken from IBD patients treated by either cannabis or placebo for 8 weeks. Immunohistochemistry for N-acyl-phosphatidylethanolamine-selective phospholipase D (NAPE-PLD) and fatty acid amide hydrolase (FAAH) expression was done on colon biopsies, and sample levels of anandamide (AEA), eCB2-arachidonylglycerol (2-AG), arachidonic acid (AA), palmitoylethanolamine (PEA), and oleoylethanolamine (OEA) were measured in patient’s sera before and after cannabis treatment. Caco-2 cells were cultured with extracts of cannabis with/without tetrahydrocannabinol (THC) and their proteins extracted, and Western blotting for NAPE-PLD and FAAH expression was done.ResultsThirteen patients with Crohn’s disease (CD) and nine patients with ulcerative colitis (UC) were treated with cannabis. Seventeen patients with CD and 10 with UC served as placebo groups. In all CD patients, the levels of eCBs remained unaltered during the treatment period. In UC patients treated with placebo, but not in those treated with cannabis, the levels of PEA, AEA, and AA decreased significantly. The percent reduction in bowel movements was negatively correlated with changes observed in the circulating AEA and OEA, whereas improvement in quality of life was positively correlated with the levels of 2-AG. In the biopsies from UC patients, FAAH levels increased over the study period. In Caco-2 cells, both cannabis extracts increased NAPE-PLD levels but reduced FAAH expression levels.ConclusionOur study supports the notion that cannabis use affects eCB “tone” in UC patients and may have beneficial effects on disease symptoms in UC patients.
- Published
- 2021
- Full Text
- View/download PDF
3. Reduced Endocannabinoid Tone in Saliva of Chronic Orofacial Pain Patients
- Author
-
Yaron Haviv, Olga Georgiev, Tal Gaver-Bracha, Sharleen Hamad, Alina Nemirovski, Rivka Hadar, Yair Sharav, Doron J. Aframian, Yariv Brotman, and Joseph Tam
- Subjects
endocannabinoids ,anandamide ,2-AG ,chronic pain ,orofacial pain ,neuropathic pain ,Organic chemistry ,QD241-441 - Abstract
Background: the endocannabinoid system (ECS) participates in many physiological and pathological processes including pain generation, modulation, and sensation. Its involvement in chronic orofacial pain (OFP) in general, and the reflection of its involvement in OFP in salivary endocannabinoid (eCBs) levels in particular, has not been examined. Objectives: to evaluate the association between salivary (eCBs) levels and chronic OFP. Methods: salivary levels of 2 eCBs, anandamide (AEA), 2-arachidonoylglycerol (2-AG), 2 endocannabinoid-like compoundsN-palmitoylethanolamine (PEA), N-oleoylethanolamine (OEA), and their endogenous precursor and breakdown product, arachidonic acid (AA), were analyzed using liquid chromatography/tandem mass spectrometry in 83 chronic OFP patients and 43 pain-free controls. The chronic OFP patients were divided according to diagnosis into musculoskeletal, neurovascular/migraine, and neuropathic pain types. Results: chronic OFP patients had lower levels of OEA (p = 0.02) and 2-AG (p = 0.01). Analyzing specific pain types revealed lower levels of AEA and OEA in the neurovascular group (p = 0.04, 0.02, respectively), and 2-AG in the neuropathic group compared to controls (p = 0.05). No significant differences were found between the musculoskeletal pain group and controls. Higher pain intensity was accompanied by lower levels of AA (p = 0.028), in neuropathic group. Conclusions: lower levels of eCBs were found in the saliva of chronic OFP patients compared to controls, specifically those with neurovascular/migraine, and neuropathic pain. The detection of changes in salivary endocannabinoids levels related to OFP adds a new dimension to our understanding of OFP mechanisms, and may have diagnostic as well as therapeutic implications for pain.
- Published
- 2022
- Full Text
- View/download PDF
4. Reversal of diet-induced hepatic steatosis by peripheral CB1 receptor blockade in mice is p53/miRNA-22/SIRT1/PPARα dependent
- Author
-
Shahar Azar, Shiran Udi, Adi Drori, Rivka Hadar, Alina Nemirovski, Kiran V. Vemuri, Maya Miller, Dana Sherill-Rofe, Yhara Arad, Devorah Gur-Wahnon, Xiaoling Li, Alexandros Makriyannis, Danny Ben-Zvi, Yuval Tabach, Iddo Z. Ben-Dov, and Joseph Tam
- Subjects
Obesity ,Fatty liver ,Endocannabinoids ,microRNAs ,Nuclear receptor ,Internal medicine ,RC31-1245 - Abstract
Objective: The endocannabinoid (eCB) system is increasingly recognized as being crucially important in obesity-related hepatic steatosis. By activating the hepatic cannabinoid-1 receptor (CB1R), eCBs modulate lipogenesis and fatty acid oxidation. However, the underlying molecular mechanisms are largely unknown. Methods: We combined unbiased bioinformatics techniques, mouse genetic manipulations, multiple pharmacological, molecular, and cellular biology approaches, and genomic sequencing to systematically decipher the role of the hepatic CB1R in modulating fat utilization in the liver and explored the downstream molecular mechanisms. Results: Using an unbiased normalized phylogenetic profiling analysis, we found that the CB1R evolutionarily coevolves with peroxisome proliferator-activated receptor-alpha (PPARα), a key regulator of hepatic lipid metabolism. In diet-induced obese (DIO) mice, peripheral CB1R blockade (using AM6545) induced the reversal of hepatic steatosis and improved liver injury in WT, but not in PPARα−/− mice. The antisteatotic effect mediated by AM6545 in WT DIO mice was accompanied by increased hepatic expression and activity of PPARα as well as elevated hepatic levels of the PPARα-activating eCB-like molecules oleoylethanolamide and palmitoylethanolamide. Moreover, AM6545 was unable to rescue hepatic steatosis in DIO mice lacking liver sirtuin 1 (SIRT1), an upstream regulator of PPARα. Both of these signaling molecules were modulated by the CB1R as measured in hepatocytes exposed to lipotoxic conditions or treated with CB1R agonists in the absence/presence of AM6545. Furthermore, using microRNA transcriptomic profiling, we found that the CB1R regulated the hepatic expression, acetylation, and transcriptional activity of p53, resulting in the enhanced expression of miR-22, which was found to specifically target SIRT1 and PPARα. Conclusions: We provide strong evidence for a functional role of the p53/miR-22/SIRT1/PPARα signaling pathway in potentially mediating the antisteatotic effect of peripherally restricted CB1R blockade.
- Published
- 2020
- Full Text
- View/download PDF
5. CB1R regulates soluble leptin receptor levels via CHOP, contributing to hepatic leptin resistance
- Author
-
Adi Drori, Asaad Gammal, Shahar Azar, Liad Hinden, Rivka Hadar, Daniel Wesley, Alina Nemirovski, Gergő Szanda, Maayan Salton, Boaz Tirosh, and Joseph Tam
- Subjects
endocannabinoids ,leptin resistance ,ER stress ,obesity ,cb1 receptor ,CHOP ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
The soluble isoform of leptin receptor (sOb-R), secreted by the liver, regulates leptin bioavailability and bioactivity. Its reduced levels in diet-induced obesity (DIO) contribute to hyperleptinemia and leptin resistance, effects that are regulated by the endocannabinoid (eCB)/CB1R system. Here we show that pharmacological activation/blockade and genetic overexpression/deletion of hepatic CB1R modulates sOb-R levels and hepatic leptin resistance. Interestingly, peripheral CB1R blockade failed to reverse DIO-induced reduction of sOb-R levels, increased fat mass and dyslipidemia, and hepatic steatosis in mice lacking C/EBP homologous protein (CHOP), whereas direct activation of CB1R in wild-type hepatocytes reduced sOb-R levels in a CHOP-dependent manner. Moreover, CHOP stimulation increased sOb-R expression and release via a direct regulation of its promoter, while CHOP deletion reduced leptin sensitivity. Our findings highlight a novel molecular aspect by which the hepatic eCB/CB1R system is involved in the development of hepatic leptin resistance and in the regulation of sOb-R levels via CHOP.
- Published
- 2020
- Full Text
- View/download PDF
6. Correction to Prediction and Experimental Confirmation of Novel Peripheral Cannabinoid-1 Receptor Antagonists.
- Author
-
Shayma El-Atawneh, Shira Hirsch, Rivka Hadar, Joseph Tam, and Amiram Goldblum
- Published
- 2020
- Full Text
- View/download PDF
7. Targeting the endocannabinoid/CB1 receptor system for treating obesity in Prader–Willi syndrome
- Author
-
Ibrahim Knani, Brian J. Earley, Shiran Udi, Alina Nemirovski, Rivka Hadar, Asaad Gammal, Resat Cinar, Harry J. Hirsch, Yehuda Pollak, Itai Gross, Talia Eldar-Geva, Daniela P. Reyes-Capo, Joan C. Han, Andrea M. Haqq, Varda Gross-Tsur, Rachel Wevrick, and Joseph Tam
- Subjects
Internal medicine ,RC31-1245 - Abstract
Objective: Extreme obesity is a core phenotypic feature of Prader–Willi syndrome (PWS). Among numerous metabolic regulators, the endocannabinoid (eCB) system is critically involved in controlling feeding, body weight, and energy metabolism, and a globally acting cannabinoid-1 receptor (CB1R) blockade reverses obesity both in animals and humans. The first-in-class CB1R antagonist rimonabant proved effective in inducing weight loss in adults with PWS. However, it is no longer available for clinical use because of its centrally mediated, neuropsychiatric, adverse effects. Methods: We studied eCB ‘tone’ in individuals with PWS and in the Magel2-null mouse model that recapitulates the major metabolic phenotypes of PWS and determined the efficacy of a peripherally restricted CB1R antagonist, JD5037 in treating obesity in these mice. Results: Individuals with PWS had elevated circulating levels of 2-arachidonoylglycerol and its endogenous precursor and breakdown ligand, arachidonic acid. Increased hypothalamic eCB ‘tone’, manifested by increased eCBs and upregulated CB1R, was associated with increased fat mass, reduced energy expenditure, and decreased voluntary activity in Magel2-null mice. Daily chronic treatment of obese Magel2-null mice and their littermate wild-type controls with JD5037 (3 mg/kg/d for 28 days) reduced body weight, reversed hyperphagia, and improved metabolic parameters related to their obese phenotype. Conclusions: Dysregulation of the eCB/CB1R system may contribute to hyperphagia and obesity in Magel2-null mice and in individuals with PWS. Our results demonstrate that treatment with peripherally restricted CB1R antagonists may be an effective strategy for the management of severe obesity in PWS. Author Video: Author Video Watch what authors say about their articles Keywords: Endocannabinoids, PWS, Magel2, Peripheral CB1 blockade, Metabolic syndrome
- Published
- 2016
- Full Text
- View/download PDF
8. Salivary Endocannabinoid Profiles in Chronic Orofacial Pain and Headache Disorders: An Observational Study Using a Novel Tool for Diagnosis and Management
- Author
-
Shimrit Heiliczer, Asaf Wilensky, Tal Gaver, Olga Georgiev, Sharleen Hamad, Alina Nemirovski, Rivka Hadar, Yair Sharav, Doron J. Aframian, Joseph Tam, and Yaron Haviv
- Subjects
Headache Disorders ,Migraine Disorders ,Organic Chemistry ,General Medicine ,Catalysis ,Computer Science Applications ,endocannabinoids ,anandamide ,2-AG ,chronic pain ,orofacial pain ,neuropathic pain ,migraine ,saliva ,Inorganic Chemistry ,Facial Pain ,Quality of Life ,Humans ,Physical and Theoretical Chemistry ,Molecular Biology ,Biomarkers ,Spectroscopy ,Endocannabinoids - Abstract
The endocannabinoid system is involved in physiological and pathological processes, including pain generation, modulation, and sensation. Its role in certain types of chronic orofacial pain (OFP) has not been thoroughly examined. By exploring the profiles of specific salivary endocannabinoids (eCBs) in individuals with different types of OFP, we evaluated their use as biomarkers and the influence of clinical parameters and pain characteristics on eCB levels. The salivary levels of anandamide (AEA), 2-arachidonoyl glycerol (2-AG), and their endogenous breakdown product arachidonic acid (AA), as well as the eCB-like molecules N-palmitoylethanolamide (PEA) and N-oleoylethanolamide (OEA), were assessed in 83 OFP patients and 43 pain-free controls using liquid chromatography/tandem mass spectrometry. Patients were grouped by diagnosis: post-traumatic neuropathy (PTN), trigeminal neuralgia (TN), temporomandibular disorder (TMD), migraine, tension-type headache (TTH), and burning mouth syndrome (BMS). Correlation analyses between a specific diagnosis, pain characteristics, and eCB levels were conducted. Significantly lower levels of 2-AG were found in the TN and TTH groups, while significantly lower PEA levels were found in the migraine group. BMS was the only group with elevated eCBs (AEA) versus the control. Significant correlations were found between levels of specific eCBs and gender, health-related quality of life (HRQoL), BMI, pain duration, and sleep awakenings. In conclusion, salivary samples exhibited signature eCBs profiles for major OFP disorders, especially migraine, TTH, TN, and BMS. This finding may pave the way for using salivary eCBs biomarkers for more accurate diagnoses and management of chronic OFP patients.
- Published
- 2022
- Full Text
- View/download PDF
9. Endocannabinoid Levels in Ulcerative Colitis Patients Correlate With Clinical Parameters and Are Affected by Cannabis Consumption
- Author
-
Liat Drucker, David Meiri, Alina Nemirovski, Timna Naftali, Shahar Azar, Shelly Tartakover Matalon, Fred M. Konikoff, Narjes Abu Jabal, Rivka Hadar, and Joseph Tam
- Subjects
Adult ,Male ,cannabis ,Crohn’s disease ,medicine.medical_specialty ,Colon ,Endocrinology, Diabetes and Metabolism ,Medical Marijuana ,Gastroenterology ,Inflammatory bowel disease ,Diseases of the endocrine glands. Clinical endocrinology ,Amidohydrolases ,chemistry.chemical_compound ,Young Adult ,Endocrinology ,Crohn Disease ,Double-Blind Method ,Fatty acid amide hydrolase ,inflammatory bowel disease ,Internal medicine ,medicine ,Phospholipase D ,Humans ,endocannabinoids ,Tetrahydrocannabinol ,Aged ,Original Research ,ulcerative colitis ,Aged, 80 and over ,Crohn's disease ,biology ,business.industry ,Anandamide ,Middle Aged ,biology.organism_classification ,medicine.disease ,RC648-665 ,Endocannabinoid system ,Ulcerative colitis ,chemistry ,lipids (amino acids, peptides, and proteins) ,Colitis, Ulcerative ,Female ,Cannabis ,Caco-2 Cells ,business ,medicine.drug - Abstract
BackgroundInflammatory bowel diseases (IBDs) are chronic, idiopathic, inflammatory, gastrointestinal disorders. The endocannabinoid system may have a role in the pathogenesis of IBD. We aimed to assess whether cannabis treatment influences endocannabinoids (eCBs) level and clinical symptoms of IBD patients.MethodsBlood samples and biopsies were taken from IBD patients treated by either cannabis or placebo for 8 weeks. Immunohistochemistry for N-acyl-phosphatidylethanolamine-selective phospholipase D (NAPE-PLD) and fatty acid amide hydrolase (FAAH) expression was done on colon biopsies, and sample levels of anandamide (AEA), eCB2-arachidonylglycerol (2-AG), arachidonic acid (AA), palmitoylethanolamine (PEA), and oleoylethanolamine (OEA) were measured in patient’s sera before and after cannabis treatment. Caco-2 cells were cultured with extracts of cannabis with/without tetrahydrocannabinol (THC) and their proteins extracted, and Western blotting for NAPE-PLD and FAAH expression was done.ResultsThirteen patients with Crohn’s disease (CD) and nine patients with ulcerative colitis (UC) were treated with cannabis. Seventeen patients with CD and 10 with UC served as placebo groups. In all CD patients, the levels of eCBs remained unaltered during the treatment period. In UC patients treated with placebo, but not in those treated with cannabis, the levels of PEA, AEA, and AA decreased significantly. The percent reduction in bowel movements was negatively correlated with changes observed in the circulating AEA and OEA, whereas improvement in quality of life was positively correlated with the levels of 2-AG. In the biopsies from UC patients, FAAH levels increased over the study period. In Caco-2 cells, both cannabis extracts increased NAPE-PLD levels but reduced FAAH expression levels.ConclusionOur study supports the notion that cannabis use affects eCB “tone” in UC patients and may have beneficial effects on disease symptoms in UC patients.
- Published
- 2021
10. CB1R regulates soluble leptin receptor levels via CHOP, contributing to hepatic leptin resistance
- Author
-
Gergő Szanda, Rivka Hadar, Joseph Tam, Maayan Salton, Shahar Azar, Liad Hinden, Alina Nemirovski, Daniel Wesley, Adi Drori, Boaz Tirosh, and Asaad Gammal
- Subjects
0301 basic medicine ,medicine.medical_specialty ,obesity ,Cannabinoid receptor ,QH301-705.5 ,Science ,030209 endocrinology & metabolism ,CHOP ,General Biochemistry, Genetics and Molecular Biology ,cb1 receptor ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,endocannabinoids ,Biology (General) ,Receptor ,Leptin receptor ,General Immunology and Microbiology ,business.industry ,General Neuroscience ,Leptin ,digestive, oral, and skin physiology ,General Medicine ,medicine.disease ,Obesity ,Endocannabinoid system ,leptin resistance ,3. Good health ,030104 developmental biology ,Endocrinology ,Medicine ,business ,ER stress ,hormones, hormone substitutes, and hormone antagonists ,Hormone - Abstract
When the human body has stored enough energy from food, it releases a hormone called leptin that travels to the brain and stops feelings of hunger. This hormone moves through the bloodstream and can affect other organs, such as the liver, which also help control our body’s energy levels. Most people with obesity have very high levels of leptin in their blood, but are resistant to its effects and will therefore continue to feel hungry despite having stored enough energy. One of the proteins that controls the levels of leptin is a receptor called sOb-R, which is released by the liver and binds to leptin as it travels in the blood. Individuals with high levels of this receptor often have less free leptin in their bloodstream and a lower body weight. Another protein that helps the body to regulate its energy levels is the cannabinoid-1 receptor, or CB1R for short. In people with obesity, this receptor is overactive and has been shown to contribute to leptin resistance, which is when the brain becomes less receptive to leptin. Previous work in mice showed that blocking CB1R reduced the levels of leptin and allowed mice to react to this hormone normally again, but it remained unclear whether CB1R affects how other organs, such as the liver, respond to leptin. To answer this question, Drori et al. blocked the CB1R receptor in the liver of mice eating a high-fat diet, either by using a drug or by deleting the gene that codes for this protein. This caused mice to have higher levels of sOb-R circulating in their bloodstream. Further experiments showed that this change in sOb-R was caused by the levels of a protein called CHOP increasing in the liver when CB1R was blocked. Drori et al. found that inhibiting CB1R caused these obese mice to lose weight and have healthier, less fatty livers as a result of their livers no longer being resistant to the effects of leptin. Scientists, doctors and pharmaceutical companies are trying to develop new strategies to combat obesity. The results from these experiments suggest that blocking CB1R in the liver could allow this organ to react to leptin appropriately again. Drugs blocking CB1R, including the one used in this study, will be tested in clinical trials and could provide a new approach for treating obesity.
- Published
- 2020
11. Author response: CB1R regulates soluble leptin receptor levels via CHOP, contributing to hepatic leptin resistance
- Author
-
Daniel Wesley, Rivka Hadar, Liad Hinden, Shahar Azar, Joseph Tam, Maayan Salton, Adi Drori, Alina Nemirovski, Boaz Tirosh, Gergő Szanda, and Asaad Gammal
- Subjects
medicine.medical_specialty ,Leptin receptor ,Endocrinology ,business.industry ,Internal medicine ,medicine ,Leptin resistance ,CHOP ,business - Published
- 2020
- Full Text
- View/download PDF
12. Author Correction: Bone Anabolic Response in the Calvaria Following Mild Traumatic Brain Injury is Mediated by the Cannabinoid-1 Receptor
- Author
-
Alina Nemirovski, Joseph Tam, Chaim G. Pick, Miaad Bader, Michal Eger, Rivka Hadar, Yankel Gabet, Dan Levy, and Dara Bree
- Subjects
Male ,medicine.medical_specialty ,Cannabinoid 1 receptor ,Anabolism ,Traumatic brain injury ,Polyunsaturated Alkamides ,lcsh:Medicine ,Calvaria ,Arachidonic Acids ,Glycerides ,Mice ,Receptor, Cannabinoid, CB1 ,Internal medicine ,Brain Injuries, Traumatic ,medicine ,Animals ,Mast Cells ,lcsh:Science ,Author Correction ,Mice, Knockout ,Mice, Inbred ICR ,Multidisciplinary ,business.industry ,lcsh:R ,Skull ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,lcsh:Q ,Rimonabant ,business ,Endocannabinoids - Abstract
Brain trauma was clinically associated with increased osteogenesis in the appendicular skeleton. We showed previously in C57BL/6J mice that mild traumatic brain injury (mTBI) transiently induced bone formation in the femur via the cannabinoid-1 (CB1) receptor. Here, we subjected ICR mice to mTBI and examined the bone response in the skull using microCT. We also measured mast cell degranulation (MCD)72 h post-injury. Finally, we measured brain and calvarial endocannabinoids levels post-mTBI. mTBI led to decreased bone porosity on the contralateral (untouched) side. This effect was apparent both in young and mature mice. Administration of rimonabant (CB1 inverse agonist) completely abrogated the effect of mTBI on calvarial porosity and significantly reduced MCD, compared with vehicle-treated controls. We also found that mTBI resulted in elevated levels of anandamide, but not 2-arachidonoylglycerol, in the contralateral calvarial bone, whereas brain levels remained unchanged. In C57BL/6J CB1 knockout mice, mTBI did not reduce porosity but in general the porosity was significantly lower than in WT controls. Our findings suggest that mTBI induces a strain-specific CB1-dependent bone anabolic response in the skull, probably mediated by anandamide, but seemingly unrelated to inflammation. The endocannabinoid system is therefore a plausible target in management of bone response following head trauma.
- Published
- 2020
13. CB1R Regulates Soluble Leptin Receptor Levels via CHOP, Contributing to Hepatic Leptin Resistance
- Author
-
Alina Nemirovski, Liad Hinden, Maayan Salton, Daniel Wesley, Adi Drori, Gergő Szanda, Boaz Tirosh, Joseph Tam, Shahar Azar, Asaad Gammal, and Rivka Hadar
- Subjects
Gene isoform ,0303 health sciences ,medicine.medical_specialty ,Leptin receptor ,Chemistry ,Leptin ,030209 endocrinology & metabolism ,Stimulation ,CHOP ,medicine.disease ,Endocannabinoid system ,3. Good health ,Blockade ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Internal medicine ,medicine ,Steatosis ,030304 developmental biology - Abstract
The soluble isoform of leptin receptor (sOb-R), secreted by the liver, regulates leptin bioavailability and bioactivity. Its reduced levels in diet-induced obesity (DIO) contributes to hyperleptinemia and leptin resistance, effects that are known to be regulated by the endocannabinoid (eCB)/CB1R system. Here we show that pharmacological activation/blockade as well as genetic overexpression/deletion of hepatic CB1R modulates sOb-R levels and consequently hepatic leptin resistance. Interestingly, peripheral CB1R blockade failed to reverse DIO-induced reduction of sOb-R levels, fat mass, dyslipidemia, and hepatic steatosis in mice lacking C/EBP homologous protein (CHOP), whereas direct activation of CB1R in hepatocytes reduced sOb-R levels in a CHOP-dependent manner. Moreover, CHOP stimulation increased sOb-R expression and release via a direct regulation of its promoter, while CHOP deletion reduced leptin sensitivity. Our findings highlight a novel molecular aspect by which the hepatic eCB/CB1R system involves in the development of hepatic leptin resistance by regulating sOb-R levels via CHOP.SummaryHere we describe a novel molecular aspect by which the hepatic endocannabinoid/CB1R system contributes to hepatic leptin resistance by regulating soluble leptin receptor levels via CHOP.
- Published
- 2020
- Full Text
- View/download PDF
14. CB
- Author
-
Adi, Drori, Asaad, Gammal, Shahar, Azar, Liad, Hinden, Rivka, Hadar, Daniel, Wesley, Alina, Nemirovski, Gergő, Szanda, Maayan, Salton, Boaz, Tirosh, and Joseph, Tam
- Subjects
Male ,obesity ,Mouse ,Cell Cycle Proteins ,Diet, High-Fat ,cb1 receptor ,Cell Line ,Receptor, Cannabinoid, CB1 ,Non-alcoholic Fatty Liver Disease ,Animals ,endocannabinoids ,Cannabinoid Receptor Antagonists ,Mice, Knockout ,Cell Biology ,Endoplasmic Reticulum Stress ,Activating Transcription Factor 4 ,leptin resistance ,Mice, Inbred C57BL ,Disease Models, Animal ,Liver ,Hepatocytes ,Receptors, Leptin ,ER stress ,hormones, hormone substitutes, and hormone antagonists ,Transcription Factor CHOP ,CHOP ,Signal Transduction ,Research Article - Abstract
The soluble isoform of leptin receptor (sOb-R), secreted by the liver, regulates leptin bioavailability and bioactivity. Its reduced levels in diet-induced obesity (DIO) contribute to hyperleptinemia and leptin resistance, effects that are regulated by the endocannabinoid (eCB)/CB1R system. Here we show that pharmacological activation/blockade and genetic overexpression/deletion of hepatic CB1R modulates sOb-R levels and hepatic leptin resistance. Interestingly, peripheral CB1R blockade failed to reverse DIO-induced reduction of sOb-R levels, increased fat mass and dyslipidemia, and hepatic steatosis in mice lacking C/EBP homologous protein (CHOP), whereas direct activation of CB1R in wild-type hepatocytes reduced sOb-R levels in a CHOP-dependent manner. Moreover, CHOP stimulation increased sOb-R expression and release via a direct regulation of its promoter, while CHOP deletion reduced leptin sensitivity. Our findings highlight a novel molecular aspect by which the hepatic eCB/CB1R system is involved in the development of hepatic leptin resistance and in the regulation of sOb-R levels via CHOP., eLife digest When the human body has stored enough energy from food, it releases a hormone called leptin that travels to the brain and stops feelings of hunger. This hormone moves through the bloodstream and can affect other organs, such as the liver, which also help control our body’s energy levels. Most people with obesity have very high levels of leptin in their blood, but are resistant to its effects and will therefore continue to feel hungry despite having stored enough energy. One of the proteins that controls the levels of leptin is a receptor called sOb-R, which is released by the liver and binds to leptin as it travels in the blood. Individuals with high levels of this receptor often have less free leptin in their bloodstream and a lower body weight. Another protein that helps the body to regulate its energy levels is the cannabinoid-1 receptor, or CB1R for short. In people with obesity, this receptor is overactive and has been shown to contribute to leptin resistance, which is when the brain becomes less receptive to leptin. Previous work in mice showed that blocking CB1R reduced the levels of leptin and allowed mice to react to this hormone normally again, but it remained unclear whether CB1R affects how other organs, such as the liver, respond to leptin. To answer this question, Drori et al. blocked the CB1R receptor in the liver of mice eating a high-fat diet, either by using a drug or by deleting the gene that codes for this protein. This caused mice to have higher levels of sOb-R circulating in their bloodstream. Further experiments showed that this change in sOb-R was caused by the levels of a protein called CHOP increasing in the liver when CB1R was blocked. Drori et al. found that inhibiting CB1R caused these obese mice to lose weight and have healthier, less fatty livers as a result of their livers no longer being resistant to the effects of leptin. Scientists, doctors and pharmaceutical companies are trying to develop new strategies to combat obesity. The results from these experiments suggest that blocking CB1R in the liver could allow this organ to react to leptin appropriately again. Drugs blocking CB1R, including the one used in this study, will be tested in clinical trials and could provide a new approach for treating obesity.
- Published
- 2020
15. Bone Anabolic Response in the Calvaria Following Mild Traumatic Brain Injury is Mediated by the Cannabinoid-1 Receptor
- Author
-
Miaad Bader, Dara Bree, Rivka Hadar, Chaim G. Pick, Michal Eger, Yankel Gabet, Dan Levy, Joseph Tam, and Alina Nemirovski
- Subjects
medicine.medical_specialty ,Cannabinoid receptor ,Traumatic brain injury ,lcsh:Medicine ,030209 endocrinology & metabolism ,Inflammation ,Calvaria ,Trauma ,Article ,Head trauma ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Rimonabant ,Internal medicine ,medicine ,lcsh:Science ,Bone ,Multidisciplinary ,business.industry ,lcsh:R ,Anandamide ,medicine.disease ,Endocannabinoid system ,Endocrinology ,medicine.anatomical_structure ,chemistry ,lcsh:Q ,lipids (amino acids, peptides, and proteins) ,medicine.symptom ,business ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Brain trauma was clinically associated with increased osteogenesis in the appendicular skeleton. We showed previously in C57BL/6J mice that mild traumatic brain injury (mTBI) transiently induced bone formation in the femur via the cannabinoid-1 (CB1) receptor. Here, we subjected ICR mice to mTBI and examined the bone response in the skull using microCT. We also measured mast cell degranulation (MCD)72 h post-injury. Finally, we measured brain and calvarial endocannabinoids levels post-mTBI. mTBI led to decreased bone porosity on the contralateral (untouched) side. This effect was apparent both in young and mature mice. Administration of rimonabant (CB1 inverse agonist) completely abrogated the effect of mTBI on calvarial porosity and significantly reduced MCD, compared with vehicle-treated controls. We also found that mTBI resulted in elevated levels of anandamide, but not 2-arachidonoylglycerol, in the contralateral calvarial bone, whereas brain levels remained unchanged. In C57BL/6J CB1 knockout mice, mTBI did not reduce porosity but in general the porosity was significantly lower than in WT controls. Our findings suggest that mTBI induces a strain-specific CB1-dependent bone anabolic response in the skull, probably mediated by anandamide, but seemingly unrelated to inflammation. The endocannabinoid system is therefore a plausible target in management of bone response following head trauma.
- Published
- 2019
16. Prediction and Experimental Confirmation of Novel Peripheral Cannabinoid-1 Receptor Antagonists
- Author
-
Shira Hirsch, Joseph Tam, Rivka Hadar, Shayma El-Atawneh, and Amiram Goldblum
- Subjects
Cannabinoid receptor ,General Chemical Engineering ,medicine.medical_treatment ,Central nervous system ,Library and Information Sciences ,Pharmacology ,Ligands ,Machine Learning ,Small Molecule Libraries ,03 medical and health sciences ,0302 clinical medicine ,Receptor, Cannabinoid, CB1 ,In vivo ,medicine ,Inverse agonist ,Computer Simulation ,Receptor ,030304 developmental biology ,0303 health sciences ,Chemistry ,Computational Biology ,General Chemistry ,Affinities ,Small molecule ,3. Good health ,Computer Science Applications ,medicine.anatomical_structure ,Cannabinoid ,030217 neurology & neurosurgery - Abstract
Small molecules targeting peripheral CB1 receptors have therapeutic potential in a variety of disorders including obesity-related, hormonal, and metabolic abnormalities, while avoiding the psychoactive effects in the central nervous system. We applied our in-house algorithm, iterative stochastic elimination, to produce a ligand-based model that distinguishes between CB1R antagonists and random molecules by physicochemical properties only. We screened ∼2 million commercially available molecules and found that about 500 of them are potential candidates to antagonize the CB1R. We applied a few criteria for peripheral activity and narrowed that set down to 30 molecules, out of which 15 could be purchased. Ten out of those 15 showed good affinity to the CB1R and two of them with nanomolar affinities (Ki of ∼400 nM). The eight molecules with top affinities were tested for activity: two compounds were pure antagonists, and five others were inverse agonists. These molecules are now being examined in vivo for their peripheral versus central distribution and subsequently will be tested for their effects on obesity in small animals.
- Published
- 2019
17. Targeting the endocannabinoid/CB1 receptor system for treating obesity in Prader–Willi syndrome
- Author
-
Rivka Hadar, Shiran Udi, Varda Gross-Tsur, Joan C. Han, Alina Nemirovski, Daniela P Reyes-Capo, Brian J. Earley, Itai Gross, Ibrahim Knani, Talia Eldar-Geva, Rachel Wevrick, Andrea M. Haqq, Harry J. Hirsch, Joseph Tam, Yehuda Pollak, Resat Cinar, and Asaad Gammal
- Subjects
Male ,0301 basic medicine ,Cannabinoid receptor ,Peripheral CB1 blockade ,Mice ,Receptor, Cannabinoid, CB1 ,Rimonabant ,Weight loss ,Receptor ,2. Zero hunger ,Sulfonamides ,PWS ,Metabolic syndrome ,Endocannabinoid system ,3. Good health ,Female ,Original Article ,medicine.symptom ,Prader-Willi Syndrome ,medicine.drug ,Adult ,medicine.medical_specialty ,congenital, hereditary, and neonatal diseases and abnormalities ,lcsh:Internal medicine ,Hypothalamus ,Arachidonic Acids ,Glycerides ,03 medical and health sciences ,Antigens, Neoplasm ,Internal medicine ,Weight Loss ,medicine ,Animals ,Humans ,lcsh:RC31-1245 ,Molecular Biology ,Magel2 ,business.industry ,Body Weight ,Antagonist ,Proteins ,nutritional and metabolic diseases ,Cell Biology ,medicine.disease ,Obesity ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,Endocrinology ,Case-Control Studies ,Pyrazoles ,business ,Endocannabinoids - Abstract
Objective Extreme obesity is a core phenotypic feature of Prader–Willi syndrome (PWS). Among numerous metabolic regulators, the endocannabinoid (eCB) system is critically involved in controlling feeding, body weight, and energy metabolism, and a globally acting cannabinoid-1 receptor (CB1R) blockade reverses obesity both in animals and humans. The first-in-class CB1R antagonist rimonabant proved effective in inducing weight loss in adults with PWS. However, it is no longer available for clinical use because of its centrally mediated, neuropsychiatric, adverse effects. Methods We studied eCB ‘tone’ in individuals with PWS and in the Magel2-null mouse model that recapitulates the major metabolic phenotypes of PWS and determined the efficacy of a peripherally restricted CB1R antagonist, JD5037 in treating obesity in these mice. Results Individuals with PWS had elevated circulating levels of 2-arachidonoylglycerol and its endogenous precursor and breakdown ligand, arachidonic acid. Increased hypothalamic eCB ‘tone’, manifested by increased eCBs and upregulated CB1R, was associated with increased fat mass, reduced energy expenditure, and decreased voluntary activity in Magel2-null mice. Daily chronic treatment of obese Magel2-null mice and their littermate wild-type controls with JD5037 (3 mg/kg/d for 28 days) reduced body weight, reversed hyperphagia, and improved metabolic parameters related to their obese phenotype. Conclusions Dysregulation of the eCB/CB1R system may contribute to hyperphagia and obesity in Magel2-null mice and in individuals with PWS. Our results demonstrate that treatment with peripherally restricted CB1R antagonists may be an effective strategy for the management of severe obesity in PWS., Highlights • Circulating levels of endocannabinoids are increased in individuals with PWS. • Magel2 is a negative regulator of hypothalamic endocannabinoid ‘tone’. • Peripherally-restricted CB1 receptor blockade reverses obesity in Magel2-null mice.
- Published
- 2016
18. HUR mRNA expression in ovarian high-grade serous carcinoma effusions is associated with poor survival
- Author
-
Betina Katz, Rivka Hadar, Claes G. Tropé, Reuven Reich, Ben Davidson, Ellen Hellesylt, and Arild Holth
- Subjects
Adult ,0301 basic medicine ,Pathology ,medicine.medical_specialty ,Blotting, Western ,Kaplan-Meier Estimate ,Transfection ,Disease-Free Survival ,ELAV-Like Protein 1 ,Pathology and Forensic Medicine ,law.invention ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,law ,Biomarkers, Tumor ,Humans ,Medicine ,RNA, Messenger ,RNA, Small Interfering ,Polymerase chain reaction ,Aged ,Proportional Hazards Models ,Aged, 80 and over ,Ovarian Neoplasms ,Messenger RNA ,Univariate analysis ,Reverse Transcriptase Polymerase Chain Reaction ,business.industry ,Proportional hazards model ,Middle Aged ,Prognosis ,Immunohistochemistry ,Cystadenocarcinoma, Serous ,Reverse transcription polymerase chain reaction ,030104 developmental biology ,Effusion ,030220 oncology & carcinogenesis ,Cancer research ,Female ,business - Abstract
The objective of this study was to analyze the expression and clinical role of the RNA-binding molecule HuR in metastatic high-grade ovarian serous carcinoma (HGSC). HUR mRNA expression by reverse-transcription polymerase chain reaction was analyzed in 66 effusions from patients diagnosed with HGSC. Protein expression was analyzed in 262 HGSC effusions using immunohistochemistry. HUR mRNA was detected in all 66 effusions. HUR mRNA levels were unrelated to clinicopathological parameters. However, higher HUR mRNA levels were significantly related to poor overall survival in the entire cohort (P=.023), as well as in analysis limited to patients with prechemotherapy primary diagnosis specimens (P=.001) in univariate analysis. Cox multivariate analysis showed an independent prognostic role for HUR mRNA in the entire cohort (P=.033) and in patients with prechemotherapy primary diagnosis specimens (P=.002). HuR protein was detected in the nucleus and cytoplasm of tumor cells in 258 (98%) of 262 and 153 (58%) of 262 effusions, respectively. Higher HuR protein expression was associated with higher serum Cancer Antigen (CA) 125 levels at diagnosis (P=.01), but its presence at both cellular compartments was otherwise unrelated to clinicopathological parameters or survival. In conclusion, HuR is widely expressed in metastatic HGSC at both the mRNA and protein level. Higher HUR mRNA levels are associated with poor survival in metastatic HGSC, whereas protein expression has no prognostic value.
- Published
- 2016
- Full Text
- View/download PDF
19. Reversal of diet-induced hepatic steatosis by peripheral CB1 receptor blockade in mice is p53/miRNA-22/SIRT1/PPARα dependent
- Author
-
Shiran Udi, Yuval Tabach, Kiran Vemuri, Dana Sherill-Rofe, Maya Miller, Iddo Z. Ben-Dov, Xiaoling Li, Joseph Tam, Devorah Gur-Wahnon, Rivka Hadar, Alina Nemirovski, Adi Drori, Alexandros Makriyannis, Danny Ben-Zvi, Shahar Azar, and Yhara Arad
- Subjects
Male ,0301 basic medicine ,lcsh:Internal medicine ,030209 endocrinology & metabolism ,Diet, High-Fat ,Mice ,03 medical and health sciences ,Oleoylethanolamide ,chemistry.chemical_compound ,0302 clinical medicine ,Receptor, Cannabinoid, CB1 ,Sirtuin 1 ,Fatty liver ,medicine ,Animals ,Humans ,PPAR alpha ,Obesity ,lcsh:RC31-1245 ,Molecular Biology ,Phylogeny ,Palmitoylethanolamide ,biology ,Chemistry ,Fatty Acids ,Hep G2 Cells ,Cell Biology ,Lipid Metabolism ,medicine.disease ,Lipids ,Endocannabinoid system ,microRNAs ,Cell biology ,Mice, Inbred C57BL ,030104 developmental biology ,Liver ,Nuclear receptor ,Lipogenesis ,Hepatocytes ,biology.protein ,Original Article ,Tumor Suppressor Protein p53 ,Steatosis ,Oxidation-Reduction ,Signal Transduction ,Endocannabinoids - Abstract
Objective The endocannabinoid (eCB) system is increasingly recognized as being crucially important in obesity-related hepatic steatosis. By activating the hepatic cannabinoid-1 receptor (CB1R), eCBs modulate lipogenesis and fatty acid oxidation. However, the underlying molecular mechanisms are largely unknown. Methods We combined unbiased bioinformatics techniques, mouse genetic manipulations, multiple pharmacological, molecular, and cellular biology approaches, and genomic sequencing to systematically decipher the role of the hepatic CB1R in modulating fat utilization in the liver and explored the downstream molecular mechanisms. Results Using an unbiased normalized phylogenetic profiling analysis, we found that the CB1R evolutionarily coevolves with peroxisome proliferator-activated receptor-alpha (PPARα), a key regulator of hepatic lipid metabolism. In diet-induced obese (DIO) mice, peripheral CB1R blockade (using AM6545) induced the reversal of hepatic steatosis and improved liver injury in WT, but not in PPARα−/− mice. The antisteatotic effect mediated by AM6545 in WT DIO mice was accompanied by increased hepatic expression and activity of PPARα as well as elevated hepatic levels of the PPARα-activating eCB-like molecules oleoylethanolamide and palmitoylethanolamide. Moreover, AM6545 was unable to rescue hepatic steatosis in DIO mice lacking liver sirtuin 1 (SIRT1), an upstream regulator of PPARα. Both of these signaling molecules were modulated by the CB1R as measured in hepatocytes exposed to lipotoxic conditions or treated with CB1R agonists in the absence/presence of AM6545. Furthermore, using microRNA transcriptomic profiling, we found that the CB1R regulated the hepatic expression, acetylation, and transcriptional activity of p53, resulting in the enhanced expression of miR-22, which was found to specifically target SIRT1 and PPARα. Conclusions We provide strong evidence for a functional role of the p53/miR-22/SIRT1/PPARα signaling pathway in potentially mediating the antisteatotic effect of peripherally restricted CB1R blockade., Graphical abstract The elucidated molecular signaling pathway by which hepatic CB1R regulates hepatic lipid homeostasis. Activation of hepatic CB1R increases p53 expression, acetylation, nuclear localization,and transcriptional activity that together promote the expression of miR-22, which in turn reduces the expression and activity of PPARα and SIRT1. These events lead to reduced fatty acid oxidation and fat accumulation in the liver (left). Treatment with AM6545, a peripherally restricted CB1R antagonist, disrupts this signaling pathway and ameliorates hepatic steatosis by also increasing hepatic OEA and PEA, which may activate PPARα directly, resulting in the enhanced efficacy of AM6545 in ameliorating hepatic steatosis (right).Image 1, Highlights • PPARα is the top-ranked NAFLD-related gene that is coevolved with the CB1R. • Hepatic PPARα and SIRT1 expression and activity are regulated by the CB1R. • Reversal of hepatic steatosis by peripheral CB1R blockade requires intact SIRT1 and PPARα signaling. • Hepatic PPARα and SIRT1 are direct targets of miR-22, whose expression is regulated via CB1R-induced modulation of p53 expression, acetylation, and transcriptional activity.
- Published
- 2020
- Full Text
- View/download PDF
20. Magel2 Modulates Bone Remodeling and Mass in Prader-Willi Syndrome by Affecting Oleoyl Serine Levels and Activity
- Author
-
Alina Nemirovski, Malka Attar-Namdar, Yshaia Langer, Yankel Gabet, Joseph Tam, Raphael Mechoulam, Shira Hirsch, Reem Smoum, Asaad Gammal, Rivka Hadar, Yehuda Pollak, Saja Baraghithy, Megan E. Rech, Itai Bab, Adi Drori, Christian P. Schaaf, and Varda Gross-Tsur
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Osteoporosis ,Osteoclasts ,030209 endocrinology & metabolism ,Bone remodeling ,Serine ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Osteoclast ,Antigens, Neoplasm ,Bone Density ,Osteogenesis ,Internal medicine ,medicine ,Animals ,Humans ,Orthopedics and Sports Medicine ,Mice, Knockout ,Osteoblasts ,business.industry ,Genetic disorder ,Proteins ,Osteoblast ,medicine.disease ,030104 developmental biology ,medicine.anatomical_structure ,Endocrinology ,Bone Remodeling ,business ,Prader-Willi Syndrome ,Homeostasis ,Hormone - Abstract
Among a multitude of hormonal and metabolic complications, individuals with Prader-Willi syndrome (PWS) exhibit significant bone abnormalities, including decreased BMD, osteoporosis, and subsequent increased fracture risk. Here we show in mice that loss of Magel2, a maternally imprinted gene in the PWS critical region, results in reduced bone mass, density, and strength, corresponding to that observed in humans with PWS, as well as in individuals suffering from Schaaf-Yang syndrome (SYS), a genetic disorder caused by a disruption of the MAGEL2 gene. The low bone mass phenotype in Magel2-/- mice was attributed to reduced bone formation rate, increased osteoclastogenesis and osteoclast activity, and enhanced trans-differentiation of osteoblasts to adipocytes. The absence of Magel2 in humans and mice resulted in reduction in the fatty acid amide bone homeostasis regulator, N-oleoyl serine (OS), whose levels were positively linked with BMD in humans and mice as well as osteoblast activity. Attenuating the skeletal abnormalities in Magel2-/- mice was achieved with chronic administration of a novel synthetic derivative of OS. Taken together, Magel2 plays a key role in modulating bone remodeling and mass in PWS by affecting OS levels and activity. The use of potent synthetic analogs of OS should be further tested clinically as bone therapeutics for treating bone loss. © 2018 American Society for Bone and Mineral Research.
- Published
- 2018
21. Proximal Tubular Cannabinoid-1 Receptor Regulates Obesity-Induced CKD
- Author
-
Brian J. Earley, Alina Nemirovski, Noa Reuveni, Liad Hinden, Joseph Tam, Resat Cinar, Shiran Udi, Rivka Hadar, and Adi Drori
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Kidney ,Cannabinoid receptor ,Kinase ,business.industry ,General Medicine ,medicine.disease ,Endocannabinoid system ,3. Good health ,Nephropathy ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Endocrinology ,medicine.anatomical_structure ,Lipotoxicity ,Nephrology ,030220 oncology & carcinogenesis ,Internal medicine ,medicine ,Signal transduction ,business ,Protein kinase A - Abstract
Obesity-related structural and functional changes in the kidney develop early in the course of obesity and occur independently of hypertension, diabetes, and dyslipidemia. Activating the renal cannabinoid-1 receptor (CB1R) induces nephropathy, whereas CB1R blockade improves kidney function. Whether these effects are mediatedviaa specific cell type within the kidney remains unknown. Here, we show that specific deletion of CB1R in the renal proximal tubule cells did not protect the mice from obesity, but markedly attenuated the obesity-induced lipid accumulation in the kidney and renal dysfunction, injury, inflammation, and fibrosis. These effects associated with increased activation of liver kinase B1 and the energy sensor AMP-activated protein kinase, as well as enhanced fatty acidβ-oxidation. Collectively, these findings indicate that renal proximal tubule cell CB1R contributes to the pathogenesis of obesity-induced renal lipotoxicity and nephropathy by regulating the liver kinase B1/AMP-activated protein kinase signaling pathway.
- Published
- 2017
22. Modulation of Renal GLUT2 by the Cannabinoid-1 Receptor: Implications for the Treatment of Diabetic Nephropathy
- Author
-
Gil Leibowitz, Matan Geron, Adi Drori, Yael Riahi, Yaakov Nahmias, Saja Baraghithy, Joseph Tam, Rivka Hadar, Anna Permyakova, Alina Nemirovski, Liad Hinden, Sabina Tsytkin-Kirschenzweig, Merav Cohen, Shiran Udi, Asaad Gammal, and Avi Priel
- Subjects
0301 basic medicine ,Blood Glucose ,Male ,Cannabinoid receptor ,Pharmacology ,Blood Urea Nitrogen ,Madin Darby Canine Kidney Cells ,Diabetic nephropathy ,Kidney Tubules, Proximal ,Mice ,0302 clinical medicine ,Receptor, Cannabinoid, CB1 ,Insulin ,Diabetic Nephropathies ,Receptor ,Glucose Transporter Type 2 ,Mice, Knockout ,Sulfonamides ,biology ,General Medicine ,3. Good health ,Renal glucose reabsorption ,Nephrology ,030220 oncology & carcinogenesis ,Creatinine ,medicine.symptom ,endocrine system ,Inflammation ,digestive system ,Streptozocin ,03 medical and health sciences ,Islets of Langerhans ,Dogs ,Diabetes mellitus ,Protein Kinase C beta ,medicine ,Albuminuria ,Animals ,business.industry ,Biological Transport ,medicine.disease ,Fibrosis ,030104 developmental biology ,Basic Research ,Glucose ,Tubulointerstitial fibrosis ,biology.protein ,GLUT2 ,Pyrazoles ,business - Abstract
Altered glucose reabsorptionviathe facilitative glucose transporter 2 (GLUT2) during diabetes may lead to renal proximal tubule cell (RPTC) injury, inflammation, and interstitial fibrosis. These pathologies are also triggered by activating the cannabinoid-1 receptor (CB1R), which contributes to the development of diabetic nephropathy (DN). However, the link between CB1R and GLUT2 remains to be determined. Here, we show that chronic peripheral CB1R blockade or genetically inactivating CB1Rs in the RPTCs ameliorated diabetes-induced renal structural and functional changes, kidney inflammation, and tubulointerstitial fibrosis in mice. Inhibition of CB1R also downregulated GLUT2 expression, affected the dynamic translocation of GLUT2 to the brush border membrane of RPTCs, and reduced glucose reabsorption. Thus, targeting peripheral CB1R or inhibiting GLUT2 dynamics in RPTCs has the potential to treat and ameliorate DN. These findings may support the rationale for the clinical testing of peripherally restricted CB1R antagonists or the development of novel renal-specific GLUT2 inhibitors against DN.
- Published
- 2017
- Full Text
- View/download PDF
23. Regulated IRE1-dependent decay participates in curtailing immunoglobulin secretion from plasma cells
- Author
-
Boaz Tirosh, Rivka Hadar, Ann-Hwee Lee, Sandrine Benhamron, Jae-Seon So, and Takao Iwawaky
- Subjects
Messenger RNA ,biology ,Immunology ,RNA splicing ,biology.protein ,Unfolded protein response ,Immunology and Allergy ,Secretion ,Antibody ,X-Box Binding Protein 1 ,Molecular biology ,Immunoglobulin secretion ,In vitro - Abstract
Inositol-requiring enzyme 1 (IRE1) is a kinase and ribonuclease that executes the splicing of X box binding protein 1 (XBP-1) mRNA in response to the accumulation of unfolded protein in the ER, a signal cascade termed the unfolded protein response. Recently, IRE1 has been implicated in mRNA and miRNA cleavage and degradation, a pathway termed regulated IRE1-dependent decay (RIDD). Deletion of XBP-1 in the liver and pancreas strongly enhances RIDD by upregulating IRE1 protein levels and enhancing its ribo-nuclease activity. Because XBP-1 is essential for generating plasma cells with developed secretory capacity, we sought to evaluate the contribution of RIDD to this regulation. Mice were conditionally deleted for XBP-1 and/or IRE1 in their B-cell lineage. Similarly to the liver, deletion of XBP-1 induces IRE1 expression in LPS-treated B cells. In vitro, IRE1 cleaves the mRNA of secretory μ chains, which explains the reduction in secretory μ mRNA and its synthesis in XBP-1 KO plasma cells. In accordance, the IgM response is partially restored in XBP-1/IRE1 double KO mice relative to XBP-1 KO mice. Interestingly, the IgG1 response is reduced to a similar level in XBP-1 KO, IRE1 KO, and their double knockout animals. Our data demonstrate a specific contribution by RIDD in curtailing immunoglobulin synthesis and secretion.
- Published
- 2013
- Full Text
- View/download PDF
24. Endoplasmic Reticulum Stress Induces a Caspase-dependent N-terminal Cleavage of RBX1 Protein in B Cells
- Author
-
Shimon Shteingart, Itamar Cohen, Boaz Tirosh, Rivka Hadar, and Tommer Ravid
- Subjects
RBX1 ,Plasma Cells ,Saccharomyces cerevisiae ,Biochemistry ,Mice ,Ubiquitin ,Plasma cell differentiation ,Animals ,Humans ,Molecular Biology ,Cells, Cultured ,biology ,Endoplasmic reticulum ,Ubiquitination ,Cell Differentiation ,Cell Biology ,RING Box Protein 1 ,Endoplasmic Reticulum Stress ,Molecular biology ,Ubiquitin ligase ,Cell biology ,Protein Synthesis and Degradation ,Caspases ,Mutation ,Proteolysis ,biology.protein ,Unfolded protein response ,Carrier Proteins ,Cullin - Abstract
Endoplasmic reticulum (ER) stress develops when the ER is overloaded with too many proteins to fold. This elicits a signaling pathway called the unfolded protein response. The unfolded protein response is physiologically required for the terminal development of B cells into antibody-secreting plasma cells. Ring Box Protein 1 (RBX1) is a 14-kDa protein necessary for ubiquitin ligation activity of the multimeric cullin ring ubiquitin ligases (CRLs). As RBX1 is shared by a large number of CRLs, alterations in its activity may lead to global changes in protein stability. We discovered that RBX1 is cleaved in the course of LPS-induced plasma cell differentiation and in multiple myeloma cell lines upon induction of pharmacological ER stress. The cleavage is executed by several caspase proteases that cleave RBX1 eight amino acids from the N terminus. To address the possible implication of RBX1 cleavage for CRL activity, we replaced the endogenous RBX1 homolog of the yeast Saccharomyces cerevisiae, Roc1, with the wild type or the N-terminal Δ8 mutant human RBX1. We show that yeast expressing the cleaved RBX1 are hypersensitive to ER stress and are impaired in CRL-mediated ubiquitination and degradation. We propose a model by which N-terminal cleavage of RBX1 impairs its activity and promotes susceptibility to ER stress induction.
- Published
- 2012
- Full Text
- View/download PDF
25. SUMOylation of Blimp-1 promotes its proteasomal degradation
- Author
-
Ari Waisman, Rivka Hadar, Boaz Tirosh, Yael David, Livnat Shimshon, Stephen L. Nutt, Avital Michaeli, and Ami Navon
- Subjects
Proteasome Endopeptidase Complex ,SENP1 ,Immunoprecipitation ,SUMO-1 Protein ,Biophysics ,SUMO protein ,Plasma cell ,Biology ,Biochemistry ,Cell Line ,Protein–protein interaction ,Structural Biology ,Endopeptidases ,Genetics ,medicine ,Humans ,Molecular Biology ,Proteasome ,Protein Stability ,HEK 293 cells ,Sumoylation ,Cell Biology ,Cell biology ,Repressor Proteins ,Cysteine Endopeptidases ,medicine.anatomical_structure ,SUMO protease ,Positive Regulatory Domain I-Binding Factor 1 ,Intracellular - Abstract
B lymphocyte induced maturation protein-1 (Blimp-1) is a transcription repressor of the Krueppel-like family. Blimp-1 plays important roles in developmental processes, such as of germ cells and hair follicle stem cells. In B lymphocytes Blimp-1 orchestrates the terminal differentiation into plasma cells. We discovered that Blimp-1 undergoes SUMOylation by SUMO-1. This SUMOylation is modulated by the SUMO protease SENP1. While Blimp-1 is relatively stable in 293T cells, a fusion with SUMO1 rendered it to rapid proteasomal degradation. Increase in SENP1 activity stabilized Blimp-1, while a decrease promoted its degradation. Our data indicate that SUMOylation of Blimp-1 regulates its intracellular stability. Structured summary of protein interactions Blimp1 physically interacts with SUMO1 by anti tag coimmunoprecipitation (View Interaction 1 , 2 ). SUMO1 physically interacts with Blimp1 by anti tag coimmunoprecipitation (View interaction) .
- Published
- 2011
- Full Text
- View/download PDF
26. Carbamoylphosphonate Matrix Metalloproteinase Inhibitors 6: cis-2-Aminocyclohexylcarbamoylphosphonic Acid, A Novel Orally Active Antimetastatic Matrix Metalloproteinase-2 Selective Inhibitor—Synthesis and Pharmacodynamic and Pharmacokinetic Analysis
- Author
-
Reuven Reich, Bashir Qadri, Julia Frant, Rivka Hadar, Yiffat Katz, Eli Breuer, Amnon Hoffman, and Sudhakar R. Bhusare
- Subjects
Male ,Matrix metalloproteinase inhibitor ,Melanoma, Experimental ,Organophosphonates ,Biological Availability ,Antineoplastic Agents ,Mice, SCID ,In Vitro Techniques ,Matrix Metalloproteinase Inhibitors ,Pharmacology ,Mice ,Structure-Activity Relationship ,Pharmacokinetics ,Cyclohexanes ,In vivo ,Oral administration ,Cell Line, Tumor ,Antimetastatic Agent ,Drug Discovery ,Extracellular fluid ,Toxicity Tests, Acute ,Animals ,Humans ,Neoplasm Invasiveness ,Tissue Distribution ,Neoplasm Metastasis ,biology ,Chemistry ,Prostatic Neoplasms ,Rats ,Bioavailability ,Mice, Inbred C57BL ,Intestinal Absorption ,Enzyme inhibitor ,biology.protein ,Molecular Medicine ,Female ,Cobamides ,Neoplasm Transplantation - Abstract
cis-2-Aminocyclohexylcarbamoylphosphonic acid ( cis-ACCP) was evaluated in vitro and in two in vivo cancer metastasis models. It reduced metastasis formation in mice by approximately 90% when administered by a repetitive once daily dosing regimen of 50 mg/kg via oral or intraperitoneal routes and was nontoxic up to 500 mg/kg, following intraperitoneal administration daily for two weeks. Pharmacokinetic investigation of cis-ACCP in rats revealed distribution restricted into the extracellular fluid, which is the site of action for the antimetastatic activity and rapid elimination ( t 1/2 approximately 19 min) from blood. Sustained and prolonged absorption ( t 1/2 approximately 126 min) occurred via paracellular mechanism along the small and large intestine with overall bioavailability of 0.3%. The in vivo concentrations of cis-ACCP in the blood in rats was above the minimal concentration for antimetastatic/MMP-inhibitory activity, thus explaining the prolonged action following once daily administration. Finally, 84% of the intravenously administered cis-ACCP to rats was excreted intact in the urine.
- Published
- 2008
- Full Text
- View/download PDF
27. Carbamoylphosphonate MMP inhibitors. Part 4: The influence of chirality and geometrical isomerism on the potency and selectivity of inhibition
- Author
-
Eli Breuer, Rivka Hadar, Yiffat Katz, and Reuven Reich
- Subjects
chemistry.chemical_classification ,Chemistry ,Stereochemistry ,Organic Chemistry ,Connective tissue ,Matrix metalloproteinase ,Catalysis ,Inorganic Chemistry ,medicine.anatomical_structure ,Enzyme ,medicine ,Potency ,Physical and Theoretical Chemistry ,Enantiomer ,Selectivity ,Chirality (chemistry) ,Alkyl - Abstract
Matrix metalloproteinases (MMPs) are a family of over twenty zinc-dependent enzymes that hydrolyze connective tissue and are involved in a variety of diseases, which are associated with undesired tissue breakdown. Previously we described the synthesis of a series of achiral alkyl and cycloalkylcarbamoylphosphonic acids and their biological evaluation. Herein we report the effect of chirality and geometrical isomerism on the potency and selectivity of inhibition. The inhibitory potencies of pairs of enantiomeric and stereoisomeric alkyl and cycloalkylcarbamoylphosphonic acids were evaluated on recombinant MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9 enzymes. The results show that the enantiomers and stereoisomers studied differ considerably in their inhibitory potencies and selectivities on the enzyme subtypes studied. Such a result is consistent with the assumption that the carbamoylphosphonates interact with a chiral environment such as an enzyme.
- Published
- 2004
- Full Text
- View/download PDF
28. Carbamoylphosphonates, a New Class of in Vivo Active Matrix Metalloproteinase Inhibitors. 1. Alkyl- and Cycloalkylcarbamoylphosphonic Acids
- Author
-
Gerd-Volker Röschenthaler, Yiffat Katz, Rivka Hadar, Weibin Chen, Claudio J. Salomon, Reuven Reich, Shuiming Lu, and Eli Breuer
- Subjects
Organophosphonates ,Connective tissue ,Angiogenesis Inhibitors ,Antineoplastic Agents ,In Vitro Techniques ,Matrix Metalloproteinase Inhibitors ,Matrix metalloproteinase ,Basement Membrane ,Mice ,Structure-Activity Relationship ,In vivo ,Cell Line, Tumor ,Drug Discovery ,medicine ,Animals ,Neoplasm Invasiveness ,Basement membrane ,chemistry.chemical_classification ,Metalloproteinase ,biology ,Chemistry ,Hydrogen-Ion Concentration ,In vitro ,Capillaries ,Zinc ,medicine.anatomical_structure ,Enzyme ,Solubility ,Biochemistry ,Enzyme inhibitor ,biology.protein ,Molecular Medicine ,Drug Screening Assays, Antitumor ,Protein Binding - Abstract
Matrix metalloproteinases (MMPs) are a family of over 20 zinc-dependent enzymes that hydrolyze connective tissue and are involved in a variety of diseases, which are associated with undesired tissue breakdown. This paper reports the synthesis, characterization, and biological evaluation of a novel class of MMP inhibitors based on the carbamoylphosphonic acid function. We report a series of 10 open chain N-alkylcarbamoylphosphonic acids (ranging from R = C(1) to C(6) groups), eight N-cycloalkylcarbamoylphosphonic acids (ranging from cyclopropyl to cyclooctyl rings), and four N,N-dialkylcarbamoylphosphonic acids. The compounds were evaluated in three in vitro models, which consisted of (a) the in vitro invasion across a reconstituted basement membrane, (b) determination of the IC(50) values on recombinant MMP-1, MMP-2 MMP-3, MMP-8, and MMP-9 enzymes, and (c) an in vitro capillary formation model, which is a model of angiogenesis. Several of the compounds were also tested in an in vivo murine melanoma model. The following general conclusions have been reached: Most compounds show selectivity for MMP-2 over the other MMP subtypes examined. Cycloalkylcarbamoylphosphonic acids are more potent than comparable open-chain alkyl compounds. Optimal activity against MMP-2 among the cycloalkyl derivatives was shown by N-cyclopentylcarbamoylphosphonic acid (3m). N,N-Dialkylcarbamoylphosphonic acids that were examined showed weak or no activity. The compounds examined showed toxic effects neither in vitro nor in vivo in the concentrations used. Carbamoylphosphonic acids are water soluble at physiological pH and are stable indefinitely.
- Published
- 2004
- Full Text
- View/download PDF
29. The effect of dental alloys on mouse lymphocyte subpopulations
- Author
-
Calderon Y, Maya Zalkind, Ruth Rabinowitz, Michael Schlesinger, and Rivka Hadar
- Subjects
CD4-Positive T-Lymphocytes ,Pathology ,medicine.medical_specialty ,Time Factors ,medicine.drug_class ,T cell ,Dermatologic Surgical Procedures ,Fluorescent Antibody Technique ,CD8-Positive T-Lymphocytes ,Monoclonal antibody ,Flow cytometry ,Andrology ,Mice ,Nickel ,T-Lymphocyte Subsets ,medicine ,Animals ,Lymphocyte Count ,Intraoperative Complications ,General Dentistry ,Skin ,B-Lymphocytes ,Mice, Inbred BALB C ,medicine.diagnostic_test ,Chemistry ,Dental alloys ,Mean fluorescence intensity ,technology, industry, and agriculture ,Antibodies, Monoclonal ,Flow Cytometry ,equipment and supplies ,Peripheral blood ,Disease Models, Animal ,medicine.anatomical_structure ,Gold Alloys ,Female ,Chromium Alloys ,Mouse Lymphocyte ,CD8 ,Dental Alloys - Abstract
The aim of the present study was to determine the effect of nickel-containing alloys on lymphocyte subsets in an experimental setting. Plates of alloys containing nickel (Ceramalloy, Talladium, Cerillium, Rexillium) or gold (Orion) were implanted subcutaneously into mice. The levels of CD4+ and CD8+ T-lymphocyte subpopulations and of Smig+ B lymphocytes were determined at various intervals following implantation, using monoclonal antibodies and flow cytometry. No changes were detected in the proportion of the lymphocyte subsets tested. One month after implantation, the mean fluorescence intensity of CD4, CD8 or Smig, in the peripheral blood lymphocytes (PBL) of the nickel alloy-implanted animals, was significantly higher than that prior to this procedure. Only a mild increase in CD4 and CD8 was noted after implantation of the gold alloy. The observed effects are most likely attributable to the surgical trauma, and do not indicate that nickel-containing dental alloys influence T cell subsets in this murine model.
- Published
- 1998
- Full Text
- View/download PDF
30. The Appearance of the CD4CD8 Phenotype on Activated T Cells
- Author
-
Rivka Hadar, Ruth Rabinowitz, and Michael Schlesinger
- Subjects
Antigenicity ,medicine.drug_class ,Lymphocyte ,T cell ,Immunology ,General Medicine ,Cycloheximide ,Biology ,Monoclonal antibody ,Molecular biology ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Antigen ,medicine ,Immunology and Allergy ,IL-2 receptor ,CD8 - Abstract
Stimulation of peripheral blood lymphocytes (PBL) with phytohemagglutinin (PHA) strikingly increased the proportion of CD4+CD8+ cells. Highly purified CD4+ and CD8+ lymphocyte populations cultured in the presence of PHA consistently failed to coexpress the CD8 and CD4 markers. Similarly, exposure of highly purified CD4+ cells to PHA and recombinant interleukin-2 resulted in augmented expression of CD25 but failed to induce the expression of CD8. When purified preparations of either CD4+ or CD8+ cells were activated separately for 3 days and incubated together for an additional 5 h, a considerable proportion of CD4+CD8+ cells was found in the mixture. Cycloheximide treatment did not prevent the appearance of the CD8 marker on CD4 cells. CD4+CD8+ cells isolated from PBL exposed for 3 days to PHA lost their CD8 antigenicity within 24–48 h in the absence of PHA. Increased levels of soluble CD4 and CD8 antigens were found in supernatant fluids of PHA-stimulated cells. T cells failed, however, to bind soluble markers even after prolonged incubation in the presence of supernatant fluids. Our studies show that activation of CD4+ cells per se does not elicit the CD4+CD8+ phenotype and that soluble T cell markers do not bind to T cells. Rather, it seems that direct cell–cell contact is required for the transfer of CD8 molecules from CD8+ cells to the membrane of CD4+ cells.
- Published
- 1997
- Full Text
- View/download PDF
31. Regulated IRE1-dependent decay participates in curtailing immunoglobulin secretion from plasma cells
- Author
-
Sandrine, Benhamron, Rivka, Hadar, Takao, Iwawaky, Jae-Seon, So, Ann-Hwee, Lee, and Boaz, Tirosh
- Subjects
Mice, Knockout ,X-Box Binding Protein 1 ,RNA Stability ,T-Lymphocytes ,Plasma Cells ,Gene Expression ,Immunoglobulins ,Membrane Proteins ,Regulatory Factor X Transcription Factors ,Protein Serine-Threonine Kinases ,Immunoglobulin Class Switching ,DNA-Binding Proteins ,Mice ,Immunoglobulin M ,Immunoglobulin G ,Antibody Formation ,Animals ,RNA, Messenger ,Transcription Factors - Abstract
Inositol-requiring enzyme 1 (IRE1) is a kinase and ribonuclease that executes the splicing of X box binding protein 1 (XBP-1) mRNA in response to the accumulation of unfolded protein in the ER, a signal cascade termed the unfolded protein response. Recently, IRE1 has been implicated in mRNA and miRNA cleavage and degradation, a pathway termed regulated IRE1-dependent decay (RIDD). Deletion of XBP-1 in the liver and pancreas strongly enhances RIDD by upregulating IRE1 protein levels and enhancing its ribo-nuclease activity. Because XBP-1 is essential for generating plasma cells with developed secretory capacity, we sought to evaluate the contribution of RIDD to this regulation. Mice were conditionally deleted for XBP-1 and/or IRE1 in their B-cell lineage. Similarly to the liver, deletion of XBP-1 induces IRE1 expression in LPS-treated B cells. In vitro, IRE1 cleaves the mRNA of secretory μ chains, which explains the reduction in secretory μ mRNA and its synthesis in XBP-1 KO plasma cells. In accordance, the IgM response is partially restored in XBP-1/IRE1 double KO mice relative to XBP-1 KO mice. Interestingly, the IgG1 response is reduced to a similar level in XBP-1 KO, IRE1 KO, and their double knockout animals. Our data demonstrate a specific contribution by RIDD in curtailing immunoglobulin synthesis and secretion.
- Published
- 2013
32. In Vitro Activation Leads to the Binding of T-Cell Markers to the Surface of B-Lymphocytes
- Author
-
Ruth Rabinowitz, Rivka Hadar, Esther Massiah, and Michael Schlesinger
- Subjects
CD4-Positive T-Lymphocytes ,medicine.drug_class ,CD8 Antigens ,T-Lymphocytes ,T cell ,Immunology ,CD2 Antigens ,CD8-Positive T-Lymphocytes ,Biology ,Lymphocyte Activation ,Monoclonal antibody ,CD19 ,Pathology and Forensic Medicine ,Flow cytometry ,Antigen ,Antigens, CD ,medicine ,Humans ,Immunology and Allergy ,Phytohemagglutinins ,Cells, Cultured ,B-Lymphocytes ,medicine.diagnostic_test ,T lymphocyte ,Molecular biology ,In vitro ,medicine.anatomical_structure ,Solubility ,Antigens, Surface ,CD4 Antigens ,biology.protein ,Biomarkers ,CD8 ,Protein Binding - Abstract
The aim of the present study was to determine whether activation of human T-cells in vitro results in the expression of markers characteristic for T-cells on the surface of B-lymphocytes and to correlate antigenic changes with the release of soluble T-cell antigens. Peripheral blood lymphocytes (PBL) were exposed in vitro to phytohemagglutinin (PHA) for 3 days. Changes in the phenotype of the cells were determined by flow cytometry and the level of soluble T-cell antigens was assessed by ELISA. PHA-activated PBL released elevated quantities of soluble CD2, CD4, and CD8 compared with control cultures. Following PHA stimulation the proportion of CD4+CD8+ and HLA-DR+ cells increased. In addition, after 3 days of activation with PHA about 80% of the CD19+ cells (B-cells) reacted with F(ab)2 fragments of CD2 monoclonal antibodies (MoAbs). A high proportion of B-cells in activated cultures also reacted with F(ab)2 fragments of anti-CD8 MoAb and anti-CD4 MoAb. The removal of either CD4+ or CD8+ T-cells from the cultures prior to stimulation with PHA drastically reduced the proportion of B-cells expressing CD4 or CD8, respectively. The attachment of T-cell markers to the surface B-lymphocytes may constitute a new mechanism for B-cell regulation by T-cells.
- Published
- 1995
- Full Text
- View/download PDF
33. Farage, a Novel Early B Cell Lymphoma Cell Line with Trisomy 11
- Author
-
Ziporah Shlomai, Frida Brok-Simoni, Elimelech Okon, Aaron Polliack, Estella Matutes, Gertrude Kohn, Hannah Ben-Bassat, Nelly Livni, Rachel Leizerowitz, Michael Schlesinger, Valerie Buchier, Rivka Hadar, and Ruth Rabinowitz
- Subjects
Cancer Research ,CD22 ,Naive B cell ,Hematology ,Biology ,medicine.disease ,Virology ,Molecular biology ,CD19 ,medicine.anatomical_structure ,Oncology ,Cytoplasm ,hemic and lymphatic diseases ,medicine ,biology.protein ,IL-2 receptor ,Antibody ,B-cell lymphoma ,B cell - Abstract
Farage, a new cell line established from a lymph node biopsy of a patient with non-Hodgkin's lymphoma (NHL), constitutes a clonal expansion of cells at a distinct stage of B-cell differentiation. The cells lack both T and myeloid surface markers, express B cell surface antigens including CD19, CD20, CD22, HLA-DR, were positive for C3 receptors and EBNA and expressed BCL-2. No immunoglobulin determinants could be demonstrated on the cell surface. Intracellular IgM and kappa chains were detected, in an unusual but distinct localization and appeared to be localized to the nucleus or to the perinuclear area without any spread to the cytoplasm, as seen in the early B cells. Southern blot DNA analysis showed rearrangement of one of the IgJH alleles. The Farage cells were negative for B cell activation antigens including CD25, CD11b, HC2 and Bly-7. The cells were negative for two anti CD-10 (CALLA) reagents but weakly positive with one. Interestingly they were strongly positive for both nuclear and cytoplasmic T...
- Published
- 1992
- Full Text
- View/download PDF
34. Direct proteasome binding and subsequent degradation of unspliced XBP-1 prevent its intracellular aggregation
- Author
-
Shimon Shteingart, Lior Zelcbuch, Boaz Tirosh, Ami Navon, Marganit Farago, Ariel Gatushkin, and Rivka Hadar
- Subjects
X-Box Binding Protein 1 ,Proteasome Endopeptidase Complex ,Proteasome Binding ,XBP-1 ,RNA Splicing ,Biophysics ,Regulatory Factor X Transcription Factors ,Biology ,Biochemistry ,Cell Line ,Unfolded protein response ,Ubiquitin ,Structural Biology ,Genetics ,Humans ,Amino Acid Sequence ,Molecular Biology ,Proteasome ,ATF6 ,In vitro degradation ,Ubiquitination ,Cell Biology ,Cell biology ,DNA-Binding Proteins ,Aggresome ,biology.protein ,ER stress ,Proteasome Inhibitors ,Intracellular ,Transcription Factors - Abstract
The non-canonical splicing of XBP-1 mRNA is a hallmark of the mammalian unfolded protein response (UPR). The proteasomal degradation of unspliced XBP-1 (XBP-1u) facilitates the termination of the UPR. Thus, understanding the mechanism of XBP-1u degradation may allow control over UPR duration and intensity.We show that XBP-1u interacts with purified 20S proteasomes through its unstructured C-terminus, which leads to its degradation in a manner that autonomously opens the proteasome gate. In living cells, the C-terminus of XBP-1u accumulates in aggresome structures in the presence of proteasome inhibitors. We propose that direct proteasomal degradation of XBP-1u prevents its intracellular aggregation.Structured summaryMINT-7302217: XBP1-u (uniprotkb:P17861-1) binds (MI:0407) to Proteasome subunit alpha 7.2 (uniprotkb:O14818) by pull down (MI:0096)MINT-7302148: Vimentin (uniprotkb:P08670) and XBP1-u (uniprotkb:P17861-1) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7302163: XBP1-u (uniprotkb:P17861-1) binds (MI:0407) to Proteasome subunit alpha 5 (uniprotkb:P28066) by pull down (MI:0096)MINT-7302186: XBP1-u (uniprotkb:P17861-1) binds (MI:0407) to Proteasome subunit alpha 6 (uniprotkb:P60900) by pull down (MI:0096)
- Published
- 2009
35. De novo ceramide synthesis is required for N-linked glycosylation in plasma cells
- Author
-
Miri Shmuel, Elad L. Laviad, Alfred H. Merrill, Meidan Goldfinger, Anthony H. Futerman, Hyejung Park, Rivka Hadar, Boaz Tirosh, Israel Ringel, and Arie Dagan
- Subjects
Lipopolysaccharides ,X-Box Binding Protein 1 ,Ceramide ,Glycosylation ,Immunology ,Plasma Cells ,Regulatory Factor X Transcription Factors ,Biology ,Ceramides ,Fumonisins ,chemistry.chemical_compound ,Mice ,N-linked glycosylation ,Immunology and Allergy ,Animals ,Ceramide synthase ,Cells, Cultured ,B-Lymphocytes ,Endoplasmic reticulum ,Cell Differentiation ,Lipid signaling ,Sphingolipid ,Cell biology ,DNA-Binding Proteins ,chemistry ,Biochemistry ,Signal transduction ,Oxidoreductases ,Metabolic Networks and Pathways ,Transcription Factors - Abstract
Plasma cells (PCs) are terminally differentiated B lymphocytes responsible for the synthesis and secretion of Igs. The differentiation of B cells into PCs involves a remarkable expansion of both lipid and protein components of the endoplasmic reticulum. Despite their importance in many signal transduction pathways, the role of ceramides, and of complex sphingolipids that are derived from ceramide, in PC differentiation has never been directly studied. To assess their putative role in PC differentiation, we blocked ceramide synthesis with fumonisin B1, a specific inhibitor of ceramide synthase. Under fumonisin B1 treatment, N-linked glycosylation was severely impaired in LPS-activated, but not in naive, B cells. We also show that ceramide synthesis is strongly induced by XBP-1 (X box-binding protein-1). In the absence of ceramide synthesis, ER expansion was dramatically diminished. Our results underscore ceramide biosynthesis as a key metabolic pathway in the process of PC differentiation and reveal a previously unknown functional link between sphingolipids and N-linked glycosylation in PCs.
- Published
- 2009
36. Expression of the peroxisome proliferator-activated receptors-alpha, -beta, and -gamma in ovarian carcinoma effusions is associated with poor chemoresponse and shorter survival
- Author
-
Helene Tuft Stavnes, Reuven Reich, Claes G. Tropé, Rivka Hadar, and Ben Davidson
- Subjects
Adult ,medicine.medical_specialty ,Receptor expression ,Peroxisome proliferator-activated receptor ,Antineoplastic Agents ,In situ hybridization ,Kaplan-Meier Estimate ,Biology ,Disease-Free Survival ,Pathology and Forensic Medicine ,Downregulation and upregulation ,Internal medicine ,medicine ,Ascitic Fluid ,Humans ,Antigens, Human Platelet ,PPAR alpha ,RNA, Messenger ,Receptor ,PPAR-beta ,In Situ Hybridization ,Aged ,chemistry.chemical_classification ,Ovarian Neoplasms ,Messenger RNA ,Reverse Transcriptase Polymerase Chain Reaction ,Carcinoma ,Peroxisome ,Middle Aged ,Prognosis ,Immunohistochemistry ,Reverse transcriptase ,Pleural Effusion, Malignant ,PPAR gamma ,Endocrinology ,Treatment Outcome ,chemistry ,Cancer research ,Female - Abstract
Summary Peroxisome proliferator–activated receptors regulate lipid metabolism, affecting inflammation and cancer. The present study analyzed the anatomical site–related expression and prognostic role of peroxisome proliferator–activated receptors in ovarian carcinoma. Fresh-frozen effusions (n = 79), primary carcinomas (n = 44), and solid metastases (n = 16) were studied for peroxisome proliferator–activated receptor– α , – β , and – γ messenger RNA expression using reverse transcriptase polymerase chain reaction. Peroxisome proliferator–activated receptor– γ messenger RNA expression was further assessed in 60 tumors (30 effusions, 20 primary carcinomas, 10 metastases) using in situ hybridization. Peroxisome proliferator–activated receptor– γ protein expression was immunohistochemically analyzed in 160 effusions. All peroxisome proliferator–activated receptors were expressed in most tumors at all anatomical sites using reverse transcriptase polymerase chain reaction, but peroxisome proliferator–activated receptor– α ( P = .004) and peroxisome proliferator–activated receptor– β ( P = .002) messenger RNA levels were higher in effusions compared with primary carcinomas and solid metastases. In situ hybridization localized peroxisome proliferator–activated receptor– γ messenger RNA to carcinoma cells in both effusions and solid lesions. Peroxisome proliferator–activated receptor– γ protein was detected in carcinoma cells in 102 of 160 (64%) effusions. Higher effusion messenger RNA levels of all peroxisome proliferator–activated receptors were associated with less favorable response to chemotherapy at diagnosis ( P = .009). In univariate survival analysis, higher messenger RNA expression of all peroxisome proliferator–activated receptors was associated with poor progression-free ( P = .045) and overall ( P = .014) survival. Higher peroxisome proliferator–activated receptor– γ protein expression was similarly associated with poor overall survival for the entire cohort ( P = .046) and for patients with disease recurrence effusions ( P = .009). Peroxisome proliferator–activated receptors were not independent predictors of survival in Cox multivariate analysis. Peroxisome proliferator–activated receptor members are frequently expressed in ovarian carcinoma, with upregulated expression in effusions. Peroxisome proliferator–activated receptor expression in effusions is associated with poor response to chemotherapy at disease recurrence and poor survival, suggesting a role in tumor biology at this unique microenvironment.
- Published
- 2008
37. Expression and clinical role of DJ-1, a negative regulator of PTEN, in ovarian carcinoma
- Author
-
Ben Davidson, Tamar Sternlicht, Juri Kopolovic, Anat Schlossberg, Björn Risberg, Vivi Ann Flørenes, Reuven Reich, Ana Slipicevic, Martina Skrede, and Rivka Hadar
- Subjects
Adult ,Pathology ,medicine.medical_specialty ,Tumor suppressor gene ,Sp1 Transcription Factor ,Protein Deglycase DJ-1 ,Pathology and Forensic Medicine ,Ovarian carcinoma ,medicine ,PTEN ,Tensin ,Ascitic Fluid ,Humans ,Aged ,Regulation of gene expression ,Oncogene Proteins ,Ovarian Neoplasms ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,Intracellular Signaling Peptides and Proteins ,PTEN Phosphohydrolase ,Cancer ,Middle Aged ,medicine.disease ,Pleural Effusion, Malignant ,Gene Expression Regulation, Neoplastic ,Sp3 Transcription Factor ,Tumor progression ,biology.protein ,Cancer research ,Immunohistochemistry ,Female - Abstract
The aim of this study was to analyze the expression and clinical role of DJ-1, a negative regulator of PTEN (phosphatase and tensin homolog deleted on chromosome 10), in ovarian carcinoma, and investigate the putative association between DJ-1 levels and expression of its transcriptional regulators specificity protein 1 (Sp1) and specificity protein 3 (Sp3). Effusions (n = 72) and solid tumors (n = 57, 42 primary and 15 metastases) were analyzed for DJ-1 messenger RNA (mRNA) expression using reverse transcriptase-polymerase chain reaction. Most specimens (48 effusions, 50 solid tumors) were additionally analyzed for Sp1 and Sp3 mRNA expression. PTEN protein expression was analyzed in 201 effusions and 92 solid tumors using immunohistochemistry. DJ-1 mRNA was expressed in more than 80% of specimens, with no preferential anatomical site. DJ-1 expression was positively associated with Sp1 expression in effusions (P = .03) and with Sp1 (P = .02) and Sp3 (P = .002) expression in solid tumors. In effusions, DJ-1 expression was higher in postchemotherapy compared with prechemotherapy specimens (P = .012). Higher DJ-1 levels (P = .027) and more advanced FIGO stage (IV versus III; P = .003) correlated with shorter progression-free survival in univariate analysis for patients with postchemotherapy effusions. PTEN expression was low in effusions and solid tumors (23% and 13%, respectively), and its expression showed no association with DJ-1 levels or survival. Our data show that DJ-1 is frequently expressed in advanced-stage ovarian carcinoma at all anatomical sites and is coexpressed with its transcriptional regulators Sp1 and Sp3. In contrast, PTEN expression is infrequent in this disease. These findings may provide one of the molecular mechanisms that mediate cancer cell survival and aggressiveness in this tumor.
- Published
- 2007
38. Expression of Snail, Slug and Sip1 in malignant mesothelioma effusions is associated with matrix metalloproteinase, but not with cadherin expression
- Author
-
Rivka Hadar, Sivan Elloul, Lina Vintman, Reuven Reich, Ben Davidson, Stine Sivertsen, and Carlos W. M. Bedrossian
- Subjects
Pulmonary and Respiratory Medicine ,Adult ,Male ,Mesothelioma ,Cancer Research ,Pathology ,medicine.medical_specialty ,Slug ,Pleural Neoplasms ,Nerve Tissue Proteins ,Snail ,biology.animal ,Gene expression ,Biopsy ,medicine ,Humans ,Zymography ,RNA, Messenger ,Aged ,Aged, 80 and over ,Tissue Inhibitor of Metalloproteinase-2 ,biology ,medicine.diagnostic_test ,Cadherin ,Reverse Transcriptase Polymerase Chain Reaction ,RNA-Binding Proteins ,Middle Aged ,biology.organism_classification ,Cadherins ,Molecular biology ,Immunohistochemistry ,Matrix Metalloproteinases ,Pleural Effusion, Malignant ,Blot ,Oncology ,Female ,Snail Family Transcription Factors ,Transcription Factors - Abstract
Snail, Slug and Sip1 regulate cadherin and protease expression and mediate epithelial-mesenchymal transition in cancer. We analyzed the expression of cadherins and matrix metalloproteinases (MMP) and their transcriptional regulators in malignant mesothelioma (MM). One hundred and ten MM specimens (86 solid, 24 effusions) and 10 non-malignant effusions with reactive mesothelial cells (RMC) were analyzed for E-cadherin, N-cadherin and P-cadherin protein expression using immunhistochemistry. MM effusions were further analyzed for expression of Snail, Slug, Sip1, E-cadherin, MMP-2, MMP-9, MT1-MMP (MMP-14) and the MMP inhibitor TIMP-2, and for MMP-2 and MMP-9 activity using RT-PCR, Western blotting, immunhistochemistry and zymography. Results were analyzed for relationship with specimen type (biopsy versus effusion) and anatomic site (pleural versus peritoneal). E-cadherin, N-cadherin and P-cadherin expression was found in 69/110 (63%), 87/110 (79%) and 84/110 (76%) MM cases, respectively. Pleural and peritoneal MM showed comparable expression, but all three cadherins were upregulated in effusions compared to solid tumors (p
- Published
- 2006
39. Carbamoylphosphonate matrix metalloproteinase inhibitors 3: in vivo evaluation of cyclopentylcarbamoylphosphonic acid in experimental metastasis and angiogenesis
- Author
-
Yiffat Katz, Reuven Reich, Eli Breuer, and Rivka Hadar
- Subjects
Cancer Research ,Pathology ,medicine.medical_specialty ,Lung Neoplasms ,Angiogenesis ,Matrix metalloproteinase inhibitor ,Cell ,Organophosphonates ,Biology ,Matrix metalloproteinase ,Matrix Metalloproteinase Inhibitors ,Metastasis ,Mice ,In vivo ,medicine ,Animals ,Humans ,Neoplasm Invasiveness ,Neoplasm Metastasis ,Melanoma ,Neovascularization, Pathologic ,Chemotaxis ,Cancer ,medicine.disease ,Primary tumor ,Mice, Inbred C57BL ,Disease Models, Animal ,medicine.anatomical_structure ,Oncology ,Female - Abstract
The spread of malignant tumor cells from a primary neoplasm to distant organs where they multiply and form new foci is the major cause of death from cancer. Despite the different modalities of cancer treatment, no effective curative therapy of metastatic lesions is available. To possess metastatic potential, a cell has to be able to invade the surrounding tissue, spread via lymphatics and/or the bloodstream, extravasate, and multiply at secondary sites. There is increasing evidence for a positive correlation between matrix metalloproteinase-2 (MMP-2) activity and tumor cell invasion. Agents blocking MMP-2 have been shown to prevent tumor cell invasion in vitro and in vivo. Inhibition of MMPs has, therefore, become the focus of considerable interest in connection with a variety of potential therapeutic applications. We have discovered a nontoxic MMP-2–selective inhibitor effective at nanomolar range on recombinant MMP. This compound, cyclopentylcarbamoylphosphonic acid, significantly inhibited cellular invasion and capillary formation in vitro. Further, i.p. or oral administration of the compound significantly reduced lung metastasis formation and s.c. tumor growth in a murine melanoma model. The effect of this novel compound on lung colonization, capillary formation, and s.c. tumor growth indicates that the compound might also be effective in treatment of primary tumor growth in reduction, or at least in prevention, of further tumor growth, thereby reducing the tumor burden of the patient by a nontoxic approach.
- Published
- 2005
40. Carbamoylphosphonate Matrix Metalloproteinase Inhibitors 6: cis-2-Aminocyclohexylcarbamoylphosphonic Acid, A Novel Orally Active Antimetastatic Matrix Metalloproteinase-2 Selective InhibitorSynthesis and Pharmacodynamic and Pharmacokinetic...
- Author
-
Amnon Hoffman, Eli Breuer, Reuven Reich, Bashir Qadri, Julia Frant, Yiffat Katz, Sudhakar R. Bhusare, and Rivka Hadar
- Published
- 2008
- Full Text
- View/download PDF
41. Modulation of the expression of CD4 on HL-60 cells by exposure to 1,25-dihydroxyvitamin D3
- Author
-
Ruth Rabinowitz, Rivka Hadar, Zvi Bar-Shavit, and Michael Schlesinger
- Subjects
CD4 antigen ,medicine.drug_class ,Immunology ,Cell ,Fluorescent Antibody Technique ,Biology ,Monoclonal antibody ,Flow cytometry ,chemistry.chemical_compound ,Calcitriol ,Tumor Cells, Cultured ,medicine ,Immunology and Allergy ,Receptor ,medicine.diagnostic_test ,Antibodies, Monoclonal ,Molecular biology ,Staining ,Kinetics ,medicine.anatomical_structure ,chemistry ,Cell culture ,Tetradecanoylphorbol Acetate ,CD4 Antigens ,Leukocytes, Mononuclear - Abstract
The CD4 molecule functions as a receptor for the binding and infectivity of the human immunodeficiency virus (HIV). It is of interest, therefore, to develop procedures for its down-regulation. In the present study, the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the expression of cell surface antigens of the HL-60 promyelocytic leukemia cell line was analyzed. Exposure of HL-60 cells to 1,25(OH)2D3 resulted in down-regulation of CD4 as assessed by their staining with the Leu-3a monoclonal antibody (MoAb). This treatment increased the staining of HL-60 cells with the monocyte-specific 63D3 MoAb. In contrast to the rapid elimination of cell surface CD4 by exposure of HL-60 to phorbol myristate acetate (PMA), the maximal reduction of CD4 by 1,25(OH)2D3 was attained within 48 h after the beginning of the exposure.
- Published
- 1989
- Full Text
- View/download PDF
42. The role of E receptors in the attachment of thymocytes and T lymphocytes to human target cells
- Author
-
Rivka Hadar, Levy J, Ruth Rabinowitz, J. Weinstock, Hannah Ben-Bassat, Michael Schlesinger, and Reuven Laskov
- Subjects
Rosette Formation ,T-Lymphocytes ,Immunology ,CD1 ,Neuraminidase ,Cell Communication ,Thymus Gland ,Biology ,Lymphocyte Activation ,Pathology and Forensic Medicine ,Cell Line ,Immunology and Allergy ,Cytotoxic T cell ,Humans ,IL-2 receptor ,Receptors, Immunologic ,Antigen-presenting cell ,Interleukin 3 ,Binding Sites ,Monosaccharides ,Antibodies, Monoclonal ,Natural killer T cell ,Molecular biology ,Thymocyte ,Biochemistry ,Interleukin 12 - Abstract
Human thymocytes, activated T lymphocytes, and neuraminidase-treated T cells possess the distinct capacity of forming conjugates with various human cell lines. The present study investigated whether E receptors, which endow human T cells with their capacity to bind sheep red blood cells (SRBC), are involved in this phenomenon. Monoclonal antibodies to human T cells and various simple sugars were studied for their effect on the attachment of human T cells to target cells. A-22, a monoclonal antibody to the E receptor, inhibited the formation of E rosettes by T cells and SRBC, and reacted in immunofluorescent-staining assays with the majority of human thymocytes and peripheral T cells, and with T-cell lines capable of forming E rosettes. When human thymus cells were treated with A-22 antibody they showed a reduction of up to 70% in their capacity to attach to the GM-4762 lymphoblast cell line and the K-562 myeloid line. Antibody treatment of the target cells, rather than of the thymus cells, had no effect on the formation of conjugates between thymus cells and target cells. Treatment of thymus cells with various monoclonal antibodies to T cells which do not react with the E receptor had no inhibitory effect. The exposure of human thymus cells to various simple sugars ( d -mannose, d -fucose, galactose, and lactose) markedly reduced their capacity of forming conjugates with target cells. Exposure of neuraminidase-treated peripheral blood lymphocytes and of activated T cells to A-22 antibody inhibited their attachment to human target cells. The present study suggests that E receptors play a role in the attachment of human thymus cells and activated T cells to other human cells, and raises the possibility that these T-cell receptors may be involved in the process of recognition of “self” structures by human T lymphocytes.
- Published
- 1983
43. Establishment of the Amsalem T-cell line from a patient with acute lymphoblastic leukemia. Expression of E-receptor-associated antigens in cells incapable of forming E-rosettes
- Author
-
H. Ben Bassat, Rivka Hadar, Ruth Rabinowitz, Aaron Polliack, and Michael Schlesinger
- Subjects
Cancer Research ,Herpesvirus 4, Human ,Rosette Formation ,medicine.drug_class ,T cell ,T-Lymphocytes ,Fluorescent Antibody Technique ,Receptors, Antigen, B-Cell ,Receptors, Fc ,Biology ,Monoclonal antibody ,Cell Line ,Hepatitis B Antigens ,Antigen ,medicine ,Cytotoxic T cell ,Humans ,Hepatitis B e Antigens ,Child ,B-Lymphocytes ,Histocytochemistry ,Antibodies, Monoclonal ,medicine.disease ,Virology ,Molecular biology ,Leukemia, Lymphoid ,Receptors, Complement ,Leukemia ,medicine.anatomical_structure ,Oncology ,Cell culture ,biology.protein ,Microscopy, Electron, Scanning ,Receptors, Virus ,Female ,Binding Sites, Antibody ,Antibody ,CD5 - Abstract
A new T-cell line (Amsalem) was established from the peripheral blood of a patient with pre-T leukemia. Amsalem cells are unique in that they possess antigenic determinants associated with the E-receptor, yet fail to form rosettes with sheep red blood cells (SRBC). Amsalem cells were found to possess morphological and cytochemical features characteristic of T-lymphocytes, and were sensitive to the cytotoxic effect of rabbit antisera specific for T-cell antigens. In immunofluorescent tests with monoclonal antibodies, Amsalem cells showed a strong reactivity with the OKT-11A and A-22 antibodies, specific for the E-receptor. The cells were reactive with OKT-4 and showed a very weak reactivity with OKT-6 and OKT-8. No reactivity was found with the OKT-3, Leu 7, Leu 11, and OKM1 antibodies. Amsalem cells failed to form rosettes with SRBC; however, mouse anti-Amsalem serum inhibited the formation of E-rosettes. It is concluded that the Amsalem cell line is a line of pre-T leukemia cells characterized by a dissociation between its inability to form E-rosettes and the presence of antigenic constituents of the E-receptor.
- Published
- 1985
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.