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Background: Breakthrough infections after SARS-CoV-2 vaccination have been reported. Clinical outcomes in these persons are not widely known. Methods: We evaluated all vaccinated persons with breakthrough infection ≥14 days after the second vaccine dose and unvaccinated controls matched on age, sex, nationality, and reason for testing between December 23, 2020 and March 28, 2021 in Qatar. Our primary outcome was severe disease defined as hospitalization, mechanical ventilation, or death. Results: Among 456 persons cases of breakthrough infection and 456 unvaccinated matched controls with confirmed infection, median age was 45 years, 60.7% were males, and ≥1 comorbid condition was present in 61.2% of the vaccinated and 47.8% of the unvaccinated persons (P=0.009). Severe disease was recorded in 48 (10.5%) of the vaccinated and 121 (26.5%) of the unvaccinated group (P40–60 years, HR 2.32; >60–70 years, HR 4.34; >70 years, HR 5.43); presence of symptoms at baseline (HR 2.42, 95%CI 1.44-4.07); and being unvaccinated (HR 2.84, 95%CI 1.80-4.47). Conclusions: In persons with breakthrough SARS-CoV-2 infection, increasing age is associated with a higher risk of severe disease or death, while vaccination is associated with a lower risk. Presence of comorbidities was not associated with severe disease or death among persons with breakthrough infection.

We investigated what proportion of the population acquired severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and whether the herd immunity threshold has been reached in 10 communities in Qatar. The study included 4,970 participants during June 21–September 9, 2020. Antibodies against SARS-CoV-2 were detected by using an electrochemiluminescence immunoassay. Seropositivity ranged from 54.9% (95% CI 50.2%–59.4%) to 83.8% (95% CI 79.1%–87.7%) across communities and showed a pooled mean of 66.1% (95% CI 61.5%–70.6%). A range of other epidemiologic measures indicated that active infection is rare, with limited if any sustainable infection transmission for clusters to occur. Only 5 infections were ever severe and 1 was critical in these young communities; infection severity rate of 0.2% (95% CI 0.1%–0.4%). Specific communities in Qatar have or nearly reached herd immunity for SARS-CoV-2 infection: 65%–70% of the population has been infected.

Treating HCV infection reduces overall mortality and reduces the risk of multiple extrahepatic complications. Whether the reduction in mortality is primarily due to a reduction in liver-related causes or extrahepatic complications is unknown.We identified HCV-positive individuals treated for HCV, and propensity score-matched them to HCV-positive/untreated and HCV-uninfected individuals in ERCHIVES between 2002-2016. We extracted cause of death data from the National Center for Health Statistics' National Death Index. Viral hepatitis-associated liver-related mortality rates among treated and untreated HCV-infected persons were calculated by treatment and attainment of sustained virologic response (SVR).Among 50,674 HCV-positive/treated (Group A), 31,749 HCV-positive/untreated (Group B) and 73,526 HCV-uninfected persons (Group C), 8.6% in Group A, 35.0% in Group B, and 14.3% in Group C died. Among those who died, viral hepatitis-associated liver-related mortality rates per 100 patient-years (95% CI) were: 0.28 (0.27-0.30) for Group A; 1.44 (1.38-1.49) for Group B; and 0.06 (0.05-0.06) for Group C; (p0.0001 for both comparisons). Among HCV-positive/treated persons, rates were 0.06 (0.05-0.06) for those with SVR vs. 0.78 (0.74-0.83) for those without SVR. In competing risks Cox proportional hazards analysis, treatment with all-oral DAA regimens (adjusted hazard ratio 0.11; 95% CI 0.09-0.14) and SVR (adjusted hazard ratio 0.10; 95% CI 0.08-0.11) were associated with reduced hazards of liver-related mortality.Treatment for HCV is associated with a significant reduction in viral hepatitis-associated liver-related mortality, which is particularly pronounced in those treated with DAA regimens and those who attain SVR. This may account for a significant proportion of the reduction in all-cause mortality reported in previous studies.Treating hepatitis C virus (HCV) infection is known to reduce overall mortality. However, whether the reduction in mortality is primarily due to a reduction in liver-related causes or extrahepatic complications was previously unknown. Herein, we show that while treating HCV with direct-acting antiviral regimens has numerous extrahepatic benefits, a significant benefit can be attributed specifically to the reduction in liver-related mortality.

Summary Background Type 2 diabetes is affecting people at an increasingly younger age, particularly in the Middle East and in north Africa. We aimed to assess whether an intensive lifestyle intervention would lead to significant weight loss and improved glycaemia in young individuals with early diabetes. Methods This open-label, parallel-group, randomised controlled trial (DIADEM-I), done in primary care and community settings in Qatar, compared the effects of an intensive lifestyle intervention with usual medical care on weight loss and glycaemic outcomes in individuals with type 2 diabetes, aged 18–50 years, with a short diabetes duration (≤3 years), had a BMI of 27·0 kg/m2 or more, and who were from the Middle East and north Africa region. Participants were randomly allocated (1:1) either to the intensive lifestyle intervention group or the usual medical care control group by a computer-generated sequence and an online randomisation service. The intensive lifestyle intervention comprised a total diet replacement phase, in which participants were given formula low-energy diet meal replacement products followed by gradual food reintroduction combined with physical activity support, and a weight-loss maintenance phase, involving structured lifestyle support. Participants in the control group received usual diabetes care, which was based on clinical guidelines. The primary outcome was weight loss at 12 months after receiving the assigned intervention. Our analysis was based on the intention-to-treat principle. Key secondary outcomes included diabetes control and remission. The trial was registered with the ISRCTN registry, ISRCTN20754766, and ClinicalTrials.gov , NCT03225339 . Findings Between July 16, 2017, and Sept 30, 2018, we enrolled and randomly assigned 158 participants (n=79 in each group) to the study. 147 participants (70 in the intervention group and 77 in the control group) were included in the final intention-to-treat analysis population. Between baseline and 12 months, the mean bodyweight of participants in the intervention group reduced by 11·98 kg (95% CI 9·72 to 14·23) compared with 3·98 kg (2·78 to 5·18) in the control group (adjusted mean difference −6·08 kg [95% CI −8·37 to −3·79], p Interpretation Our findings show that the intensive lifestyle intervention led to significant weight loss at 12 months, and was associated with diabetes remission in over 60% of participants and normoglycaemia in over 30% of participants. The provision of this lifestyle intervention could allow a large proportion of young individuals with early diabetes to achieve improvements in key cardiometabolic outcomes, with potential long-term benefits for health and wellbeing. Funding Qatar National Research Fund.

Encouraging patients to improve their self-management behavior based on a strict definition of the intervention is important for a standardized delivery but, until recently, there was no consensus on the core attributes that define such an intervention. The purpose of this study is to generate a core-attribute based and stakeholder-informed problem-based curriculum for promotion of type 2 diabetes self-management structured around five core attributes derived from a previous concept analysis that defined the intervention.Using a Delphi process for consensus achievement, physicians, clinical epidemiologists and allied health care professionals completed eleven rounds of online meetings over 6 months.Core self-management skills were identified by consensus for each of the five attributes and then used to design a model case and interactions of a problem-based self-management education intervention for delivery in a health care setting. Five model cases and associated interactions were developed by consensus for delivery in group-based and problem-based learning sessions.The final structured curriculum will be useful to inform and standardize diabetes self-management based on a clear conceptual definition of the intervention and can thus help make the latter more effective tools for encouraging persons with type 2 diabetes to self manage their condition.

This retrospective study compares the severity of SARS-CoV-2 infection among persons infected with BA.1 and BA.2 sublineages by vaccination status.

Objective: Polycystic ovarian syndrome (PCOS) is a heterogeneous endocrine disorder associated with mitochondrial dysfunction and insulin resistance (IR). MOTS-c, a mitochondrial peptide, promotes insulin sensitivity (IS) through activating AKT and AMPK-dependent pathways. The current study was designed to examine the response of MOTS-c to lipids (intralipid) followed by insulin in PCOS and healthy subjects. Methods: All subjects underwent 5-hour intralipid/saline infusion with a hyperinsulinemic-euglycaemic clamp in the final 2 hours. Plasma samples were collected to measure circulating MOTS-c using a commercial ELISA kit. Subsequently, this was repeated following an eight-week exercise intervention. Results: Intralipid significantly increased plasma MOTS-c both in controls and PCOS subjects, whilst the insulin infusion blunted the intralipid-induced response seen for both lipids and MOT-c. Intralipid elevated plasma MOTS-c to 232±124% of basal in control (P < 0.01) and to 349 ± 206% of basal in PCOS (P < 0.001) subjects. Administration of insulin suppressed intralipid-induced MOTS-c from 232 ± 124% to 165 ± 97% (NS) in control and from 349 ± 206% to 183 ± 177% (P < 0.05) in PCOS subjects, respectively. Following exercise, intralipid elevated plasma MOTS-c to 305 ± 153% of basal in control (P < 0.01) and to 215 ± 103% of basal in PCOS (P < 0.01) subjects; insulin suppressed intralipid-induced MOTS-c only in controls. Conclusions In conclusion, this is the first study to show increased lipid enhanced circulating MOTS-c whilst insulin attenuated the MOTS-c response in human. Further, eight weeks of moderate exercise training did not show any changes in circulating MOTS-c levels in healthy controls and in women with PCOS.

Background and purpose Neutrophil elastase (NE) has been implicated in the pathogenesis of airway inflammation in cystic fibrosis (CF) patients and it impairs defenses against Pseudomonas aeruginosa (PA) infection or colonization. Sputum NE may act as a biomarker of neutrophilic inflammation in CF patients. This study aimed to determine sputum and plasma total NE levels in clinically stable adult CF patients and control subjects, and their correlation to PA colonization and lung functions. Methods This is a cross-sectional study. Total NE was measured on spontaneously expectorated sputum and plasma obtained from 21 CF patients, aged 18-40 years, during routine visits to the adult CF clinic. This was compared to plasma obtained from 22 matching healthy controls. The levels of NE were measured by the magnetic bead-based multiplex assay. Results Sputum and plasma NE levels had a significant positive correlation (Pearson r=0.533, P=0.013) with PA colonization. Sixteen CF patients (76.2%) were chronically colonized with PA. Both median sputum and plasma NE were found to be higher in CF patients with PA as compared with non-PA patients, even though this difference was statistically insignificant. Sputum and plasma NE levels did not correlate with the percentage predicted forced expiratory volume in one second (FEV1), the forced vital capacity (FVC), and FEV1/FVC and no association with PA. Conclusion The findings suggest that clinically stable adult CF patients colonized with PA may have higher NE levels in both plasma and sputum as compared to non-PA CF patients and probably total NE does not influence lung functions.

Aims: Attributes that operationally conceptualize diabetes self-management education (DSME) interventions have never been studied previously to assess their impact on relevant outcomes of interest in people with type 2 diabetes (T2D). The aim of this study was to determine the impact of existing interventions classified by their delivery of skills or information related attributes on immediate (knowledge), intermediate (physical activity), post-intermediate (HbA1c), and long-term (quality of life) outcomes in people with T2D. Methods: PubMed, Embase, PsycINFO, and Cochrane Library/Cochrane CENTRAL as well as the grey literature were searched to identify interventional studies that examined the impact of DSME interventions on the four different outcomes. Eligible studies were selected and appraised independently by two reviewers. A meta-regression analysis was performed to determine the impact of delivery of the skills- and information-related attributes on the chosen outcomes. Results: 142 studies (n = 25,511 participants) provided data, of which 39 studies (n = 5278) reported on knowledge, 39 studies (n = 8323) on physical activity, 99 studies (n = 17,178) on HbA1c and 24 studies (n = 5147) on quality of life outcomes. Meta-regression analyses demonstrated that skills-related attributes had an estimated effect suggesting improvement in knowledge (SMD [standardized mean difference] increase of 0.80; P = 0.025) and that information-related attributes had an estimated effect suggesting improvement in quality of life (SMD increase of 0.96; P = 0.405). Skill- and information-related attributes did not have an estimated effect suggesting improvement in physical activity or in HbA1c. Conclusions: The study findings demonstrate that the skills and information related attributes contribute to different outcomes for people with T2D. This study provides, for the first time, preliminary evidence for differential association of the individual DSME attributes with different levels of outcome. LFK was supported by Australian National Health and Medical Research Council Early Career Fellowships ( APP1158469 ). Scopus

Background: The fibroblast growth factors (FGF) 19 subfamily, also referred to as endocrine FGFs, includes FGF19, FGF21, and FGF23 are metabolic hormones involved in the regulation of glucose and lipid metabolism. Fetuin-A is a hepatokine involved in the regulation of beta-cell function and insulin resistance. Endocrine FGFs and fetuin-A are dysregulated in metabolic disorders including obesity, type 2 diabetes, non-alcoholic fatty liver disease and polycystic ovary syndrome (PCOS). Our study was designed to examine the response of endocrine FGFs and fetuin-A to an acute intralipid, insulin infusion and exercise in PCOS and healthy women. Subjects and Measurements: Ten healthy and 11 PCOS subjects underwent 5-h saline infusions with a hyperinsulinemic-euglycemic clamp (HIEC) performed during the final 2 h. One week later, intralipid infusions were undertaken with a HIEC performed during the final 2 h. After an 8 week of exercise intervention the saline, intralipid, and HIEC were repeated. Plasma levels of endocrine FGFs and fetuin-A were measured. Results: Baseline fetuin-A was higher in PCOS women but FGF19, FGF21, and FGF23 did not differ and were unaffected by exercise. Insulin administration elevated FGF21 in control and PCOS, suppressed FGF19 in controls, and had no effects on FGF23 and fetuin-A. Intralipid infusion suppressed FGF19 and increased FGF21. Insulin with intralipid synergistically increased FGF21 and did not have effects on lipid-mediated suppression of FGF19 in both groups. Conclusion: Our study provides evidence for insulin and lipid regulation of endocrine FGFs in healthy and PCOS women, suggesting that FGF family members play a role in lipid and glucose metabolism. Clinical Trial Registration: www.isrctn.org, Identifier: ISRCTN42448814.

Background There are conflicting data regarding the risk of hepatocellular carcinoma (HCC) after direct-acting antiviral agent (DAA) treatment. Risk of HCC in HCV genotype-3 infected persons after DAA therapy is not well known. Methods We prospectively studied HCV infected persons initiated on a DAA regimen between October 2014 and March 2017 at two centers in Pakistan. All persons were free of HCC at study initiation. HCC was confirmed based on characteristic CT scan findings. Patients were followed for 12 months after the completion of therapy. Results A total of 662 persons initiated treatment. Median age (IQR) was 50 (41, 57) years and 48.8% were male. At baseline, 49.4% were cirrhotic, 91% were genotype 3 and 91.9% attained SVR. Treatment regimens used were: Sofosbuvir (SOF)/ribavirin (RBV)/pegylated interferon (PEG-IFN), 25.2%; SOF/RBV, 62.4%; SOF/RBV/daclatasavir (DCV), 10.6%; SOF/DCV, 2.0%. Incident HCC was detected in 42 patients (12.8%) in the 12-month period after treatment completion and was exclusively observed in those with cirrhosis. In multivariable Cox regression analysis, SVR was associated with a reduction in HCC risk (HR, 95% CI: 0.35, 0.14,0.85). In Kaplan-Meier plots by treatment regimen, those treated with SOF/RBV, SOF/RBV/DCV, or SOF/DCV regimens had a shorter HCC-free survival compared with those treated with a SOF/RBV/PEG-IFN regimen. Conclusion In a predominantly genotype 3 cohort, incident HCC occurred frequently and early after treatment completion, and exclusively in those with pre-treatment cirrhosis. SVR reduced the risk of HCC. Treating HCV infected persons before development of cirrhosis may reduce risk of HCC.

Patient: Male, 44-year-old Final Diagnosis: Subacute thyroiditis Symptoms: Fever Medication: — Clinical Procedure: None Specialty: General and Internal Medicine Objective: Rare disease Background: Fever of unknown origin (FUO) is a diagnosis that requires a demanding workup from physicians before confirming a diagnosis. Thyroid diseases are a rare cause of FUO. Subacute thyroiditis is an inflammatory disease that can lead to a wide spectrum of presentations. Case Report: We report a case of a previously healthy male who presented with persistent fever of 4 weeks following an upper respiratory tract infection associated with constitutional symptoms. His laboratory workup included complete blood counts (CBC), complete metabolic panel (blood urea and creatinine, liver function tests, and serum electrolytes), blood cultures, abdominal and pelvic ultrasound, and computed tomography abdomen and pelvis that were inconclusive. His thyroid function tests showed a hyperthyroid state and a thyroid scan confirmed a picture of thyroiditis. The patient was treated with Ibuprofen and then with prednisolone; he showed significant improvement over a few days and was discharged with treatment of tapering doses of prednisolone over 6 weeks. Two weeks after discharge the patient had a follow-up at an outpatient clinic and was found to be in good health with resolution of his symptoms. Conclusions: Thyroid disorders are not a common cause of FUO, and even if the clinical assessment of the patient is not suggestive of thyroid disease, we should consider it a possible cause. and thyroid function test should be performed to exclude thyroid problems.

Background Cystic fibrosis (CF) lung disease is associated with chronic inflammation leading to progress in lung function. Adiponectin is a predominantly anti-inflammatory adipokine that may have a role in CF lung. This study aims to determine total sputum and total plasma adiponectin levels in clinically stable adults CF patients with CFTR I1234V mutation, compared to plasma adiponectin levels in healthy controls and to investigate their correlations with body mass index (BMI) and spirometry in patients with CF. Methods A cross-sectional study comprises 17 CF patients and 18 healthy controls. Adiponectin levels were measured by magnetic bead-based multiplex assay. Results The mean age of adult CF patients was 22.9 years±3.8 (18–30) and 76.5% CF patients had pancreatic sufficiency. The mean BMI in healthy controls was slightly higher than CF patients. The mean sputum adiponectin level was significantly lower than plasma adiponectin levels in CF patients and healthy controls (p r = 0.47, p = 0.06). Sputum and plasma adiponectin levels in CF patients were correlated negatively with BMI and percentage predicted forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC). Conclusions Sputum adiponectin may provide a minimally invasive tool in the assessment of inflammatory status in CF patients. A further larger study to address any difference in sputum and plasma adiponectin levels among CF patients with pancreatic sufficiency versus pancreatic insufficiency.

Background Newer direct acting antiviral agents against HCV (DAAs) are safe and efficacious in persons with chronic kidney disease (CKD). Whether approval of newer DAAs has resulted in more persons with CKD initiating HCV treatment remains unknown. Methods We identified HCV+ persons in ERCHIVES between October 1999 and July 2016. We excluded HIV+ and HBsAg+ and those with missing baseline HCV RNA and baseline eGFR data. We identified persons initiated on any approved DAA-regimen through July 2016, by CKD stage. Logistic regression analyses were used to determine factors associated with treatment initiation. Results Among 83 706 evaluable persons, 21.1% initiated treatment. Rates differed significantly by CKD stage: 22.1% for eGFR>90 mL/min/1.73 m2 and CKD stage-2; 14.9% for CKD stage 3; and 8.0% for CKD stage-4/5. Those with CKD stage-3 were 33% less likely and those with CKD stage-4/5 were 60% less likely to initiate treatment with a DAA compared with those with baseline eGFR>90 mL/min/1.73 m2 . Treatment initiation was less likely in HCV genotype 2 (OR 0.59; 95%CI 0.53,0.66) or 3 (OR 0.53; 95%CI 0.47,0.61) and those with diabetes (OR 0.87, 95% CI 0.81,0.94), cardiovascular disease (OR 0.77, 95% CI 0.70,0.84), alcohol abuse or dependence (OR 0.74, 95% CI 0.70,0.79) or cirrhosis (OR 0.86, 95% CI 0.80,0.92) at baseline. Conclusions Persons with more advanced CKD are less likely to receive treatment for HCV despite recent data on safety and efficacy. Strategies are needed to improve treatment rates in the HCV/CKD population.

IntroductionDecreased insulin sensitivity occurs early in type 2 diabetes (T2D). T2D is highly prevalent in the Middle East and North Africa regions. This study assessed the variations in insulin sensitivity in normal apparently healthy subjects and the levels of adiponectin, adipsin and inflammatory markers.Research design and methodsA total of 60 participants (aged 18–45, body mass index 2/min) and body composition test by dual-energy X-ray absorptiometry scan. Blood samples were assayed for glucose, insulin, C peptide, inflammatory markers, oxidative stress markers, adiponectin and adipsin.ResultsThe subjects showed wide variations in the whole-body glucose disposal rate (M value) from 2 to 20 mg/kg/min and were divided into three groups: most responsive (M>12 mg/kg/min, n=17), least responsive (M≤6 mg/kg/min, n=14) and intermediate responsive (M=6.1–12 mg/kg/min, n=29). Insulin and C peptide responses to OGTT were highest among the least insulin sensitive group. Triglycerides, cholesterol, alanine transaminase (ALT) and albumin levels were higher in the least responsive group compared with the other groups. Among the inflammatory markers, C reactive protein (CRP) was highest in the least sensitivity group compared with the other groups; however, there were no differences in the level of soluble receptor for advanced glycation end products and Tumor Necrosis Factor Receptor Superfamily 1B (TNFRS1B). Plasma levels of insulin sensitivity markers, adiponectin and adipsin, and oxidative stress markers, oxidized low-density lipoprotein, total antioxidant capacity and glutathione peroxidase 1, were similar between the groups.ConclusionsA wide range in insulin sensitivity and significant differences in triglycerides, cholesterol, ALT and CRP concentrations were observed despite the fact that the study subjects were homogenous in terms of age, gender and ethnic background, and all had normal screening comprehensive chemistry and normal glucose response to OGTT. The striking differences in insulin sensitivity reflect differences in genetic predisposition and/or environmental exposure. The low insulin sensitivity status associated with increased insulin level may represent an early stage of metabolic abnormality.

Background and objective The risk factors for breakthrough infections among healthcare workers (HCW) after completion of a full course of vaccination are poorly understood. Our objective was to determine the risk factors for breakthrough SARS-CoV-2 infection among HCWs at a national healthcare system in Qatar. Methods We identified all HCWs at Hamad Medical Corporation in Qatar between December 20, 2020 and May 18, 2021 with confirmed SARS-CoV-2 RT-PCR infection >14 days after the second vaccine dose. For each case thus identified, we identified one control with a negative test after December 20, 2020, matched on age, sex, nationality, job family and date of SARS-CoV-2 testing. We excluded those with a prior positive test and temporary workers. We used Cox regression analysis to determine factors associated with breakthrough infection. Results Among 22,247 fully vaccinated HCW, we identified 164 HCW who had breakthrough infection and matched them to 164 controls to determine the factors associated with SARS-CoV-2 breakthrough infection. In the breakthrough infection group the nursing and midwifery job family constituted the largest group, spouse was identified as the most common positive contact followed by a patient. Exposure to a confirmed case, presence of symptoms and all other job families except Allied Health Professionals when compared with nursing and Midwifery staff independently predicted infection. Conclusion Presence of symptoms and contact with a confirmed case are major risk factors for breakthrough SARS-CoV-2 infection after vaccination, and these groups should be prioritized for screening even after full vaccination.

Post-transplantation diabetes mellitus (PTDM) is a major complication in kidney transplant recipients leading to reduced allograft and patient survival. Given the high prevalence of diabetes in Qatar, which is twice the global average, we were interested in determining the incidence of PTDM, identifying risk factors, and comparing clinical outcomes in kidney transplant recipients with and without diabetes. We retrospectively followed up 191 adult kidney allograft recipients transplanted between January 1, 2012, and December 31, 2016, for a median of 41 months. A total of 76 patients (40%) had pre-existing diabetes. A total of 39 patients developed PTDM during follow-up; they represent 34% of patients who did not have diabetes prior to transplantation. Two thirds of PTDM occurred within 3-6 months post-transplantation. Prediabetes before transplant [OR = 6.07 (1.24-29.74), P = .026] older recipient's age at the time of transplantation [OR = 1.10 (1.00-1.20), P = .039] and average fasting blood sugar during 3-6 months post-transplant [OR = 1.06 (1.01-1.11), P = .010] were independently associated with PTDM. Patient and kidney allograft survival rates exceeded 97% in all groups. The incidence of PTDM in kidney transplant recipients living in Qatar is high. Older age and prediabetes are independent risk factors for developing PTDM.

For persons with baseline Fibrosis-4 1.46–3.25, cirrhosis incidence/1000 patient-years was 49.3 among hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfected and 18.2 among HCV monoinfected (P = .03). Cirrhosis risk was numerically higher but statistically nonsignificant among HBV/HCV coinfected (hazards ratio [HR] 1.51; 95% confidence intervals [CI], .37–6.05) but lower among those who attained sustained virologic response (HR, .52; 95% CI, .42–.63).

Prediabetes is a condition leading to increased risk of diabetes and its complications and cardiovascular disease. Annually, ∼10% prediabetic subjects progress to T2D. We, and other investigators, reported that grape skin extract (GSE) impacts postprandial glycemia through alpha glucosidase inhibition. This study aims to examine the effect of GSE on glycemic response to a starch challenge in healthy prediabetic subjects. The study was approved by the IRB of Hamad Medical Corporation. Subjects were screened from a high-risk population based on family history and/or fasting glucose (5.7-7.3 mmol) and IGT confirmed with 75 gram OGTT. Subjects were randomized to GSE capsule 600 (N=4), 1200 (N=8), 1800 (N=15) or 2400 mg (N=14). Each received a meal of 35 gram (uncooked weight) rice with or without the assigned dose of GSE and blood glucose was measured at time 0, 15, 30, 60 and 120 minutes. Area under the curve (AUC) was calculated using the trapezoidal method and the subjects were classified into “responders” or “non-responders” if AUC after GSE was reduced by at least 1 SD. A total of 41 eligible subjects (83% male; age 29±8 years; BMI 23.2%±5.9, 34% Arab, 24% African, 17% Asian, 24% Indian) with prediabetes were enrolled. A total of 4 (9.7%)subjects decreased AUC by 2SD; 24% decreased by 1 SD and the remainder had no positive response to a single dose of GSE. There were no responders to 600 mg; 2 in 1200 mg; 4 in 1800 mg; and 3 in 2400 mg dose. There were no differences between the responders and non-responders in clinical or biochemical characteristics. In conclusion, 24% of prediabetic subjects had a positive response to GSE in a starch challenge test. The value of the test in characterizing prediabetic subjects who may benefit from GSE to reverse their prediabetic condition is currently under further investigation. In Qatar, the prevalence of diabetes is 17% and expected to increase. Studies to develop natural products to prevent diabetes are of great public health interest. Disclosure M. Alkasem: None. I. Abdalhakam: None. N.N. Suleiman: None. A.N. Iskandarani: None. T.A. Samra: None. F.A. Mir: None. R.M. Mohammad: None. A. Abou-Samra: None. K. Zhou: None. M.C. Skarulis: None. Funding Qatar National Research Fund

Background The effects of interferon-based therapies for hepatitis C virus (HCV) upon the risk of diabetes are controversial. The effects of newer, directly acting antiviral agents (DAA) upon this risk are unknown. We sought to determine the effects of HCV treatment upon the risk and incidence of diabetes. Methods Using the Electronically Retrieved Cohort of HCV Infected Veterans (ERCHIVES) database for persons with chronic HCV infection (n = 242 680), we identified those treated with a pegylated interferon and ribavirin regimen (PEG/RBV, n = 4764) or a DAA-containing regimen (n = 21 279), after excluding those with diabetes at baseline, those with a human immunodeficiency virus or hepatitis B virus coinfection, and those treated with both PEG/RBV and DAA regimens. Age-, race-, sex-, and propensity score–matched controls (1:1) were also identified. Results Diabetes incidence rates per 1000 person-years were 20.6 (95% confidence interval [CI] 19.6–21.6) among untreated persons, 19.8 (95% CI 18.3–21.4) among those treated with PEG/RBV, and 9.89 (95% CI 8.7–11.1) among DAA-treated persons (P < .001). Among the treated, rates were 13.3 (95% CI 12.2–14.5) for those with a sustained virologic response (SVR) and 19.2 (95% CI 17.4–21.1) for those without an SVR (P < .0001). A larger reduction was observed in persons with more advanced fibrosis/cirrhosis (absolute difference 2.9 for fibrosis severity score [FIB-4] < 1.25; 5.7 for FIB-4 1.26–3.25; 9.8 for FIB-4 >3.25). DAA treatment (hazard ratio [HR] 0.53, 95% CI .46–.63) and SVR (HR 0.81, 95% CI .70–.93) were associated with a significantly reduced risk of diabetes. DAA-treated persons had longer diabetes-free survival rates, compared to untreated and PEG/RBV-treated persons. There was no significant difference in diabetes-free survival rates between untreated and PEG/RBV-treated persons. The results were similar in inverse probability of treatment and censoring weight models. Conclusions DAA therapy significantly reduces the incidence and risk of subsequent diabetes. Treatment benefits are more pronounced in persons with more advanced liver fibrosis.

ObjectivesDiabetes Intervention Accentuating Diet and Enhancing Metabolism-I (DIADEM-I) is the first randomised controlled trial (RCT) in the Middle East and North Africa (MENA) region testing the effectiveness of an intensive lifestyle intervention (ILI) for weight loss and diabetes remission. We report on the recruitment process and baseline characteristics of the DIADEM-I cohort based on origin (Middle East vs North Africa), and waist circumference.DesignDIADEM-I is an open-label randomised, controlled, parallel group RCT recruiting young individuals (18–50 years) with early type 2 diabetes (≤3 years since diagnosis) originating from MENA. Individuals from primary care were randomised to usual medical care or ILI (total dietary replacement phase using meal replacement products, followed by staged food reintroduction and physical activity support). The primary outcome is weight loss at 12 months. Other outcomes are glycaemic control and diabetes remission.SettingPrimary care, Qatar.Participants147 (73% men) randomised within DIADEM-I who were included in the final trial data analysis.Outcome measuresRecruitment metrics, and baseline clinical and metabolic characteristics.ResultsOf 1498 people prescreened, 267 (18%) were invited for screening and 209 (78%) consented. 173 (83%) were eligible. 15 (7%) withdrew before randomisation and the remaining 158 were randomised. Mean age was 42.1 (SD 5.6) years and mean body mass index was: 36.3 (5.5) kg/m2 (women) and 34.4 (5.4) kg/m2 (men). Mean diabetes duration was 1.8 (1.0) years and mean glycosylated haemoglobin (HbA1c) was 7.0% (1.30) (52.5 mmol/mol (SD 14.3)). Participants originated from 13 countries. Those from North Africa reported greater physical activity and had lower family history of diabetes. 90% of subjects were taking diabetes medications and 31% antihypertensives. Those with greater waist circumference had significantly higher insulin resistance and lower quality of life.ConclusionRecruitment of participants originating from the MENA region into the RCT was successful, and study participation was readily accepted. While DIADEM-I participants originated from 13 countries, there were few baseline differences amongst participants from Middle East versus North Africa, supporting generalisability of RCT results.Trial registration numberISRCTN20754766; NCT03225339

Background Chronic kidney disease (CKD) was a relative contraindication to hepatitis C virus (HCV) treatment in the interferon/ribavirin era. Aim To determine the efficacy, tolerability and safety of sofosbuvir/ledipasvir (SOF/LDV) and paritaprevir/ritonavir/ombitasvir/dasabuvir (PrOD) regimens in persons with CKD. Methods We identified persons initiated on a SOF/LDV or PrOD regimen from October 30, 2014 to April 30, 2016. We excluded those with missing HCV genotype or eGFR values. We determined treatment completion and sustained virologic response (SVR) rates, and proportion developing worsening renal function or grade 3/4 haematologic toxicity. Results Among 13 663 persons on SOF/LDV±ribavirin, 14% and 1% persons had CKD Stage 3 and 4-5 respectively, 67.8% completed treatment, 98.2% achieved SVR. Treatment completion or SVR rates did not decline with advanced CKD or ribavirin administration. Among 3961 persons on PrOD±ribavirin, 9% and 3% persons had CKD Stage 3 and 4-5, respectively, 74.0% completed treatment and 98.2% achieved SVR. A decrease in treatment completion rates was seen in CKD stage 4-5 and those on ribavirin, but this did not impact SVR rates. A >10 mL/min/1.73 m2 drop in eGFR from baseline was observed in 30%-38% of persons with baseline eGFR ≥60 mL/min/1.73 m2 , but in only 0%-6% with CKD4-5. Grade 3/4 anaemia was more frequent in persons with CKD4-5, but ribavirin co-administration did not appear to affect this. Conclusions SOF/LDV and PrOD achieved high SVR rates in CKD population. Treatment completion rates were lower than expected. A decline in eGFR and development of anaemia were observed in a substantial proportion of persons, but the clinical implications remain unclear.

Insulin resistance, which plays a central role in the pathogenesis of type 2 diabetes (T2D), is an early indicator that heralds the occurrence of T2D. It is imperative to understand the metabolic changes that occur at the cellular level in the early stages of insulin resistance. The objective of this study was to determine the pattern of circulating lactate levels during oral glucose tolerance test (OGTT) and hyperinsulinemic euglycemic clamp (HIEC) study in normal nondiabetic subjects. Lactate and glycerol were determined every 30 minutes during OGTT and HIEC on 22 participants. Lactate progressively increased throughout the HIEC study period (P<0.001). Participants with BMI < 30 had significantly higher meanM-values compared to those with BMI ≥ 30 at baseline (P<0.05). This trend also continued throughout the OGTT. In addition, those with impaired glucose tolerance test (IGT) had significantly higher mean lactate levels compared to those with normal glucose tolerance (P<0.001). In conclusion, we found that lactate increased during HIEC study, which is a state of hyperinsulinemia similar to the metabolic milieu seen during the early stages in the development of T2D.

Recent studies have reported higher rates of hepatocellular carcinoma (HCC) in individuals treated with direct-acting antivirals (DAAs). However, making definitive conclusions has been challenging because of the heterogeneous populations and methodologies of these reports. We investigated whether DAA use is associated with higher rates of incident HCC compared to treatment with interferon (IFN)-based regimens. We performed a retrospective, population-based cohort study using the Electronically Retrieved Cohort of HCV Infected Veterans (ERCHIVES) database. In a cohort of 17,836 persons, sustained virological response (SVR) was achieved by 66.6% and 96.2% of the IFN and DAA groups, respectively. Among all treated persons, risk of HCC was not higher in the DAA group compared to the IFN group (hazard ratio, 1.07; 95% confidence interval, 0.55, 2.08). Among persons with cirrhosis who achieved SVR, neither the HCC incidence rate nor HCC-free survival were significantly different in the DAA group compared to the IFN group (21.2 vs. 22.8 per 1,000 person-years; P = 0.78 and log-rank P = 0.17, respectively). Untreated persons with cirrhosis had a significantly higher HCC incidence rate (45.3 per 1,000 person-years) compared to those treated with either IFN or DAAs (P = 0.03). Both groups of treated persons had significantly lower probability of HCC development compared to untreated persons (log-rank, P = 0.0004). Conclusion DAA treatment is not associated with a higher risk of HCC in persons with cirrhosis with chronic HCV infection in the short term. Previously reported higher rates of HCC associated with DAA treatment may be explained by both the presence of relatively fewer baseline HCC risk factors in persons treated with IFN as well as selection bias, given that DAA regimens were used to treat persons at higher risk for developing HCC. (Hepatology 2018;67:2244-2253).

Background Higher risk of hepatitis B reactivation (HBV-r) has been reported in patients with hepatitis C treated with newer directly acting antiviral agents (DAAs). Aim To determine the proportion of persons who develop HBV-r and its clinical consequences among DAA treated vs pegylated interferon/ribavirin (PEG/RBV) treated persons. Methods We calculated the proportion of persons who developed HBV viral reactivation (HBV-r; new detectable HBV DNA or increase of >1 log10 ); serum alanine aminotransferase flare (>5 times baseline); all-cause mortality and hepatic decompensation in persons treated with a newer DAA regimen or PEG/RBV. Kaplan-Meier curves were used to demonstrate survival and hepatic decompensation by treatment group and HBV-r. Results In 34 632 persons treated with DAA and 23 475 treated with PEG/RBV, HBV-r rate per 1000 person-years was 30.04 (10.41, 49.67) and 25.42 (95% CI 17.23, 33.62) respectively (P = .8). When stratified by SVR or by baseline HBsAg status, HBV-r was not different between groups. Kaplan-Meier survival curves comparing each regimen stratified by presence or absence of HBV-r did not demonstrate a significant difference in incidence of hepatic decompensation over time. For overall survival, there was no difference between PEG/RBV treated persons with or without HBV-r. For DAA treated persons, those with HBV-r had a shortened survival, though the numbers at risk were small. Conclusions HBV-r is relatively uncommon after DAA therapy and not higher than among those treated with a PEG/RBV regimen. The small numbers of persons treated with a DAA regimen who do develop HBV-r have a shortened survival compared to those without HBV-r.

Background Proton pump inhibitors are among the most commonly prescribed medications in the United States. Their safety in cirrhosis has recently been questioned, but their overall effect on disease progression in noncirrhotic patients with chronic liver disease remains unclear. Aim To determine the impact of proton pump inhibitors on the progression of liver disease in noncirrhotic patients with hepatitis C virus (HCV) infection. Methods Using the electronically retrieved cohort of HCV-infected veterans (ERCHIVES) database, we identified all subjects who received HCV treatment and all incident cases of cirrhosis, hepatic decompensation and hepatocellular carcinoma. Proton pump inhibitor use was measured using cumulative defined daily dose. Multivariate Cox regression analysis was performed after adjusting univariate predictors of cirrhosis and various indications for proton pump inhibitor use. Results Among 11 526 eligible individuals, we found that exposure to proton pump inhibitors was independently associated with an increased risk of developing cirrhosis (hazard ratio [HR]: 1.32; 95% confidence interval: [1.17, 1.49]). This association remained robust to sensitivity analysis in which only patients who achieved sustained virologic response were analysed as well as analysis excluding those with alcohol abuse/dependence. Proton pump inhibitor exposure was also independently associated with an increased risk of hepatic decompensation (HR: 3.79 [2.58, 5.57]) and hepatocellular carcinoma (HR: 2.01 [1.50, 2.70]). Conclusions In patients with chronic HCV infection, increasing proton pump inhibitor use is associated with a dose-dependent risk of progression of chronic liver disease to cirrhosis, as well as an increased risk of hepatic decompensation and hepatocellular carcinoma.

Background Risk of acute myocardial infarction (AMI) among hepatitis C virus (HCV)-positive versus HCV-negative persons with similar lipid levels is unknown. We determined incident AMI rates among HCV-positive and HCV-negative men among various lipid strata. Methods We created a propensity score matched (PSM) cohort and a low cardiovascular disease (CVD) risk cohort. Primary outcome was incident AMI rates by HCV status in each lipid strata using National Cholesterol Program guidelines for lipid strata. Results We identified 85863 HCV-positive and HCV-negative men in the PSM population. The incidence rates/1000 patient-years (95% confidence interval [CI]) for AMI among total cholesterol (TC) 200-239 stratum were 5.3 (4.89, 5.71) for HCV-positive versus 4.71 (4.42, 5) for HCV-negative men (P = .02) and for TC >240 mg/dL were 7.38 (6.49, 8.26) versus 6.17 (5.64, 6.71) (P = .02). For low-density lipoprotein cholesterol (LDL) of 130-159 mg/dL, AMI rates were 5.44 (4.97, 5.91) for HCV-positive and 4.81 (4.48, 5.14) for HCV-negative men (P = .03). The rise in risk with increasing lipid levels was greater in younger HCV-positive than in HCV-negative men (e.g., TC > 240 mg/dL: age >50 HR 1.38 [HCV-positive] and 1.12 [HCV-negative]; age ≤50 HR 1.6 [HCV-positive] and 1.29 [HCV-negative]), and more profoundly altered in HCV-positive men by lipid lowering therapy (change in HR with lipid-lowering therapy for TC >240 mg/dL from 1.82 to 1.19 [HCV-positive] from 1.48 to 1.03 [HCV-negative]). Conclusions HCV-positive men have a higher risk of AMI than HCV-negative men at higher TC/LDL levels; this risk is more pronounced at a younger age. Lipid lowering therapy significantly reduces this risk, with more profound reduction among HCV-positive versus HCV-negative men at similar lipid levels.

Background Interferon-based regimens are associated with a substantial survival benefit for persons infected with hepatitis C virus (HCV). Survival data with direct-acting antiviral agents are not available. We conducted this study to quantify the effect of paritaprevir/ritonavir, ombitasvir, dasabuvir (PrOD) and ledipasvir/sofosbuvir (LDV/SOF) regimens upon mortality. Methods In the Electronically Retrieved Cohort of HCV Infected Veterans (ERCHIVES), a well-established national cohort of HCV-infected Veterans, we identified HCV-infected persons initiated on PrOD or LDV/SOF, excluding those with human immunodeficiency virus, hepatitis B surface antigen positivity, hepatocellular carcinoma, or missing HCV RNA or FIB-4 scores. For each case, we identified a propensity score-matched control never initiated on treatment. Primary outcome was survival. Outcomes were assessed using frequency of events, Kaplan-Meier curves, and Cox proportional hazards regression analyses. Results We identified 1473 persons on PrOD, 5497 on LDV/SOF, and 6970 propensity score-matched untreated persons. Treated persons were more likely to be obese and have cirrhosis, but less likely to have stage 3-5 chronic kidney disease (CKD), alcohol or drug abuse or dependence diagnosis, and anemia. The proportion of persons who died was higher in the untreated group compared with either treatment group (PrOD, 0.3%; LDV/SOF, 1.4%; untreated controls, 2.5%; P < .001). A significantly larger percentage of treated patients survived to 18 months of follow-up, compared with untreated controls (P < .001). In multivariable Cox regression analysis, treatment with either regimen (hazard ratio [HR], 0.43; 95% confidence interval [CI], .33-.57) and attainment of sustained virologic response (SVR) were associated with significantly lower mortality (HR, 0.57; 95% CI, .33-.99). Conclusions Treatment with PrOD or LDV/SOF and SVR are associated with a significant mortality benefit, apparent within the first 18 months of treatment.

Infection with hepatitis virus C (HCV) is associated with an increased risk of cardiovascular disease (CVD) events. It is not clear whether treatment with direct-acting antiviral (DAA) agents affects risk of CVD.We searched the Electronically Retrieved Cohort of HCV-Infected Veterans database for patients with chronic HCV infection (n = 242,680) and identified patients who had been treated with a pegylated interferon and ribavirin regimen (n = 4436) or a DAA-containing regimen (n = 12,667). Treated patients were matched for age, race, sex, and baseline values with patients who had never received treatment for HCV infection (controls). All subjects were free of any CVD event diagnosis of HCV infection at baseline. The primary outcome was incident CVD events, identified by International Classification of Diseases, Ninth Edition, Clinical Modification or International Classification of Diseases, Tenth Edition code, in the different groups and in patients with vs without a sustained virologic response to therapy.There were 1239 (7.2%) incident CVD events in the treated groups and 2361 (13.8%) events in the control group. Incidence rates were 30.9 per 1000 patient-years (95% CI 29.6-32.1) in the control group and 20.3 per 1000 patient-years (95% CI 19.2-21.5) in the treated groups (P.0001). Treatment with pegylated interferon and ribavirin (hazard ratio 0.78; 95% CI 0.71-0.85) or a DAA regimen (hazard ratio 0.57; 95% CI 0.51-0.65) was associated with a significantly lower risk of a CVD event compared with no treatment (controls). Incidence rates for CVD events were 23.5 per 1000 patient-years (95% CI 21.8-25.3) in the group treated with the pegylated interferon and ribavirin regimen, 16.3 per 1000 patient-years (95% CI 14.7-18.0) in the group treated with a DAA regimen, and 30.4 (95% CI 29.2-31.7) in the control group. A sustained virologic response was associated with a lower risk of incident CVD events (hazard ratio 0.87; 95% CI 0.77-0.98).In an analysis of a cohort of HCV-infected veterans, treatment of HCV infection was associated with a significant decrease in risk of CVD events. Patients treated with a DAA regimen and patients who achieved sustained virologic responses had the lowest risk for CVD events.

ObjectivesMetabolic syndrome is a cluster of conditions—increased blood pressure, a high blood sugar level, abdominal fat accumulation and abnormal cholesterol levels—that occur together, increasing the risk of heart disease, stroke and type 2 diabetes mellitus (T2DM). Mitochondria play a central role in the energy metabolism. Mitochondrial dysfunction contributes to the pathogenesis of metabolic disorders. Abnormality in mitochondrial function is a leading cause for development of insulin resistance and is promoted, at least partly, through lipid accumulation in ectopic tissues, including liver and skeletal muscle. Many growth and transcription factors involved in the regulation of mitochondrial gene expression also contribute to the pathophysiology of obesity, insulin resistance and type-2 diabetes. The role of mitochondria as functional organelles, and the signaling molecules produced by them are critical in the regulation of cellular energy metabolism and homeostasis. MOTS-c (mitochondrial open reading frame of the 12S rRNA type-c) encoding a 16-amino-acid peptide is a recently identified peptide. The skeletal muscle appears to be the main target organ for MOTS-c and its cellular actions inhibit the folate cycle and its tethered de novo purine biosynthesis, leading to AMPK activation. MOTS-c increases glucose utilization, promotes insulin sensitivity and metabolic homeostasis through activation of AMPK dependent mechanisms in skeletal muscle. In rodent studies MOTS-c has been demonstrated to protect against insulin resistance induced by diet and ageing. However the role of MOTS-c in adipocytes is largely unknown. In this current study we aimed to study the effect of MOTS-c on adipocyte development and metabolism in cultured mouse adipocytes.Methods3T3L1 cells were grown in DMEM media containing 10% FBS. Cells were stimulated with various concentrations of MOTS-c (100 nM to 50 μM) to study the effect of MOTS-c on cell viability. For differentiation pre-adipocytes were grown in differentiation induction medium containing dexamethasone, IBMX and insulin for two days. The media was replaced with medium containing insulin only for the next six days. About 60–70% differentiation was achieved by day 8. For treatment group pre-adipocytes were pre-treated with MOTS-c for 24 hours, and then differentiated into adipocytes for eight days. Quantitative real-time PCR was used to investigate the effect of MOTS-c on adipogenic genes expression:, Peroxisome Proliferator-Activated Receptor Gamma (PPARg), AP2, adiponectin and leptin in mouse 3T3-L1 pre-adipocytes.ResultMOTS-c treatment did not induce any significant changes in cell viability at 24h following treatment. Pretreatment with MOTS-c prior to induction of differentiation down regulated expression of adipogenic markers including leptin, adiponectin, PPARg and PPARg-coactivator 1-alpha (PGC1a) mRNA levels, compared to differentiated adipocyte controls.ConclusionOur primary result indicates that MOTS-c inhibits adipogenesis through down-regulation of multiple genes involved in development of adipocytes, and this inhibition could contribute to the reduced abdominal adiposity. Future studies are currently in progress to further assess the effects of MOTS-c on adipocytes lipolysis, glucose uptake, glucose transporter (GLUT) family and other insulin-signaling pathway protein including GSK3B, IGF1R, IGF2R, and PIK3K are needed to understand the role of MOTS-c in mouse 3T3-L1 adipocytes.

SummaryInsulin resistance manifest in skeletal muscle, liver and adipocytes. Insulin stimulates muscle glucose uptake, suppresses the rate of hepatic glucose production (HGP) and restrains lipolysis. In insulin resistant individuals, insulin-stimulated glucose uptake is markedly reduced in skeletal muscle, impaired insulin-mediated suppression of hepatic glucose production (HGP) and inhibition of lipolysis. It is evident from human and animal studies that diabetes alters miRNAs expression in metabolically important organs (adipose, liver and skeletal muscle).micRNA are small non coding RNA molecules. However, they play critical role in the regulation of gene expression via post-transcriptional mechanisms. They are small in size (21?23 nucleotides) and recent studies have demonstrated that they play important role in many human complex diseases including diabetes. The ability of miRNA that simultaneously regulate many target genes makes them attractive candidates for regulating insulin production/secretion and action. mRNA are secreted to the circulation and are taken up from the circulation by several tissues, making them an attractive mechanism for inter-tissue signaling molecules. Thus, if micro RNA play role in the pathogenesis of insulin resistance or in communicating between insulin resistant tissues and the beta cell to regulate the level of beta cell function in concert with the prevailing level of insulin resistance, we anticipate a change in the circulatory profile of micro RNA in insulin resistant individuals compared to insulin sensitive individuals. Such a distinct circulatory profile of micro RNA in insulin sensitive versus insulin resistant individuals could provide a signature for the identification of insulin resistant individuals. Moreover, differentially expressed micro RNA molecules in insulin resistant individuals could serve signaling molecules which convey messages between insulin resistant tissues, i.e. liver, skeletal muscle and adipocytes and the beta cell. Insulin sensitivity is commonly assessed to predict the risk and evaluate the management of type 2 diabetes in clinical and research settings. Insulin sensitivity can be measured using a variety of techniques that are commonly employed in diabetes research and care. Among them, euglycemic hyperinsulemic clamp is the gold-standard method to quantify the sensitivity to insulin.The aim of the present study is to determine the profile of miRNA in the plasma in insulin sensitive Arab individuals and compare the result to that in insulin resistant Arab individuals.specific aims are;1. To discover the circulatory profile of microRNA in insulin sensitive and insulin resistant Arab individuals by using next generation sequencing technology.2. To identify novel microRNA/targets which are differentially expressed in insulin resistant individuals by real time Taq-Man PCR.3. To explore the effects changes of these miRNAs in insulin resistance diabetes β-Cell Biology. The experiments range from relevant tissue and cell cultures systems to human physiology. Design and methods: The circulating miRNA profile was assessed in a pilot study of 20 healthy volunteers whom glucose tolerance status was determined by the OGTT, and their insulin sensitivity was quantitated by the gold standard method the euglycemic hyperinsulemic clamp. Based on Glucose Infusion rate (GIR: mg/kg/min), before and after a 6-h hyperinsulinemeic euglycemic clamp, we selected two groups: 10 with high levels of GIR (insulin-sensitive group) and 10 with Very low levels of GIR (insulin resistant group).The serum samples was collected from the two groups for miRNA extraction and subsequent sequencing using the True-seq Illumina protocol. A small RNA library was generated from samples using the Illumina Truseq™ Small. The purified cDNA library was used for cluster generation on Illumina's Cluster Station and then sequenced on Illumina GAIIx following vendor's instruction for running the instrument. Raw sequencing reads (40 nts) were obtained using Illumina's Sequencing Control Studio software version 2.8 (SCS v2.8) following real-time sequencing image analysis and base-calling by Illumina's Real-Time Analysis version 1.8.70 (RTA v1.8.70). Result: Sequencing of the small circulating RNA isolated from insulin-resistant and insulin-sensitive healthy samples produced 69,559,764 raw reads. A total of 41,697,300 mappable reads was obtained after sequence filtering. Using a 2-fold expression difference as a cutoff, 33 miRNAs showed significally differential expression between insulin sensitive and insulin-resistant group. Among which, 10 were up-regulated and 22 were down-regulated. This RNA-seq discovery study shows that the most changes in miRNAs expression is in accordance with previous studies performed to explore circulating miRNAs in human insulin resistance or T2DM. Indeed, among the 54 selected miRNAs, we have identified the same changes in mir-126 expression that has described by Zampetaki and colleagues. This group reported that mir-126 is a unique plasma miRNA signature in 800 patients with T2D and observed that the reduced levels of mir-126 showed the strongest association with T2D. From the 33 miRNAs, a relative number of them are much documented to be associated with insulin resistance and type 2 diabetes. Nevertheless, some identified miRNAs are potential novel candidates and need to be deeply exploring during the event of the pathogenesis of T2D. Conclusion: This study provides a comparative profiling of circulating miRNAs in insulin-resistant versus insulin–sensitive subjects and the identification of specific miRNAs in circulation that changes are associated with insulin action. To our knowledge, this is the first study to investigate insulin resistance in Arab population using euglycemic hyperinsulemic clamp the gold-standard method to assess insulin sensitivity and aim to identify changes in circulating miRNAs expression associated to insulin action and signaling. The study also provides evidence that Insulin Resistance in human is related to changes in multiples microRNAs. Functional Validation studies of the differentially expressed miRNAs and relevant target and signaling pathways are ongoing.

Background Chronic kidney disease (CKD) was a relative contraindication to HCV treatment in the interferon/ribavirin era due to poor tolerability and lower efficacy. Our aim was to determine the effectiveness treatment completion, and safety of sofosbuvir/ledipasvir (SOF/LDV) and paritaprevir/ritonavir/ombitasvir/dasabuvir (PrOD) regimens in persons with CKD. Methods We identified all persons started on a SOF/LDV or PrOD regimen in ERCHIVES before 30 April 2016. We excluded those with missing HCV genotype, or eGFR values. We determined treatment completion, sustained virologic response (SVR) rates and proportion of persons with worseningrenal function or developing grade 3/4 anemia. Results We identified 9,837 persons on SOF/LDV, 3,826 on SOF/LDV+RBV, 1,017 on PrOD and 2,944 on PrOD+RBV. Genotype 1a was the predominant genotype for SOF/LDV+RBV (77.3% no RBV; 70.0% with RBV) and PrOD+RBV (79.5%) groups, while only 4.3% of PrOD with no RBV group were genotype 1a. Among treated patients, the prevalence of patients with stage 4–5 CKD was 0.8% (SOF/LDV + RBV), 1.1% (SOF/LDVno RBV), 2.2% (PrOD +RBV) and 5.4% (PrOD no RBV). Among 13,663 total persons on SOF/LDV, 67.8% completed treatment while the treatment completion rate of those on PrOD was 74.0% (N = 2,932/3,961) (Table 1). The overall SVR rates of persons on SOF/LDV or PrOD regimens were 96.3%. A drop in treatment completion rates was seen in CKD stage 4–5 and those on PrOD+RBV, but the impact of RBV on SVR was unclear. While about one-third of the persons with a CKD stage 1–2 experienced a >10 mL/minute/1,73m2, about 15% decline among those with CKD stage 3. The incidence of grade3/4 anemia by CKD stages increased significantly across the treatment groups. Grade 3/4 anemia ranged from 9.7% (SOF/LDV) to 21.8% (PrOD) among patients with CKD stage 4–5 (Table 2). Conclusion SVR rates among persons treated with SOF/LDV or PrOD were high in the CKD population despite 22% not completing the treatment regimen. Incidence of grade3/4 anemia increased significantly in CKD stage 4–5 across the treatment groups. Disclosures A. Butt, Merck: Investigator, Grant recipient.A. Puenpatom, Merck: Employee, Salary. J. M. Arduino, Merck: Employee, Salary. R. Kumar, Merck: Employee, Salary

Background Changes in lipid levels over time after acquiring HCV infection, and how they differ from HCV-uninfected persons are unknown. Methods We used ERCHIVES to identify those with a known HCV seroconversion window and persistently negative controls. We excluded subjects with HIV and hepatitis B and those who received lipid lowering agents. Total Cholesterol (TC), low-density lipoproteins (LDL), high-density lipoproteins (HDL), triglycerides (TG) and non-HDL cholesterol were retrieved at yearly intervals and plotted over time. Results Among 1,270 HCV+ and 5,070 HCV- subjects, median age [IQR] was 47[37,53] for HCV+ and 52[47,57] for the HCV- group; 69 % were White and 91 % were males in each group. Mean BMI [SD] was 26.94[6.73] in the HCV+ and 28.15 [5.98] in the HCV- group (P

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been variably noted to affect hepatitis C virus (HCV) treatment response, fibrosis progression, and hepatocellular carcinoma (HCC) incidence, with some having a more potent effect than others. We sought to determine the impact of adding statins to antiviral therapy upon sustained virological response (SVR) rates, fibrosis progression, and HCC development among HCV-infected persons using the Electronically Retrieved Cohort of HCV Infected Veterans (ERCHIVES), an established, longitudinal, national cohort of HCV-infected veterans. Within ERCHIVES, we identified those who received HCV treatment and a follow-up of24 months after treatment completion. We excluded those with human immunodeficiency virus coinfection, hepatitis B surface antigen positivity, cirrhosis, and HCC at baseline. Our main outcomes were liver fibrosis progression measured by FIB-4 scores, SVR rates, and incident HCC (iHCC). Among 7,248 eligible subjects, 46% received statin therapy. Statin use was significantly associated with attaining SVR (39.2% vs. 33.3%; P 0.01), decreased cirrhosis development (17.3% vs. 25.2%; P 0.001), and decreased iHCC (1.2% vs. 2.6%; P 0.01). Statins remained significantly associated with increased odds of SVR (odds ratio = 1.44; 95% confidence interval [CI] = 1.29, 1.61), but lower fibrosis progression rate, lower risk of progression to cirrhosis (hazard ratio [HR] = 0.56; 95% CI = -0.50, 0.63), and of incident HCC (HR = 0.51; 95% CI = 0.34, 0.76) after adjusting for other relevant clinical factors.Statin use was associated with improved virological response (VR) rates to antiviral therapy and decreased progression of liver fibrosis and incidence of HCC among a large cohort of HCV-positive Veterans. These data support the use of statins in patients with HCV.

Diabetes is highly prevalent in Qatar and about 1/3 of patients are not aware of their diseases. Screening for undiagnosed diabetes is essential for effective management and prevention of diabetes and its complications. The effectiveness and cost analysis of several diabetes screening programs have been the subject of intensive investigation. Point of care (POC) measurement of capillary blood glucose (CBG) is very simple and can be applied widely, however, random CBG values are hard to interpret unless a high cut-off point is utilized, such as >200 mg/dL. A high cut off point would miss a large number of diabetics and pre-diabetics. POC CBG measurement of fasting and post-prandial values is difficult to organize in a community sitting. In Qatar, and all Muslim countries, most people observe fasting. If POC CBG is applied between 12:00 and sunset, then all values are at least 9 h after the morning meal and are considered fasting values. Similarly, POC CBG measured after evening prayer (Taraweeh) is equivalent to a late post-prandial value (~3 h after evening meal). Here we piloted a study to evaluate the usefulness of POC CBG to screen for diabetes in Ramadan after Juma'a prayer (~9 h of fast) and after Taraweeh prayer (3-4 h after evening meal - Iftar) in the large Mosq in Doha. We also administered a questionnaire to learn about known diabetes, co-morbidities and family history. A total of 2177 individuals were screened in 2 days, 75% were men and 25% were women representative of 40 different nationalities with most from Egypt (743, 38%), India (348, 23%) and Qatar (146, 7%). The distribution of CBG values were not statistically different between afternoon and evening values and were pooled for this analysis. 57% of all values were normal (

Insulin resistance and beta cell dysfunction are core defects in type 2 diabetes (T2DM). Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are intermediate states in the transition in glucose tolerance from normal to T2DM, both of which are associated with increased conversion rate to T2DM. Understanding the metabolic abnormalities that lead to the development of IFG and IGT will help develop strategies to prevent the development of T2DM. in the present study, we have examined the metabolic abnormalities responsible for the development of IFG and IGT in Arab individuals. 43 subjects with NGT (n=17), isolated IFG (N=17) and isolated IGT (n=9) received 75-gram OGTT and plasma glucose, insulin and C-peptide concentrations were measured at baseline and every 15 minutes for 3 hours after the glucose drink. Insulin secretion was measured with the incremental area under the plasma insulin and C-peptide concentration curves and insulin sensitivity was measured with the Matsuda Index. Beta cell function was measured with the Disposition Index as the product of insulin secretion and insulin sensitivity indices. IGT subjects manifested severe insulin resistance compared to IFG and NGT subjects. The Matsuda Index was 3.7±0.4, 7.2±1.0 and 8.4±1.1, respectively (p

The PTH/PTHrP receptor binds to two ligands with distinct functions: the calcium-regulating hormone, parathyroid hormone (PTH), and the paracrine factor, PTH-related protein (PTHrP). Each ligand, in turn, is likely to activate more than one receptor. The functions of the PTH/PTHrP receptor were investigated by deletion of the murine gene by homologous recombination. Most PTH/PTHrP receptor (-/-) mutant mice died in mid-gestation, a phenotype not observed in PTHrP (-/-) mice, perhaps because of the effects of maternal PTHrP. Mice that survived exhibited accelerated differentiation of chondrocytes in bone, and their bones, grown in explant culture, were resistant to the effects of PTHrP and Sonic hedgehog. These results suggest that the PTH/PTHrP receptor mediates the effects of Indian Hedgehog and PTHrP on chondrocyte differentiation.

CRF is the primary neuroregulator of the function of the hypothalamic-pituitary-adrenal axis. We have recently cloned a mouse CRF receptor (mCRF-R) complementary DNA (cDNA) from an AtT-20 cell cDNA library by polymerase chain reaction. To compare the functions of mCRF-R to those of the human type I and type II CRF receptors (hCRF-RI and hCRF-RII), cDNAs were cloned into the expression vector pcDNA1 and transfected into COS-7 cells. CRF binding and CRF-stimulated cAMP accumulation as well as phosphoinositide hydrolysis were measured. Scatchard analysis of the binding of 125I-labeled [Tyr0]r/hCRF ([125I]CRF) to COS-7 cells expressing mCRF-R and hCRF-RI cDNAs revealed the same apparent Kd (9 nM). In contrast, the apparent binding Kd for hCRF-RII was 20 nM CRF. Maximal stimulatory concentrations (1 microM) of rat/human CRF-(1-41) (r/hCRF) increased cAMP accumulation in COS-7 cells transfected with mCRF-R, hCRF-RI, and hCRF-RII cDNA plasmid (10 micrograms each) from basal values of 8-19 pmol/10(5) cells.15 min to 84 +/- 10, 87 +/- 16, and 45 +/- 16 pmol/10(5) cells.15 min, respectively. The EC50 values of r/hCRF-stimulated cAMP accumulation in COS-7 cells expressing mCRF-R and hCRF-RI cDNAs were similar at 0.4 +/- 0.2 and 0.7 +/- 0.2 nM, respectively. Conversely, the EC50 of r/hCRF-stimulated cAMP accumulation in hCRF-RII-transfected COS-7 cells was 47.5 +/- 18.9 nM. As the level of expression of hCRF-RII was lower than that of hCRF-RI, we compared r/hCRF-stimulated cAMP accumulation in COS-7 cells expressing low and high levels of hCRF-RI. The EC50 for r/hCRF-stimulated cAMP accumulation in COS-7 cells transfected with hCRF-RI did not change when receptor expression was varied by a factor of 1- to 8.4-fold. In contrast, the EC50 for r/hCRF-stimulated cAMP accumulation mediated by hCRF-RII was at least 100-fold higher than that mediated by the hCRF-RI in COS-7 cells, which suggests poor coupling between hCRF-RII and adenylate cyclase. Inositol phosphate (IP) levels were also determined in mCRF-R, hCRF-RI, and hCRF-RII cDNA-transfected COS-7 cells stimulated with increasing concentrations of r/hCRF. r/hCRF-stimulated IPs accumulation was dose dependent in COS-7 cells expressing mCRF-R and hCRF-RI using 100 and 1000 nM r/hCRF. Concentrations of 10 (or less) nM r/hCRF had no effect on IP generation. hCRF-RII did not mediate stimulation of IP even at 1000 nM r/hCRF.(ABSTRACT TRUNCATED AT 400 WORDS)

The pulsatile but not the continuous application of parathyroid hormone (PTH) increase bone mass in vivo. To study the effects of intermittent hormonal administration on bone-derived cells in vitro, we established a perifusion system using the human osteosarcoma cell line SaOS-2. Cells were grown in suspension culture attached to collagen beads and were then loaded into a 3 ml syringe for perifusion experiments. The application of PTH(1-34) resulted in a dose-dependent increase of cAMP release by SaOS-2 cells into the effluent medium. Cyclic AMP accumulation was rapidly desensitized by approx. 80% after 30 min of continuous exposure to PTH(1-34) (10(-7) M), while cells remained responsive to forskolin. The recovery of PTH responsiveness required at least 2 h of hormone-free perifusion. Desensitization in the experimental setting was dose-dependent (EC50 = 1 x 10(-10) M PTH(1-34)). Neither 8Br-cAMP (2 x 10(-4) M) nor PMA(1 x 10(-7) M) had an effect on the PTH(1-34)-induced desensitization of the adenylate cyclase. Radioreceptor assays showed that [125I]-[Tyr36]hPTHrP(1-36)amide binding to SaOS-2 cells was decreased by 60-70% by PTH(1-34) (1 x 10(-6) M), bPTH(1-84) (1.8 x 10(-6) M) and bPTH(3-34) (2 x 10(-6) M), whereas 8Br-cAMP (2 x 10(-4) M) had no effect on radioligand binding. PMA (1 x 10(-7) M) appeared to slightly increase [125I]PTHrP binding. This observation is consistent with a small (3-fold) increase in PTH-induced cAMP release as a result of PMA pre-treatment. Receptor internalization was dose-dependent EC50 = 3 x 10(-7) M PTH(1-34)). The maximal effect occurred after 10-30 min and was largely reversible within 2 h. Monensin (3 x 10(-5) M) inhibited the recovery from receptor internalization. We conclude that a perifusion system using SaOS-2 cells is a suitable model to study the effect of discontinuous application of PTH on cAMP release. A rapid, homologous desensitization of PTH(1-34) stimulated cAMP accumulation has been observed that does not appear to involve protein kinase A or C.

Homologous down-regulation of PTH/PTH-related peptide (PTHrP) receptor expression occurs in several PTH-responsive osteoblastic cell lines, but the mechanisms responsible are not well understood. We have used wild-type SaOS-2 human osteoblastic cells, in which homologous PTH/PTHrP receptor down-regulation occurs within 4 h, and a mutant cAMP-resistant subclone (Ca4A strain), to investigate the mechanisms by which PTH/PTHrP receptor mRNA is regulated. SaOS-2 cells expressed a single 2.2- to 2.5-kilobase transcript of PTH/PTHrP receptor mRNA, as assessed by Northern blot analysis of total RNA with a cDNA probe encoding the human PTH/PTHrP receptor. Homologous down-regulation of this PTH/PTHrP receptor mRNA first became significant when SaOS-2 cells had been treated with human (h) PTH-(1-34) (10(-7) M) for 8-12 h. By 24 h, steady state levels of PTH/PTHrP receptor mRNA were reduced by about 50%. This effect was mimicked by both (Bu)2cAMP (DBcAMP; 0.5 mM) and forskolin (Fsk; 10(-5) M). In contrast, down-regulation of PTH/PTHrP receptor mRNA by hPTH-(1-34), DBcAMP or Fsk was almost completely blocked in cAMP-resistant Ca4A cells. Short term (4-6 h) treatment with hPTH-(1-34), DBcAMP, or Fsk did not reduce steady state levels of PTH/PTHrP receptor mRNA in either SaOS-2 or Ca4A cells, although down-regulation was induced by 4-6 h of treatment with active phorbol esters such as 12-O-tetradecanoyl phorbol-13-acetate (200 nM) or phorbol-12,13-didecanoate (200 nM). Neither thapsigargin (1 microM) nor ionomycin (200 nM), both of which stimulate calcium transients in these cells, altered PTH/PTHrP receptor mRNA expression. Treatment with hPTH-(39-84) and hPTH-(53-84), which do not activate either cAMP-dependent protein kinase or protein kinase-C, but do stimulate 45Ca2+ uptake in these cells, did not alter PTH/PTHrP receptor mRNA expression. In the presence of actinomycin-D (1 microgram/ml), down-regulation of PTH/PTHrP receptor mRNA by hPTH-(1-34) was not observed. Cycloheximide (10 micrograms/ml) did not block down-regulation of PTH/PTHrP receptor mRNA induced by hPTH-(1-34). We conclude that homologous down-regulation of PTH/PTHrP receptor mRNA in SaOS-2 cells occurs later than the decline in functional surface receptors via a mechanism that does not involve enhanced mRNA degradation or new protein synthesis, but is dependent upon cAMP/cAMP-dependent protein kinase.

The renal PTH/PTHrP receptor is down-regulated in rats with chronic renal failure. Hypocalcemia, hyperphosphatemia, and resistance to the action of PTH are well characterized features in the setting of advanced chronic renal failure (CRF). Although the underlying mechanisms are ill-understood, clinical and experimental evidence points to both PTH receptor down-regulation and post-receptor abnormalities in their pathogenesis. In the present study we have examined the effect of advanced CRF in rats on the renal expression of PTH/PTHrP receptor (PTH-R). CRF was created by a standard two-step operation (5/6 nephrectomy). Four weeks thereafter, 19 uremic rats were compared with 23 sham-operated rats. Uremic rats had higher mean (± SD) plasma creatinine levels than control rats, 164 ± 107 µM versus 43 ± 5 µM, respectively. They also had higher plasma phosphorus and iPTH levels, 4.70 ± 1.71mM versus 2.59 ± 0.37mM and 561 ± 336 versus 27 ± 18 pg/ml, respectively. Mean plasma total calcium and blood ionized calcium were significantly lower in uremic than in control rats, 2.13 ± 0.06mM versus 2.61 ± 0.10mM and 1.07 ± 0.11 versus 1.31 ±0.06mM, respectively. Mean plasma calcitriol concentration was also significantly lower in uremic than in control rats, 39.8 ± 14.6 and 80.4 ± 15.2 pg/ml, respectively. Nine out of the 19 rats were examined for renal PTH-R gene expression. We show for the first time that the level of PTH-R mRNA in the kidney of uremic rats was markedly decreased compared with that of normal rats, the ratio PTH-R mRNA/β-actin mRNA being 0.47 ± 0.12 versus 0.99 ± 0.23, respectively, and the ratio PTH-R mRNA/28S being 8.9 ± 4.7 versus 19.6 ± 11.1, respectively. This decrease was associated with a marked reduction in PTH-sensitive adenylyl cyclase activity in crude renal membranes from uremic rats. The values of basal adenylyl cyclase activity and subsequently after stimulation by forskolin and NaF were also significantly reduced in comparison to that of normal rats. These data indicate that rats with severe CRF have reduced renal PTH-R expression, associated with diminished basal and PTH-sensitive adenylyl cyclase activity. These abnormalities could be important in the pathogenesis of the secondary hyperparathyroidism of CRF.

The recombinant human PTH/PTH-related peptide (PTHrP) receptor, when transiently expressed in COS-7 cells, binds [Nle8,18,Tyr34] bovine PTH-(7-34)amide [PTH-(7-34)], human PTH-(10-34)amide [PTH-(10-34)], and bovine PTH-(15-34)amide [PTH-(15-34)] with at least 50-fold higher affinity than does the rat receptor homolog. In contrast, PTH-(1-34) binding affinities are similar for both receptor homologs. To map those areas of the PTH/PTHrP receptors that determine the binding specificity for carboxyl-terminal fragments of PTH-(1-34), we constructed chimeric rat/human PTH/PTHrP receptors. These bound PTH-(1-34) with normal affinity and, therefore, must have an overall conformation that resembles that of native receptors. Chimeras with the amino-terminal extracellular domain of the human PTH/PTHrP receptor have a considerably higher binding affinity for PTH-(7-34), PTH-(10-34), and PTH-(15-34) than do the reciprocal receptor constructs in which the amino-terminal region is from the rat PTH/PTHrP receptor. The opossum PTH/PTHrP receptor homolog also binds PTH-(7-34) with higher affinity than the rat receptor, and studies of rat/opossum chimeras confirm the importance of the amino-terminal extracellular domain in determining the PTH-(7-34) binding specificity. Mutant rat and human PTH/PTHrP receptors in which either residues 61-105 of the extracellular region or most of the intracellular tail were deleted have PTH-(7-34) binding characteristics indistinguishable from those of either wild-type receptor. These findings indicate that the amino-terminal extracellular region of the PTH/PTHrP receptor contains a domain(s) that largely determines the binding affinity of amino-terminally truncated PTH analogs. This region, therefore, is likely to constitute a site for ligand-receptor interaction.

PTH elicits multiple second messenger signals in target cells. This signaling diversity may reflect coupling of a single species of PTH receptors to multiple effectors, the action of different subtypes of PTH receptors, or both. We recently reported the expression cloning, from rat and opossum cells, of closely related cDNAs encoding receptors for PTH [and PTH-related peptide (PTHRP)]. To determine if these cloned PTH/PTHRP receptors can activate multiple intracellular effectors when present at near-physiological levels in intact target cells, we have stably expressed the rat and opossum PTH/PTHRP receptor cDNAs in LLC-PK1 porcine renal epithelial cells. These cells lack endogenous PTH/PTHRP receptors, but do express abundant calcitonin receptors and many features of a proximal tubular phenotype. Subclones of transfected LLC-PK1 cells exhibited high affinity binding (Kd, 1-5 nM) of [Nle8.18,Tyr34]bovine PTH-(1-34)amide (PTH) and dose-dependent activation by PTH of both cAMP accumulation (EC50, 1 nM) and increased release of cytosolic free calcium from intracellular stores (EC50,or = 20-50 nM) across a wide range of receptor expression. Expressed rat and opossum receptors exhibited similar properties, except for a 5-fold lower binding affinity of the rat receptor for PTH-(7-34). Stimulation by PTH of both cAMP accumulation and elevated cytosolic free calcium was augmented in cells expressing higher numbers of PTH/PTHRP receptors. Like calcitonin, PTH (1-100 nM) reduced the rate of cell proliferation and augmented the rate of inorganic phosphate transport after 24 and 5 h of preincubation, respectively. The growth effect was mimicked by cAMP analogs, forskolin, phorbol esters, and calcium ionophores. Regulation of phosphate transport, however, was mimicked by phorbols, but not by cAMP analogs or forskolin. We conclude that LLC-PK1 cells provide a useful model in which to study the function of cloned PTH/PTHRP receptors. In these cells, a single species of cloned PTH/PTHRP receptors, stably expressed at near-physiological numbers, activates multiple second messenger responses and regulates subsequent biological responses, including at least one (phosphate transport) that is mediated by mechanisms independent of cAMP.

Identical complementary DNAs (cDNAs) that encode a 593-amino acid human PTH (PTH)/PTH-related peptide (PTHrP) receptor were isolated by hybridization techniques from two cDNA libraries which had been constructed from human kidney and human osteoblast-like osteosarcoma cells (SaOS-2). Northern blot analysis of total RNA from human bone- and kidney-derived tissue revealed one single major messenger RNA species of about 2.5 kilobases in both tissues. The human PTH/PTHrP receptor has 91% and 81% identity, respectively, with the previously cloned rat and opossum receptors, indicating a high degree of conservation among mammals. Despite this striking degree of amino-acid conservation, the human PTH/PTHrP receptor has several unique biological properties when transiently expressed in COS-7 cells. The apparent dissociation constants for [Nle8,18,Tyr34] bovine PTH(1-34) amide [bPTH(1-34)] are similar for the human and the rat receptor (approximately 8 vs. approximately 15 nM) whereas [Tyr36]PTHrP(1-36) amide has a slightly lower affinity for the human (15-40 nM) than for the rat receptor (approximately 15 nM). Both ligands stimulate efficiently and with similar efficacy the accumulation of intracellular cAMP. The affinities for the antagonists [Nle8,18,Tyr34] bPTH(3.34) amide [bPTH(3-34)] and in particular for [Nle8,18,Tyr34] bPTH(7-34) amide [bPTH(7-34)] are considerably higher for the human receptor, e.g. approximately 8 nM vs. 30 nM for bPTH(3-34) and approximately 100 nM vs. 5000 nM for bPTH(7-34), respectively. Similar biological findings were previously attributed to differences in species- and/or organ-specific PTH/PTHrP receptors. The expression of the recombinant, highly homologous rat and human receptors in a uniform environment indicate that the moderate differences in the primary receptor structure have profound consequences for the receptor binding affinity of amino-terminally truncated PTH analogs. Furthermore, the molecular cloning of identical cDNAs encoding a human PTH/PTHrP receptor from the two major target organs for PTH, bone and kidney, provides strong evidence for one single PTH/PTHrP receptor in both organs, although additional and/or alternatively spliced receptors cannot be excluded.

Corticotropin-releasing factor (CRF) stimulates adrenocorticotropin (ACTH) release via the adenylate cyclase/cAMP-dependent protein kinase system. Because calcium is necessary for receptor-mediated release of ACTH, we have examined the effect of CRF on 45 Ca 2+ uptake in a corticotroph cell line model, AtT-20. Treatment of AtT-20 cells with CRF (10 −9 − 10 −6 M) resulted in dose- and time-dependent increases in 45 Ca 2+ uptake, up to 2.2-fold above control values. The effect was statistically significant at 1 min and persisted for at least 10 min. Treatment with forskolin (1–30 μM), 8-Br-cAMP (0.5 mM), cholera toxin (CT, 100 ng/ml) and K + (20 mM) also increased cell-associated 45 Ca 2+ . The effect of K + was completely blocked by nifedipine (100 μM), whereas the effects of CRF (10 −8 M) were only partially inhibited by this calcium channel antagonist. These data suggested a role of voltage-dependent calcium channels in 45 Ca 2+ uptake. Short term pretreatment (1–2 h) of AtT-20 cells with CRF (10 −8 M) significantly desensitized both CRF-stimulated cAMP accumulation and ACTH release, but did not attenuate CRF-stimulated 45 Ca 2+ uptake. Pretreatment with CRF (10 −8 M) for 4 h did not alter CT- or forskolin-stimulated cAMP accumulation and ACTH release. This suggests that the molecular mechanisms of desensitization are proximal to adenylate cyclase. Conversely, long term pretreatment (24 h) of AtT-20 cells with CRF (10 −8 M) induced significant desensitization of CRF-stimulated 45 Ca 2+ uptake. These results indicate that CRF stimulates calcium uptake in AtT-20 cells via cAMP-dependent and cAMP-independent mechanisms, and that the cellular mechanisms involved in desensitization of cAMP accumulation and ACTH release and those involved in desensitization of calcium uptake are qualitatively different.

In this paper we describe the cloning of the mouse Parathyroid Hormone/Parathyroid Hormone related Peptide Receptor (PTH/PTHrPR) cDNA and expression of its mRNA during mouse postimplantation development from day 5.5 until day 15.5 post coitum (p.c.). In support of a model from previous studies, in which parietal endoderm differentiation is regulated by the interaction of the PTH/PTHrPR and Parathyroid Hormone related Peptide (PTHrP), high levels of PTH/PTHrPR mRNA levels were detected in developing parietal endoderm from day 5.5 p.c. and onwards. In the embryo proper, PTH/PTHrPR mRNA expression was mainly detected at sites of epithelium/mesenchyme interactions, starting at day 9.5 p.c. in the epithelium of the intestine and later in the mesenchyme of the lung, the epithelium of meso- and metanephric tubuli, the dermis and at all sites where bone formation takes place. The complexity of the PTH/PTHrPR expression pattern suggests tight developmental regulation and indicates multiple roles in embryogenesis for the receptor and its ligands, not only in extraembryonic tissue but also in the formation of various organs.

To study mechanisms controlling the expression of PTH/PTH-related peptide (PTHrP) receptors in ROS 17/2.8 and OK cells, we investigated the regulation of PTH/PTHrP receptor availability and receptor mRNA levels by glucocorticoids and PTH. Treatment of ROS 17/2.8 cells with dexamethasone (1 microM) for 2, 4, and 6 days increased specific binding of PTH to 148 +/- 12%, 203 +/- 10%, and 344 +/- 9% (mean +/- SD), respectively, compared to that in untreated control cells. PTH-stimulated cAMP accumulation also increased with dexamethasone treatment (1 microM) from 230 +/- 15%, 382 +/- 9%, and 820 +/- 9% after 2, 4 and 6 days, respectively, compared to that in untreated cells. Treatment of ROS 17/2.8 cells with [Nle8,Nle18,Tyr34]bovine PTH-(1-34) amide (NlePTH; 100 nM) alone or together with dexamethasone (1 microM), however, markedly decreased PTH binding and PTH-stimulated cAMP accumulation. Northern blot analysis showed that dexamethasone dramatically increased steady state levels of PTH/PTHrP receptor mRNA in a time- and dose-dependent manner, which did not occur when NlePTH (100 nM) was added concomitantly to the cultures. As previously reported, daily NlePTH treatment of ROS 17/2.8 cells reduced PTH/PTHrP receptor availability and PTH-stimulated cAMP accumulation markedly within 2 days, which remained at these low levels during continued PTH treatment. In contrast, the identical treatment reduced steady state levels of PTH/PTHrP receptor mRNA in ROS 17/2.8 transiently and to only a slight extent, which then returned to pretreatment levels. Treatment of OK cells with NlePTH (100 nM) for 1, 2, and 4 days decreased PTH binding to 56 +/- 6%, 44 +/- 4%, and 64 +/- 4% (mean +/- SD) and PTH-stimulated cAMP accumulation to 42 +/- 6%, 19 +/- 4%, and 21 +/- 3% (mean +/- SD), respectively, compared to values in untreated control cells. The same treatment, however, had no significant effect on steady state levels of PTH/PTHrP receptor transcripts. In contrast to its effects in ROS 17/2.8 cells, dexamethasone (1 microM) treatment of OK cells for 1-4 days did not affect PTH binding, nor did it significantly affect steady state levels of PTH/PTHrP receptor mRNA, although the latter was slightly lowered by dexamethasone treatment. PTH-stimulated cAMP accumulation was unchanged after 1-day treatment with dexamethasone and modestly rose to 142 +/- 4% of the control value by day 4 of glucocorticoid exposure.(ABSTRACT TRUNCATED AT 400 WORDS)