Search

Objective The main objective of this study is to design a custom-made weight-drop impactor device to produce a consistent spinal cord contusion model in rats in order to examine the efficacy of potential therapies for post-traumatic spinal cord injuries (SCIs). Methods Adult female Sprague-Dawley rats (n = 24, 11 weeks old) were randomly divided equally into two groups: sham and injured. The consistent injury pattern was produced by a 10 g stainless steel rod dropped from a height of 30 mm to cause (0.75 mm) intended displacement to the dorsal surface of spinal cord. The neurological functional outcomes were assessed at different time intervals using the following standardized neurobehavioral tests: Basso, Beattie, and Bresnahan (BBB) scores, BBB open-field locomotion test, Louisville Swim Scale (LSS), and CatWalk gait analysis system. Results Hind limb functional parameters between the two groups using BBB scores and LSS were significantly different (p < 0.05). There were significant differences (p < 0.05) between the SCI group and the sham group for the hind limb functional parameters using the CatWalk gait analysis. Conclusion We developed an inexpensive custom-made SCI device that yields a precise adjustment of the height and displacement of the impact relative to the spinal cord surface.

The musculoskeletal system consisting of bones and muscles have been recognized as endocrine organs secreting hormones that are involved in regulating metabolic and inflammatory pathways. Obesity and type 2 diabetes (T2D) are associated with several musculoskeletal system complications. We hypothesized that an interaction exists between adipomyokines namely, irisin and METRNL, and various molecules involved in bone remodeling in individuals with obesity and T2D. A total of 228 individuals were enrolled in this study, including 124 non-diabetic (ND) and 104 T2D. A Multiplex assay was used to assess the level of various osteogenic molecules namely osteoactivin, Syndecan, osteoprotegerin (OPG) and osteonectin/SPARC. Our data shows elevated levels of Osteoactivin, Syndecan, OPG and SPARC in T2D as compared to ND individuals (p ≤ 0.05). Using Spearman’s correlation, a positive correlation was observed between irisin and Osteoactivin as well as OPG (p < 0.05). Similarly, a positive association was observed between METRNL and Osteoactivin (p < 0.05). The strong positive association shown in this study between irisin, METRNL and various molecules with osteogenic properties emphasize a possible interaction between these organs. This report suggests that having a dysregulation in the level of the aforementioned molecules could potentially affect the development of bone and muscle related complications that are associated with obesity and T2D.

The musculoskeletal system consisting of bones and muscles have been recognized as endocrine organs secreting hormones that are involved in regulating metabolic and inflammatory pathways. Obesity and type 2 diabetes (T2D) are associated with several musculoskeletal system complications. We hypothesized that an interaction exists between adipomyokines namely, irisin and METRNL, and various bone markers in individuals with obesity and T2D. A total of 228 individuals were enrolled in this study, including 124 non-diabetic and 104 T2D. A Multiplex assay was used to assess the level of various bone markers namely Osteoactivin, Syndecan, osteoprotegerin (OPG) and osteonectin/SPARC. Our data shows elevated levels of Osteoactivin, Syndecan, OPG and SPARC in T2D as compared to non-T2D individuals (p ≤ 0.05). Using Spearman’s correlation, irisin was positively correlated only with Osteoactivin and OPG (p < 0.05). Similarly, a positive association was observed between METRNL and Osteoactivin (p < 0.05). The strong positive association shown in our study between irisin, METRNL and various bone markers emphasises the strong interaction between these organs. This suggests that a dysregulation in the functional interaction between these molecules could play a possible role in the development of bone and muscle related complications that are associated with obesity and T2D.

Background Bariatric surgery is well established as a treatment for obesity and associated complications. This procedure improves metabolic homeostasis through changes in energy expenditure. We hypothesized that sleeve gastrectomy (SG) improves metabolic homeostasis by modulating energy expenditure and enhancing thermogenesis through increasing the expression level of meteorin-like protein (METRNL) and fibronectin type III domain-containing protein 5 (FNDC5/Irisin) through uncoupling proteins 1/2/3 (UCP1, UCP2, and UCP3). Objectives To study the effect of SG on the levels of proteins involved in thermogenesis process. Setting Laboratory rats at Kuwait University. Methods Male Sprague-Dawley rats, aged 4 to 5 weeks, were divided into 2 groups, control (n = 11) and diet-induced obesity (DIO) (n = 22). The control group was fed regular rat chow ad libitum, whereas the DIO group was fed cafeteria diet “high-fat/carbohydrate diet” ad libitum. At 21 weeks, rats in the DIO group that weighed 20% more than the control group animals underwent surgery. These rats were randomly subdivided into Sham and SG operation groups. Gene expression was evaluated, and enzyme-linked immunosorbent assays were employed to assess the changes in gene and protein levels in tissue and circulation. Results The protein expression data revealed an increase in METRNL levels in the muscles and white adipose tissue of SG animals. METRNL level in circulation in SG animals was reduced compared with control and Sham rats. The level of Irisin increased in the muscle of SG animals compared with the control and Sham group animals; however, a decrease in Irisin level was observed in the white adipose tissue and brown adipose tissue of SG animals compared with controls. Gene expression analysis revealed decreased METRNL levels in muscle tissues in the SG group compared with the control group animals. Increased expression of FNDC5 (Irisin), UCP2, and UCP3 in the muscle tissue of SG animals was also observed. Furthermore, the levels of UCP1, UCP2, UCP3, and METRNL in the brown adipose tissue of SG animals were upregulated. No significant alteration in the gene expression of Irisin was observed in brown adipose tissue. Conclusions Sleeve gastrectomy induces weight loss through complex mechanisms that may include browning of fat.

Obesity and type 2 diabetes (T2D) are linked to metabolic dysregulation and chronic inflammation. Adipose tissue and skeletal muscles are key endocrine organs. Dysregulation in adipomyokines secreted by these organs could play a role in obesity-induced complications. Obesity, T2D and bone metabolism are interrelated. Our objective was to study the expression of two adipomyokines-Irisin and Meteorin-like protein (METRNL) in obesity and T2D and understand their association with various bone markers. Overall, 228 individuals were enrolled in this study, including 124 nondiabetic and 104 T2D . Plasma level of MTRNL and irisin were assessed by ELISA. Plasma level of METRNL and irisin were significantly higher in T2D (1263.5 ± 24.9 pg/ml and 623.0± 21.8 pg/ml respectively) compared to nondiabetic individuals (1198.5 ± 24.2 pg/ml for METRNL and 508.2 ± 15.3 pg/ml for irisin) p-Value < 0.05. METRNL and irisin were significantly higher in obese (1267.9 ± 24.8 pg/ml and 593.4 ± 18.1 pg/ml respectively) compared to non-obese individuals (1186.3 ± 24.2 pg/ml and 519.9 ± 19.1 respectively) p-Value < 0.05. Plasma level of bone markers Osteoactivin, Syndecan, OPG and SPARC were significantly higher in obese and T2D individuals compared to non-obese and nondiabetic individuals (P-values ≤0.01). Correlation analysis on nondiabetic population showed significant positive correlation between METRNL and irisin. Irisin showed a strong positive association with Osteoactivin, Syndecan, OPG, and SPARC. A strong positive association was observed between METRNL and Osteoactivin. The interplay between these bone markers is linked to bone remodeling. The strong positive association between the adipomyokines and bone markers suggests that, a dysregulation in the functional interaction between them may play a possible role in the development of bone related complications associated with obesity and T2D. We are currently conducting further experiments to understand mechanistically the significance of their interplay. Disclosure M. Abu-farha: None. P.T. Cherian: None. I. Al khairi: None. M. Jamal: None. S. Al-Sabah: None. H. Ali: None. C. Dsouza: None. F.K. AlOtaibi: None. W. Al-Ali: None. G.M. Al-Khaledi: None. J. Abubaker: None. F. Al-Mulla: None. Funding Dasman Diabetes Institute

The role of adenosine in allergic inflammation is unclear. This study investigated the effects of the non-selective adenosine receptor agonist, 5-N-ethylcarboxamidoadenosine (NECA), on immunized only and immunized and airway challenged mice. The adenosine receptor sub-type(s) mediating the NECA effects and the A(2A) receptor mRNA expression were also investigated. In mice that were only immunized, intranasal NECA (1 mM) administration caused a significant increase in bronchoalveolar lavage total cell count (TCC), neutrophils and eosinophils (1.5-,6 and60-fold, respectively). Two and four intranasal ovalbumin (OVA) challenges induced a significant (P0.05) increase in TCC (2.1- and4-fold, respectively) and eosinophils (350- and1700-fold, respectively). Real-time PCR analysis showed that the A(2A) receptor sub-type mRNA was significantly increased (P0.05) in the lung tissue of immunized mice following both two and four OVA challenges. NECA (0.3 mM) treatment caused a significant reduction in the increase induced by the two and four OVA challenges in the TCC by 46.1% and 56.6%, respectively, eosinophils by 70.1% and 75.6%, respectively, and in the A(2A) receptor sub-type mRNA by 43.2% and 41.0%, respectively. Treatment with the A(2A) receptor antagonist, 7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine), SCH-58261, completely reversed both the NECA-mediated reduction in TCC and eosinophilia. Moreover, OVA challenge of immunized mice, over 2 consecutive days, resulted in a significant (P0.05) increase in TCC (4.5-fold) and eosinophils (2000-fold) that was detected 72 h later. NECA (0.3 mM) treatment, at 24 and 48 h post OVA challenge, significantly reduced the increase in both TCC and eosinophils by 45.0% and 74.8%, respectively. Our data show that in immunized, but not OVA-challenged mice, high dose of NECA (1 mM) induces an inflammatory airway response. In contrast, in models of inflammation, NECA, at mainly 0.3 mM, induces a significant anti-inflammatory effect when administered prior to the induction of airway inflammation or therapeutically following its establishment. The data also indicate that the anti-inflammatory action of NECA seems to be mediated via the A(2A) receptor sub-type and hence the use of selective A(2A) receptor agonists as potential therapeutic agents in the treatment of inflammatory diseases such as asthma should be investigated further.

We investigated the effect of green tea (GT) in unilateral chronic constriction injury (CCI) to the rat scaitic nerve. Five groups (n = 6 rats/group) sham group: rats which underwent operation but with no ligation to the scaitic nerve, and received tap water for two weeks before and for five weeks after the surgery. Four experimental groups underwent CCI to the right sciatic nerve, divided randomly as follows: group E were given tap water throughout the study. Group B received GT before and after CCI. Group C was given GT following CCI. Group D received GT for two weeks prior to CCI. Groups which consumed GT showed significant improvement in the toe spread (P < 0.001) and foot positioning (P < 0.001) tests compared to the experimental control group. In addition, these groups showed a significant decrease in the behavioral mechanical hyperalgesia (P < 0.0001) and allodynia (P < 0.0002). Consumption of GT improves both reflexes and sensation which are often affected in the course of peripheral neuropathy.

Currently, the most effective treatment for obesity is bariatric surgery. Gastroduodenal bypass surgery produces sustained weight loss and improves glycemic control and insulin sensitivity. Previous studies have shown that sleeve gastrectomy (SG) produces similar results and implicate changes in incretin hormone release in these effects.Male Sprague-Dawley rats were divided into four groups; lean control (lean), diet-induced obesity (DIO), DIO animals that had undergone SG (SG), and DIO animals that had undergone a sham operation (sham).After a 2-week recovery period, the incretin response to a standard test meal was measured. Blood sampling was performed in free-moving rats at various time points using chronic vascular access to the right jugular vein. There was a significant increase in the bodyweight of DIO animals fed a high-fat/high-sugar diet compared with the lean animals, which was reversed by SG. DIO caused an impairment of the GLP-1 response to a standard test meal, but not the GIP response. SG resulted in a dramatic increase in the GLP-1 response to a standard test meal but had no effect on the GIP response.A rapid rise in blood sugar was observed in the SG group following a standard test meal that was followed by reactive hypoglycemia. SG dramatically increases the GLP-1 response to a standard test meal but has no effect on GIP in a rat model of DIO.

Spinal cord injury (SCI) causes severe and long lasting motor and sensory deficits, chronic pain, and autonomic dysreflexia. (-)-epigallocatechin-3-gallate (EGCG) has shown to produce neuroprotective effect in a broad range of neurodegenerative disease animal models. This study designed to test the efficacy of intravenous infusion of EGCG for 36 h, in acutely injured rats' spinal cord: within first 4 h post-injury and, in chronically SC injured rats: after one year of injury. Functional outcomes measured using standard BBB scale, The Louisville Swim Scale (LSS) and, pain behavior assessment tests. 72 Female adult rats subjected to moderate thoracic SCI using MASCIS Impactor, blindly randomized as the following: (I) Acute SCI + EGCG (II) Acute SCI + saline. (III) Chronic SCI + EGCG. (IV) Chronic SCI + saline and, sham SCI animals. EGCG i.v. treatment of acute and, chronic SCI animals resulted in significantly better recovery of motor and sensory functions, BBB and LSS (P < 0.005) and (P < 0.05) respectively. Tactile allodynia, mechanical nociception (P < 0.05) significantly improved. Paw withdrawal and, tail flick latencies increase significantly (P < 0.05). Moreover, in the EGCG treated acute SCI animals the percentage of lesion size area significantly reduced (P < 0.0001) and, the number of neurons in the spinal cord increased (P < 0.001). Percent areas of GAP-43 and GFAP immunohistochemistry showed significant (P < 0.05) increase. We conclude that the therapeutic window of opportunity for EGCG to depict neurological recovery in SCI animals, is viable up to one year post SCI when intravenously infused for 36 h.

Cognitive impairment is a common feature of both lead exposure and hyperphosphorylation of tau. We, therefore, investigated whether lead exposure would induce tau hyperphosphorylation. Wistar rat pups were exposed to 0.2% lead acetate via their dams' drinking water from postnatal day 1 to 21. Lead in blood and brain were measured by atomic absorption spectrophotometry and the expression of tau, phosphorylated tau and various serine/threonine protein phosphatases (PP1, PP2A, PP2B and PP5) in the brain was analyzed by Western blot. Lead exposure significantly impaired learning and resulted in a significant reduction in the expression of tau but increased the phosphorylation of tau at Ser199/202, Thr212/Ser214 and Thr231. PP2A expression decreased, whereas, PP1 and PP5 expression increased in lead-exposed rats. These results demonstrate that early postnatal exposure to lead decrease PP2A expression and induce tau hyperphosphorylation at several serine and threonine residues. Hyperphosphorylation of tau may be a mechanism of Pb-induced deficits in learning and memory.

Serine/threonine protein phosphatases regulate several key cellular events in the brain, including learning and memory. These enzymes, when over-activated, are known to function as a constraint on learning and memory. We investigated whether these phosphatases are implicated in lead (Pb)-induced deficits in learning and memory. Wistar rat pups were exposed to 0.2% Pb-acetate via their dams' drinking water from postnatal day (PND) 1-21 and directly in drinking water until PND 30. Pb levels in blood, brain and hippocampus were measured and expression of PP1, PP2A, PP2B and PP5 in hippocampus was analyzed. Total phosphatase activity, and PP1 and PP2A activities were determined. Tau phosphorylation at various epitopes was determined by Western blot. Spatial learning and memory was determined by Morris water maze test. Pb exposure significantly increased levels of Pb in blood, brain and hippocampus, reduced the number of synapses in hippocampus and impaired learning and long-term memory (LTM). Short-term memory (STM) was only affected in rats at PND21. Pb exposure increased the expression and activity of PP1 and decreased phosphorylation of tau at threonine-231 in hippocampus at both PND21 and PND30. Pb-induced phosphorylation of tau at serine-199/202 (AT8) paralleled with PP2A activity; at PND21 PP2A activity increased and AT8 phosphorylation decreased; at PND30 PP2A activity decreased and AT8 phosphorylation increased. Increased PP1 activity in hippocampus by Pb is associated with learning and LTM impairment, whereas, increased PP2A activity is associated with STM impairment. These findings suggest the overactivation of PP1 and PP2A, together with changes in tau phosphorylation, as a potential mechanism of lead-induced deficits in learning and memory.

Cardiovascular diseases are one of the principal causes of death and disability in people with spinal cord injury (SCI). The present study was designed to investigate if acute treatment with FPTIII (an inhibitor of Ras-GTPase farnesylation) or MG132 (an inhibitor of ubiquitin-proteasome pathway [ UPS]) or administration of angiotensin( 1-7), also known as Ang-(1-7), (a known inhibitor of cardiac NF-kB) would be cardioprotective. The weight drop technique produced a consistent contusive injury of the spinal cord at the T13 segment. Hearts were isolated from rats either 6 months (SCI-6) or 12 months (SCI-12) after SCI. Hearts were perfused for 30 min and then subjected to 30 min ischemia followed by 30 min reperfusion (I/R). Recovery of cardiac function after I/R was measured as left ventricular developed pressure (P-max) and coronary flow (CF). Drugs were given during perfusion before hearts were exposed to ischemia and reperfusion. Percent recovery (%R) in P-max and CF in hearts from control animals were 48 +/- 6 and 50 +/- 5, respectively, whereas none of the hearts from animals with SCI recovered after 30 min of ischemia. Treatment with FPTIII, MG 132, or Ang-(1-7) before ischemia for 30min led to significant recovery of heart function following ischemia in SCI-6 but not in SCI-12 animals. Thus we have shown that acute treatments with FPTIII, MG132, or Ang-(1-7) improve cardiac recovery following ischemic insult in animals with SCI and may represent novel therapeutic agents for preventing ischemia-induced cardiac dysfunction in patients with SCI., Cardiovascular diseases are one of the principal causes of death and disability in people with spinal cord injury (SCI). The present study was designed to investigate if acute treatment with FPTIII (an inhibitor of Ras-GTPase farnesylation) or MG132 (an inhibitor of ubiquitin-proteasome pathway [UPS]) or administration of angiotensin-(1-7), also known as Ang-(1-7), (a known inhibitor of cardiac NF-kB) would be cardioprotective. The weight drop technique produced a consistent contusive injury of the spinal cord at the T13 segment. Hearts were isolated from rats either 6 months (SCI-6) or 12 months (SCI-12) after SCI. Hearts were perfused for 30 min and then subjected to 30 min ischemia followed by 30 min reperfusion (I/R). Recovery of cardiac function after I/R was measured as left ventricular developed pressure (P(max)) and coronary flow (CF). Drugs were given during perfusion before hearts were exposed to ischemia and reperfusion. Percent recovery (%R) in P(max) and CF in hearts from control animals were 48±6 and 50±5, respectively, whereas none of the hearts from animals with SCI recovered after 30 min of ischemia. Treatment with FPTIII, MG 132, or Ang-(1-7) before ischemia for 30 min led to significant recovery of heart function following ischemia in SCI-6 but not in SCI-12 animals. Thus we have shown that acute treatments with FPTIII, MG132, or Ang-(1-7) improve cardiac recovery following ischemic insult in animals with SCI and may represent novel therapeutic agents for preventing ischemia-induced cardiac dysfunction in patients with SCI.