Effective Inhibition of TNF-α/mTOR Axis-Mediated Liver Inflammation and Fibrosis Induced by TAA Using a Combination of Metformin and Resveratrol in Association with the Inhibition of the Profibrotic Gene and Protein Expression

SUMMARY: The response of the immune system to harmful stimuli leads to inflammation, and the adverse effects of the toxic hepatitis chemical, thioacetamide (TAA) on the human body are well documented. This article investigated the degree of protection provided by the combined pleotropic drug, metformin (Met) and the plant polyphenolic and the antiinflammatory compound, resveratrol (Res) on liver tissue exposed to TAA possibly via the inhibition of the inflammatory cytokine, tumor necrosis factor-α (TNF-α) / mammalian target of rapamycin (mTOR) axis-mediated liver fibrosis, as well as amelioration of profibrotic gene and protein expression. Rats were either given TAA (200 mg/kg via intraperitoneal injection) for 8 weeks beginning at the third week (experimental group) or received during the first two weeks of the experiment combined doses of metformin (200 mg/kg) and resveratrol (20 mg/kg) and continued receiving these agents and TAA until experiment completion at week 10 (treated group). A considerable damage to hepatic tissue in the experimental rats was observed as revealed by tissue collagen deposition in the portal area of the liver and a substantial increase (p<0.0001) in hepatic levels of the inflammatory marker, tumor necrosis factor-α (TNF-α), as well as blood levels of hepatocellular injury biomarkers, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). TAA also augmented hepatic tissue levels of the signalling molecule that promotes liver fibrosis (mTOR), and profibrogenic markers; alpha-smooth muscle actin (α-SMA) protein, tissue inhibitor of metalloproteinases-1 (TIMP-1) mRNA, and matrix metalloproteinase-9 (MMP-9) mRNA. All these parameters were protected (p≤0.0016) by Met+Res. In addition, a significant correlation was detected between liver fibrosis score and inflammation, liver injury enzymes, mTOR, and profibrogenesis markers. Thus, these findings suggest that Met+Res effectively protect the liver against damage induced by thioacetamide in association with the downregulation of the TNF-α/mTOR/fibrosis axis.

La respuesta del sistema inmunológico a estímulos dañinos conduce a la inflamación y los efectos adversos de la tioacetamida (TAA), una sustancia química tóxica para el hígado, están bien documentadas. Este artículo investigó el grado de protección proporcionado por el fármaco pleotrópico combinado metformina (Met), el polifenólico vegetal y el compuesto antiinflamatorio resveratrol (Res) en el tejido hepático expuesto a TAA, posiblemente a través de la inhibición de la citoquina inflamatoria, factor de necrosis tumoral α (TNF-α)/objetivo de la fibrosis hepática mediada por el eje de rapamicina (mTOR), así como mejora de la expresión de genes y proteínas profibróticas. Las ratas recibieron TAA (200 mg/kg mediante inyección intraperitoneal) durante 8 semanas a partir de la tercera semana (grupo experimental) o recibieron durante las dos primeras semanas del experimento dosis combinadas de metformina (200 mg/kg) y resveratrol (20 mg/kg) y continuaron recibiendo estos agentes y TAA hasta completar el experimento en la semana 10 (grupo tratado). Se observó un daño considerable al tejido hepático en las ratas experimentales, como lo revela el depósito de colágeno tisular en el área portal del hígado y un aumento sustancial (p<0,0001) en los niveles hepáticos del marcador inflamatorio, el factor de necrosis tumoral-α (TNF- α), así como los niveles sanguíneos de biomarcadores de lesión hepatocelular, alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST). TAA también aumentó los niveles en el tejido hepático de la molécula de señalización que promueve la fibrosis hepática (mTOR) y marcadores profibrogénicos; proteína actina del músculo liso alfa (α- SMA), inhibidor tisular de las metaloproteinasas-1 (TIMP-1) mRNA y matriz metaloproteinasa-9 (MMP-9) mRNA. Todos estos parámetros fueron protegidos (p≤0.0016) por Met+Res. Además, se detectó una correlación significativa entre la puntuación de fibrosis hepática y la inflamación, las enzimas de lesión hepática, mTOR y los marcadores de profibrogénesis. Por lo tanto, estos hallazgos sugieren que Met+Res protege eficazmente el hígado contra el daño inducido por la tioacetamida en asociación con la regulación negativa del eje TNF-α/mTOR/fibrosis.

A Rat Model of Rheumatoid Arthritis: TDZD-8 is Associated with the Protection Against the Induction of the Synovium Knee Joint IL-17A/GSK3β/ROS/α-SMA Axis of Fibrosis

SUMMARY: Rheumatoid arthritis (RA) that affects the synovial knee joint causes swelling of the synovial membrane and tissue damage. Interleukin-17A (IL-17A) and the enzyme glycogen synthase kinase-3β (GSK3β) are involved in the pathogenesis of RA. The link between IL-17A, GSK3β, the oxidative stress, and the profibrogenic marker alpha-smooth muscle actin (α-SMA) with and without TDZD-8, GSK3β inhibitor has not been studied before. Consequently, active immunization of rats was performed to induce RA after three weeks using collagen type II (COII) injections. The treated group received daily injection of 1 mg/kg TDZD-8 for 21 days following the immunization protocol (COII+TDZD-8). Blood and synovium tissue samples were harvested at the end of the experiment. RA development was confirmed as corroborated by a substantial increase in blood levels of the highly specific autoantibody for RA, anti-citrullinated protein antibody as well as augmentation of reactive oxidative species (ROS) levels measured as lipid peroxidation. RA induction also increased synovium tissue levels of IL-17A and the profibrogenic marker, α-SMA. All these parameters seemed to be significantly (p<0.0001) ameliorated by TDZD-8. Additionally, a significant correlation between IL-17A, ROS, and α-SMA and biomarkers of RA was observed. Thus, knee joint synovium RA induction augmented IL-17A/GSK3β/ROS/α-SMA axis mediated arthritis in a rat model of RA, which was inhibited by TDZD-8.

La artritis reumatoide (AR) que afecta la articulación sinovial de la rodilla provoca inflamación de la membrana sinovial y daño tisular. La interleucina-17A (IL-17A) y la enzima glucógeno sintasa quinasa-3β (GSK3β) están involucradas en la patogenia de la AR. No se ha estudiadol vínculo entre IL-17A, GSK3β, el estrés oxidativo y el marcador profibrogénico actina de músculo liso alfa (α-SMA) con y sin inhibidor de TDZD-8, GSK3β. En consecuencia, se realizó una inmunización activa de ratas para inducir la AR después de tres semanas usando inyecciones de colágeno tipo II (COII). El grupo tratado recibió una inyección diaria de 1 µg/ kg de TDZD-8 durante 21 días siguiendo el protocolo de inmunización (COII+TDZD-8). Se recogieron muestras de sangre y tejido sinovial al final del experimento. El desarrollo de AR se confirmó como lo corroboró el aumento sustancial en los niveles sanguíneos del autoanticuerpo altamente específico para AR, el anticuerpo antiproteína citrulinada, así como el aumento de los niveles de especies oxidativas reactivas (ROS) medidos como peroxidación lipídica. La inducción de AR también aumentó los niveles de tejido sinovial de IL-17A y el marcador profibrogénico, α-SMA. Todos estos parámetros parecían mejorar significativamente (p<0,0001) con TDZD-8. Además, se observó una correlación significativa entre IL- 17A, ROS y α-SMA y biomarcadores de AR. Por lo tanto, la inducción de AR en la sinovial de la articulación de la rodilla aumentó la artritis mediada por el eje IL-17A/GSK3β/ROS/α-SMA en un modelo de rata de AR, que fue inhibida por TDZD-8.

A rat model of rheumatoid arthritis: TDZD-8 is associated with the protection against the induction of the synovium knee joint IL-17A/GSK3beta/ROS/alpha-SMA axis of fibrosis / Un modelo de rata de artritis reumatoide: TDZD-8 está asociado con la protección contra la inducción del eje de fibrosis de la articulación sinovial de la rodilla IL-17A/GSK3ß/ROS/α-SMA

SUMMARY: Rheumatoid arthritis (RA) that affects the synovial knee joint causes swelling of the synovial membrane and tissue damage. Interleukin-17A (IL-17A) and the enzyme glycogen synthase kinase-3β (GSK3β) are involved in the pathogenesis of RA. The link between IL-17A, GSK3β, the oxidative stress, and the profibrogenic marker alpha-smooth muscle actin (α-SMA) with and without TDZD-8, GSK3β inhibitor has not been studied before. Consequently, active immunization of rats was performed to induce RA after three weeks using collagen type II (COII) injections. The treated group received daily injection of 1 mg/kg TDZD-8 for 21 days following the immunization protocol (COII+TDZD-8). Blood and synovium tissue samples were harvested at the end of the experiment. RA development was confirmed as corroborated by a substantial increase in blood levels of the highly specific autoantibody for RA, anti-citrullinated protein antibody as well as augmentation of reactive oxidative species (ROS) levels measured as lipid peroxidation. RA induction also increased synovium tissue levels of IL-17A and the profibrogenic marker, α-SMA. All these parameters seemed to be significantly (p<0.0001) ameliorated by TDZD-8. Additionally, a significant correlation between IL-17A, ROS, and α-SMA and biomarkers of RA was observed. Thus, knee joint synovium RA induction augmented IL-17A/GSK3β/ROS/α-SMA axis mediated arthritis in a rat model of RA, which was inhibited by TDZD-8.

La artritis reumatoide (AR) que afecta la articulación sinovial de la rodilla provoca inflamación de la membrana sinovial y daño tisular. La interleucina-17A (IL-17A) y la enzima glucógeno sintasa quinasa-3β (GSK3β) están involucradas en la patogenia de la AR. No se ha estudiadol vínculo entre IL-17A, GSK3β, el estrés oxidativo y el marcador profibrogénico actina de músculo liso alfa (α-SMA) con y sin inhibidor de TDZD-8, GSK3β. En consecuencia, se realizó una inmunización activa de ratas para inducir la AR después de tres semanas usando inyecciones de colágeno tipo II (COII). El grupo tratado recibió una inyección diaria de 1 µg/ kg de TDZD-8 durante 21 días siguiendo el protocolo de inmunización (COII+TDZD-8). Se recogieron muestras de sangre y tejido sinovial al final del experimento. El desarrollo de AR se confirmó como lo corroboró el aumento sustancial en los niveles sanguíneos del autoanticuerpo altamente específico para AR, el anticuerpo antiproteína citrulinada, así como el aumento de los niveles de especies oxidativas reactivas (ROS) medidos como peroxidación lipídica. La inducción de AR también aumentó los niveles de tejido sinovial de IL-17A y el marcador profibrogénico, α-SMA. Todos estos parámetros parecían mejorar significativamente (p<0,0001) con TDZD-8. Además, se observó una correlación significativa entre IL- 17A, ROS y α-SMA y biomarcadores de AR. Por lo tanto, la inducción de AR en la sinovial de la articulación de la rodilla aumentó la artritis mediada por el eje IL-17A/GSK3β/ROS/α-SMA en un modelo de rata de AR, que fue inhibida por TDZD-8.

Metformin ameliorates ROS-p53-collagen axis of fibrosis and dyslipidemia in type 2 diabetes mellitus-induced left ventricular injury.

BACKGROUND: The link between oxidative stress (ROS), apoptosis (p53) and fibrosis (collagen) in type 2 diabetes mellitus (T2DM)-induced cardiac injury in the presence and absence of the antidiabetic drug, metformin has not been investigated before. MATERIAL AND METHODS: T2DM was induced in rats by a combination of high carbohydrate and fat diets (HCFD) and streptozotocin (50 mg/kg) injection. The protection group started metformin (200 mg/kg) treatment 14 days prior to the induction of diabetes and continued on metformin and HCFD until being sacrificed at week 12. RESULTS: Diabetes significantly induced blood levels of ROS and left ventricular p53 and collagen expression that was inhibited by metformin. Metformin also significantly reduced glycated haemoglobin and dyslipidemia induced by diabetes. In addition, a significant correlation between ROS-p53-collagen axis and glycaemia and hyperlipidaemia was observed. CONCLUSIONS: These findings show that metformin provides substantial protection against diabetic cardiomyopathy-induced ROS-p53 mediated fibrosis and dyslipidemia.

Independent Association of 25[OH]D Level on Reduced Glutathione and TNF-α in Patients with Diabetes and/or Hypertension.

Purpose: Oxidative and inflammatory pathways play a significant role in the pathophysiology of a wide variety of non-communicable diseases such as type 2 diabetes mellitus (T2DM) and hypertension. However, the effect of serum 25-hydroxyvitamin D (25[OH]D) on these pathways is still controversial. To evaluate the association of 25[OH]D on antioxidant and pro-inflammatory biomarkers, reduced glutathione (GSH) and tumor necrosis factor (TNF)-α, in T2DM and hypertensive patients. Patients and Methods: This is a cross-sectional study of a consecutive sample of patients attending the the Family Medicine clinic at King Abdullah bin Abdulaziz University Hospital (KAAUH). Participants were screened for eligibility according to the following criteria: aged above 18 years and diagnosed with T2DM and/or hypertension for at least one year. Patients receiving any kind of vitamin D or calcium supplements within the last three months were excluded, as were those with a history of renal failure, cancer, liver, thyroid, or any other chronic inflammatory diseases. Results: In total 424 T2DM and/or hypertensive patients (mean age 55±12 years) were recruited. In addition to routine physical and laboratory examinations, levels of serum 25[OH]D, GSH and TNF-α were measured. The prevalence of 25[OH]D deficiency (<50 nmol/L) was 35.1%, which was independent from GSH and TNF-α levels. In T2DM, hypertensive and patients having both diseases, GSH levels were 349.3±19, 355.4±19 and 428.8±20 µmol/L, respectively. Uncontrolled T2DM and hypertension patients showed significantly higher GSH compared with the controlled group. Males showed slightly higher level of TNF-α compared with females and uncontrolled hypertensive patients had relatively higher TNF-α level when evaluated against controlled hypertensive patients. . Conclusion: 25[OH]D level is independent of oxidative stress and inflammation, assessed by levels of GSH and TNF-α, respectively, in T2DM and hypertensive Saudi patients. .

Metformin Is Associated with the Inhibition of Renal Artery AT1R/ET-1/iNOS Axis in a Rat Model of Diabetic Nephropathy with Suppression of Inflammation and Oxidative Stress and Kidney Injury.

Diabetes is the most common cause of end-stage renal disease, also called kidney failure. The link between the renal artery receptor angiotensin II type I (AT1R) and endothelin-1 (ET-1), involved in vasoconstriction, oxidative stress, inflammation and kidney fibrosis (collagen) in diabetes-induced nephropathy with and without metformin incorporation has not been previously studied. Diabetes (type 2) was induced in rats and another group started metformin (200 mg/kg) treatment 2 weeks prior to the induction of diabetes and continued on metformin until being culled at week 12. Diabetes significantly (p < 0.0001) modulated renal artery tissue levels of AT1R, ET-1, inducible nitric oxide synthase (iNOS), endothelial NOS (eNOS), and the advanced glycation end products that were protected by metformin. In addition, diabetes-induced inflammation, oxidative stress, hypertension, ketonuria, mesangial matrix expansion, and kidney collagen were significantly reduced by metformin. A significant correlation between the AT1R/ET-1/iNOS axis, inflammation, fibrosis and glycemia was observed. Thus, diabetes is associated with the augmentation of the renal artery AT1R/ET-1/iNOS axis as well as renal injury and hypertension while being protected by metformin.

Metformin Protects against Diabetic Cardiomyopathy: An Association between Desmin-Sarcomere Injury and the iNOS/mTOR/TIMP-1 Fibrosis Axis.

The intermediate filament protein desmin is essential for maintaining the structural integrity of sarcomeres, the fundamental unit of cardiac muscle. Diabetes mellitus (DM) can cause desmin to become dysregulated, following episodes of nitrosative stress, through the activation of the iNOS/mTOR/TIMP-1 pathway, thereby stimulating collagen deposition in the myocardium. In this study, type 2 diabetes mellitus (T2DM) was induced in rats. One group of animals was pre-treated with metformin (200 mg/kg) prior to diabetes induction and subsequently kept on metformin until sacrifice at week 12. Cardiac injuries developed in the diabetic rats as demonstrated by a significant (p < 0.0001) inhibition of desmin immunostaining, profound sarcomere ultrastructural alterations, substantial damage to the left ventricular tissue, collagen deposition, and abnormal ECG recordings. DM also significantly induced the cardiac expression of inducible nitric oxide synthase (iNOS), mammalian target of rapamycin (mTOR), and the profibrogenic biomarker tissue inhibitor of metalloproteinase-1 (TIMP-1). The expression of all these markers was significantly inhibited by metformin. In addition, a significant (p < 0.0001) correlation between desmin tissue levels/sarcomere damage and glycated hemoglobin, heart rate, iNOS, mTOR, and fibrosis was observed. These findings demonstrate an association between damage of the cardiac contractile unit­desmin and sarcomere­and the iNOS/mTOR/TIMP-1/collagen axis of fibrosis in T2DM-induced cardiomyopathy, with metformin exhibiting beneficial cardiovascular pleiotropic effects.

Developing, conducting and evaluating the internship preparatory program (Ipp).

BACKGROUND: Medical schools worldwide have employed different practices to facilitate a smooth transition from medical school into the internship phase to promote success in graduates' future professional life. The College of Medicine at Princess Nourah University (PNU) has developed a unique internship preparatory program focusing on soft and clinical skills. OBJECTIVE: The aim of this study was to describe the internship preparatory program (IPP) and evaluate its effectiveness in improving medical students' transition to internship. MATERIALS AND METHODS: The IPP for fifth-year medical students at PNU was planned and designed based on students' needs, the Saudi-Med framework, and similar national/international programs. The one-year longitudinal IPP in 2016-2017 covered four modules conducted as ten workshops focusing on soft skills, clinical skills, and professional development for the future. All data were analyzed by using SPSS version 20. RESULTS: The IPP was attended and evaluated by 48 participants; 70% of them attended 80% of the IPP workshops. The satisfaction rate for workshop participants was 6.8-8.8 out of 10. Most participants were either satisfied or strongly satisfied with respect to each item on the IPP satisfaction scale; the median satisfaction score was 4 out of 5. A positive significant correlation between the satisfaction score and the number of workshops attended was detected. CONCLUSION: The IPP was a satisfying initiative for most participants. It refines their clinical and soft skills, facilitates future planning, and provides a smooth transition from medical school to internship.

Inhibition of glycogen synthase kinase-3ß protects against collagen type II-induced arthritis associated with the inhibition of miR155/24 and inflammation and upregulation of apoptosis in rats.

MicroRNAs have been implicated in the pathogenesis of rheumatoid arthritis (RA) and their syntheses are modulated by glycogen synthase kinase-3ß (GSK-3ß). Therefore, we hypothesised that the GSK-3ß inhibitor, TDZD-8 can protect against collagen-induced arthritis (CIA) via downregulating miR155 and miR-24 expression. Rats were randomly allocated into four groups (n = 6) as follows: Control, Control + TDZD-8 (1 mg/kg), CIA, and CIA + TDZD-8. Rats were sacrificed after 6 weeks. We observed in the model group (CIA) significant (p<.05) increase in arthritis score and serum levels of RA biomarkers, which were significantly (p < .05) inhibited by TDZD-8. TDZD-8 also significantly (p<.05) inhibited CIA-induced synovial tissue levels of miR155, miR-24, and inflammation. In addition, a significant (p<.05) modulation of biomarkers of survival (Bcl-2) and apoptosis (cleaved caspase-3) by TDZD-8 was observed. Thus, TDZD-8 protects against CIA in rats for a period of 6 weeks, which is associated with the inhibition of miR155/24 and inflammation, and apoptosis augmentation.

Suppression of knee joint osteoarthritis induced secondary to type 2 diabetes mellitus in rats by resveratrol: role of glycated haemoglobin and hyperlipidaemia and biomarkers of inflammation and oxidative stress.

Background: We investigated whether the anti-inflammatory and antioxidant agent, resveratrol can inhibit type 2 diabetes mellitus (T2DM)-induced osteoarthritis (OA) in rats and whether it is associated with the suppression of glycaemia, dyslipidemia and inflammatory and oxidative stress biomarkers.Materials and methods: T2DM was induced by streptozotocin (50 mg/kg body weight) and high carbohydrate and fat diet (HCFD). The protective group was put on resveratrol (30 mg/kg) 14 days prior to the induction of diabetes and continued on resveratrol and HCFD until being sacrificed at week 12.Results: Diabetic rats showed a substantial damage to the knee joints and loss of proteoglycans from the articular cartilage, which were effectively but not completly protected by resveratrol. Resveratrol also significantly (p ≤ .0029) reduced diabetic up-regulation of HbA1c, hyperlipidaemia, inflammation and oxidative stress.Conclusions: Resveratrol protects against T2DM-induced OA associated with the inhibition of glycated haemoglobin, dyslipidemia, and biomarkers of oxidative stress and inflammation.

Paracetamol poisoning induces acute liver injury in rats: inhibition of miR-155/cd45 axis-mediated antioxidant depletion and hepatotoxicity using quercetin and resveratrol / La intoxicación por paracetamol induce daño hepático agudo en ratas: inhibición de la depleción de antioxidantes mediado por el eje miR-155/cd45 y hepatotoxicidad usando quercetina y resveratrol

SUMMARY: Ingestion of an overdose of paracetamol (also called acetaminophen, or APAP) induces hepatotoxicity that can lead to liver failure. The link between the pro-inflammatory microRNA-155 (miR-155) and leukocyte infiltration (CD45) in APAP- antioxidant depletion and liver toxicity with and without the natural polyphenolic compounds, quercetin (QUR) plus resveratrol (RES) has not been previously studied. Therefore, acute hepatic injury was induced in rats by 2 g/kg APAP (single dose, orally) and another group started QUR (50 mg/kg) plus RES (30 mg/kg) treatment one week prior to APAP ingestion. Animals were culled 24 hours post the paracetamol treatment. APAP overdose induced hepatic and blood levels of miR-155 expression, CD45 (leukocyte common antigen) immunostaining, degenerated hepatocytes, and hepatic injury enzymes; alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which were markedly decreased by QUR+RES. Whereas, APAP intoxication ameliorated liver tissue levels of the antioxidants, glutathione peroxidase and superoxide dismutase that were augmented by QUR+RES. Moreover, a significant (p<0.05) correlation between miR-155/CD45 axis and liver tissue injury was observed. These findings show that paracetamol intoxication augments miR- 155/CD45 axis-mediated modulation of antioxidants and liver injury in rats, and is protected by QUR+RES.

RESUMEN: La ingestión de una sobredosis de paracetamol (también llamado acetaminofeno o APAP) induce hepatotoxicidad que puede provocar insuficiencia hepática. El vínculo entre el microARN-155 proinflamatorio (miR-155) y la infiltración de leucocitos (CD45) en el agotamiento de APAP- antioxidante y la toxicidad hepática con y sin los compuestos polifenólicos naturales, quercetina (QUR) más resveratrol (RES) no ha sido previamente investigado. En este estudio, se indujo daño hepático agudo en ratas con 2 g/kg de APAP (dosis única, por vía oral) y otro grupo comenzó el tratamiento con QUR (50 mg/ kg) más RES (30 mg/kg) una semana antes de la ingestión de APAP. Los animales se sacrificaron 24 horas después del tratamiento con paracetamol. La sobredosis de APAP indujo niveles hepáticos y sanguíneos de expresión de miR-155, inmunotinción de CD45 (antígeno leucocitario común), degeneración de los hepatocitos y daño hepático enzimático; alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST), disminuyeron notablemente con QUR+RES. Mientras que la intoxicación con APAP mejoró los niveles de antioxidantes, glutatión peroxidasa y superóxido dismutasa en el tejido hepático los que aumentaron con QUR+RES. Además, se observó una correlación significativa (p<0,05) entre el eje miR-155/CD45 y la lesión del tejido hepático. Estos hallazgos muestran que la intoxicación por paracetamol aumenta la modulación mediada por el eje miR-155/CD45 de los antioxidantes y la lesión hepática en ratas, y está protegida por QUR+RES.

Suppression of type 2 diabetes mellitus-induced aortic ultrastructural alterations in rats by insulin: an association of vascular injury biomarkers.

Diabetes represents a major public health problem and an estimated 70% of people with diabetes die of cardiovascular complications. The protective effect of insulin treatment against ultrastructural damage to the tunica intima and tunica media of the aorta induced by type 2 diabetes mellitus (T2DM) has not been investigated before using transmission electron microscopy (TEM). Therefore, we induced T2DM in rats using high fat diet and streptozotocin (50 mg/kg) and administered insulin daily by i.v injection for 8 weeks to the treatment group. Whereas, the T2DM control group were left untreated for the duration of the experiment. A comparison was also made between the effect of insulin on aortic tissue and the blood level of biomarkers of vascular injury, inflammation, and oxidative stress. T2DM induced profound ultrastructural damage to the aortic endothelium and vascular smooth muscle cells, which were substantially protected with insulin. Furthermore, insulin returned blood sugar to a control level and significantly (p < .05) inhibited diabetic up-regulation of endothelial and leukocyte intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein 1 (VCAM-1), endothelial cell adhesion molecules, P-selectin and E-selectin, tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and malondialdehyde (MDA). Furthermore, insulin augmented the blood level of the anti-oxidant enzyme superoxide dismutase (SOD). We conclude that in a rat model of T2DM, insulin treatment substantially reduces aortic injury secondary to T2DM for a period of 8 weeks, possibly due to the inhibition of hyperglycemia, vascular activation, inflammation, and oxidative stress.

Inhibition of GSK3ß protects against collagen type II-induced arthritis associated with a decrease in synovial leukocyte infiltration and inhibition of endoplasmic reticulum stress and autophagy biomarkers.

We sought to determine whether TDZD-8, the inhibitor of the glycogen synthase kinase-3ß (GSK3ß), can protect the synovial membrane of the knee joint against injuries induced by collagen type II immunization (CIA) possibly via the downregulation of synovial leukocyte infiltration, endoplasmic reticulum stress (ERS), and autophagy. The model group of rats (CIA) were immunized over a period of 3 weeks with collagen type II, whereas the treated group of rats (CIA + TDZD-8) were treated with TDZD-8 (1 mg/kg) for 21 days after the completion of the immunization regimen. All rats were then killed at week 6. Harvested synovial tissues were prepared for immunohistochemistry staining, and synovial homogenates were assayed for biomarkers of ERS, autophagy, apoptosis, and cell survival and proliferation. In addition, blood samples were assayed for biomarkers of arthritis. Synovial tissue images showed that CIA enhanced leukocyte recruitment as demonstrated by an increased CD45+ (leukocyte common antigen) immunostaining, which was markedly decreased by TDZD-8. TDZD-8 also significantly (P < .05) inhibited collagen-induced autophagy biomarkers Beclin-1 and LC3II, the ERS biomarkers GRP-78, IRE1-α, XBPIs, and eIF2a, and the survival protein Bcl-2. Whereas, the collagen-induced proliferative biomarkers Akt and mTOR were not inhibited by TDZD-8, and CIA inhibited the apoptotic proteins CHOP and cleaved caspase-3, which were augmented by TDZD-8. We further demonstrated a significant (P < .05) correlation between autoantibodies generated during the course of arthritis and biomarkers of ERS and autophagy. We conclude that TDZD-8 inhibits CIA and decreases synovial leukocyte infiltration, ERS, and autophagy, which is independent of Akt/mTOR signalling.