Forced Swimming-Induced Depressive-like Behavior and Anxiety Are Reduced by Chlorpheniramine via Suppression of Oxidative and Inflammatory Mediators and Activating the Nrf2-BDNF Signaling Pathway.

The first-generation antihistamine chlorpheniramine (CPA) is believed to have both anxiolytic and antidepressant properties. The current study sought to assess the mechanisms behind the antidepressant and anxiolytic effects of CPA therapy concerning oxidative stress, inflammation, and nuclear factor p45 for erythroid 2-Brain-derived neurotrophic factor (Nrf2-BDNF) signaling pathway in forced swimming-induced depressive-like behavior and anxiety. Eighteen male Wistar rats (180-200 gm) rats were separated into three groups (n = 6): a stressed group (acute stress) that underwent the forced swimming test (FST) and a stressed group that received pretreatment with CPA (10 mg/kg body weight) for 3 weeks (CPA + acute stress). Animals were subsequently put through the following behavioral tests after undergoing a forced swim test (FST) for 5 min: an immobility test, open field test, and elevated plus maze test. Serum cortisol levels were measured when the rats were euthanized at the end of the experiments. Brain neurotransmitters (cortisol, serotonin, and noradrenaline), oxidative stress (SOD and MDA), inflammatory (IL-6 and IL-1) biomarkers, and the Nrf2-BDNF signaling pathway in the hippocampus and cerebral cortex tissues was determined. CPA prevented stress-induced increases in cortisol levels (p < 0.0001), decreased brain neurotransmitters, and increased oxidative stress and inflammation. CPA also upregulated the Nrf2-BDNF signaling pathway. Thus, CPA mitigates depressive-like behavior and anxiety by inhibiting oxidative stress and inflammation and upregulating the Nrf2-BDNF signaling pathway in the brain tissues.

Metformin Suppresses Thioacetamide-Induced Chronic Kidney Disease in Association with the Upregulation of AMPK and Downregulation of Oxidative Stress and Inflammation as Well as Dyslipidemia and Hypertension.

Toxic chemicals such as carbon tetrachloride and thioacetamide (TAA) are reported to induce hepato-nephrotoxicity. The potential protective outcome of the antidiabetic and pleiotropic drug metformin against TAA-induced chronic kidney disease in association with the modulation of AMP-activated protein kinase (AMPK), oxidative stress, inflammation, dyslipidemia, and systemic hypertension has not been investigated before. Therefore, 200 mg/kg TAA was injected (via the intraperitoneal route) in a model group of rats twice a week starting at week 3 for 8 weeks. The control rats were injected with the vehicle for the same period. The metformin-treated group received 200 mg/kg metformin daily for 10 weeks, beginning week 1, and received TAA injections with dosage and timing similar to those of the model group. All rats were culled at week 10. It was observed that TAA induced substantial renal injury, as demonstrated by significant kidney tissue damage and fibrosis, as well as augmented blood and kidney tissue levels of urea, creatinine, inflammation, oxidative stress, dyslipidemia, tissue inhibitor of metalloproteinases-1 (TIMP-1), and hypertension. TAA nephrotoxicity substantially inhibited the renal expression of phosphorylated AMPK. All these markers were significantly protected by metformin administration. In addition, a link between kidney fibrosis and these parameters was observed. Thus, metformin provides profound protection against TAA-induced kidney damage and fibrosis associated with the augmentation of the tissue protective enzyme AMPK and inhibition of oxidative stress, inflammation, the profibrogenic gene TIMP-1, dyslipidemia, and hypertension for a period of 10 weeks in rats.

Quercetin and resveratrol are associated with the downregulation of TNFalpha/NF-kB/inos axis-mediated acute liver injury in rats induced by paracetamol poisoning / La quercetina y el resveratrol están asociados con la regulación decreciente de la lesión hepática aguda mediada por el eje TNF-alfa/NF-kB/inos en ratas inducida por envenenamiento con paracetamol

SUMMARY: Paracetamol (known as acetaminophen, or APAP) poisoning causes acute liver damage that can lead to organ failure and death. We sought to determine that APAP overdose can augment tumor necrosis factor-alpha (TNF-α)/ nuclear factor kappa B (NF-kB)/induced nitic oxide synthase (iNOS) axis-mediated hepatotoxicity in rats, and the anti-inflammatory polyphenolic compounds, quercetin (QUR) plus resveratrol (RES) can ameliorate these parameters. Therefore, we induced acute hepatotoxicity in rats using APAP overdose (2 g/kg, orally) and the protective group of rats were treated with 50 mg/kg QUR plus 30 mg/kg RES for one week before APAP ingestion. Animals were killed at day 8. APAP poisoning caused the induction of hepatic tissue levels of TNF-α, NF-kB, and iNOS, which were significantly (p<0.05) decreased by QUR+RES. QUR+RES, also inhibited liver injury biomarkers, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Additionally, a link between liver injury and TNF-α /NF-kB / iNOS axis mediated hepatotoxicity was observed. Thus, the presented data backing the conclusion that intoxication by paracetamol increases TNF-α / NF-kB / iNOS axis -mediated hepatotoxicity, and is protected by a combination of quercetin and resveratrol.

El envenenamiento por paracetamol (conocido como acetaminofeno o APAP) causa daño hepático agudo que puede provocar una insuficiencia orgánica y la muerte. El objetivo de este trabajo fue determinar si la sobredosis de APAP puede aumentar la hepatotoxicidad mediada por el eje del factor de necrosis tumoral alfa (TNF-α)/factor nuclear kappa B (NF-kB)/óxido nítico sintasa inducida (iNOS) en ratas, y si el polifenólico antiinflamatorio compuesto por quercetina (QUR) más resveratrol (RES) pueden mejorar estos parámetros. Por lo tanto, inducimos hepatotoxicidad aguda en ratas usando una sobredosis de APAP (2 g/kg, por vía oral). El grupo protector de ratas se trató con 50 mg/ kg de QUR más 30 mg/kg de RES durante una semana antes de la ingestión de APAP. Los animales se sacrificaron el día 8. El envenenamiento con APAP en el tejido hepático provocó la inducción de niveles de TNF-α, NF-kB e iNOS, que se redujeron significativamente (p<0,05) con QUR+RES. QUR+RES, también inhibió los biomarcadores de daño hepático, la alanina aminotransferasa (ALT) y el aspartato aminotransferasa (AST). Además, se observó una relación entre la lesión hepática y la hepatotoxicidad mediada por el eje TNF-α /NF-kB/iNOS. Por lo tanto, los datos presentados respaldan la conclusión de que la intoxicación por paracetamol aumenta la hepatotoxicidad mediada por el eje TNF-α /NF-kB / iNOS, y está protegida por una combinación de quercetina y resveratrol.

Vitamin E protects against the modulation of TNF-α-AMPK axis and inhibits pancreas injury in a rat model of L-arginine-induced acute necrotising pancreatitis.

BACKGROUND: Acute pancreatitis (AP) associated with the modulation of TNF-α-AMPK axis in the presence and absence of vitamin E has not been investigated before. MATERIAL AND METHODS: Rats were either injected with L-arginine (2.5 gm/kg) before being sacrificed after 48 h or were pre-treated with vitamin E (60 mg/kg) and continued receiving vitamin E until the end of the experiment. RESULTS: AP was developed as demonstrated by infiltration of inflammatory cells and profound pancreas tissue damage, which were substantially protected by vitamin E. In addition, L-arginine injections significantly (p < .0001) increased the expression of TNF-α mRNA and protein, and decreased phospho-AMPK and IL-10 mRNA and protein that was significantly (p < .0001) protected by vitamin E. Furthermore, vitamin E inhibited L-arginine-induced blood levels of LDH, amylase, and myeloperoxidase. CONCLUSIONS: L-arginine-induced acute pancreatitis modulates TNF-α-AMPK axis, IL-10 and other AP biomarkers, which is protected by vitamin E; thus, may offer therapeutic potential in humans.

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.

MiR-155 Dysregulation Is Associated with the Augmentation of ROS/p53 Axis of Fibrosis in Thioacetamide-Induced Hepatotoxicity and Is Protected by Resveratrol.

Liver fibrosis is a hallmark of thioacetamide (TAA) intoxications. MicroRNAs (miRs), such as miR-155, have been implied in the pathogenesis of liver disease, and regulated by the antioxidant and anti-inflammatory compound resveratrol (RES). The link between reactive oxygen species (ROS), tumour suppressor p53 (p53), and liver fibrosis-during the pathogenesis of TAA-induced liver injury-associated with miR-155 dysregulation with and without RES incorporation has not been previously studied. Therefore, one group of rats received TAA injections of 200 mg/kg; twice a week at the beginning of week 3 for 8 weeks (TAA group; or model group), whereas the protective group was pretreated daily with RES suspension (20 mg/kg; orally) for the first two weeks and subsequently sustained on receiving both RES and TAA until being sacrificed at the 10th week. Liver injuries developed in the model group were confirmed by a significant (p < 0.0001) elevation of hepatic tissue levels of miR-155, ROS, p53, and the profibrogenic biomarkers: tissue inhibitor of metalloproteinases-1 and α-smooth muscle actin, as well as collagen deposition (fibrosis). All these parameters were significantly (p ≤ 0.0234) protected by resveratrol (RES + TAA). In addition, we observed a significant (p < 0.0001) correlation between ROS/p53 axis mediated liver fibrosis and miR-155. Thus, TAA intoxication induced miR-155 imbalance and ROS/p53-mediated liver fibrosis, with resveratrol, conversely displaying beneficial hepatic pleiotropic effects for a period of 10 weeks.

Association of resveratrol with the suppression of TNF-α/NF-kB/iNOS/HIF-1α axis-mediated fibrosis and systemic hypertension in thioacetamide-induced liver injury.

Chronic liver injury can lead to hepatic failure and the only available method of treatment would be liver transplantation. The link between inflammation (TNF-α), nuclear factor-kappa B (NF-kB), nitrosative stress (iNOS) and hypoxia-inducible factor-1α (HIF-1α) in thioacetamide (TAA) induced liver fibrosis, and hypertension with and without the incorporation of the anti-inflammatory and antioxidant resveratrol (RES) has not been investigated before. Consequently, we injected rats with either 200 mg/kg TAA for 8 weeks starting at week 2 (model group) or pretreated them before TAA injections with RES (20 mg/kg) for 2 weeks and continued them on RES and TAA until being culled at week 10 (protective group). In the model group, we documented the induction of hepatic fibrosis and upregulation of tumor necrosis factor-α (TNF-α), NF-kB, inducible nitric oxide synthase (iNOS), HIF-1α and the profibrotic biomarkers alpha-smooth muscle actin (α-SMA) and matrix metalloproteinase-9 (MMP-9) that was significantly (p ≤ 0.0014) ameliorated by RES. RES also significantly (p ≤ 0.0232) reduced triglycerides (TG), cholesterol (CHOL), very low-density lipoprotein (vLDL-C), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure, and heart rate (HR) induction by TAA. Also, a significant (p < 0.0001) positive correlation between TNF-α/NF-kB/iNOS/HIF-1α axis-mediated fibrosis and hypertension and liver injury biomarkers was observed. These findings suggest that in the hepatotoxic compound, TAA is associated with TNF-α/NF-kB/iNOS/HIF-1α-mediated fibrosis and hypertension, whilst being inhibited by RES.

Inflammatory biomarkers and severity of COVID-19: Cross sectional study among Egyptian patients.

The newly emerging coronavirus disease 2019 (COVID-19) is characterized by multisystem inflammatory syndrome. The development of SARS-CoV-2 complications usually starts within few days following infection, and the severity of the disease determines its outcome. Vitamin D insufficiency is associated with risk of lung infections, also cell-based studies reported the ability of vitamin D to control enveloped virus growth. We aimed to investigate the relationship between the most eminent inflammatory biomarkers and the level of vitamin D aiming to provide a tool for early diagnosis and prediction of disease progression. The current study was approved by Research Ethics Committee (REC), Kasr Al-Ainy. After confirmation of being COVID-19 by PCR, the admitted patients were categorized as mild-moderate, and severe-critically ill based on clinical and radiologic data. The total levels of serum 25(OH)D, as well as other pro-inflammatory biomarkers were measured and were analyzed by receiver operating characteristic curve (ROC) analysis for detection of their association with COVID-19 disease severity and to determine their sensitivity and specificity at optimum cutoff points. The area under the curve (AUC) ROC for predicting COVID-19 disease severity was the highest (of 0.97) for vitamin D, inflammatory cytokines, liver enzymes, ferritin, and D-Dimer. In addition, high serum levels of creatinine, and elevated liver enzymes associated with severe-critical COVID-19. The low 25(OH)D was associated with the disease severity.

Lipopolysaccharide induces acute lung injury and alveolar haemorrhage in association with the cytokine storm, coagulopathy and AT1R/JAK/STAT augmentation in a rat model that mimics moderate and severe Covid-19 pathology.

Progress in the study of Covid-19 disease in rodents has been hampered by the lack of angiotensin-converting enzyme 2 (ACE2; virus entry route to the target cell) affinities for the virus spike proteins across species. Therefore, we sought to determine whether a modified protocol of lipopolysaccharide (LPS)-induced acute respiratory distress syndrome in rats can mimic both cell signalling pathways as well as severe disease phenotypes of Covid-19 disease. Rats were injected via intratracheal (IT) instillation with either 15 mg/kg of LPS (model group) or saline (control group) before being killed after 3 days. A severe acute respiratory syndrome (SARS)-like effect was observed in the model group as demonstrated by the development of a "cytokine storm" (>2.7 fold increase in blood levels of IL-6, IL-17A, GM-CSF, and TNF-α), high blood ferritin, demonstrable coagulopathy, including elevated D-dimer (approximately 10-fold increase), PAI-1, PT, and APTT (p < 0.0001). In addition, LPS increased the expression of lung angiotensin II type I receptor (AT1R)-JAK-STAT axis (>4 fold increase). Chest imaging revealed bilateral small patchy opacities of the lungs. Severe lung injury was noted by the presence of both, alveolar collapse and haemorrhage, desquamation of epithelial cells in the airway lumen, infiltration of inflammatory cells (CD45+ leukocytes), widespread thickening of the interalveolar septa, and ultrastructural alterations similar to Covid-19. Thus, these findings demonstrate that IT injection of 15 mg/kg LPS into rats, induced an AT1R/JAK/STAT-mediated cytokine storm with resultant pneumonia and coagulopathy that was commensurate with moderate and severe Covid-19 disease noted in humans.

Prenatal intake of omega-3 promotes Wnt/ß-catenin signaling pathway, and preserves integrity of the blood-brain barrier in preeclamptic rats.

BACKGROUND: Preeclampsia is a systemic, multi-organ endotheliopathy, associated with oxidative injury to the blood-brain barrier (BBB). Preeclampsia initiates a cascade of events that include neuroinflammation. Recently, it was documented that Wnt/ß-catenin signaling pathway exerts neuroprotective effects and maintain BBB integrity. We investigate the protective effect of omega-3 against neurovascular complication of preeclampsia and its relation to Wnt/ß-catenin signaling pathway. METHODOLOGY: After confirmation of day 0 pregnancy (G0), 24 adult pregnant female Wistar rats were divided into four groups control pregnant, pregnant supplemented with omega-3, preeclampsia (PE); female rats received N (ω)-nitro-L-arginine methyl ester (L-NAME) (50 mg/kg/day SC from day 7 to day 16 of pregnancy for induction of preeclampsia) and PE rats supplemented with omega-3. The intake of omega-3 started on day zero (0) of pregnancy until the end of the study (144 mg/kg\day orally). RESULTS: We found that omega-3 supplementation significantly improved cognitive functions and EEG amplitude, decreased blood pressure, water contents of brain tissues, sFlt-1, oxidative stress, proteinuria, and enhanced Wnt\ß-catenin proteins. Histological examination showed improved cerebral microangiopathy, increased expression of claudin-1 and -3, CD31, and VEGF in the cerebral cortical microvasculature and choroid plexus in PE rats treated with omega-3. A positive correlation between protein expression level of Wnt \ß-catenin and cognitive functions, and a negative correlation between claudin-5 relative expression, claudin-1 and -3 area % from one side and water content of the brain tissues from the other side were observed. CONCLUSION: Wnt/ß-catenin signaling pathway suspected to have an important role to improve BBB integrity. Neuroprotective, antioxidant, and anti-inflammatory effects of omega-3 were observed and can be suggested as protective supplementation for preeclampsia.

Resveratrol suppresses cholestasis-induced liver injury and fibrosis in rats associated with the inhibition of TGFß1-Smad3-miR21 axis and profibrogenic and hepatic injury biomarkers.

Cholestasis caused by slowing or blockage of bile flow is a serious liver disease that can lead to liver fibrosis and cirrhosis. The link between transforming growth factor beta 1 (TGFß1), Smad family member 3 (Smad3), and microRNA 21 (miR21) in bile duct ligation (BDL)-induced liver fibrosis in the presence and absence of the anti-inflammatory and antioxidant compound, resveratrol (RSV), has not been previously studied. Therefore, we tested whether RSV can protect against BDL-induced liver fibrosis associated with the inhibition of the TGFß1-Smad3-miR21 axis and profibrogenic and hepatic injury biomarkers. The model group of rats had their bile duct ligated (BDL) for 3 weeks before being killed, whereas, the BDL-treated rats were separated into three groups that received 10, 20, and 30 mg/kg RSV daily until the end of the experiment. Using light microscopy and ultrasound examinations, we documented in the BDL group, the development of hepatic injury and fibrosis as demonstrated by hepatocytes necrosis, bile duct hyperplasia, collagen deposition, enlarged liver with increased echogenicity, irregular nodular border and dilated common bile duct, which were more effectively inhibited by the highest used RSV dosage. In addition, RSV significantly (p ≤ 0.0027) inhibited BDL-induced hepatic TGFß1, Smad3, miR21, the profibrogenic biomarker tissue inhibitor of metalloproteinases-1 (TIMP-1), malondialdehyde (MDA), interleukin-17a (IL-17a), and blood levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin. These findings show that RSV at 30 mg/kg substantially protects against BDL-induced liver injuries, which is associated with the inhibition of TGFß1-Smad3-miR21 axis, and biomarkers of profibrogenesis, oxidative stress, and inflammation.

Hydrogen sulfide and mesenchymal stem cells-extracted microvesicles attenuate LPS-induced Alzheimer's disease.

Both hydrogen sulfide (H2 S) and mesenchymal stem cells (MSCs) extracted microvesicles (MVs) are potent anti-inflammatory molecules. They play an essential role in lowering the production of tumor necrosis factor-alpha (TNF-α). The latter could strongly stimulate MiR-155 that contributes to neurodegeneration and Alzheimer's disease (AD). miR-155 could repress the expression of inositol 5-phosphatase-1 (SHIP-1) leading eventually to activation of Akt kinase and neurofibrillary development in AD. The current study was conducted to evaluate the role of miR-155 in a rat model of lipopolysaccharide (LPS)-induced AD and to investigate the effect of using MVs and H2 S that were given either separately or combined in regulating pro-inflammatory signaling. Thirty female Wistar albino rats aged 6 months to 1 year were equally divided into five groups; control group, LPS-induced AD group, LPS + MVs group, LPS + NaHS group, and LPS + MVs and NaHS group. The increased miR-155 level was associated with decreased SHIP-1 level and positively correlated with TNF-α. In addition, treatment with MVs and/or NaHS resulted in attenuation of inflammation, decreasing miR-155, pAkt levels, and downregulation of apoptosis along with improvement of the hippocampal and cortical histopathological alterations. LPS enhanced production of malondialdehyde (MDA) and reduced glutathione (GSH) levels indicating oxidative stress-induced neural damage, whereas MVs and NaHS could mitigate oxidative damage and accelerate antioxidant capacity via increasing catalase enzyme. In conclusion, downregulation of TNF-α, miR-155, and pAkt and increased SHIP-1 could improve the neuro-inflammatory state and cognitive function of LPS-induced Alzheimer's disease.

Hypoxia-induced downregulation of cyclooxygenase 2 leads to the loss of immunoprivilege of allogeneic mesenchymal stem cells.

Allogeneic mesenchymal stem cells (MSCs) from young and healthy donors are reported to hold the potential to treat several immunological and degenerative disorders. However, recent data from animal studies and clinical trials demonstrate that immunogenicity and poor survival of transplanted MSCs impaired the efficacy of cells for regenerative applications. It is reported that initially immunoprivileged under in vitro conditions, MSCs are targeted by the host immune system after transplantation in the ischemic tissues in vivo. We performed in vitro (in MSCs) and in vivo (in the rat model of myocardial infarction [MI]) studies to elucidate the mechanisms responsible for the change in the immunophenotype of MSCs from immunoprivileged to immunogenic under ischemic conditions. We have recently reported that a soluble factor prostaglandin E2 (PGE2) preserves the immunoprivilege of allogeneic MSCs. In the current study, we found that PGE2 levels, which were elevated during normoxia, decreased in MSCs following exposure to hypoxia. Further, we found that proteasome-mediated degradation of cyclooxygenase-2 (COX2, rate-limiting enzyme in PGE2 biosynthesis) in hypoxic MSCs is responsible for PGE2 decrease and loss of immunoprivilege of MSCs. While investigating the mechanisms of COX2 degradation in hypoxic MSCs, we found that in normoxic MSCs, COP9 signalosome subunit 5 (CSN5) binds to COX2 and prevents its degradation by the proteasome. However, exposure to hypoxia leads to a decrease in CSN5 levels and its binding to COX2, rendering COX2 protein susceptible to proteasome-mediated degradation. This subsequently causes PGE2 downregulation and loss of immunoprivilege of MSCs. Maintaining COX2 levels in MSCs preserves immunoprivilege in vitro and improves the survival of transplanted MSCs in a rat model of MI. These data provide novel mechanistic evidence that PGE2 is downregulated in hypoxic MSCs which is responsible for the post-transplantation rejection of allogeneic MSCs. Therefore, our data suggest that the new strategies that target CSN5-COX2 signaling may improve survival and utility of transplanted allogeneic MSCs in the ischemic heart.

Hypoxia-induced increase in Sug1 leads to poor post-transplantation survival of allogeneic mesenchymal stem cells.

Allogeneic mesenchymal stem cells (MSCs) from young and healthy donors are immunoprivileged and have the potential to treat numerous degenerative diseases. However, recent reviews of clinical trials report poor long-term survival of transplanted cells in the recipient that turned down the enthusiasm regarding MSC therapies. Increasing evidence now confirm that though initially immunoprivileged, MSCs eventually become immunogenic after transplantation in the ischemic or hypoxic environment of diseased tissues and are rejected by the host immune system. We performed in vitro (in rat and human cells) and in vivo (in a rat model) investigations to understand the mechanisms of the immune switch in the phenotype of MSCs. The immunoprivilege of MSCs is preserved by the absence of cell surface immune antigen, major histocompatibility complex II (MHC-II) molecule. We found that the ATPase subunit of 19S proteasome "Sug1" regulates MHC-II biosynthesis in MSCs. Exposure to hypoxia upregulates Sug1 in MSCs and its binding to class II transactivator (CIITA), a coactivator of MHC-II transcription. Sug1 binding to CIITA in hypoxic MSCs promotes the acetylation and K63 ubiquitination of CIITA leading to its activation and translocation to the nucleus, and ultimately MHC-II upregulation. In both rat and human MSCs, knocking down Sug1 inactivated MHC-II and preserved immunoprivilege even following hypoxia. In a rat model of myocardial infarction, transplantation of Sug1-knockdown MSCs in ischemic heart preserved immunoprivilege and improved the survival of transplanted cells. Therefore, the current study provides novel mechanisms of post-transplantation loss of immunoprivilege of MSCs. This study may help in facilitating better planning for future clinical trials.

Suppression of thioacetamide-induced hepatic injury in rats treatment with resveratrol: role of mammalian target of rapamycin (mTOR) cell signaling / Supresión de la lesión hepática inducida por tioacetamida en ratas tratadas con resveratrol: rol de la vía de señalización mTOR (mammalian target of rapamycin)

Chronic hepatotoxicity is a debilitating and frequently life-threatening disease resulting in progressive liver failure. The toxic chemical, thioacetamide (TAA) is used to evaluate hepatoprotective agents, and the polyphenolic compound, resveratrol was proposed as a novel treatment for diseases with hyperactivation of the mammalian target of rapamycin (mTOR) cell signaling pathway. This analysis sought to investigate the potential protective effect of resveratrol against liver injury induced by TAA via the inhibition of hepatic mTOR. Model group rats received several injections of TAA (200 mg/kg; twice a week for 8 weeks) before being sacrificed at week 10 and the protective group was pretreated with resveratrol (20 mg/kg) daily for two weeks prior to TAA injections and continued receiving both agents until the end of the experiment. Harvested liver tissues were examined using light microscopy and liver homogenates were assayed for biomarkers of inflammation and assessed the levels of mTOR protein in all animal groups. In addition, blood samples were assayed for biomarkers of liver injury enzyme. TAA substantially damaged the hepatic tissue of the model group such as infiltration of inflammatory cells, vacuolated cytoplasm, dark pyknotic nuclei, and dilated congested blood vessel that were effectively protected by resveratrol. Resveratrol also significantly (p<0.05) inhibited TAA-induced mTOR, high sensitivity c-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in harvested liver homogenates and blood samples. Thus, we conclude that resveratrol effectively protects against TAA-induced hepatotoxicity in rats, possibly due to the inhibition of mTOR and inflammation.

La hepatotoxicidad crónica es una enfermedad debilitante y potencialmente mortal que produce insuficiencia hepática progresiva. La toxicidad del químico de la tioacetamida (TAA) se utiliza para evaluar los agentes hepatoprotectores y el compuesto polifenólico, resveratrol, se propuso como un nuevo tratamiento para enfermedades con hiperactivación de la vía de señalización celular mTOR (mammalian Target of Rapamycin). Aquí buscamos investigar el posible efecto protector del resveratrol contra la lesión hepática inducida por TAA a través de la inhibición de la vía de señalización mTOR en hepatocitos. Las ratas del grupo modelo recibieron varias inyecciones de TAA (200 mg / kg; dos veces por semana durante 8 semanas) antes de ser sacrificadas en la semana 10 y el grupo protector se trató previamente con resveratrol (20 mg / kg) diariamente durante dos semanas antes de las inyecciones de TAA y continuó recibiendo ambos agentes hasta el final del experimento. Se examinaron los tejidos hepáticos recolectados usando microscopía óptica y se analizaron los homogeneizados hepáticos para detectar biomarcadores de inflamación y se evaluaron los niveles de proteína mTOR en todos los grupos de animales. Además, se analizaron muestras de sangre para detectar biomarcadores de la enzima de lesión hepática. TAA dañó sustancialmente el tejido hepático del grupo modelo, con infiltración de células inflamatorias, citoplasma vacuolado, núcleos picnóticos oscuros y vasos sanguíneos congestionados dilatados que estaban efectivamente protegidos por el resveratrol. El resveratrol también inhibió significativamente (p <0.05) mTOR, proteína C-reactiva (hs-CRP), factor de necrosis tumoral alfa (TNF-α), interleucina-6 (IL-6), alanina aminotransferasa (ALT ) y aspartato aminotransferasa (AST) en las muestras de sangre y de hígados recolectados. En conclusión, el resveratrol protege eficazmente contra la hepatotoxicidad inducida por TAA en ratas, posiblemente debido a la inhibición de mTOR y de la inflamación.