concanavalin-a and Fibrosis

Aging kidneys are characterized by an increased vulnerability to glomerulosclerosis and a measurable decline in renal function. Evidence suggests that renal and systemic klotho and sirtuin 1 (SIRT1) deficiencies worsen kidney damage induced by exogenous stresses. The aim of this study was to explore whether resveratrol would attenuate concanavalin A (Con A)-induced renal oxidative stress and advanced glomerulosclerosis in aged mice. Aged male C57BL/6 mice were treated orally with resveratrol (30 mg/kg) seven times (12 h intervals) prior to the administration of a single tail-vein injection of Con A (20 mg/kg). The plasma and urinary levels of kidney damage markers were evaluated. The kidney histopathology, renal parameters, and oxidative stress levels were measured. Furthermore, klotho was downregulated in mouse kidney mesangial cells that were pretreated with 25 µM resveratrol followed by 20 µg/mL Con A. The urinary albumin/creatinine ratio, blood urea nitrogen, kidney mesangial matrix expansion, tubulointerstitial fibrosis, and renal levels of α-smooth muscle actin, transforming growth factor beta, fibronectin, procollagen III propeptide, and collagen type I significantly increased in Con A-treated aged mice. Aged mice kidneys also showed markedly increased levels of 8-hydroxydeoxyguanosine (8-OH-dG) and reactive oxygen species (ROS), with reduced superoxide dismutase activity and levels of glutathione, klotho, and SIRT1 after Con A challenge. Furthermore, in kidney mesangial cells, klotho silencing abolished the effects of resveratrol on the Con A-mediated elevation of the indices of oxidative stress and the expression of glomerulosclerosis-related factors. These findings suggest that resveratrol protects against Con A-induced advanced glomerulosclerosis in aged mice, ameliorating renal oxidative stress via the SIRT1-mediated klotho expression.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Animals; Cell Line; Concanavalin A; Fibronectins; Fibrosis; Glucuronidase; Kidney; Kidney Diseases; Klotho Proteins; Male; Mesangial Cells; Mice; Mice, Inbred C57BL; Oxidative Stress; Reactive Oxygen Species; Resveratrol; Signal Transduction; Sirtuin 1; Superoxide Dismutase; Up-Regulation

Autoimmune hepatitis (AIH) is an immunity disorder that is the result of antibodies in the liver tissue of the patient that are attacked by activated immune cells due to an unknown cause. In this study, we aimed to investigate the anti-inflammatory effect of Yongdamsagan-tang (YST) extracts and confirm effects on autoimmune hepatitis models as the therapeutic agent using the YST extracted by various solvents. YST, a mixture of 11 herbal extracts, is known in traditional Korean medicine as a widely used treatment for inflammatory diseases. We proposed the AIH-condition in vitro model by the addition of recombinant IL-17A and then observed several markers linked to AIH symptoms, including an increase of IL-6 expression, lipid accumulation, and fibrosis. In AIH-condition hepatic cell model, YST reduced IL-6 expression and lipid accumulation caused by treatment of IL-17 combination in hepatocyte cells. Also, YST blocked several activated fibrosis factors including transforming growth factor-β (TGF- β1), collagen type 1 (Col-α1(I)), and α-smooth muscle actin (α-SMA) in liver stellate cells. Furthermore, pretreatment with YST protected hepatic damage and reduces histological injury by suppressing apoptosis mediator and inflammatory cytokines expression in concanavalin A (Con A)-induced autoimmune hepatitis mice model. The findings here improve our understanding of YST extracted by 80% ethanol, suggesting that YST can be used as a therapeutic treatment for AIH.

Topics: Animals; Apoptosis; Cell Survival; Concanavalin A; Disease Models, Animal; Drugs, Chinese Herbal; Fibrosis; Hep G2 Cells; Hepatitis, Autoimmune; Humans; Interleukin-17; Interleukin-6; Liver Function Tests; Macrophages; Nitric Oxide; Recombinant Proteins

Sirtuin 1 (SIRT1) depletion in vascular endothelial cells mediates endothelial dysfunction and premature senescence in diverse cardiovascular and renal diseases. However, the molecular mechanisms underlying these pathologic effects remain unclear. Here, we examined the phenotype of a mouse model of vascular senescence created by genetically ablating exon 4 of Sirt1 in endothelial cells (Sirt1(endo-/-)). Under basal conditions, Sirt1(endo-/-) mice showed impaired endothelium-dependent vasorelaxation and angiogenesis, and fibrosis occurred spontaneously at low levels at an early age. In contrast, induction of nephrotoxic stress (acute and chronic folic acid-induced nephropathy) in Sirt1(endo-/-) mice resulted in robust acute renal functional deterioration followed by an exaggerated fibrotic response compared with control animals. Additional studies identified matrix metalloproteinase-14 (MMP-14) as a target of SIRT1. In the kidneys of Sirt1(endo-/-) mice, impaired angiogenesis, reduced matrilytic activity, and retention of the profibrotic cleavage substrates tissue transglutaminase and endoglin accompanied MMP-14 suppression. Furthermore, restoration of MMP-14 expression in SIRT1-depeleted mice improved angiogenic and matrilytic functions of the endothelium, prevented renal dysfunction, and attenuated nephrosclerosis. Our findings establish a novel mechanistic molecular link between endothelial SIRT1 depletion, downregulation of MMP-14, and the development of nephrosclerosis.

Topics: Acute Kidney Injury; Animals; Cellular Senescence; Concanavalin A; Down-Regulation; Endothelium, Vascular; Exons; Extracellular Matrix; Fibrosis; Folic Acid; Gene Expression Regulation, Enzymologic; Human Umbilical Vein Endothelial Cells; Kidney; Kidney Failure, Chronic; Male; Matrix Metalloproteinase 14; Mice; Mice, Mutant Strains; Mice, Transgenic; Neovascularization, Physiologic; Nephrosclerosis; Regeneration; Sirtuin 1; Vasodilation

Tumor necrosis factor alpha (TNF-α) plays an important role in the pathogensis of hepatitis C virus (HCV) infection induced liver injury. This study aimed to evaluate the effects of TNF-α inhibition with pentoxifylline (PTX) on concanavalin A (Con A)-induced hepatic injury in rats. The rats were distributed among 3 groups: (i) control group (1 mL saline·week(-1) by intravenous injection (i.v.)); (ii) Con A treatment group (20 mg Con A·(kg body mass)(-1)·week(-1), i.v.), and (iii) rats treated with Con A and with PTX (200 mg PTX·(kg body mass)(-1)·day(-1), per oral) group. Blood samples and livers were collected at the end of weeks 1, 2, 4, and 8 of Con A treatment. Portal pressure (PP) was measured at the end of week 8. The administration of PTX was found to confer significant protection against the injurious effects of Con A on the liver, by reducing serum levels of aspartate aminotransferase, alanine aminotransferase, hepatic TNF-α, and malondialdehyde. Histopathological examination revealed that treatment with PTX significantly suppressed early inflammation, reduced alpha smooth muscle actin, and the apoptosis of hepatocytes induced by Con A. Moreover, PTX significantly (P < 0.05) reduced PP, and quantitative analyses of the area of fibrosis induced by treatment with Con A showed a significant reduction at the end of week 8. We conclude that rats treated with PTX revealed a more or less normal hepatocyte architecture as well as marked improvement in fibrosis and PP.

Topics: Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Fibrosis; Hepatocytes; Image Processing, Computer-Assisted; Liver; Malondialdehyde; Pentoxifylline; Phosphodiesterase Inhibitors; Portal Pressure; Protective Agents; Rats; Tumor Necrosis Factor-alpha

Emerging evidence suggest that tumor necrosis factor (TNF)-α plays a major role in pathogenesis of auto-immune hepatitis (AIH) induced liver injury. Blockade of TNF-α synthesis or bio-activity protects against experimental AIH. TNF-α converting enzyme (TACE) is a member of the ADAM (a disintegrin and metalloproteinase) family which processes precursor TNF-α to release soluble TNF-α. We hypothesized that selective inhibition of TACE might protect AIH. To investigate this, we studied the effects of a selective TACE inhibitor DPC-333 on murine model of liver injury and fibrosis induced with concanavalin A (Con A). Pre-treatment with DPC-333 significantly suppressed plasma alanine transaminase, aspartate transaminase and cytokines such as TNF-α, interferon (IFN)-γ, interleukin (IL)-2 and IL-6 levels due to acute Con A challenge. Interestingly; DPC-333 inhibited liver poly (ADP-ribose) polymerase (PARP)-1 activity which was associated with reduced number of necrotic hepatocytes in histological examination and mortality associated with Con A. In fibrosis study, repeated Con A administration significantly up-regulated liver collagen deposition as assessed by measurement of hydroxyproline content which was further confirmed in liver histology with Masson's trichrome staining. Treatment with 30mg/kg of DPC-333 was able to suppress liver hydroxyproline and fibrous tissue proliferation which corroborated well with inhibition in expression of pro-fibrotic genes such as tissue inhibitor of metalloproteinase (TIMP)-1 and transforming growth factor (TGF)-β1. These observations suggest that selective TACE inhibition is an effective approach for the treatment of both immune mediated hepatic inflammation and fibrosis.

Topics: ADAM Proteins; ADAM17 Protein; Alanine Transaminase; Animals; Aspartate Aminotransferases; Cells, Cultured; Concanavalin A; Cytokines; Disease Models, Animal; Down-Regulation; Fibrosis; Hepatitis, Autoimmune; Hepatocytes; Inflammation Mediators; Liver; Mice; Mice, Inbred BALB C; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Quinolines; Tissue Inhibitor of Metalloproteinase-1; Transcriptional Activation

Young and middle-aged CBA mice were injected with "street" heroin in increasing doses for 14 days. Volume density of perisinusoid argirophilic fibers increased in both age groups (the increase being more pronounced in middle-aged mice), while the levels of spontaneous, LPS- and ConA-stimulated splenocyte proliferation decreased in young mice. Six months after heroin discontinuation further progress of liver fibrosis was observed in young mice.

Topics: Age Factors; Animals; Cells, Cultured; Concanavalin A; Fibrosis; Heroin; Lipopolysaccharides; Liver; Mice; Mice, Inbred CBA; Spleen; Substance Withdrawal Syndrome; Substance-Related Disorders; Time Factors

We previously reported on an altered immune-endocrine feedback loop via the hypothalamo-pituitary-adrenal (HPA) axis in Obese strain (OS) chickens afflicted with spontaneous autoimmune thyroiditis. These animals are deficient in plasma corticosterone increase after antigenic challenge or application of cytokine-containing conditioned medium of mitogen-stimulated spleen cells (CM). To investigate whether the impaired ability to respond to cytokines with glucocorticoid-increasing factor (GIF) activity, e.g. interleukin 1 (IL 1), is restricted to OS chickens as a model for an organ-specific autoimmune disease, we extended our experiments to another autoimmune-prone animal strain, the chickens of the University of California at Davis line 200 (UCD-200). These animals develop an inherited inflammatory fibrotic disease that closely resembles human progressive systemic sclerosis (scleroderma). Application of GIF-containing CM to UCD-200 chickens leads to a transient increase in glucocorticoid serum levels within 1-2 hours comparable to that of controls. But, while corticosterone levels in the latter returned to normal baseline levels after 4 hours, they were still elevated in autoimmune chickens. Although the peak of the glucocorticoid hormone serum concentrations was equal to that of controls, UCD-200 had to secrete twice as much adrenocorticotropic hormone to achieve this corticosterone serum level due to an apparent hyporesponsiveness of the adrenal gland to this secretagogue. The altered cytokine-induced glucocorticoid secretion is found in early as well as in chronic, sclerotic stages of the disease. Cellular alterations in the peripheral blood of UCD-200 chickens during the prolonged elevated corticosterone section, i.e. between 2-4 hours after CM application, are characterized by a significant decrease in the percentage of CD4+ and CD8+ cells. Furthermore, a significant increase in B cells up to 24 hours with a maximum after 1 hour was found. The proliferative response to the mitogen concanavalin A of peripheral mononuclear cells was inversely correlated to the serum corticosterone level, showing a permanent decrease of 80-90% after 1-4 hours in autoimmune animals. This functional alteration in UCD-200 was accompanied by an 80% decrease in serum interleukin 2 (sIL 2) activity 4 hours after CM application. Twenty-four hours later an eight-fold increase in sIL 2 rebound activity was found, indicating that the inhibitory effect of corticosterone in UCD-200 c

Topics: Adrenocorticotropic Hormone; Animals; Autoimmune Diseases; Biological Factors; Cells, Cultured; Chickens; Concanavalin A; Connective Tissue Diseases; Corticosterone; Culture Media, Conditioned; Disease Models, Animal; Feedback; Fibrosis; Immunologic Factors; Interleukin-2; Leukocyte Count; Lymphocyte Activation; Lymphocyte Subsets; Pituitary-Adrenal System; Scleroderma, Systemic; Spleen