The role of TGF-β1/Smad3 signaling pathway and oxidative stress in the inhibition of osteoblast mineralization by copper chloride

To explore the relationship of oxidative stress and TGF-β 1/Smad3 pathway in the inhibition of osteoblast mineralization by copper chloride (CuCl₂), the osteoblasts were treated with CuCl₂ (0, 50 μM, 100 μM, 150 μM CuCl₂ 5H₂O) for 24 h. We found that Cu impaired the osteoblast structure, inhibited the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, alkaline phosphatase (ALP) content, mRNA expression of collagen I (COL-I), osteocalcin (OCN), insulin-like growth factor I (IGF-I), bone morphogenetic protein-2 (BMP-2), transforming growth factor β1 (TGF-β1) and core-binding factor α1 (Cbfα1), promoted the reactive oxygen species (ROS) production, inactivated the TGF-β1/Smad3 pathway. It indicates that the inactivated TGF-β1/Smad3 pathway leads to osteoblast impairment by CuCl₂. It will contribute to clarify the influence of CuCl₂ on the osteoblast mineralization.     

Ganoderic acid hinders renal fibrosis via suppressing TGF-β/Smad and MAPK signaling pathways

OBJECTIVE To investigatethe anti-renal fibrotic effect of Ganoderic acid(GA) and the related mechanisms in vivo and in vitro. METHODS We investigated whether GA could hinder renal fibrosis and the related mechanisms in a unilateral ureteral obstruction(UUO) mouse model and TGF-β1-stimulated HK-2 cells model. The C57 mice were randomly devided into sham group, sham with GA administration group, UUO group and UUO with GA treatment group. After UUO surgery,the mice were treated with GA(3.125, 12.5 and 50 mg·kg~(-1) per day, ip) for 14 d. Then the mice were sacrificed for collecting blood and kidneys. The kidney functions were revealed by blood urea nitrogen and serum creatinine.The fibrosis and tubules injury levels were detected by Masson staining and HE staining. The epithelial-mesenchymal transition(EMT) level was detected by Western blotting and immunohistochemical staining. The changes of related signaling pathways and underlying mechanisms were demonstrated by Western blotting. The cell model was adopted to identify the potent inhibitor of renal fibrosis. RESULTS After 14 d treatment, GA dosedependently attenuated UUO-induced tubular injury and renal fibrosis; GA(50 mg·kg~(-1)) significantly ameliorated renal disfunction during fibrosis progression. We further revealed that GA treatment significantly decreased the expression of mesenchymal cell markers alpha-smooth muscle actin(α-SMA) and vimentin, and up-regulated E-cadherin expression in the kidney, suggesting the suppression of tubular EMT. Further study showed that GA downregulated both TGF-β/Smad and MAPK(ERK,JNK, P38) signaling pathways both in vivo and in vitro.GA-A, a GA monomer, was identified as a potent inhibitor on renal fibrosis in TGF-β1-stimulated HK-2 cell model.CONCLUSION GA inhibits renal interstitial fibrosis induced by UUO, mostly by suppressing EMT progression and inhibiting TGF-β/Smad and MAPK signaling pathways. In conclusion, our results suggest that GA and its purified monomer GA-A might be developed as a potential therapeutic agent in the treatment of renal fibrosis.     

Ubiquitination and regulation of Smad7 in the TGF-β1/Smad signaling of aristolochic acid nephropathy

Abstract

Aristolochic acid I (AAI) affects TGF-β1/Smad signaling, which causes AA nephropathy (AAN), but the mechanisms are not fully understood. We aimed to clarify whether Arkadia and UCH37 participate in TGF-β1/Smad signaling via Smad7, and the regulatory mechanisms of Smad7. One side, mice and cultured mouse renal tubular epithelial cells (RTECs) were treated with various AAI doses and concentrations, respectively; on the other side, RTECs were transfected with small interfering RNA (siRNA) expression vectors against Arkadia and UCH37 and then treated with 10?µg/ml AAI. And then detect the mRNA and protein levels of Smad7, UCH37, Arkadia and any other relative factors by RT-PCR and Western blotting. In kidney tissues and RTECs, the mRNA and protein levels of Smad7 decreased with increasing AAI doses concentrations by real-time PCR and Western blotting, whereas those of Arkadia, UCH37, Smad2, Smad3 and TβRI increased. Cells transfected with the Arkadia siRNA expression vector showed reduced mRNA and protein levels of vimentin, α-SMA, Smad2, Smad3 and TβRI after AAI treatment, while those of CK18 and Smad7 increased compared with those of untransfected RTECs. Conversely, cells transfected with the UCH37 siRNA expression vector showed the opposite effect on analyzed signaling molecules after AAI treatment. Arkadia and UCH37 participate in TGF-β1/Smad signaling-mediated renal fibrosis, and Smad7 blocks TGF-β1 signaling by inhibiting Smad2/Smad3 phosphorylation and enhancing the degradation of TβRI.     

Evodiamine ameliorates liver fibrosis in rats via TGF-β1/Smad signaling pathway

Liver fibrosis is considered to be a result of chronic liver pathological changes, and hepatic stellate cells (HSCs) play an important role during this process. Evodiamine, an indole alkaloid derived from Evodia rutaecarpa, exhibits pharmacological activities. This study focused on the effects of evodiamine on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats and HSCs in vitro via the TGF-β1/Smad signaling pathway. A liver fibrosis rat model was established by the intraperitoneal injection of CCl₄ (3 ml/kg, 30% in olive oil). Evodiamine (15 and 25 mg/kg) was administered orally for 8 weeks. HSCs were treated with different evodiamine concentrations. The results indicated that evodiamine could improve the histopathological abnormalities in liver tissues and decrease the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), hydroxyproline, and total bilirubin (TBIL). Concentrations of IL-6, tumor necrosis factor-α (TNF-α), collagen-I (COL-I), and collagen-III (COL-III) were reduced by evodiamine. Western blotting and real-time PCR showed that protein expression of transforming growth factor-β (TGF-β1), p-Smad 2/3 (phosphorylation of Smad 2/3), and smooth muscle alpha-actin (α-SMA) as well as mRNA expression of TGF-β1 and α-SMA in liver tissues were downregulated by evodiamine. The cell proliferation, production of hydroxyproline, and the protein expression of TGF-β1, p-Smad 2/3, and α-SMA in HSCs were dose-dependently reduced by evodiamine. Collectively, evodiamine had an antifibrosis effect in CCl₄-induced liver fibrosis, and reduced HSCs proliferation and collagen metabolism in vitro. The major mechanism was downregulation of relative expression of TGF-β1, p-Smad 2/3, and α-SMA.     

Parthenolide,an NF-κB inhibitor,alleviates peritoneal fibrosis by suppressing the TGF-β/Smad pathway

Transforming growth factor (TGF)-β/Smad signalling plays a central role in the pathogenesis of peritoneal fibrosis related to peritoneal dialysis (PD). Parthenolide (PTL), a naturally occurring phytochemical, is isolated from the shoots of feverfew (Tanacetum parthenium) and displays analgesia, anti-inflammation and anticancer activities. In this study, we examined the therapeutic potential of PTL on PD-related peritoneal fibrosis induced by daily intraperitoneal injection of 4.25% dextrose-containing PD fluid (PDF) in vivo and TGF-β1-induced epithelial-mesenchymal transition (EMT) in vitro. PTL was administered daily before PDF injection or after 14 days of PDF injection. Both PTL treatments showed a protective effect on peritoneal fibrosis and prevented peritoneal dysfunction. Similarly, PTL suppressed the expression of fibrotic markers (fibronectin and collagen I) and restored the expression of the epithelial marker (E-cadherin) in TGF-β1-treated HMrSV5 cells. Furthermore, PTL inhibited TGF-β1-induced Smad2 and Smad3 phosphorylation and nuclear translocation but did not influence Smad1/5/9 phosphorylation or activate other downstream signalling pathways of TGF-β1, including AKT, extracellular signal-regulated kinase (ERK) or p38. In conclusion, PTL treatment may represent an effective and novel therapy for PD-associated peritoneal fibrosis by suppressing the TGF-β/Smad pathway.     

Ursodeoxycholyl lysophosphatidylethanolamide attenuates hepatofibrogenesis by impairment of TGF-β1/Smad2/3 signalling

Background and Purpose

Chronic hepatic inflammation results in liver fibrosis. As effective anti-fibrogenic agents are lacking, we investigated ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE), a synthetic bile acid–phospholipid conjugate with anti-inflammatory and anti-apoptotic properties for tis effects on hepatic fibrogenesis.

Experimental Approach

To stimulate fibrogenesis, LX2 hepatic stellate cells were cultured with conditioned medium from CL48 liver cells after exposure to stress-inducing conditions – methionine–choline-deficient (MCD) medium or TNFα/cycloheximide (CHX) – with or without UDCA-LPE preincubation. Anti-fibrogenic effects of UDCA-LPE were further studied in CL48 and LX2 cells and in primary human hepatic stellate cells (HHStec) directly exposed to TGF-β1. To test UDCA-LPE in vivo, C57BL/6 mice were fed a MCD diet for 11 weeks followed by 30 mg·kg⁻¹ UDCA-LPE 3× per week for 2.5 weeks.

Key Results

Expression of α-smooth muscle actin (α-SMA), α1-collagen, vimentin and TGF-β1 was down-regulated by up to 93% by UDCA-LPE in LX-2 cells cultured with conditioned medium. Also, UDCA-LPE inhibited Smad3 phosphorylation in CL48 cells incubated with MCD medium or TNFα/CHX and in LX2 cells exposed to conditioned medium. UDCA-LPE also decreased phosphorylated Smad3 and Smad2 directly induced by TGF-β1. Inhibition of TGF-β1/Smad2/3 signalling with down-regulation of target genes was confirmed in HHStec. In vivo, UDCA-LPE decreased hepatic α-SMA, α1-collagen and TGF-β1 expression and markedly lowered α-SMA protein and collagen deposition in MCD mice.

Conclusions and Implications

By blocking TGF-β1/Smad2/3 signalling, UDCA-LPE suppressed key mediators of hepatic fibrogenesis. Thus, UDCA-LPE could be suitable for prevention of fibrotic progression of chronic liver disease.     

Schisandrin B suppresses TGFβ1 signaling by inhibiting Smad2/3 and MAPK pathways

TGFβ1 plays a crucial role in the pathogenesis of vascular fibrotic diseases. Schisandra chinensis (S. chinensis), which is used as an oriental herbal medicine, is effective in the treatment of vascular injuries that cause aberrant TGFβ1 signaling. In this study, we investigated whether S. chinensis extract and its active ingredients inhibit TGFβ1 signaling in A7r5 vascular smooth muscle cells. We found that S. chinensis extract suppressed TGFβ1 signaling via inhibition of Smad2/3 phosphorylation and nuclear translocation. Among the active ingredients of S. chinensis extract, schisandrin B (SchB) most potently inhibited TGFβ1 signaling. SchB inhibited sustained phosphorylation and nuclear translocation of Smad2/3. Moreover, SchB suppressed TGFβ1-induced phosphorylation of p38 and JNK, which contributed to Smad2/3 inactivation. The present study is the first to demonstrate that S. chinensis extract and SchB inhibit TGFβ1 signaling. Our results may help future investigations to understand vascular fibrosis pathogenesis and to develop novel therapeutic strategies for treatment of vascular fibrotic diseases.     

CCM111 prevents hepatic fibrosis via cooperative inhibition of TGF-β, Wnt and STAT3 signaling pathways

CCM111 is an aqueous extract of Antrodia cinnamomea (AC) that has exhibited anti-liver fibrosis functions. However, the detailed mechanisms of AC action against liver fibrosis have not been elucidated yet. The present research showed that CCM111 significantly lowered the levels of the hepatic enzyme markers glutamate oxaloacetate transaminase (GOT) and glutamic pyruvic transaminase (GPT), prevented liver damage and collagen deposition, and downregulated TGF-β/Smad signaling in a dose-dependent manner compared with CCl₄ treatment alone. CCM111 markedly inhibited TGF-β, Wnt and STAT3 signaling pathway-regulated downstream genes in the liver by next-generation sequencing. The antifibrotic mechanisms of CCM111 were further demonstrated in HSC-T6 cells. Our data demonstrated for the first time that CCM111 can protect against CCl₄-induced liver fibrosis by the cooperative inhibition of TGF-β-, Wnt- and STAT3-dependent proinflammatory and profibrotic mediators, suggesting that CCM111 might be a candidate for preventing and treating chronic fibrotic liver diseases.     

Effect of TGF-β/Smad signaling pathway on lung myofibroblast differentiation

AIM: Myofibroblasts play important roles in the pathogenesis of lung fibrosis. Transforming growth factor (TGF)-beta 1 has been widely recognized as a key fibrogenic cytokine. The major signaling pathway of (TGF)-beta(1) is through cytoplasmic Smad proteins. Our study investigated the role of individual (TGF)-beta(1)/Smad signal proteins in mediating alpha-smooth muscle actin (alpha-SMA) gene expression, which is a well-known key marker of myofibroblast differentiation. METHODS: We transiently cotransfected alpha-SMA promoter-luciferase fusion plasmid (p895-Luc) and Smad expression plasmids and measured Luc activity in (TGF)-beta(1)-treated human fetal lung fibroblasts. We induced Smad3 knockout mice lung fibrosis by bleomycin. alpha-SMA protein expression was assessed by Western blotting. Collagen protein was analyzed by measuring hydroxyprolin. Myofibroblast morphology was assessed by immunohistochemistry. RESULTS: We found that the overexpression of Smad3, not Smad2 markedly increased (TGF)-beta(1)-induced alpha-SMA promoter activity and alpha-SMA protein expression in vitro, whereas the overexpression of dominant negative mutant Smad3 and Smad7 repressed (TGF)-beta(1)-induced alpha-SMA gene expression. Compared to wild-type mice, Smad3 knockout mice showed attenuated lung fibrosis after bleomycin treatment, manifested by lower collagen production and myofibroblast differentiation. CONCLUSION: Our study suggested (TGF)-beta(1)/Smad3 is a major pathway which regulated the myofibroblast differentiation. This result indicates a potential significance for future attempts of attenuating the progression of human lung fibrosis by the inhibition of the Smad3 cascade.     

Houttuynia cordata inhibits lipopolysaccharide-induced rapid pulmonary fibrosis by up-regulating IFN-γ and inhibiting the TGF-β1/Smad pathway

This study aimed to explore the effect and mechanism of H. cordata vapor extract on acute lung injury (ALI) and rapid pulmonary fibrosis (RPF). We applied the volatile extract of HC to an RPF rat model and analyzed the effect on ALI and RPF using hematoxylin-eosin (H&E) staining, routine blood tests, a cell count of bronchoalveolar lavage fluid (BALF), lactate dehydrogenase (LDH) content, van Gieson (VG) staining, hydroxyproline (Hyp) content and the dry/wet weight ratio. The expression of IFN-γ/STAT(1), IL-4/STAT(6) and TGF-β(1)/Smads was analyzed using ELISA, immunohistochemistry and western blotting methods. The active ingredients of the HC vapor extract were analyzed using a gas chromatograph-mass spectrometer (GC-MS), and the effects of the active ingredients of HC on the viability of NIH/3T3 and RAW264.7 cells were detected using an MTT assay. The active ingredients of the HC vapor extract included 4-terpineol, α-terpineol, l-bornyl acetate and methyl-n-nonyl ketone. The results of the lung H&E staining, Hyp content, dry/wet weight ratio and VG staining suggested that the HC vapor extract repaired lung injury and reduced RPF in a dose-dependent manner and up-regulated IFN-γ and inhibited the TGF-β1/Smad pathway in vivo. In vitro, it could inhibit the viability of RAW264.7 and NIH/3T3 cells. It also dose-dependently inhibited the expression of TGF-β1 and enhanced the expression of IFN-γ in NIH/3T3. The HC vapor extract inhibited LPS-induced RPF by up-regulating IFN-γ and inhibiting the TGF-β1/Smad pathway.     

Salidroside protects against diabetes mellitus-induced kidney injury and renal fibrosis by attenuating TGF-β1 and Wnt1/3a/β-catenin signalling

This study evaluated if the nephroprotective effect of Salidroside in type 1 diabetes mellitus (T1DM) involves modulation of Wnt/β-catenin signalling pathways. Control or Streptozotocin (STZ, 50 mg/kg, iv)-induced T1DM adult male Wister rats were treated with the vehicle and Salidroside (100 mg/kg, orally) for 8 weeks daily. As compared to T1DM-induced rats, Salidroside improved kidney structure, reduced urinary protein and albumin level, increased creatinine clearance, and suppressed renal fibrosis. It also decreased mRNA and protein levels of Wnt1, Wnt3, and TGF-β1, phosphorylation of Smad-3, total and nuclear levels of β-catenin, and levels and activities of cleaved caspase-3. Concomitantly, Salidroside significantly increased the levels of p-β-catenin (Ser^33/37/Thr⁴¹) and suppressed protein levels of Axin-2, fibronectin, and, mRNA and protein levels of collagen IIIa, the main targets of β-catenin. In both control and T1DM rats, Salidroside significantly lowered fasting glucose levels and reduced renal levels of reactive oxygen species (ROS) p-and GS3Kβ (Ser9) but significantly increased levels of SOD and GSH. In conclusion, Salidroside protected the kidney of rats against T1DM-induced injury and fibrosis by activating GS3Kβ-induced inhibition of Wnt1/Wnt3a β-catenin. This was associated with hypoglycaemic and antioxidant effects.     

Role of TGF-β/Smad signaling pathway in pulmonary fibrosis after rheumatoid arthritis in mice北大核心CSCD

Aim To investigate the role of TGF-β/Smad signaling pathway in rheumatoid arthritis (RA) - associated postinterstitial pulmonary fibrosis in mice. Methods The mouse model of RA was constructed by subcutaneous administration of complete Freund's adjuvant (CFA) and chicken II collagen (Col-II) to the tail root of mice. The blank group was given the same amount of distilled water, and the control group was given the same amount of glacial acetic acid (solvent). The degree of toe swelling (joint swelling degree and arthritis index) was monitored to evaluate the mouse modeling. The pathological changes of mouse lung tissues were observed by HE and Masson staining. The expression of TGF-β in lung tissues were observed by immunohistochemical staining. The level of hydroxyproline in lung tissues was measured by chemiluminescence method. The expressions of Smad2, Smad3 and phosphorylated p-Smad2 and phosphorylated p-Smad3 in lung tissues were detected by Western blot. Results Compared with blank group and solvent group, the joint swelling and arthritis index of model group significantly increased. Twenty-one days after administration, HE staining showed inflammatory changes in lung interstitium of the model group, Masson staining showed collagen fiber deposition and obvious fibrosis in lung interstitium of the model group, and immunohistochemical staining showed that the expression of TGF-β in cytoplasm of lung interstitial cells of the model group increased, which was brown and yellow. Meanwhile, hydroxyproline was significantly raised in lung tissue homogenate of the model group. Further WB analysis showed that compared with blank group and solvent group, the expression of p-Smad2 and pSmad3 in lung tissues of the model group was significantly up-regulated (P < 0. 05, P < 0. 01). Conclusions RA can give rise to pulmonary fibrosis, and the expressions of p-Smad2 and p-Smad3 are up-regulated, which is be pivotal in pulmonary fibrosis and RA-related post-interstitial pulmonary fibrosis. © 2023 Publication Centre of Anhui Medical University. All rights reserved.     

Neferine attenuates development of testosterone-induced benign prostatic hyperplasia in mice by regulating androgen and TGF-β/Smad signaling pathways

Benign prostatic hyperplasia (BPH) is a common urinary disease among the elderly, characterized by abnormal prostatic cell proliferation. Neferine is a dibenzyl isoquinoline alkaloid extracted from Nelumbo nucifera and has antioxidant, anti-inflammatory and anti-prostate cancer effects. The beneficial therapeutic effects and mechanism of action of neferine in BPH remain unclear.A mouse model of BPH was generated by subcutaneous injection of 7.5 mg/kg testosterone propionate (TP) and 2 or 5 mg/kg neferine was given orally for 14 or 28 days. Pathological and morphological characteristics were evaluated. Prostate weight, prostate index (prostate/body weight ratio), expression of type Ⅱ 5α-reductase, androgen receptor (AR) and prostate specific antigen were all decreased in prostate tissue of BPH mice after administration of neferine. Neferine also downregulated the expression of pro-caspase-3, uncleaved PARP, TGF-β1, TGF-β receptor Ⅱ (TGFBR2), p-Smad2/3, N-cadherin and vimentin. Expression of E-cadherin, cleaved PARP and cleaved caspase-3 was increased by neferine treatment.1–100 μM neferine with 1 μM testosterone or 10 nM TGF-β1 were added to the culture medium of the normal human prostate stroma cell line, WPMY-1, for 24 h or 48 h. Neferine inhibited cell growth and production of reactive oxygen species (ROS) in testosterone-treated WPMY-1 cells and regulated the expression of androgen signaling pathway proteins and those related to epithelial-mesenchymal transition (EMT). Moreover, TGF-β1, TGFBR2 and p-Smad2/3, N-cadherin and vimentin expression were increased but E-cadherin was decreased after 24 h TGF-β1 treatment in WPMY-1 cells. Neferine reversed the effects of TGF-β1 treatment in WPMY-1 cells. Neferine appeared to suppress prostate growth by regulating the EMT, AR and TGF-β/Smad signaling pathways in the prostate and is suggested as a potential agent for BPH treatment.     

Ulinastatin inhibits unilateral ureteral obstruction-induced renal interstitial fibrosis in rats via transforming growth factor β (TGF-β)/Smad signalling pathways

This study aims to explore the protective effects and mechanisms of ulinastatin (UTI), which is a urinary trypsin inhibitor, of the renal interstitial fibrosis of rats subjected to unilateral ureteral obstruction (UUO). A total of 36 male Wistar rats were divided in random into three groups, namely, the sham operation (SOR) group (n = 12), the UUO group (n = 12), and the UTI treatment group (n = 12). Six rats from each group were euthanised after unilateral ureteral obstruction operation on the seventh and fourteenth days, respectively. Blood samples were harvested for blood urea nitrogen (BUN) and serum creatinine (Scr) measurement. The interstitial pathological changes of the tissue from the obstructed kidneys were observed using haematoxylin–eosin (H&E) and Masson staining. The expression of the transforming growth factor β type 1 (TGF-β1), α-smooth muscle actin (α-SMA), type I collagen (Col-I), and phosphorylated Smad2/3 (p-Smad2/3) was determined using immunohistochemistry. The protein expression levels of TGF-β1, α-SMA, and p-Smad2/3 were examined using Western blot analysis. The results show that ulinastatin has no statistically significant effect on the BUN and Scr levels (P > 0.05), but it can significantly reduce renal interstitial injury and suppress interstitial collagen deposits. The renoprotective effect of ulinastatin is likely realised through the TGF-β/Smad signalling pathways.     

Naringenin ameliorates streptozotocin-induced diabetic rat renal impairment by downregulation of TGF-β1 and IL-1 via modulation of oxidative stress correlates with decreased apoptotic events

Context: Naringenin, a flavonone and a nutritive antioxidant which is mostly obtained from grapefruit, orange or tomato skin, has been extensively studied due to its radical scavenging activity.

Objective: The present study investigates the protective effect of naringenin on rat kidney after streptozotocin-induced diabetes.

Materials and methods: Sixty male Wistar rats were divided into six groups. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50?mg/kg) in groups II, III and IV. Naringenin 5?mg/kg body weight was given to groups III and V, but 10?mg/kg was given to groups IV and VI, orally once a day for 10 weeks. After which all animals were sacrificed, and the biochemical, histopathological, immunohistochemical and apoptotic assays were conducted.

Results: Naringenin treatment with 5 and 10?mg/kg significantly decreased (p?<?0.05) the serum biochemical parameters, elevated tissue malondialdehyde levels and increased (p?<?0.01) the reduced superoxide dismutase, catalase and reduced glutathione enzyme activities in the diabetic kidney. Diabetes-induced naringenin-treated groups showed an improved histology and revealed a significant reduction in apoptosis activity (7.2?±?0.01 and 1.8?±?0.05) and in expression of TGF-β1 (18.9?±?3.4 and 10.2?±?2.1) at a dose of 5 and 10?mg/kg, respectively. Similarly, in contrast to the diabetic group, a significant difference was observed in the IL-1 expression (15.68?±?4.3) in 5?mg/kg and (9.85?±?2.1) in 10?mg/kg naringenin-treated groups.

Conclusion: Naringenin acts as a protective agent in diabetic renal impairment by altering oxidative stress, modulation of cytokines expression and apoptotic events.     

Modulation of bleomycin-induced oxidative stress and pulmonary fibrosis by N-acetylcysteine in rats via AMPK/SIRT1/NF-κβ

The efficacy of bleomycin (BLM) as an antineoplastic drug is limited to the development of dose and time-dependent pulmonary fibrosis. This study was intended to investigate the effect of N-acetylcysteine (NAC) on BLM-induced pulmonary fibrosis in rats. Twenty rats were randomly divided to the following four groups: Group one served as control; group two received BLM (15 mg/kg, intraperitoneal (ip)) for five consecutive days; group three received NAC (200 mg/kg, ip) for five consecutive days; and group four received NAC 1 hour before BLM for 5 days. The expression of connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), silent information regulator l (SIRT1), AMP-activated protein kinase (AMPK) were determined by qRT-PCR in lung tissues. The changes in transforming growth factor-beta1 (TGF-β1), tumour necrosis factor-α (TNF-α), interleukin-β1 (IL-β1) and nuclear factor kappa-β (NF-κβ) in serum were measured by ELISA. The tissue antioxidant status was determined biochemically. BLM administration caused pulmonary fibrosis as evidenced by increased levels of inflammatory mediators (TGF-β1, TNF-α, IL-β1 and NF-κβ) in serum (P < .05), elevated lipid peroxidation and nitric oxide and depleted endogenous antioxidants in lung tissue (P < .05). The expression levels of SIRT1 and AMPK were significantly decreased (P < .05), while the expression levels of CTGF and PDGF were increased significantly in the BLM group as compared to the control group (P < .05). These alterations were normalized by NAC intervention. NAC markedly attenuated the lung histopathological changes and reduced collagen deposition. These results suggest that NAC exerted an ameliorative effect against BLM-induced oxidative damage and pulmonary fibrosis via SIRT1/ AMPK/ NF-κβ pathways.     

α-Lipoic acid inhibits liver fibrosis through the attenuation of ROS-triggered signaling in hepatic stellate cells activated by PDGF and TGF-β

Reactive oxygen species (ROS) have been implicated in hepatic stellate cell activation and liver fibrosis. We previously reported that α-lipoic acid (LA) and its reduced form dihydrolipoic acid (DHLA) inhibited toxicant-induced inflammation and ROS generation. In the present study, we further examined the effects of LA/DHLA on thioacetamide (TAA)-induced liver fibrosis in rats and the possible underlying mechanisms in hepatic stellate cells in vitro. We found that co-administration of LA to rats chronically treated with TAA inhibited the development of liver cirrhosis, as indicated by reductions in cirrhosis incidence, hepatic fibrosis, and AST/ALT activities. We also found that DHLA inhibited TGF-β/PDGF-stimulated HSC-T6 activation and ROS generation. These effects could be mediated by the MAPK and PI3K/Akt pathways. According to our current results, LA may have a beneficial role in the treatment of chronic liver diseases caused by ongoing hepatic damage.     

β-Arrestin2 deficiency attenuates oxidative stress in mouse hepatic fibrosis through modulation of NOX4

Hepatic fibrosis is a disease characterized by excessive deposition of extracellular matrix(ECM)in the liver.Activation of hepatic stellate cells(HSCs)is respon...     

Astragaloside IV attenuates myocardial fibrosis by inhibiting TGF-β1 signaling in coxsackievirus B3-induced cardiomyopathy

Myocardial fibrosis plays an important role in coxsackievirus B3 (CVB3) induced dilated cardiomyopathy. Excessive transforming growth factor (TGF)-β1 contributes to a pathologic excess of tissue fibrosis. We investigated the effect of astragaloside IV on myocardial fibrosis in CVB3-induced dilated cardiomyopathy. BALB/c mice were inoculated with CVB3 to induce acute viral myocarditis on day 7 (acute VMC group), monthly for 3 months to induce chronic myocarditis (chronic VMC group), and monthly for 9 months to induce dilated cardiomyopathy (DCM group). The same method was used for the DCM+Astra group as that of the DCM group, but former group was given with astragaloside IV-containing drinking water. Compared to DCM group, astragaloside IV treatment significantly increased the survival rate. Histological findings and the collagen volume fraction showed that astragaloside IV decreased fibrosis in heart tissues. Astragaloside IV decreased the level of the serum carboxy-terminal propeptide of procollagen type I (PICP) and the ratio of PICP/ N-terminal type I procollagen propeptide (PINP). Ameliorated myocardial fibrosis was consistent with the downregulated expression of TGF-β1 and its downstream pSmad2/3 and Smad4 in the myocardium of the DCM+Astra group compared to the DCM group. The level of type I collagen was lower in the DCM+Astra group than the DCM group. The same effect was found in the in vitro study. These findings showed that astragaloside IV had a potent preventive effect on myocardial fibrosis in CVB3-induced dilated cardiomyopathy that might be due to downregulation of TGF-β1-Smad signaling.