Hydrogen sulfide protects against toxicant acrolein-induced ferroptotic cell death in Sertoli cells.

Acrolein (ACR) is a ubiquitous environmental pollutant and byproduct of lipid peroxidation that has been implicated in male infertility. However, the molecular mechanisms underlying ACR-induced toxicity in Sertoli cells remain unclear. Given its role in inducing oxidative stress, we examined whether ferroptosis, an iron-dependent form of regulated cell death, could mediate ACR toxicity in Sertoli cells. We also tested if hydrogen sulfide (H2S), which has antioxidant and ACR detoxifying properties, could protect Sertoli cells from ACR-induced ferroptosis. ACR exposure decreased Sertoli cell viability, increased protein carbonylation and p38 MAPK phosphorylation, indicating oxidative injury. ACR also depleted glutathione (GSH), downregulated the cystine importer SLC7A11, increased intracellular ferrous iron (Fe2+) and lipid peroxidation, suggesting activation of ferroptosis. Consistently, the ferroptosis inhibitor deferoxamine (DFO) markedly attenuates ACR-induced cell death. Further studies revealed that ACR-induced ferroptotic changes were prevented by exogenous H2S and exaggerated by inhibition of endogenous H2S production. Furthermore, H2S also suppressed GPX4 inhibitor RSL3-induced intracellular ACR accumulation and ferroptosis. In summary, our study demonstrates that ACR induces ferroptotic cell death in Sertoli cells, which can be prevented by H2S through multiple mechanisms. Targeting the H2S pathway may represent a therapeutic strategy to mitigate ACR-induced Sertoli cell injury and preserve male fertility.

Gut bacteria exacerbates TNBS-induced colitis and kidney injury through oxidative stress.

Gut microbiota has been implicated in the initiation and progression of various diseases; however, the underlying mechanisms remain elusive and effective therapeutic strategies are scarce. In this study, we investigated the role and mechanisms of gut microbiota in TNBS-induced colitis and its associated kidney injury while evaluating the potential of dietary protein as a therapeutic intervention. The intrarectal administration of TNBS induced colitis in mice, concurrently with kidney damage. Interestingly, this effect was absent when TNBS was administered intraperitoneally, indicating a potential role of gut microbiota. Depletion of gut bacteria with antibiotics significantly attenuated the severity of TNBS-induced inflammation, oxidative damage, and tissue injury in the colon and kidneys. Mechanistic investigations using cultured colon epithelial cells and bone-marrow macrophages unveiled that TNBS induced cell oxidation, inflammation and injury, which was amplified by the bacterial component LPS and mitigated by thiol antioxidants. Importantly, in vivo administration of thiol-rich whey protein entirely prevented TNBS-induced colonic and kidney injury. Our findings suggest that gut bacteria significantly contribute to the initiation and progression of colitis and associated kidney injury, potentially through mechanisms involving LPS-induced exaggeration of oxidative cellular damage. Furthermore, our research highlights the potential of dietary thiol antioxidants as preventive and therapeutic interventions.

Rapamycin protects Sertoli cells against BPA-induced autophagy disorders.

Bisphenol A (BPA) is a well-known environmental contaminant that can negatively impact reproductive function. Disruption of autophagy is implicated in BPA-induced cell injury, the specific molecular mechanisms through which BPA affects autophagy in Sertoli cells are still unknown. In the present study, TM4 cells were exposed to various doses of BPA (10, 100, and 200 µM), and the results indicated that BPA exposure led to the accumulation of autophagosomes, this change was accompanied by increased expression of p-mTOR and decreased expression of Atg12, a protein involved in regulating autophagy initiation. Additionally, BPA exposure upregulated the expression levels of p62, a protein involved in autophagic degradation. The inhibition of autophagy initiation and autophagic degradation contributes to the accumulation of autophagosomes. Further studies showed that BPA exposure didn't affect the expression of the lysosome protein LAMP1; however, decreased cytoplasmic retention of acridine orange in TM4 cells may explain the disruption of autophagy. The role of rapamycin and chloroquine (CQ), an autophagy inhibitor that impairs lysosomal degradation also confirmed the effect of BPA on autophagy regulation. Specifically, rapamycin can protect Sertoli cells against BPA-induced cell injury by promoting autophagy. These findings contribute to our understanding of the mechanisms underlying reproductive toxicity caused by BPA.

Ferroptosis contributes to cyclophosphamide-induced hemorrhagic cystitis.

Cyclophosphamide (CYP) is extensively used in tumor therapy, but its clinical application is limited by its toxic effects on the bladder. Since CYP-induced cystitis is believed to be mediated by acrolein (ACR), a product of lipid peroxidation that triggers ferroptosis, we hypothesized that ferroptosis might be an essential molecular mechanism underlying CYP-induced cystitis. The purpose of this study was to test this hypothesis. Intraperitoneal injection of CYP led to bladder hemorrhage and edema, along with increased oxidation, inflammation, and cell injury. Further analysis revealed these changes were associated with altered ferroptosis markers in the bladder, such as FPN1, ACSL4, SLC7A11, and GPX4, indicating the existence of ferroptosis. Administration of ferroptosis inhibitor dexrazoxane (DXZ) improved ferroptosis and prevented CYP-induced pathological changes in the bladder. Collectively, our study revealed that ferroptosis is an important mechanism underlying CYP-induced cystitis, and therapeutic approaches targeting ferroptosis could be developed to treat CYP-induced cystitis.

Hydrogen sulfide protects Sertoli cells against toxicant Acrolein-induced cell injury.

Acrolein (ACR), a highly toxic α,ß-unsaturated aldehyde, is considered to be a common mediator behind the reproductive injury induced by various factors. However, the understanding of its reproductive toxicity and prevention in reproductive system is limited. Given that Sertoli cells provide the first-line defense against various toxicants and that dysfunction of Sertoli cell causes impaired spermatogenesis, we, therefore, examined ACR cytotoxicity in Sertoli cells and tested whether hydrogen sulfide (H2S), a gaseous mediator with potent antioxidative actions, could have a protective effect. Exposure of Sertoli cells to ACR led to cell injury, as indicated by reactive oxygen species (ROS) generation, protein oxidation, P38 activation and ultimately cell death that was prevented by antioxidant N-acetylcysteine (NAC). Further studies revealed that ACR cytotoxicity on Sertoli cells was significantly exacerbated by the inhibition of H2S-synthesizing enzyme cystathionine γ-lyase (CSE), while significantly suppressed by H2S donor Sodium hydrosulfide (NaHS). It was also attenuated by Tanshinone IIA (Tan IIA), an active ingredient of Danshen that stimulated H2S production in Sertoli cells. Apart from Sertoli cells, H2S also protected the cultured germ cells from ACR-initiated cell death. Collectively, our study characterized H2S as endogenous defensive mechanism against ACR in Sertoli cells and germ cells. This property of H2S could be used to prevent and treat ACR-related reproductive injury.

Microsurgical interfascicular dissection operation is a viable treatment of carpal tunnel syndrome caused by Lipofibromatous hamartoma: A case report.

Lipofibromatous Hamartoma (LFH) is a rare and slow growing benign tumor affecting the peripheral nerves, which usually involves the median nerve. Median nerve involvement commonly causes pain, numbness, paresthesia and carpal tunnel syndrome (CTS). This article describes a case of lipofibromatous hamartoma in a 6-years-old girl, complained of the mass and numbness in her left distal forearm. Microsurgical interfascicular dissection operation was performed to remove the epineural proliferation tissue, numbness disappeared after the operation. At the 12-months follow-up appointment she remained asymptomatic and there was no change in mass size.

Hydrogen sulfide as a potent scavenger of toxicant acrolein.

Acrolein (ACR) is a metabolic byproduct in vivo and a ubiquitous environmental toxicant. It is implicated in the initiation and development of many diseases through multiple mechanisms, including the induction of oxidative stress. Currently, our understanding of the body defense mechanism against ACR toxicity is still limited. Given that hydrogen sulfide (H2S) has strong antioxidative actions and it shares several properties of ACR scavenger glutathione (GSH), we, therefore, tested whether H2S could be involved in ACR detoxification. Taking advantage of two cell lines that produced different levels of endogenous H2S, we found that the severity of ACR toxicity was reversely correlated with H2S-producing ability. In further support of the role of H2S, supplementing cells with exogenous H2S increased cell resistance to ACR, whereas inhibition of endogenous H2S sensitized cells to ACR. In vivo experiments showed that inhibition of endogenous H2S with CSE inhibitor markedly increased mouse susceptibility to the toxicity of cyclophosphamide and ACR, as evidenced by the increased mortality and worsened organ injury. Further analysis revealed that H2S directly reacted with ACR. It promoted ACR clearance and prevented ACR-initiated protein carbonylation. Collectively, this study characterized H2S as a presently unrecognized endogenous scavenger of ACR and suggested that H2S can be exploited to prevent and treat ACR-associated diseases.

Tanshinone IIA Stimulates Cystathionine γ-Lyase Expression and Protects Endothelial Cells from Oxidative Injury.

Tanshinone IIA (Tan IIA), an active ingredient of Danshen, is a well-used drug to treat cardiovascular diseases. Currently, the mechanisms involved remain poorly understood. Given that many actions of Tan IIA could be similarly achieved by hydrogen sulfide (H2S), we speculated that Tan IIA might work through the induction of endogenous H2S. This study was to test this hypothesis. Exposure to endothelial cells to Tan IIA elevated H2S-synthesizing enzyme cystathionine γ-Lyase (CSE), associated with an increased level of endogenous H2S and free thiol activity. Further analysis revealed that this effect of Tan IIA was mediated by an estrogen receptor (ER) and cAMP signaling pathway. It stimulated VASP and CREB phosphorylation. Inhibition of ER or PKA abolished the CSE-elevating effect, whereas activation of ER or PKA mimicked the effect of Tan IIA. In an oxidative endothelial cell injury model, Tan IIA potently attenuated oxidative stress and inhibited cell death. In support of a role of endogenous H2S, inhibition of CSE aggerated oxidative cell injury. On the contrary, supplement of H2S attenuated cell injury. Collectively, our study characterized endogenous H2S as a novel mediator underlying the pharmacological actions of Tan IIA. Given the multifaceted functions of H2S, the H2S-stimulating property of Tan IIA could be exploited for treating many diseases.

Reductively modified albumin attenuates DSS-Induced mouse colitis through rebalancing systemic redox state.

Albumin (Alb) is the most abundant plasma protein with multiple biological functions, including antioxidative property through its thiol activity. Given that inflammatory bowel disease is associated with a decreased level of Alb and an increased level of Alb oxidation, we asked whether Alb could have a therapeutic effect on colitis. Here we tested this possibility. Bovine serum albumin (BSA) was reductively modified with dithiothreitol (DTT) and administrated via gavage or intraperitoneal injection. Dextran sulfate sodium (DSS)-induced mice colitis was associated with massive oxidative stress, as indicated by the elevated sulfenic acid formation in blood, colon tissues, and feces. Treatment of mice with the reductively modified albumin (r-Alb) attenuated the oxidative stress and reduced local inflammation and tissue injury. These effects of r-Alb were only partially achieved by unmodified Alb and wholly lost after blocking the -SH groups with maleimide. In cultured colon epithelial cells, r-Alb prevented DSS- and H2O2-induced ROS elevation and barrier dysfunction, preceded by inhibition of sulfenic acid formation and P38 activation. Further analysis revealed that Alb was susceptible to H2O2-induced oxidation, and it detoxified H2O2 in a -SH group-dependent way. Moreover, Alb reacted with GSH/GSSG via thiol-disulfide exchange and reciprocally regulated the availability of -SH groups. Collectively, our study shows that r-Alb effectively attenuates DSS colitis via -SH group-mediated antioxidative action. Given that the oxidative stress underlies many life-threatening diseases, r-Alb, functioning as a potent antioxidant, could have a wide range of applications.

A kinetic/thermodynamic study of transparent co-adsorbents and colored dye molecules in visible light based on microgravimetric quartz-crystal microbalance on porous TiO2 films for dye-sensitized solar cells.

In this study, a quartz crystal microbalance (QCM) in situ method is used to study the kinetic and thermodynamic processes of the adsorption of ruthenium-based dyes (N719, N3, N749), and the co-adsorbent chenodeoxycholic acid (CDCA) on the TiO2 film surface. The results of the kinetic studies show that the adsorption rate of N749 is slightly higher than the other two dyes, and the adsorption rate of CDCA is more sensitive to temperature change. The adsorption mechanism of the dye and CDCA on the surface of TiO2 can be reasonably inferred based on the result of the activation energy. The isotherm adsorption model studies show that the ratio of the number of surface molecules (296 K) is n(N719) : n(N3) : n(N749) : n(CDCA) = 0.69 : 1.48 : 0.50 : 1. The Keq value of CDCA is about two orders of magnitude smaller than that of all the dye molecules, which indicates that the adsorption strength of CDCA is much weaker than that of the dye molecules. Thermodynamic studies show that the adsorption reaction is an endothermic reaction. The ΔS is ΔS(N3 = 143.11 J mol-1) > ΔS(N719 = 112.72 J mol-1) > ΔS(N749 = 109.43 J mol-1) > ΔS(CDCA = 96.14 J mol-1). The Gibbs free energy ΔG is negative, and indicates that the adsorption reaction of the four molecules on the surface of the TiO2 film is spontaneous. The results of this paper show that the tedious and lengthy experimental process of the traditional method can be simplified by QCM. In addition, the development of this study provides a certain theoretical and experimental basis for future studies on the interaction mechanism between dyes and co-adsorbents.

Gap junctions amplify TRPV4 activation-initiated cell injury via modification of intracellular Ca2+ and Ca2+-dependent regulation of TXNIP.

The elevated intracellular Ca2+ and oxidative stress are well-reported mechanisms behind renal tubular epithelial injury initiated by various insults. Given that TRPV4 and connexin43 (Cx43) channels are activated by a wide range of stimuli and regulate both intracellular Ca2+ and redox status, we speculated an involvement of these channels in renal tubular cell injury. Here, we tested this possibility and explored the potential underlying mechanisms. Our results demonstrated that exposure of renal tubular epithelial cells to aminoglycoside G418 led to cell death, which was attenuated by both TRPV4 and gap junction (Gj) inhibitor. Activation of TRPV4 caused cell damage, which was associated with an early increase in Cx43 expression and function. Inhibition of Cx43 with chemical inhibitor or siRNA largely prevented TRPV4 activation-induced cell damage. Further analysis revealed that TRPV4 agonists elicited a rise in intracellular Ca2+ and caused a Ca2+-dependent elevation in TXNIP (a negative regulator of the antioxidant thioredoxin). In the presence of Gj inhibitor, however, these effects of TRPV4 were largely prevented. The depletion of intracellular Ca2+ with Ca2+ chelator BAPTA-AM or downregulation of TXNIP with siRNA significantly alleviated TRPV4 activation-initiated cell injury. Collectively, our results point to a critical involvement of TRPV4/Cx43 channel interaction in renal tubular cell injury through mechanisms involving a synergetic induction of intracellular Ca2+ and oxidative stress. Channel interactions could be an important mechanism underlying cell injury. Targeting channels could have therapeutic potential for the treatment of acute tubular cell injury.

Hydrogen Sulfide Mediates Tumor Cell Resistance to Thioredoxin Inhibitor.

Thioredoxin (Trx) is a pro-oncogenic molecule that underlies tumor initiation, progression and chemo-resistance. PX-12, a Trx inhibitor, has been used to treat certain tumors. Currently, factors predicting tumor sensitivity to PX-12 are unclear. Given that hydrogen sulfide (H2S), a gaseous bio-mediator, promotes Trx activity, we speculated that it might affect tumor response to PX-12. Here, we tested this possibility. Exposure of several different types of tumor cells to PX-12 caused cell death, which was reversely correlated with the levels of H2S-synthesizing enzyme CSE and endogenous H2S. Inhibition of CSE sensitized tumor cells to PX-12, whereas addition of exogenous H2S elevated PX-12 resistance. Further experiments showed that H2S abolished PX-12-mediated inhibition on Trx. Mechanistic analyses revealed that H2S stimulated Trx activity. It promoted Trx from the oxidized to the reduced state. In addition, H2S directly cleaved the disulfide bond in PX-12, causing PX-12 deactivation. Additional studies found that, besides Trx, PX-12 also interacted with the thiol residues of other proteins. Intriguingly, H2S-mediated cell resistance to PX-12 could also be achieved through promotion of the thiol activity of these proteins. Addition of H2S-modified protein into culture significantly enhanced cell resistance to PX-12, whereas blockade of extracellular sulfhydryl residues sensitized cells to PX-12. Collectively, our study revealed that H2S mediated tumor cell resistance to PX-12 through multiple mechanisms involving induction of thiol activity in multiple proteins and direct inactivation of PX-12. H2S could be used to predict tumor response to PX-12 and could be targeted to enhance the therapeutic efficacy of PX-12.

An in situ exchange mechanism for dye molecules and cations at the nano-semiconductor film/electrolyte interface.

This communication uses electrochemical quartz crystal microbalance (EQCM) in combination with the potentiostatic method to study the in situ exchange mechanism for dye molecules and cations on the nano-film surface under a constant potential. The relationship between dye molecule desorption mass and charge was analyzed. A theoretical model was established to obtain the important parameters of cation exchange number and apparent valence electron number during dye desorption, and the microscopic desorption mechanism of the dye is further revealed.

Connexin43 Is Required for the Effective Activation of Spleen Cells and Immunoglobulin Production.

Gap junctions (Gjs), formed by specific protein termed connexins (Cxs), regulate many important cellular processes in cellular immunity. However, little is known about their effects on humoral immunity. Here we tested whether and how Gj protein connexin43 (Cx43) affected antibody production in spleen cells. Detection of IgG in mouse tissues and serum revealed that wild-type (Cx43+/+) mouse had a significantly higher level of IgG than Cx43 heterozygous (Cx43+/-) mouse. Consistently, spleen cells from Cx43+/+ mouse produced more IgG under both basal and lipopolysaccharide (LPS)-stimulated conditions. Further analysis showed that LPS induced a more dramatic activation of ERK and cell proliferation in Cx43+/+ spleen cells, which was associated with a higher pro-oxidative state, as indicated by the increased NADPH oxidase 2 (NOX2), TXNIP, p38 activation and protein carbonylation. In support of a role of the oxidative state in the control of lymphocyte activation, exposure of spleen cells to exogenous superoxide induced Cx43 expression, p38 activation and IgG production. On the contrary, inhibition of NOX attenuated the effects of LPS. Collectively, our study characterized Cx43 as a novel molecule involved in the control of spleen cell activation and IgG production. Targeting Cx43 could be developed to treat certain antibody-related immune diseases.

Connexin43 Contributes to Inflammasome Activation and Lipopolysaccharide-Initiated Acute Renal Injury via Modulation of Intracellular Oxidative Status.

Aims: Inflammasome activation plays a pivotal role in many inflammatory diseases. Given that connexin (Cx) channels regulate numerous cellular events leading to inflammasome activation, we determined whether and how connexin affected inflammasome activation and inflammatory cell injury. Results: Exposure of mouse peritoneal macrophages (PMs) to lipopolysaccharide (LPS) plus ATP caused NLRP3 inflammasome activation, together with an increased connexin43 (Cx43). Inhibition of Cx43 blunted inflammasome activation. Consistently, PMs from the Cx43 heterozygous mouse (Cx43+/-) exhibited weak inflammasome activation, in comparison with those from the Cx43+/+ mouse. Further analysis revealed that inflammasome activation was preceded by an increased reactive oxygen species (ROS) production, nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase 2 (NOX2), protein carbonylation, and mitogen-activated protein kinase (MAPK) activation. Suppression of ROS with antioxidant, downregulation of NOX2 with small interfering RNA (siRNA), or inhibition of NADPH oxidase or MAPKs with inhibitors blocked Cx43 elevation and inflammasome activation. Intriguingly, suppression of Cx43 also blunted NOX2 expression, protein carbonylation, p38 phosphorylation, and inflammasome activation. In a model of acute renal injury induced by LPS, the Cx43+/- mouse exhibited a significantly lower level of blood interleukin-1ß (IL-1ß), blood urea nitrogen, and urinary protein, together with milder renal pathological changes and renal expression of NLRP3 and NOX4, as compared with the Cx43+/+ mouse. Moreover, inhibition of gap junctions suppressed IL-1ß- and tumor necrosis factor-α-induced expression of NOX4 in glomerular podocytes and tubular epithelial cells. Innovation and Conclusion: Our study indicates that Cx43 contributes to inflammasome activation and the progression of renal inflammatory cell injury through modulation of intracellular redox status. Cx43 could be a novel target for the treatment of certain inflammatory diseases.

Hydrogen sulfide donor NaHS alters antibody structure and function via sulfhydration.

Hydrogen sulfide (H2S) has emerged as an important biological mediator with numerous pathophysiological roles. One of the well-documented actions of H2S is to inhibit immunity, especially cellular immunity. Currently, limited information is available regarding its effects on humoral immunity. Given that H2S has reducing activity and that the effector molecules in humoral immunity, such as antibody and complement, contain abundant disulfide bonds that are indispensable for their functions, we speculated that H2S might regulate antibody activity via modification of disulfide bonds. Here we addressed this possibility. Exposure of antibodies to H2S donors resulted in cleavage of the disulfide bonds between the heavy and light chains of antibodies, which was associated with antibody sulfhydration. Further analysis revealed that H2S-treated antibodies exhibited a marked reduction in antigen binding ability. It potently prevented the antibody-mediated agglutination of red blood cells and interrupted aggregation of antibody-coated microspheres. H2S also greatly inhibited antibody-induced and complement-mediated cell lysis in glomerular mesangial cells, as well as anti-CD95 IgM antibody-initiated cell apoptosis in Jurkat cells. Moreover, it significantly suppressed the alternative complement activation pathway. Collectively, our results revealed, for the first time, that pharmacologic levels of H2S inhibit humoral immune responses via direct sulfhydration of the effector molecules. Our study thus provides novel mechanistic insights into the immunoregulatory actions of H2S and suggests that H2S may have potential to treat certain humoral immune diseases.

Pharmacological levels of hydrogen sulfide inhibit oxidative cell injury through regulating the redox state of thioredoxin.

Hydrogen sulfide (H2S) is a gaseous mediator with multifaceted biological activities. It has anti-inflammatory and anti-oxidative effects. Currently, the mechanisms are not fully understood. Given that Trx/ASK1/P38 signaling pathway mediates many oxidative cell responses, we tested whether and how H2S affected this pathway. Exposure of podocytes to Adriamycin (ADR), an antitumor drug, led to a P38-mediated oxidative cell injury, as evidenced by the increased protein carbonylation, oxidative activation of P38, and prevention of the cell death by antioxidants, NADPH oxidase inhibitor and P38 inhibitor. In the presence of H2S donor NaHS, however, the podocyte injury was largely prevented. NaHS also significantly prevented cell death elicited by H2O2, menadione, and thioredoxin (Trx) inhibitors. These effects of H2S were also associated with a potent inhibition of P38. Further analysis revealed that H2S did not affect the protein level of TXNIP and Trx, two pivotal regulators of ASK1/P38 activation, but it promoted the dissociation of Trx from TXNIP. Moreover, it disrupted the H2O2-initiated polymerization of Trx and converted Trx from the oxidized to the reduced form. In HepG2 cells, inhibition of H2S-producing enzyme cystathionine γ-lyase (CSE) increased Trx oxidation, promoted Trx binding to TXNIP and exaggerated cell injury caused by Trx inhibition. Collectively, our results indicate that H2S exerted its antioxidative effects through the regulation of the redox state of Trx and interference with Trx/ASK1/P38 signaling pathway. Given the importance of the pathway in the mediation of multiple oxidative cell responses, our study thus provides novel mechanistic insight into the action of H2S.

Induction of inactive TGF-ß1 monomer formation by hydrogen sulfide contributes to its suppressive effects on Ang II- and TGF-ß1-induced EMT in renal tubular epithelial cells.

Hydrogen sulfide (H2S), an endogenous gas mediator with multifaced biological functions, has been shown to be effective in the prevention and treatment of renal sclerosis in several models of chronic renal diseases. The mechanisms involved are still unclear. Given that Ang II- and TGF-ß-induced renal tubular epithelial-mesenchymal transition (EMT) is a pivotal cellular event leading to renal sclerosis, we examined whether and how H2S intervened the processes of EMT. Ang II stimulated EMT in renal tubular epithelial cells, as indicated by the increased level of α-smooth muscle actin and a decreased level of E-cadherin. This effect of Ang II was blocked by a TGF-ß receptor kinase inhibitor, indicative of a mediating role of TGF-ß. Consistently, Ang II stimulated TGF-ß activation and addition of the exogenous TGF-ß1 also induced EMT. In the presence of H2S donor NaHS, the EMT-promoting actions of Ang II and TGF-ß1 were abolished, which was associated with a reduced TGF-ß activity. Further analysis using a human recombinant active TGF-ß1 revealed that H2S cleaved the disulfide bond in the dimeric active TGF-ß1 and promoted the formation of inactive TGF-ß1 monomer. Collectively, these results indicate that H2S counteracted Ang II- and TGF-ß1-induced EMT through mechanisms involving direct inactivation of TGF-ß1. Our study thus provides novel mechanistic insight into the anti-fibrotic actions of H2S and suggest that H2S could be used to treat renal sclerotic diseases.

Multi-glycoside of Tripterygium wilfordii Hook. f. attenuates glomerulosclerosis in a rat model of diabetic nephropathy by exerting anti-microinflammatory effects without affecting hyperglycemia.

Multi-glycoside of Tripterygium wilfordii Hook. f. (GTW) has been proven to be clinically effective in relieving microinflammation in patients with early diabetic nephropathy (DN). However, the therapeutic mechanisms involved in vivo remain unclear. In the process of early DN, microinflammation and activation of p38 mitogen­activated protein kinase (MAPK) and canonical nuclear factor (NF)-κB signaling pathways are the important mechanisms by which hyperglycemia contributes to glomerulosclerosis (GS). Therefore, this study aimed to examine the ameliorative effects of GTW on GS, and then to clarify its anti­microinflammatory mechanisms by inhibiting p38 MAPK and NF-κB signaling activities in the kidney. All rats were divided into 4 groups: the sham group, the sham + GTW group, the vehicle group and the GTW group. The suitable dose of GTW and vehicle were daily administered for 8 weeks after the induction of DN by unilateral nephrectomy combined with intraperitoneal injections of streptozotocin (STZ). The general status of the rats, biochemical parameters, renal histological changes and macrophages in glomeruli, as well as expression of the key proteins in the p38 MAPK and canonical NF-κB signaling pathways and inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and transforming growth factor (TGF)-ß1 in the kidney were examined, respectively. The results revealed that, GTW improved the general cond-ition and biochemical parameters of the rats, but did not lower blood glucose; GTW attenuated GS and suppressed glomerular microinflammation including the infiltration of ED1+ cells in glomeruli and the protein overexpression of TNF-α, IL-1ß and TGF-ß1 in the kidney; GTW inhibited the protein overexpression of key signaling molecules of p38 MAPK and canonical NF-κB pathways in the kidney including phosphorylated p38 MAPK, phosphorylated inhibitor protein IκB and NF-κB (p65). On the whole, we expounded that GTW, as a natural regulator in vivo, alleviates GS without affecting hyperglycemia, by exerting anti-microinflammatory effects, including reducing macrophage infiltration in glomeruli, suppressing TNF-α, IL-1ß and TGF-ß1 overexpression in the kidney and inhibiting p38 MAPK and NF-κB signaling activities.

[Effects and mechanisms of UCG ameliorating renal interstitial fibrosis by regulating TGF-ß1/SnoN/Smads signaling pathway in renal failure rats].

This study was aimed to demonstrate preliminarily the effects and mechanisms of uremic clearance granule (UCG) ameliorating renal interstitial fibrosis (RIF) by regulating transforming growth factor (TGF)-ß1/SnoN/Smads signaling pathway in vivo. Fifteen rats were randomly divided into 3 groups：the normal group,the model group and the UCG group. The rats with renal failure were induced by intragastric administration of adenine and unilateral ureteral obstruction (UUO). After modeling,the rats in the UCG group and in the other groups were intervened by intragastric administration of UCG and distilled water respectively during 3 weeks. The body weight and 24 h urinary protein excretion (Upro) in all rats were tested after drug administration. All rats were killed after drug administration for 3 weeks,blood and kidneys were collected and weighted,kidney appearance and renal morphological characteristics were observed. In addition,serum biochemical indices and the protein expressions of TGF-ß1,SnoN,phosphorylated Smad2/3 (p-Smad2/3) and Smad7 in the kidney were evaluated respectively. The results indicated that,after the intervention of UCG,the general state of health,kidney appearance,serum creatinine (Scr),blood urea nitrogen (BUN),uric acid (UA),albumin (Alb),Upro and renal morphological change in model rats were improved in different degrees,respectively. Moreover,UCG down-regulated the protein expressions of TGF-ß1 and p-Smad2/3,and up-regulated the protein expressions of SnoN and Smad7 in the kidney. In conclusion,UCG reduces extracellular matrix (ECM) synthesis and delays the progression of renal failure via possibly multi-targeting at regulating TGF-ß1/SnoN/Smads signaling pathway in vivo.