Linggui Zhugan Decoction Improves High Glucose-Induced Autophagy in Podocytes

Objective To explore the influence of Linggui Zhugan Decoction(LGZGD)on high glucose induced podocyte autophagy Methods LGZGD containing serum were prepared by intragastric administation of 4.2 g·kg^(-1)(low dose),8.4 g·kg^(-1)(medium dose),and 12.6 g·kg^(-1)(high dose)LGZGD into SD rats respectively.MPC5 and AB8/13 cells were treated with 60 mmol/L glucose to establish diabetic nephropathy podocyte model in vitro.Podocytes,MPC5 and AB8.13,were divided into control group,high glucose group,low dose LGZGD group,medium dose LGZGD group,and high dose LGZGD group,respectively.For the three LGZGD groups,before LGZGD intervention,podocytes were treated with 60 mmol/L glucose for 3 days.After treated with LGZGD containing serum,cells were collected to analyze cell migration using Transwell assay,proliferation using CCK8,apoptosis and cell cycle using flow cytometry,,autophagosome formation using transmission electron microscopy,and expression levels of Beclin-1,Atg5,LC3II/I,and P62 proteins using western blot.Results Compared with the control group,the proliferation and migration of MPC5 and AB8.13 cells in high glucose group showed slightly decreased,whereas these parameters restored after intervention with low and medium concentrations of LGZGD,with the medium dose LGZGD having the best effect.Flow cytometry analysis showed that the medium dose LGZGD group had a lower apoptosis rate(P<0.05)and higher survival rate(P>0.05)compared to the high dose group.High glucose arrested podocytes in G1 phase,whereas LGZGD shifted podocytes from being predominant in G1 phase to increasing into G2.High dose LGZGD significanly reduced increased autophagosome formation due to high glucose in both podocytes(P<0.05).Western blot analysis showed that Beclin-1,Atg5,LC3Ⅱ/Ⅰ,and P62 expressions were increased in MPC5 cells treated with high glucose,and reversed after adminstration of low and medium doses of LGZGD(P<0.05).Conclusion LGZGD reduced apoptosis and enhanced autophagy in high glucose treated podocytes via regulating Beclin-1/LC3II/I/Atg5 expression.

Glycyrrhizic Acid Protects Glomerular Podocytes Induced by High Glucose by Modulating SNARK/AMPK Signaling Pathway

Objective:Diabetic nephropathy is one of the most important microvascular complications of diabetes,which mainly refers to glomerular capillary sclerosis.Podocytes are an important part of glomerular capillaries.Previous clinical and basic studies have shown that fibrosis is the main factor of diabetic nephropathy.This study aimed to assess the protective mechanism of glycyrrhizic acid(GA)on glomerular podocytes induced by high glucose as we hypothesized that GA may have antifibrotic and anti-inflammatory effects on podocytes through regulation of the adenosine 5'-monophosphate-activated protein kinase(AMPK)/sucrose nonfermenting AMPK-related kinase(SNARK)signaling pathway.Methods:SNARK siRNA was used to transfect podocytes.Real-time quantitative polymerase chain reaction and immunofluorescence staining assays were used for molecular and pathological analysis.The expression levels of key pathway proteins(including TGF-β1,α-SMA,SITR1,AMPKα,LKB1,PGC-1α,NF-κB,IL-6,and TNF-α)were verified by Western blotting.The expression of inflammatory factors in podocytes was detected by ELISA.Results:We demonstrated that GA decreased the expression of podocyte fibrosis signaling pathway-related factors by upregulating the AMPK pathway and its related factors.However,after transfection of podocytes with SNARK siRNA,there was an increased expression of fibrosis-related factors and inflammation-related factors.Conclusion:GA can protect podocytes and alleviate fibrosis and inflammation induced by high glucose,which is related to the AMPK signaling pathway.Meanwhile,knockdown of SNARK protein can inhibit the AMPK signaling pathway,aggravate fibrosis,and increase inflammation.

Albumin Modulates the Production of Matrix Metalloproteinases-2 and -9 in Podocytes

To investigate the effects of albumin on the production of matrix metalloproteinases-2 （MMP-2） and matrix metalloproteinases-9 （MMP-9）in podocytes. Podocytes were treated with bovine serum albumin （BSA） at the concentration of 0.1, 0.5, 1, 2 g/L, respectively. Conditioned media were harvested 12, 24, 48 and 72 h after the treatment. The expression of MMP-2 and MMP-9 was assayed by gelatin zymography, RT-PCR and Western blotting analysis. Our results showed that in comparison with the control group, BSA increased the expression of MMP-2 and MMP-9 mRNA and protein in a doseand time-dependent manner （P〈0.05）. Meanwhile, the enzymatic activities of MMP-2 and MMP-9 in the culture supernatants of podocytes were also increased （P〈0.05）. It is concluded that albumin up-regulated the expression of MMP-2 and MMP-9 at gene and protein levels in a time-and dose-dependent manner.

Effects of Qidi Tangshen granules and their separate prescriptions on podocytes in mice with diabetic nephropathy

Objective:Previous studies have found that Qidi Tangshen granules(QDTS),a combination therapy of supplementing essence(Tianjing,TJ)and unblocking the collaterals(Tongluo,TL),can reduce kidney damage in db/db mice.This study aimed to explore the effect of QDTS and their separate prescriptions on podocytes in mice with diabetic nephropathy.Methods:The db/db mice were used in this experiment as an animal model,while wild-type C57BL/6J mice were used as normal controls.At the age of 12 weeks,the db/db mice were randomly divided into 5 groups(db/db,db/dbþvalsartan,db/dbþQDTS,db/dbþTJ and db/dbþTL).The urine albumin excretion ratio(UAE)was measured by enzyme-linked immunosorbent assay before and after the intervention.The ultrastructure of the kidney podocytes was observed by transmission electron microscopy.The protein expression levels of nephrin and desmin were detected by immunohistochemistry.Results:QDTS and their separate prescriptions significantly decreased the UAE and attenuated the renal pathological injury.QDTS and their separate prescriptions also reduced the fusion rate of the foot processes and increased the expression of nephrin protein.In contrast,QDTS and their separate prescriptions(TJ and TL)reduced the expression level of desmin protein.Conclusion:QDTS and their separate prescriptions might reduce diabetes-induced renal injury by reducing podocyte damage.The therapeutic effect of QDTS was more pronounced than TJ and TL.

Effect of Down-regulation of TRPC6 on the Puromycin Aminonucleoside-induced Apoptosis of Mouse Podocytes

Eukaryotic expression vectors carrying the small hairpin RNA （shRNA） for TRPC6 mRNA were constructed, and the effects of knocking-down TRPC6 on puromycin aminonucleoside （PAN）-induced apoptosis of mouse podocytes were observed. Two eukaryotic expression vectors containing small hairpin structure targeting TRPC6 named pGCsi-TRPC6A and pGCsi-TRPC6B were designed and synthesized. The plasmids were transfected into conditionally immortalized murine podocyte cell line by liposome. The changes in the TRPC6 mRNA and protein expression were observed by RT-PCR and Western blot after 48 h. Cultured podocytes were divided into four groups： control group, PAN treatment group, PAN treatment＋shRNA transfection group, and PAN treatment＋negative control group. The expression of Bax and Bcl-2 mRNA and proteins was detected by RT-PCR and Western-blot respectively. The apoptotic rate of podocytes was measured by flow cytometry. The results showed that the expression of TRPC6 mRNA and protein was decreased in the podocytes when transfected with pGCsi-TRPC6A, and pGCsi-TRPC6B. The expression of Bax was increased, and that of Bcl-2 was decreased at protein and mRNA levels in the podocytes after treated with PAN for 48 h. These changes was attenuated by knocking-down TRPC6. Knocking-down TRPC6 could effectively decrease the PAN-induced apoptosis of podocytes. It was concluded that TRPC6 may play an important role in the PAN-induced apoptosis of podocytes. Knocking-down TRPC6 gene could effectively prevent the podocytes from apoptosis induced by PAN.

Losartan Protects Podocytes against High Glucose-induced Injury by Inhibiting B7-1 Expression

The role of B7-1 in podocyte injury has received increasing attention.The aim of this study was to investigate whether losartan protects podocytes of patients with diabetic kidney disease(DKD)by regulating B7-1 and the underlying mechanisms.Rats with streptozotocin-induced DKD were treated with losartan for 8 weeks.Biochemical changes in blood and urine were analyzed.Kidneys were isolated for electron microscopy,immunofluorescence,real-time quantitative PCR(RT-PCR),and Western blot analysis.Immortalized mouse podocyte cells were cultured in normal or high glucose medium in the presence or absence of losartan for 48 h,and then the cells were collected for immunofluorescence,PCR,Western blotting and monolayer permeability detection.The phosphatidylinositol 3-kinase(PI3K)110a subunit and angiotensin II type 1 receptor(AT1R)plasmids were transfected into podocytes,respectively,and then Western blotting was performed to assess the expression of B7-1 protein.The results showed that losartan ameliorated podocyte structure and function in the rat model of DKD,and reduced the expression of B7-1 protein.Overexpression of PI3K 110a subunit in podocytes attenuated the inhibitory effect of losartan on B7-1 expression in high glucose-stimulated podocytes.The expression of B7-1 was significantly increased by overexpression of ATI R and significantly reduced by blocking PI3K 110a subunit.We conclude that losartan protects podocytes against high glucose-induced injury by inhibiting AT1R-mediated B7-1 expression.This effect is dependent on the AT1R-PI3K 110a subunit pathway.

Immune Reactive Ezrin Surface Area Increases in Glomerular Podocytes of STZ Diabetic Rats Precede Their Detachment, Is Prevented by Phlorizin But Not by Insulin

Glomerular tuft immune reactive Ezrin surface area (EzA) and fraction of EzA to total glomerular tuft area significantly increased, indicating podocyte growth, rounding and altered cytoskeletal interactions at 1 week of STZ diabetes. Podocyte number per glomerulus (WT1+ nuclei) did not change indicating no detachment, but density decreased due to tuft hypertrophy. Treatment with PLZ or Insulin for one week, prevented increase in proteinuria and hyperglycemia but not the decrease in podocyte density. PLZ but not Insulin prevented increase in ezrin positive area in glomeruli and per podocyte. In podocytes in culture neither 25 mM glucose with or without PLZ (2.5 or 25 uM) altered Ezrin expression measured in western blots. In summary, the Ezrin positive glomerular surface area increase seen after 1 week of STZ diabetes, reflects altered podocyte morphology and cytoskeletal interactions, prevented by PLZ but not by insulin. Ezrin area increase preceded podocyte detachment and in podocytes in culture is not associated with increases in podocyte Ezrin protein expression. It is a likely precursor of shape changes in podocytes and of alterd interactions with basement membrane that contribute to detachment and thickening. Glomerular capillary tuft hypertrophy and reduced podocyte density persisted despite PLZ or insulin treatments, independently of levels of glycemia and of proteinuria.

Influence of Bushenhuoxue on podocytes of focal segmental glomerulosclerosis mice

OBJECTIVE: To observe the effects and mechanisms of Bushenhuoxue on desmin and nephrin expression in mice podocytes, and to investigate its effects on wt1 expression in Wilms' tumor.METHODS: Adriamycin(ADR) was used to induce focal segmental glomerulous sclerosis(FSGS) in mice. Bushenhuoxue was used to treat FSGS for 6 weeks. We measured body mass and right renal mass, and determined serum albumin(ALB) levels,protein content in urine, and urinary protein and albumin creatinine ratio(UACR). Changes in renal tissue morphology were evaluated by microscopy.wt1 and nephrin expression in podocytes were detected using immunofluorescence. Expression levels of desmin, wt1 and nephrin m RNAs in renal tissue were determined using reverse transcription polymerase chain reaction assays.RESULTS: Protein levels in urine and UACR were significantly increased in FSGS model mice compared with Bushenhuoxue-treated and control mice.Body mass and ALB levels were decreased in FSGS mice compared with control and Bushenhuoxue-treated mice. Expression of the wt1 protein was observed in control mice. Compared with controls,wt1 expression levels were reduced in Bushenhuoxue-treated mice, and to a greater extent in FSGS mice. Nephrin protein expression was widespread in FSGS mice, and significantly reduced in control and Bushenhuoxue mice. Expression levels of wt1 and nephrin m RNAs in FSGS mice were lower compared with those in control and Bushenhuoxue-treated mice. Desmin m RNA levels in FSGS mice were reduced compared with those in control and Bushenhuoxue-treated mice.CONCLUSION: Bushenhuoxue ameliorated albuminuria in FSGS mice; this was possibly related to the up-regulation of wt1 and nephrin, and down-regulation of desmin.

Foodborne toxin Aflatoxin B_(1)induced glomerular podocyte inflammation through proteolysis of RelA,downregulation of miR-9 and CXCR4/TXNIP/NLRP3 pathway

Aflatoxin B_(1)(AFB_(1))is a naturally-occurring mycotoxin and recognized as the most toxic foodborne toxin,particularly causing damages to kidney.Glomerular podocytes are terminally differentiated epithelial cells.AFB_(1)induces podocyte inflammation,proteinuria and renal dysfunction.Studying the mechanism of AFB_(1)-induced podocyte inflammation and murine kidney dysfunction,we detected that AFB_(1)increased ubiquitindependent degradation of the transcription factor RelA through enhanced interaction of RelA with E3 ubiquitin ligase tripartite motif containing 7(TRIM7)in mouse podocyte clone-5(MPC-5)and mouse glomeruli.Reduction of RelA resulted in decreasing microRNA-9(miR-9)and activating the chemokine receptor 4(CXCR4),thioredoxin interacting protein(TXNIP),and NOD-like receptor pyrin domain-containing 3(NLRP3)signaling axis(CXCR4/TXNIP/NLRP3 pathway),leading to podocyte inflammation.We also determined that downregulation of miR-9 led to CXCR4 expression and the downstream TXNIP/NLRP3 pathway activation.Overexpression of miR-9 or deletion of CXCR4 suppressed AFB_(1)-induced CXCR4/TXNIP/NLRP3 pathway,resulting in alleviating podocyte inflammation and kidney dysfunction.Our findings indicated that ubiquitin-dependent proteolysis of RelA,downregulation of miR-9,and activation of CXCR4/TXNIP/NLRP3 pathway played an essential role in AFB_(1)-induced glomerular podocyte inflammation.Our study revealed a novel mechanism,via RelA,for the control of AFB_(1)’s nephrotoxicity,leading to an effective protection of food safety and public health.

Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND In this study,we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis(LN)who un-derwent repeated renal biopsy.CASE SUMMARY Clinical data of three diffuse proliferative LN patients with different pathological characteristics(case 1 was LN IV-G(A),case 2 was LN IV-G(A)+V,and case 3 was LN IV-G(A)+thrombotic microangiopathy)were reviewed.All patients underwent repeated renal biopsies 6 mo later,and renal biopsy specimens were studied.Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining,and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage.After treatment,Case 1 changed to LN III-(A),Case 2 remained as type V LN lesions,and Case 3,which changed to LN IV-S(A),had the worst prognosis.We observed reduced macro-phage infiltration after therapy.However,two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium.Before treatment,the three patients showed discontinuous expression of podocin.Notably,the integrity of podocin was restored after treatment in Case 1.CONCLUSION It may be possible to reverse podocyte damage and decrease the infiltrating ma-crophages in LN patients through effective treatment.

Corilagin alleviates podocyte injury in diabetic nephropathy by regulating autophagy via the SIRT1-AMPK pathway

BACKGROUND Diabetic nephropathy(DN)is the most frequent chronic microvascular consequence of diabetes,and podocyte injury and malfunction are closely related to the development of DN.Studies have shown that corilagin(Cor)has hepatoprotective,anti-inflammatory,antibacterial,antioxidant,anti-hypertensive,antidiabetic,and anti-tumor activities.AIM To explore the protective effect of Cor against podocyte injury in DN mice and the underlying mechanisms.METHODS Streptozotocin and a high-fat diet were combined to generate DN mice models,which were then divided into either a Cor group or a DN group(n=8 in each group).Mice in the Cor group were intraperitoneally injected with Cor(30 mg/kg/d)for 12 wk,and mice in the DN group were treated with saline.Biochemical analysis was used to measure the blood lipid profiles.Hematoxylin and eosin staining was used to detect pathological changes in kidney tissue.Immunohistochemistry and Western blotting were used to assess the protein expression of nephrin and podocin.Mouse podocyte cells(MPC5)were cultured and treated with glucose(5 mmol/L),Cor(50μM),high glucose(HG)(30 mmol/L),and HG(30 mmol/L)plus Cor(50μM).Real-time quantitative PCR and Western blotting RESULTS Compared with the control group,the DN mice models had increased fasting blood glucose,glycosylated hemoglobin,triglycerides,and total cholesterol,decreased nephrin and podocin expression,increased apoptosis rate,elevated inflammatory cytokines,and enhanced oxidative stress.All of the conditions mentioned above were alleviated after intervention with Cor.In addition,Cor therapy improved SIRT1 and AMPK expression(P<0.001),inhibited reactive oxygen species and oxidative stress,and elevated autophagy in HG-induced podocytes(P<0.01).CONCLUSION Cor alleviates podocyte injury by regulating autophagy via the SIRT1-AMPK pathway,thereby exerting its protective impact on renal function in DN mice.

Long noncoding RNA protein-disulfide isomerase-associated 3 regulated high glucose-induced podocyte apoptosis in diabetic nephropathy through targeting miR-139-3p

BACKGROUND Podocyte apoptosis plays a vital role in proteinuria pathogenesis in diabetic nephropathy(DN).The regulatory relationship between long noncoding RNAs(lncRNAs)and podocyte apoptosis has recently become another research hot spot in the DN field.AIM To investigate whether lncRNA protein-disulfide isomerase-associated 3(Pdia3)could regulate podocyte apoptosis through miR-139-3p and revealed the underlying mechanism.METHODS Using normal glucose or high glucose(HG)-cultured podocytes,the cellular functions and exact mechanisms underlying the regulatory effects of lncRNA Pdia3 on podocyte apoptosis and endoplasmic reticulum stress(ERS)were explored.LncRNA Pdia3 and miR-139-3p expression were measured through quantitative real-time polymerase chain reaction.Relative cell viability was detected through the cell counting kit-8 colorimetric assay.The podocyte apoptosis rate in each group was measured through flow cytometry.The interaction between lncRNA Pdia3 and miR-139-3p was examined through the dual luciferase reporter assay.Finally,western blotting was performed to detect the effect of lncRNA Pdia3 on podocyte apoptosis and ERS via miR-139-3p.RESULTS The expression of lncRNA Pdia3 was significantly downregulated in HG-cultured podocytes.Next,lncRNA Pdia3 was involved in HG-induced podocyte apoptosis.Furthermore,the dual luciferase reporter assay confirmed the direct interaction between lncRNA Pdia3 and miR-139-3p.LncRNA Pdia3 overexpression attenuated podocyte apoptosis and ERS through miR-139-3p in HG-cultured podocytes.CONCLUSION Taken together,this study demonstrated that lncRNA Pdia3 overexpression could attenuate HG-induced podocyte apoptosis and ERS by acting as a competing endogenous RNA of miR-139-3p,which might provide a potential therapeutic target for DN.

Advanced oxidation protein products decrease expression of nephrin and podocin in podocytes via ROS-dependent activation of p38 MAPK

Accumulation of plasma advanced oxidation protein products(AOPPs) promotes progression of proteinuria and glomerulo-sclerosis.To investigate the molecular basis of AOPPs-induced proteinuria,normal Sprague-Dawley rats were treated with AOPPs-modified rat serum albumin.The expression of glomerular podocyte slit diaphragm(PSD)-associated proteins,nephrin and podocin,was significantly decreased coincident with the onset of albuminuria in rats treated with AOPPs.Chronic inhibi-tion of NADPH oxidase by apocynin prevented down-regulation of nephrin and podocin and decreased albuminuria in AOPPs-challenged rats.This suggested that accumulation of AOPPs promotes proteinuria,possibly via down-regulating the expression of PSD-associated proteins.

Tongluo Digui decoction(通络地龟汤)treats renal injury in diabetic rats by promoting autophagy of podocytes

OBJECTIVE:To investigate the effects of Tongluo Digui decoction on renal injury and streptozotocin-induced podocyte autophagy in diabetic rats.METHODS:Male Sprague-Dawley rats were randomly divided into six groups:normal,model,Tongluo Digui decoction(high,medium,and low dose)and valsartan.Streptozotocin was injected intraperitoneally to replicate the diabetic animal model.After 8 weeks,proteinuria was evaluated to establish the diabetic nephropathy model.Treatments were administered daily via the intragastric route.At 16 weeks after gavage,we determined 24 h urine protein concentration,and blood glucose,serum creatinine,and urea nitrogen concentrations.Then,rats were sacrificed,and kidneys were harvested and stained with periodic acid-Schiff to evaluate the pathological changes in glomeruli,including glomerular podocytes by transmission electron microscopy.Western blot analysis was used to determine the expression of nephrin,podocin,p62,beclin-1,LC3Ⅱ/Ⅰ,and p-m TOR/m TOR protein in kidney tissues.RESULTS:Compared with the model group,Tongluo Digui decoction was associated with decreases in 24 h urine protein concentration,and blood glucose,hemoglobin A1 c,serum creatinine,urea nitrogen concentrations,total serum protein and albumin.Concurrently,mesangial mesenteric broadening and fusion of foot processes were reduced,the glomerular basement membrane was not significantly thickened,and the number of podocytes and the number of autophagosomes in the podocytes was increased.Further,expression of nephrin,podocin,LC3Ⅱ,and beclin-1 protein in kidney tissue was up-regulated,while expression of p62 protein was down-regulated and m TOR phosphorylation was inhibited.CONCLUSION:Tongluo Digui decoction may inhibit the progression of diabetic nephropathy by inhibiting m TOR phosphorylation,thereby increasing autophagy to protect podocytes and reducing proteinuria.

Pathogenesis of childhood idiopathic nephrotic syndrome:a paradigm shift from T-cells to podocytes

Background:Nephrotic syndrome is the most common cause of kidney disease in children,but its pathogenesis remains unclear.This article reviews the novel aspects of the mechanisms underlying massive proteinuria in minimal-change disease,which is the most common form of childhood nephrotic syndrome.Data sources:This article integrates the findings of a PubMed database search for English language articles published in the past 40 years(from September 1974 to February 2014)using the key words"pathogenesis","minimal change nephrotic syndrome"or"idiopathic ne phrotic syndrome".Results:Unknown humoral factors associated with T-cell dysfunction have been thought to play an important role in the pathogenesis of minimal-change disease.However,recent findings are changing this paradigm,i.e,visceral glomerular epithelial cells(podocytes)may be involved via expression of molecules such as CD80 and angiopoietin-like 4.Conclusions:Recent evidence suggests that minimal-change disease results from interactions between humoral factors and dysfunctional podocytes.In addition to immunosuppressant drugs that target lymphocytes,a biological agent such as an antibody against the abnormal molecule(S)expressed by podocytes may provide novel drug treatment for minimal-change disease.

Establishment and functional characterization of the reversibly immortalized mouse glomerular podocytes(imPODs)

Glomerular podocytes are highly specialized epithelial cells and play an essential role in establishing the selective permeability of the glomerular filtration barrier of kidney.Maintaining the viability and structural integrity of podocytes is critical to the clinical management of glomerular diseases,which requires a thorough understanding of podocyte cell biology.As mature podocytes lose proliferative capacity,a conditionally SV40 mutant tsA58-immortalized mouse podocyte line(designated as tsPC)was established from the Immortomouse over 20 years ago.However,the utility of the tsPC cells is hampered by the practical inconvenience of culturing these cells.In this study,we establish a user-friendly and reversibly-immortalized mouse podocyte line(designated as imPOD),on the basis of the tsPC cells by stably expressing the wildtype SV40 T-antigen,which is flanked with FRT sites.We show the imPOD cells exhibit long-term high proliferative activity,which can be effectively reversed by FLP recombinase.The imPOD cells express most podocyte-related markers,including WT-1,Nephrin,Tubulin and Vinculin,but not differentiation marker Synaptopodin.The imPOD cells do not form tumor-like masses in vivo.We further demonstrate that TGFb1 induces a podocyte injury-like response in the FLP-reverted imPOD cells by suppressing the expression of slit diaphragm-associated proteins P-Cadherin and ZO-1 and upregulating the expression of mesenchymal markers,a-SMA,Vimentin and Nestin,as well as fibrogenic factors CTGF and Col1a1.Collectively,our results strongly demonstrate that the newly engineered im-POD cells should be a valuable tool to study podocyte biology both under normal and under pathological conditions.

Total flavonoids of Scutellaria barbata improving podocyte injury induced by high glucose through Smad4/PKM2/HIF‑1α pathway

Objective: To observe the effect of total flavonoids of Scutellaria barbata (TF‑SB) on the injury of high glucose induced podocytes (MPC‑5) and the influence of Smad4/PKM2/HIF‑1α pathway. Methods: Firstly, CCK8 was used to analyze the safety and efficacy concentration of TF‑SB on MPC‑5 cells. Then, MPC‑5 was then divided into the control group, model group and TF‑SB group. In addition to the control group, model group and TF‑SB group were induced by high glucose to establish MPC‑5 cell injury model. The effects of TF‑SB on ATP, apoptosis and ROS levels of MPC‑5 cells were detected respectively. The contents of IL‑1β, TNF‑α, and MCP‑1 were determined by ELISA, the expression abundance of glycolytic genes (GLU1, PFK1 and HK1) were detected by RT‑PCR. Western blot method was used to detect the expression level of related proteins in Smad4/PKM2/HIF‑1α pathway. Results: Compared with the blank group, ATP content, GLU1, PKF1 and HK1 expression abundance of MPC‑5 cells in the model group decreased significantly, apoptosis, ROS level and IL‑1 β、 TNF‑ α And MCP‑1 significantly increased (P<0.01);Compared with model group, ATP content, GLU1, PKF1 and HK1 expression abundance, apoptosis, ROS level and IL‑1β in TF‑SB group were significantly increased , TNF‑ α The contents of MCP‑1 and MCP‑1 decreased significantly (P<0.01). In addition, compared with the blank group, the model group Smad4 and HIF‑1 α The protein expression and PKM2 expression in nucleus were significantly increased, while PKM2 expression in cytoplasm was significantly decreased (P<0.01);Compared with model group, TF‑SB group Smad4, HIF‑1 α The expression of PKM2 in the nucleus and expression of PKM2 were significantly decreased, while the expression of PKM2 in the cytoplasm was significantly increased (P<0.01). Conclusion: TF‑SB promotes the mitochondrial activity of MPC‑5 cells to induce glycolysis, and then inhibits the secretion of inflammation, which may play a role in treating diabetes nephropathy by inhibiting Smad4/PKM2/HIF‑1α signaling pathway.

Exosomal miR-30a-5p targets NLRP3 to suppress podocyte pyroptosis in diabetic nephropathy

Background:Mesenchymal stem cell(MSC)-derived exosomes are closely related to pyroptosis in diabetic nephropathy(DN).This study aimed to explore the protective effect of exosomal miR-30a-5p on podocyte pyroptosis in DN.Methods:Streptozotocin was used to establish the mouse model of DN.Human bone marrow MSC-derived exosomes were extracted and identified via transmission electron microscopy,nanoparticle tracking analysis,and western blotting.MiR-30a-5p mimics and non-control(NC)mimics were transfected into MSCs and podocytes,and exosomes were isolated from the MSCs.High glucose(HG)-induced podocyte model was established to determine the effect of exosomal miR-30a-5p on pyroptosis and inflammation in vitro.Results:MiR-30a-5p was expressed at low levels in DN models,while NLR family pyrin domain containing 3(NLRP3),caspase-1,gasdermin-N(GSDMD-N),and pro-inflammatory factors(tumor necrosis factor-alpha,interleukin(IL)-1beta,and IL-18)were augmented.In vitro,miR-30a-5p expression in the HG-damaged podocytes was down-regulated,while NLRP3 was up-regulated.Interestingly,miR-30a-5p overexpression diminished HG-induced podocyte injury,as proven by increased activity and decreased pyroptosis of podocytes.Concurrently,the up-regulation of miR-30a-5p could inhibit the expression of pro-inflammatory factors,caspase-1,GSDMD-N,and NLRP3 in HG-induced podocytes.MSC-derived exosomal miR-30a-5p treatment of HG-damaged cells has similar effects to miR-30a-5p mimics treatment.Overexpression of NLRP3 reversed the effect of miR-30a-5p mimics on HG-induced podocytes.Conclusion:This research confirmed that exosomal miR-30a-5p regulates pyroptosis via mediating NLRP3 in DN.

霉酚酸酯对局灶节段性肾小球硬化(FSGS)治疗作用的研究

目的:用霉酚酸酯(MMF)对以阿霉素肾病大鼠建立的局灶节段性肾小球硬化(FSGS)模型,进行干预,检测结缔组织生长因子(CTGF)的表达,研究霉酚酸酯对FSGS的治疗作用,并探讨作用机理。方法:SD大鼠18只,分为对照组、阿霉素肾病组、MMF治疗组(每组大鼠6只)。肾病组、治疗组大鼠尾静脉一次性注入阿霉素7.5mg/kg,对照组大鼠尾静脉注入等量生理盐水。治疗组于第6周起MMF 20mg.kg-1.d-1混悬于1mL蒸馏水灌胃,其他组等量蒸馏水灌胃。第10周处死所有大鼠,观察肾组织病理变化,并以免疫组织化学、Western blot方法检测肾组织CTGF蛋白水平。结果:阿霉素肾病组大鼠较对照组大鼠肾小球系膜及基质明显增生,免疫组织化学染色及western blot显示肾小球和肾小管区CTGF蛋白表达明显上升(P<0.05),霉酚酸酯治疗组肾小球系膜和基质增生较肾病组明显减轻,肾小球和肾小管区CTGF蛋白表达明显低于肾病组(P<0.05)。结论:霉酚酸酯可以减轻肾脏间质纤维化病变,机理与抑制CTGF的表达有关。

Correlation between podocyte excretion and proteinuria in diabetic nephropathy patients

Objective： To observe the podocyte injury in diabetic nephropathy （DN） patients by identifying the urinary podocytes and the situation of detached podocytes in glomeruli and to demonstrate the correlation between podocyte excretion and proteinuria, blood glucose, serum creatinine in different phases in DN patients. Methods： Urinary podocytes and the podocalyxin （PCX） expression state of podocytes in glomeruli were identified and observed by indirect immunofluorescent method. The DN patients were divided into three groups according to the volume of proteinuria, namely small, medium and large volume proteinuria groups. The podocytes in the urine of every group were calculated. The DN patients were divided into five groups according to the chronic kidney disease （CKD） phases, then the positive podocytes in urine were calculated. Meanwhile, the 24-hour protein in urine, fasting blood glucose （FBG） and the serum creatinine of DN patients were tested. The correlations among the proteinuria, serum creatinine, FBG and the number of positive podocytes in the urine of DN patients were statistically analyzed. Results： Urinary positive podocytes were found in 88% of the patients with DN, whereas podocytes were found in 0% of patients with minimal changed disease （MCD） and healthy cases. The expression of PCX was absent in DN patients. In contrast, PCX was expressed integrally in MCD patients. The positive podocytes was 1.49±0.95/ml in small-volume proteinuria group, 2.15±0.70/ml in the medium-volume proteinuria group, and 3.48±1.27/ml in the large-volume proteinuria group. There was no significant difference between the small- and medium- volume proteinuria groups, and there were significant differences between other groups （P〈0.05）. The positive podocyte number tended to increase as proteinuria was increased. By Pearson analysis, the correlation between podocyte number and proteinuria was podocytes in urine from different groups of DN patients, CKD pc I sitive statistically. The difference of the number of positive -V group was significant statistically. The correlation between serum creatinine of CKD Ⅰ -Ⅲ group and positive podocytes in urine was positive statistically. The correlation between serumcreatinine of CKD Ⅳ- Ⅴ group and positive podocytes in urine was not significant statistically. The correlation between FBG and positive podocytes in urine was not significant either. Conclusion： The mechanism of the podocyte injury in DN patients is present. The podocyte injury in DN may positively correlate to proteinuria and serum creatinine of CKD Ⅰ -ⅢDN patients, but not to the FBG and serum creatinine of CKD Ⅳ-Ⅴ patients.