Tiliroside protects against diabetic nephropathy in streptozotocininduced diabetes rats by attenuating oxidative stress and inflammation

BACKGROUND Diabetic nephropathy(DN),affecting half of diabetic patients and contributing significantly to end-stage kidney disease,poses a substantial medical challenge requiring dialysis or transplantation.The nuanced onset and clinical progression of kidney disease in diabetes involve consistent renal function decline and persistent albuminuria.AIM To investigate Tiliroside's(Til)protective effect against diabetic nephropathy(DN)in rats under diabetic conditions.METHODS Five groups of six rats each were included in this study:Rats treated with DMSO by intraperitoneal injection as controls,those treated with STZ by intraperitoneal injection,those treated with STZ+Til(25 mg/kg body weight[bwt])or Til(50 mg/kg bwt),and those treated with anti-diabetic medication glibenclamide(600μg/kg bwt).Biochemical markers,fasting blood glucose,food intake,kidney weight,antioxidant enzymes,inflammatory and fibrotic markers,and renal injury were monitored in different groups.Molecular docking analysis was performed to identify the interactions between Til and its targeted biomarkers.RESULTS Til significantly reduced biochemical markers,fasting blood glucose,food intake,and kidney weight and elevated antioxidant enzymes in diabetic rats.It also mitigated inflammatory and fibrotic markers,lessened renal injury,and displayed inhibitory potential against crucial markers associated with DN as demonstrated by molecular docking analysis.CONCLUSION These findings suggest Til's potential as a therapeutic agent for DN treatment,highlighting its promise for future drug development.

Asiaticoside improves diabetic nephropathy by reducing inflammation, oxidative stress, and fibrosis: An in vitro and in vivo study

BACKGROUND Diabetic nephropathy(DN)is a severe microvascular complication of diabetes characterized by inflammation,oxidative stress,and renal fibrosis.Asiaticoside(AC)exhibits anti-inflammatory,antioxidant,and anti-fibrotic properties,suggesting potential therapeutic benefits for DN.This study aimed to investigate the protective effects of AC against DN and elucidate the underlying mechanisms involving the nuclear factor erythroid 2-related factor 2(NRF2)/heme oxygenase-1(HO-1)antioxidant pathway.METHODS The effects of AC on high glucose(HG)-induced proliferation,inflammation,oxidative stress,and fibrosis were evaluated in rat glomerular mesangial cells(HBZY-1)in vitro.A streptozotocin-induced DN rat model was established to assess the in vivo impact of AC on renal injury,inflammation,oxidative stress,and fibrosis.The involvement of the NRF2/HO-1 pathway was examined using pharmacological inhibition studies in the cell model.RESULTS AC inhibited HG-induced HBZY-1 cell proliferation and significantly improved various indicators of DN in rats,including reduced body weight,and elevated blood glucose,serum creatinine,blood urea nitrogen,and 24-h urine protein.Both in vitro and in vivo studies demonstrated that AC decreased inflammation and oxidative stress by reducing interleukin(IL)-6,IL-8,tumor necrosis factor-alpha,reactive oxygen species,and malondialdehyde levels while increasing superoxide dismutase activity.Additionally,AC suppressed the expression of fibrogenic markers such as collagen I,collagen IV,and fibronectin.AC activated NRF2 expression in the nucleus and increased HO-1 and NAD(P)H dehydrogenase(Quinone)1 protein expression in renal tissues and HG-induced HBZY-1 cells.CONCLUSION AC improves DN by reducing inflammation,oxidative stress,and fibrosis through the activation of the NRF2/HO-1 signaling pathway.These findings not only highlight AC as a promising therapeutic candidate for DN but also underscore the potential of targeting the NRF2/HO-1 pathway in developing novel treatments for other chronic kidney diseases characterized by oxidative stress and inflammation.

Diabetic nephropathy and inflammation

Diabetic nephropathy(DN) is the leading cause of end-stage renal failure worldwide. Besides, diabetic nephropathy is associated with cardiovascular disease, and increases mortality of diabetic patients. Several factors are involved in the pathophysiology of DN, including metabolic and hemodynamic alterations, oxidative stress, and activation of the renin-angiotensin system. In recent years, new pathways involved in the development and progression of diabetic kidney disease have been elucidated; accumulated data have emphasized the critical role of inflammation in the pathogenesis of diabetic nephropathy. Expression of cell adhesion molecules, growth factors, chemokines and pro-inflammatory cytokines are increased in the renal tissues of diabetic patients, and serum and urinary levels of cytokines and cell adhesion molecules, correlated with albuminuria. In this paper we review the role of inflammation in the development of diabetic nephropathy, discussing some of the major inflammatory cytokines involved in the pathogenesis of diabetic nephropathy, including the role of adipokines, and take part in other mediators of inflammation, as adhesion molecules.

Pathophysiological role and therapeutic implications of inflammation in diabetic nephropathy

Diabetes mellitus and its complications are becoming one of the most important health problems in the world. Diabetic nephropathy is now the main cause of end-stage renal disease. The mechanisms leading tothe development and progression of renal injury are not well known. Therefore, it is very important to f ind new pathogenic pathways to provide opportunities for early diagnosis and targets for novel treatments. At the present time, we know that activation of innate immunity with development of a chronic low grade inflammatory response is a recognized factor in the pathogenesis of diabetic nephropathy. Numerous experimental and clinical studies have shown the participation of different inflammatory molecules and pathways in the pathophysiology of this complication.

Inflammation in diabetic retinopathy: possible roles in pathogenesis and potential implications for therapy

Diabetic retinopathy, characterized as a microangiopathy and neurodegenerative disease, is the leading cause of visual impairment in diabetic patients. Many clinical features observed in diabetic retinopathy, such as capillary occlusion, acellular capillaries and retinal non-perfusion, aggregate retinal ischemia and represent relatively late events in diabetic retinopathy. In fact, retinal microvascular injury is an early event in diabetic retinopathy involving multiple biochemical alterations, and is manifested by changes to the retinal neurovascular unit and its cellular components. Currently, intravitreal anti-vascular endothelial growth factor therapy is the firstline treatment for diabetic macular edema, and benefits the patient by decreasing the edema and improving visual acuity. However, a significant proportion of patients respond poorly to anti-vascular endothelial growth factor treatments, indicating that factors other than vascular endothelial growth factor are involved in the pathogenesis of diabetic macular edema. Accumulating evidence confirms that low-grade inflammation plays a critical role in the pathogenesis and development of diabetic retinopathy as multiple inflammatory factors, such as interleukin-1β, monocyte chemotactic protein-1 and tumor necrosis factor-α, are increased in the vitreous and retina of diabetic retinopathy patients. These inflammatory factors, together with growth factors such as vascular endothelial growth factor, contribute to blood-retinal barrier breakdown, vascular damage and neuroinflammation, as well as pathological angiogenesis in diabetic retinopathy, complicated by diabetic macular edema and proliferative diabetic retinopathy. In addition, retinal cell types including microglia, Müller glia, astrocytes, retinal pigment epithelial cells, and others are activated, to secrete inflammatory mediators, aggravating cell apoptosis and subsequent vascular leakage. New therapies, targeting these inflammatory molecules or related signaling pathways, have the potential to inhibit retinal inflammation and prevent diabetic retinopathy progression. Here, we review the relevant literature to date, summarize the inflammatory mechanisms underlying the pathogenesis of diabetic retinopathy, and propose inflammation-based treatments for diabetic retinopathy and diabetic macular edema.

Inhibition of inflammation and autophagy involves in the berberine nephroprotective effect of berberine in diabetic nephropathy mice

Aim To investigate the nephroprotective activity of berberine in diabetic nephropathy （DN） mice. Methods Diabetic nephropathy was induced by intraperitoneal injection with 55 mg · kg^-1 streptozotocin（STZ） , Berberine was administered at daily doses of 50, 100 and 200 mg· kg^-1 by gavage for 8 weeks. To detect serum creatinine and blood urea nitrogen （BUN） levels, blood were collected after the last dose of berberine, renal cortex was separated on ice after heart peffusion by precooled normal saline. The specimen was stored in -80℃ for the next experiments, and some of the kidney tissue were immobilized by 4% paraformaldehyde solution and 3% glut- araldehyde solution for the preparation of paraffin tissue slides and electron microscope biopsy respectively. After that, PAS staining and electron microscope were used to observe the glomerular morphology changes; ELISA was used to measure proinflammatory chemokines and cytokines levels in renal cortex. Real time RT-PCR was taken to detect the level of nucleotide binding oligomerzation domain 2 （NOD2） mRNA, Western blot was used to test the ex- pression of NOD2 and autophagy marker light chain 3 （LC3） in renal cortex. Results Histopathological changes and the increase in serum creatinine and BUN in DN mice were significantly ameliorated by berberine in a dose-de- pendent manner. Additionally, The expression of tumor necrosis factor-or （TNF-α）, interleukin-6 （IL-6） and in- tercellular adhesion molecule-1 （ICAM-1） was markedly suppressed by berberine, indicating the inhibition of in- flammatory response. Treatment of DN mice with berberine also significantly reduced the expression of NOD2 and LC3 in the kidneys. Conclusion The current study showed the nephroprotective activity of berberine in DN mice could be attributed to the inhibition of inflammation and

The role of innate immunity in diabetic nephropathy and their therapeutic consequences

Diabetic nephropathy (DN) is an enduring condition that leads to inflammation and affects a substantial number of individuals with diabetes worldwide. A gradual reduction in glomerular filtration and emergence of proteins in the urine are typical aspects of DN, ultimately resulting in renal failure. Mounting evidence suggests that immunological and inflammatory factors are crucial for the development of DN. Therefore, the activation of innate immunity by resident renal and immune cells is critical for initiating and perpetuating inflammation. Toll-like receptors (TLRs) are an important group of receptors that identify patterns and activate immune responses and inflammation. Meanwhile, inflammatory responses in the liver, pancreatic islets, and kidneys involve inflammasomes and chemokines that generate pro-inflammatory cytokines. Moreover, the activation of the complement cascade can be triggered by glycated proteins. This review highlights recent findings elucidating how the innate immune system contributes to tissue fibrosis and organ dysfunction, ultimately leading to renal failure. This review also discusses innovative approaches that can be utilized to modulate the innate immune responses in DN for therapeutic purposes.

Jianpi Gushen Huayu decoction ameliorated diabetic nephropathy through modulating metabolites in kidney,and inhibiting TLR4/NF-κB/NLRP3 and JNK/P38 pathways

BACKGROUND Jianpi Gushen Huayu Decoction(JPGS)has been used to clinically treat diabetic nephropathy(DN)for many years.However,the protective mechanism of JPGS in treating DN remains unclear.AIM To evaluate the therapeutic effects and the possible mechanism of JPGS on DN.METHODS We first evaluated the therapeutic potential of JPGS on a DN mouse model.We then investigated the effect of JPGS on the renal metabolite levels of DN mice using non-targeted metabolomics.Furthermore,we examined the effects of JPGS on c-Jun N-terminal kinase(JNK)/P38-mediated apoptosis and the inflammatory responses mediated by toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB)/NOD-like receptor family pyrin domain containing 3(NLRP3).RESULTS The ameliorative effects of JPGS on DN mice included the alleviation of renal injury and the control of inflammation and oxidative stress.Untargeted metabolomic analysis revealed that JPGS altered the metabolites of the kidneys in DN mice.A total of 51 differential metabolites were screened.Pathway analysis results indicated that nine pathways significantly changed between the control and model groups,while six pathways significantly altered between the model and JPGS groups.Pathways related to cysteine and methionine metabolism;alanine,tryptophan metabolism;aspartate and glutamate metabolism;and riboflavin metabolism were identified as the key pathways through which JPGS affects DN.Further experimental validation showed that JPGS treatment reduced the expression of TLR4/NF-κB/NLRP3 pathways and JNK/P38 pathway-mediated apoptosis related factors.CONCLUSION JPGS could markedly treat mice with streptozotocin(STZ)-induced DN,which is possibly related to the regulation of several metabolic pathways found in kidneys.Furthermore,JPGS could improve kidney inflammatory responses and ameliorate kidney injuries in DN mice via the TLR4/NF-κB/NLRP3 pathway and inhibit JNK/P38 pathwaymediated apoptosis in DN mice.

WJD 5^(th) Anniversary Special Issues(2): Type 2 diabetes Inflammation in diabetic kidney disease

Diabetes mellitus entails significant health problems worldwide.The pathogenesis of diabetes is multifactorial,resulting from interactions of both genetic and environmental factors that trigger a complex network of pathophysiological events,with metabolic and hemodynamic alterations.In this context,inflammation has emerged as a key pathophysiology mechanism.New pathogenic pathways will provide targets for prevention or future treatments.This review will focus on the implications of inflammation in diabetes mellitus,with special attention to inflammatory cytokines.

Association of NFKB1 gene polymorphism (rs28362491) with levels of inflammatory biomarkers and susceptibility to diabetic nephropathy in Asian Indians

AIM To investigate the association of NFKB1 gene-94 ATTG insertion/deletion(rs28362491) polymorphism with inflammatory markers and risk of diabetic nephropathy in Asian Indians.METHODS A total of 300 subjects were recruited(100 each), normoglycemic,(NG); type 2 diabetes mellitus(T2DM) without any complications(DM) and T2 DM with diabetic nephropathy [DM-chronic renal disease(CRD)]. Analysis was carried out by polymerase chain reaction-restriction fragment length polymorphism and ELISA. Pearson's correlation, analysis of variance and logistic regression wereused for statistical analysis.RESULTS The allelic frequencies of-94 ATTG insertion/deletion were 0.655/0.345(NG), 0.62/0.38(DM) and 0.775/0.225(DM-CRD). The-94 ATTG ins allele was associated with significantly increased levels of urinary monocyte chemoattractant protein-1(u MCP-1); u MCP-1(P = 0.026) and plasma tumor necrosis factor-alpha(TNF-α); TNF-α(P = 0.030) and almost doubled the risk of diabetic nephropathy(OR = 1.91, 95%CI: 1.080-3.386, P = 0.025).CONCLUSION-94 ATTG ins/ins polymorphism might be associated with increased risk of developing nephropathy in Asian Indian subjects with diabetes mellitus.

Anti-angiogenesis and anti-inflammatory effects of Moringa oleifera leaf extract in the early stages of streptozotocin-induced diabetic nephropathy in rats

Objective:To investigate the effect of Moringa oleifera leaf extract on angiogenesis and inflammatory process in a rat model of streptozotocin-induced diabetic nephropathy.Methods:Four weeks after a single injection of 50 mg/kg streptozotocin,rats were treated with 100 or 200 mg/kg/day Moringa oleifera leaf extract,1 mg/kg/day dapagliflozin,or a combination of Moringa oleifera leaf extract and dapagliflozin for further eight weeks.Renal function,kidney histology,and gene expression were evaluated at the end of the experiment.Results:Renal function of diabetic rats was significantly impaired as evidenced by increased blood urea nitrogen,albuminuria,24-h proteinuria,and high creatinine clearance which indicated glomerular hyperfiltration.In addition,diabetic rats showed an increase in gene expressions of vascular endothelial growth factor-A(VEGF-A),angiopoietin-2(Ang2),the Ang2/Ang1 ratio,tumor necrosis factor-α,interleukin-1βand monocyte chemoattractant protein-1.Immunohistochemical staining demonstrated a significant increase in the density of glycoprotein CD34.Moringa oleifera leaf extract markedly improved all renal dysfunction markers and modulated the upregulated expression of angiogenic factors and inflammatory genes.Conclusions:Moringa oleifera leaf extract could suppress abnormal angiogenesis and inflammatory processes possibly by downregulating gene expression of angiogenesis factors and proinflammatory cytokines.

Actinidia deliciosa as a complemental therapy against nephropathy and oxidative stress in diabetic rats

This study aimed to evaluate the anti-hyperglycemic and antioxidant role of Actinidia deliciosa(kiwifruits)aqueous extract in streptozotocin-treated rats.Animals were distributed into;control,A.deliciosa aqueous extract(ADAE;1 g/kg orally),streptozotocin(STZ;50 mg/kg,i.p,single dose),and STZ plus ADAE,respectively.Results showed that ADAE had high antioxidant and radical scavenging potency.Elevation in blood sugar level,lipid peroxidation(LPO),kidney function biomarkers,and perturbations in hematological parameters were observed in diabetic rats.While,enzymatic and non-enzymatic antioxidants,protein content,and alkaline phosphatase(ALP)activity declined.Furthermore,histological,immunohistochemical alpha-smooth muscle actin immunoreactivity(α-SMA-ir)and histochemical(collagen,total protein,DNA,and RNA)alterations were observed in rat kidneys.Moreover,STZ produced upregulation of inflammatory associated genes(tumor necrosis factor-alpha;TNF-αand transforming growth factorβ1;TGF-β1)and triggered apoptosis by upregulating apoptotic related gene[Bcl2-associated X protein(Bax)]and downregulating anti-apoptotic related gene B-cell lymphoma-2(Bcl-2)based on real-time PCR data.Moreover,diabetic rats administered with ADAE showed significant restoration in LPO,antioxidant status,and biochemical indices besides tissue architecture,and genes improvement regarding STZ group.Conclusively,A.deliciosa has a valuable ameliorative infl uence and can restore glucose levels and improve kidney dysfunction in diabetic rats.

Targeting inflammation in diabetes: Newer therapeutic options

Inflammation has been recognised to both decrease beta cell insulin secretion and increase insulin resis-tance. Circulating cytokines can affect beta cell function directly leading to secretory dysfunction and increased apoptosis. These cytokines can also indirectly affect beta cell function by increasing adipocyte inflamma-tion.The resulting glucotoxicity and lipotoxicity further enhance the inflammatory process resulting in a vicious cycle. Weight reduction and drugs such as metformin have been shown to decrease the levels of C-Reactive Protein by 31% and 13%, respectively. Pioglitazone, insulin and statins have anti-inflammatory effects. In-terleukin 1 and tumor necrosis factor-α antagonists are in trials and NSAIDs such as salsalate have shown an improvement in insulin sensitivity. Inhibition of 12-lipo-oxygenase, histone de-acetylases, and activation of sirtuin-1 are upcoming molecular targets to reduce in-flammation. These therapies have also been shown to decrease the conversion of pre-diabetes state to diabe-tes. Drugs like glicazide, troglitazone, N-acetylcysteine and selective COX-2 inhibitors have shown benefit in diabetic neuropathy by decreasing inflammatory mark-ers. Retinopathy drugs are used to target vascular en-dothelial growth factor, angiopoietin-2, various protein-ases and chemokines. Drugs targeting the proteinases and various chemokines are pentoxifylline, inhibitors of nuclear factor-kappa B and mammalian target of rapa-mycin and are in clinical trials for diabetic nephropathy. Commonly used drugs such as insulin, metformin, per-oxisome proliferator-activated receptors, glucagon like peptide-1 agonists and dipeptidyl peptidase-4 inhibitors also decrease inflammation. Anti-inflammatory thera-pies represent a potential approach for the therapy of diabetes and its complications.

Nrf2 activator corosolic acid meliorates alloxan induced diabetic nephropathy in mice

Objective: To determine whether corosolic acid(CA) targeting nuclear protein expression of Nrf2 activation can be used to attenuate renal damage and preserve renal function in alloxan diabetic mice.Methods: A mouse model with diabetic nephropathy was established to examine the Nrf2 expression. Mice were randomly divided into control, diabetic control, and CA groups treated at 0.4 mg/kg, 2 mg/kg and 10 mg/kg p.o. for 8 weeks. Diabetes was induced in mice by single intraperitoneal injection of alloxan 200 mg/kg in all groups except the control. The mice with fasting blood glucose level over 200 mg/d L were considered as diabetic and were employed in the study. After 4 th and 8 th weeks, urine samples were collected(using metabolic cages) to measure protein and urea. Animals were euthanized, and serum samples were collected to estimate the glucose, creatinine, total protein, urea and blood urea nitrogen. Kidney was isolated at the end of experiment for histology to evaluate anti-oxidant parameters. Immunohistochemistry was performed to examine the Nrf2 expression.Results: CA treatment showed dose dependent reduction in level of biochemical parameters in serum and urine. CA group(10 mg/kg) showed significantly higher body weight and reduced kidney weight. Histopathological examination revealed reduced inflammation, collagen deposition and glomerulosclerosis in renal tissue. CA attenuated renal dysfunction, oxidative stress and inflammatory pro-cytokine levels.Conclusions: CA treatment exhibited ameliorative effect on kidney in mice with its enhanced Nrf2 expression.

Diabetic nephropathy:Treatment with phosphodiesterase type 5 inhibitors

The importance of nitric oxide(NO) in vascular physiology is irrefutable;it stimulates the intracellular production of cyclic guanosine monophosphate(cGMP),initiating vascular smooth muscle relaxation.This biochemical process increases the diameter of small arteries,regulating blood flow distribution between arterioles and the microvasculature.The kidney is no exception,since NO predominantly dilates the glomerular afferent arterioles.It is now evident that the vascular production of cGMP can be augmented by inhibitors of phosphodiesterase type 5(PDE 5),the enzyme which breakdowns this cyclic nucleotide.This has clinical relevance,since diabetic nephropathy(DN) a major microvascular complication of diabetes mellitus and the most common cause of end-stage renal disease,increases intraglomerular capillary pressure,leading to glomerular hypertension.PDE 5 inhibitors may have,therefore,the potential to reduce glomerular hypertension.This review describes the use of PDE 5 inhibitors to improve the metabolic,haemodynamic and inflammatory pathways/responses,all of which are dysfunctional in DN.

NF-kB Inhibitor Parthenolide Promotes Renal Tubules Albumin Uptake in Type 2 Diabetic Nephropathy

Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy;however,the underlying mechanism has not been fiilly elucidated.In this study,we aimed to explore whether reducing inflammation and remodeling the insulin signaling pathway could improve albumin uptake of renal tubules.Methods 8-week-old male db/db mice(n=8),a type 2 diabetic nephropathy model,administered with nuclear factor kappa-B(NF-kB)inhibitor parthenolide(PTN,1 mg/kg)intraperitoneally every other day for 8 weeks,were as the treatment group.Meanwhile,the age-matched male db/m mice(n=S)and db/db mice(n=8)were treated with saline as the control group and type 2 diabetic nephropathy group.When the mice were sacrificed,blood and urine were collected to examine homeostasis model assessment of insulin resistance(HOMA-IR)and urine albumin creatinine ratio,and kidney samples were used to analyze histopathologic changes with periodic acid-Schiff(PAS)staining,NF-kB p65,phosphorylation of AKT(p-AKT),amnionless and cubilin expressions with immunohistochemistry as well as western blot,and the albumin uptake of renal tubules by using immunofluorescence.In addition,HKC cells were divided into the insulin group treated with insulin alone,the TNF-a group treated with insulin and tumor necrosis factor(TNF-a),and the TNF-a+PTN group exposed to PTN,insulin and TNF-a.The levels of albumin uptake and expression levels of NF-kB p65,p-IRS-l/IRS-1,p-AKT/AKT,amnionless and cubilin in HKC cells were measured.Results Compared with the db/db group,the db/db+PTN group demonstrated decreased levels of HOMA-IR(36.83±14.09 vs.31.07+28.05)and urine albumin creatinine ratio(190.3±7.3 vs.143.0±97.6 mg/mmol);however,the differences were not statistically significant(P>0.05).Periodic acid-Schiff staining showed PTN could alleviate the glomerular hypertrophy and reduce the matrix in mesangial areas of db/db mice.The renal expression of NF-kB p65 was increased and p-AKT(s473)decreased in the db/db group compared with the db/m group(P<0.05).PTN significantly reduced the renal expression of NF-kB p65 and ameliorated the decline of p-AKT(s473)compared with the db/db group(P<0.05).Compared with the db/m group,the expression of amnionless and cubilin decreased and albumin uptake in tubules were reduced in the db/db group(P<0.05),and PTN could significantly increase the expression of cubilin(P<0.05),and improve albumin uptake in tubules.Insulin promoted albumin uptake and the expression of amnionless and cubilin in HKC cells(P<0.05).TNF-a stimulated the expression of NF-kB p65,increased p-IRS-1(s307)and reduced p-AKT(s473)in HKC cells(PV 0.05).In theTNF-a+PTN group,the expression of NF-kB p65 declined and p-IRS-1(s307)and p-AKT(s473)were restored,compared with theTNF-a group(P<0.05).The expression of amnionless and cubilin decreased in theTNF-a group(P<0.05),and PTN could significantly increase the expression of cubilin(P<0.05).Conclusions Inflammation caused damage to insulin signaling,which reduced amnionless-cubilin expression and albumin uptake.PTN could reduce inflammation and remodel the impaired insulin signaling pathway,which promoted the expression of cubilin and albumin uptake.Our study can shed light on the role of inflammation in the reduction of albumin uptake of renal tubules in type 2 diabetic nephropathy.

Role of angiotensin converting enzyme and angiotensinogen gene polymorphisms in angiotensin converting enzyme inhibitor-mediated antiproteinuric action in type 2 diabetic nephropathy patients

AIM To investigate the role of genetic variants of angiotensin converting enzyme(ACE) and angiotensinogen(AGT) genes in the antiproteinuric efficacy of ACE inhibitor therapy in diabetic nephropathy(DN) patients.METHODS In the present study, 270 type 2 diabetes mellitus patients with nephropathy were enrolled and treated with ACE inhibitor(ramipril) and followed at 6 mo for renal function and albumin excretion by estimating serum creatinine, end stage renal disease, and albumin/creatinine ratio(ACR) in urine. Genotyping of ACE I/D and AGT M235 T polymorphisms were performed by using primer specific polymerase chain reaction(PCR) and PCR-RFLP techniques, respectively. RESULTS Forty-eight percent of DN patients(responders) benefited with respect to proteinuria from ACE inhibitor therapy at 6 mo follow-up. A significant reduction in ACR was observed after 6 mo treatment with ACE inhibitor irrespective of whether DN patients were micro-albuminuric(≥ 30 and < 300 mg/g creatinine) or macro-albuminuric(≥ 300 mg/g creatinine) at the time of enrollment. However, macro-albuminuric patients(55%) showed better response to therapy. A reduction in urinary ACR was found independent of genotypes of ACE I/D and AGT M235 T polymorphisms although macro-albuminuric patients having TT genotype showed statistically insignificant increased response(72%). CONCLUSION ACE inhibitor therapy reduced urinary ACR by ≥ 30% in 50% of DN patients and the response is independent of ACE I/D and AGT M235 T polymorphisms.

Ameliorative effect of berberine on high-fat diet/streptozotocin-induced early diabetic nephropathy in rats

OBJECTIVE To investigate possible protective effect of berberine,an isoquinoline alkaloid,is the major active constituent of Rhizoma coptidis and Cortex phellodendri,on high-fat diet/streptozotocin-induced early diabetic nephropathy in rats and various mechanisms underlie this effect.METHODS The diabetic rat model was generated by a single intraperitoneal injection of streptozotocin(STZ,50 mg·kg-1).Diabetic rats were randomlyassigned into the following five groups:control,DN,losartan(30 mg·kg-1·d-1),berberine(100,200 mg·kg-1·d-1).Berberine and losartan were given intragastricly for nine weeks.At the end of the experiment,urine of each group was collected in a 24 h period.Rats were weighed and then sacrificed.Plasma and kidneys were collected.The levels of blood glucose,creatinine(Cr),triglycerides(TG),total cholesterol(TCH)and malondialdehyde(MDA)in serum were determined using commercial kits according to the manufacturer′s instructions.Transforming growth factor(TGF)-β1and intracellular adhesion molecule-1(IAM-1)mR NA levels were evaluated by RT-PCR.The renal histopathology was observed by light microscopy.Further biochemical analysis of IKKβ1 and p65(nucleus/cytoplasm)was provided using Western blotting techniques.RESULTS Our study has demonstrated that berberine has various pharmacological activities.The DN rats had significantly higher kidney/body weight ratio(17.4±1.4)mg·g-1,and berberine treatment could reduce this ratio change 13.6±0.6 and(11.6±0.8)mg·g-1,respectively;glucose control still remains the only disease-modifying therapy for diabetic complications,FBG was also recorded in the experiment.The findings reveal that the DN group showed a significantly higher glucose level(28.67±2.78)mmol·L-1.Treatment with8 weeks of berberine improved these parameters except blood glucose〔(18.67±2.59)mmol·L-1and 16.45±1.80 vs(28.67±2.78)mmol·L-1:plasma levels of urea nitrogen(15.67±2.48)mmol·L-1and 14.45±2.40 vs(12.26±2.40)mmol·L-1〕;plasma levels of 24 h urine albuminuria〔30.48±1.56 and 25.72±2.24 vs(15.26±0.12)μg·d-1〕;based on these results,berberine supposed to improve renal functions in diabetic rats.Berberine also ameliorated the inflammatory changes of DN in diabetic animals;levels of TG,TCH and MDA in berberine-treatment rats were significantly lower compared with those in the DN group:TG〔2.78±0.24 and 2.45±0.36 vs(5.20±0.60)mmol·L-1〕;TCH〔4.26±0.46 and 3.74±0.68 vs(6.26±0.50)mmol·L-1〕;MDA〔4.94±1.19 and 4.28±0.64 vs(4.28±0.64)nu·mL-1〕.Chronic inflammation,as is observed in diabetes,is associated with increased production of TGF-β1and IAM-1.Compared with the renal tissues of DN group,TGF-β1and IAM-1 gene expressions in berberine treated groups were reduced at the dose levels(100 and 200 mg·kg-1).And TGF-β1and IAM-1levels in berberine treated groups were reduced in a dosedependent manner:Relative expression of TGF-β1mR NA level(3.56±0.28 and 3.12±0.14 vs 5.12±0.44);Relative expression of IAM-1 mR NA leve(l1.78±0.56 and 1.42±0.24vs 4.36±0.35).Research finds that the NF-κB signaling pathway is activated in the renal tissue of diabetic mice and berberine inhibits activation of the NF-κB pathway:staining score for IKKβ1(4.34±0.26 and 3.82±0.24 vs 6.23±0.76),staining score for p65(2.34±0.26 and 1.74±0.78 vs 6.23±0.24)in nucleus and staining score for p65(7.21±0.13 and8.15±0.45 vs 4.23±0.54)in cytoplasm.CONCLUSION In this field,berberine suppresses the increased expression of p65 in the nucleus and decreases it in cytoplasm,which leads to the inhibition of the NF-κB pathway.These changes will result in decreasing the transcription and translation of many inflammatory mediators,such as TGF-β1and IAM-1.Additionally,these changes decrease the number of inflammatory cells and mononuclear macrophage infiltration into glomeruli and renal interstitium.These results indicated that berberine can protect the kidney of STZ-diabetic rats by reducing the expression of TGF-β1and IAM-1 in the renal tubulointerstitium.And we propose that berberinemayfunction as an effective therapeutic agent for diabetic nephropathy and attenuate the progression of renal injury.

Mechanisms of Dihuang(Rehmanniae Radix)in treating diabetic nephropathy complicated with depression based on network pharmacology

Objective To predict the molecular mechanism of Dihuang(Rehmanniae Radix)in the treatment of diabetic nephropathy(DN)complicated with depression based on network pharmacology.Methods The components of Dihuang(Rehmanniae Radix)were identified from the Integrated Pharmacology-based Research Platform of Traditional Chinese Medicine(TCMIP),Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP),and relevant literature.The component targets were detected by combining the SwissTargetPrediction and Pub Chem databases.Disease targets were collected from the Therapeutic Target Database(TTD),Dis Ge NET,and Ensembl databases with“diabetic nephropathy”and“depression”as keywords.The disease-component targets were mapped using Venny 2.1.0 to obtain potential targets.A protein-protein interaction(PPI)network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins(STRING)database and Cytoscape 3.7.2.The co-expression genes of the key targets were collected based on the COXPRESdb 7.3.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis were performed for potential targets using R language.Target-component docking was verified and evaluated using Discovery Studio 4.5.Results According to the databases and literature reports,Dihuang(Rehmanniae Radix)contained 65 active components,and had 155 related targets for the treatment of DN complicated with depression.PPI screening showed that the key targets included serine/threonine protein kinase 1(AKT1),signal transducer and activator transcription 3(STAT3),interleukin 6(IL-6),mitogen-activated protein kinase 1(MAPK1),and vascular endothelial growth factor A(VEGFA),etc.GO enrichment analysis mainly involved biological processes,such as lipid metabolism,protein secretion regulation,cell homeostasis,and phosphatidylinositol 3 kinase activity.KEGG pathway enrichment analysis included the role of the AGE-RAGE signaling pathway in diabetic complements,insulin resistance(IR),neurotrophin signal path,Toll-like receptor signaling pathway,relaxin signaling pathway,epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs),etc.Molecular docking showed that the target had high affinity for stachyose,manninotriose,verbascose,nigerose,etc.Conclusion Based on network parmacology,this study preliminarily predict the effects of Dihuang(Rehmanniae Radix)in treating DN complicated with depression by regulating inflammation,glucose metabolism,nution nerve,etc.

Clopidogrel delays and can reverse diabetic nephropathy pathogenesis in type 2 diabetic db/db mice

BACKGROUND Diabetic nephropathy(DN)is the principal cause of end-stage renal disease.Previous studies have shown that clopidogrel can prevent the early progression of renal injury.AIM To elucidate whether clopidogrel is beneficial against DN by using a db/db mouse model.METHODS db/db mice with a higher urinary albumin/creatinine ratio(ACR)relative to ageand sex-matched wild-type control mice were randomly allocated to clopidogrel and vehicle treatment groups.Clopidogrel was administered at doses of 5,10,and 20 mg/kg by gavage for 12 wk.Body mass,blood glucose level,and urinary creatinine and albumin concentrations in each group were measured before and after the intervention.Renal fibrosis was evaluated using periodic acid-Schiff and Masson’s trichrome staining.The renal protein expression of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and F4/80 was assessed using immunohistochemistry.Urinary TNF-α,monocyte chemoattractant protein-1(MCP-1),and IL-6 levels were analyzed using enzyme-linked immunosorbent assay;TNF-αand IL-1βmRNA expression was measured using real-time quantitative polymerase chain reaction.The protein expression of fibronectin(FN)and collagen I was assessed using immunohistochemistry.RESULTS Clopidogrel treatment did not affect the body mass or blood glucose level of the db/db mice;however,it increased bleeding time and reduced urinary ACR in a dose-dependent manner.Immunohistochemical staining revealed an amelioration of renal fibrosis,significantly lower deposition of FN and collagen I,and significantly lower expression of the proinflammatory cytokines TNF-αand IL-1βand lower levels of urinary TNF-αand MCP-1 in the clopidogrel-treated db/db mice(P<0.05).Furthermore,clopidogrel significantly reduced macrophage infiltration into the glomeruli of the db/db mice.CONCLUSION Clopidogrel significantly reduced renal collagen deposition and fibrosis and prevented renal dysfunction in db/db mice,most likely through inhibition of renal macrophage infiltration and the associated inflammation.