Rat Model Of Diabetic Nephropathy Research Articles

Tangshenping granule inhibits pyroptosis in a rat model of streptozotocin-induced diabetic nephropathy via the NLRP3/caspase-1/GSDMD pathway

To explore the inhibitory effect of Tangshenping (TSP) on pyroptosis in a streptozotocin-induced diabetic nephropathy (DN) rat model. DN was established in Sprague–Dawley rats. Rats were randomly divided into DN (model group), irbesartan, and TSP low-, medium-, and high-dose groups, besides the control group. The 24 h albuminuria content, and serum content of TC, TGs, Scr, IL-1β, UREA, LDLs, and IL-18 were assessed. Hematoxylin & eosin and Mallory staining were performed to examine pathological changes in the kidney. The mRNA and protein expression of NLRP3, caspase 1, and GSDMD in the kidney were also examined. The 24 h albuminuria content was obviously lower in the treatment groups compared to the model group (all P < .01). Levels of TC, TGs, Scr, UREA, LDLs, and IL-18 after drug interventions were obviously lower compared to the model group (all P < .05). The serum content of IL-1β in the TSP medium- and high-dose groups were much lower compared to the model group ( P = .013 and P = .001, respectively). Through immunohistochemistry and western blotting, we observed that the protein expressions of NLRP3, caspase-1, GSDMD, IL-1β, and IL-18 were lower after drug interventions compared to the model group (all P < .05). Using qPCR, we observed that the mRNA expressions of caspase-1, IL-1β, IL-18, and GSDMD after drug interventions were significantly lower compared to the model group (all P < .05). The mRNA expressions of NLRP3 in the TSP medium- and high-dose groups were both lower compared to the model group (all P < .05). TSP downregulated mRNA and protein expressions of NLRP3, caspase-1, and GSDMD. Our findings demonstrate that the beneficial effects of TSP on renal function are at least partly mediated by the inhibition of micro-inflammation and modulation of the expression of pyroptosis-related factors.

Overexpressing STAMP2 attenuates diabetic renal injuries via upregulating autophagy in diabetic rats

Diabetic nephropathy (DN) is one of the most serious and major renal complications of diabetes. Previously, Six-transmembrane Protein of Prostate 2 (STAMP2) was reported to contribute to nutritional stress. The purpose of this study is to investigate whether overexpression of STAMP2 attenuates diabetic renal injuries in DN rats. We induced the DN rat model by high-fat diet and low-dose streptozotocin and evaluated the metabolite and urine albumin/creatinine. Recombinant adeno-associated virus vectors were injected for overexpression of STAMP2. Pathophysiologic and ultrastructure features of DN by histochemical stain and transmission electron microscope, autophagy-related proteins and signaling pathway by western blotting were assessed. We found the expression of STAMP2 was decreased and autophagy was blunted in DN rat kidneys. Overexpressing STAMP2 significantly ameliorated metabolic disturbance, insulin resistance, and specifically restoring diabetic renal injury. Furthermore, overexpressing STAMP2 improved the autophagy deficiency in DN rats, as revealed by changes in the expressions of Beclin1, p62, and LC3. Furthermore, STAMP2 overexpressing promoted autophagy by inhibiting the mTOR and activating the AMPK/SIRT1 signaling pathway. Our results suggested that STAMP2 overexpression attenuated renal injuries via upregulating autophagy in DN rats. STAMP2 overexpressing promoted autophagy may been involved with inhibition of the mTOR/ULK1 and activation of the AMPK/SIRT1 signaling pathway.

Retraction.

Retraction: "Effects of microRNA-370 on mesangial cell proliferation and extracellular matrix accumulation by binding to canopy 1 in a rat model of diabetic nephropathy," by Feng-Na Yu, Ming-Lan Hu, Xin-Fang Wang, Xiang-Ping Li, Bei-Hao Zhang, Xiao-Qing Lu, Rui-Qiang Wang, J Cell Physiol. 2019; 6898-6907: The above article, published online on 14 October 2018 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/jcp.27448) has been retracted by agreement between the journal's Editor in Chief, Prof. Dr. Gregg Fields, and Wiley Periodicals LLC. The retraction has been agreed following an investigation based on allegations raised by a third party. A detailed investigation revealed that several image elements of the experimental data were published elsewhere in a different scientific context. Thus, the editors consider the conclusions of this article to be invalid.

Apelin‑13 alleviates diabetic nephropathy by enhancing nitric oxide production and suppressing kidney tissue fibrosis.

Diabetes is a serious metabolic disease, and the kidney damage induced by diabetes also seriously affects the survival of patients. Apelin is a molecule that plays a crucial role in lipid metabolism, and recent studies have revealed that apelin-13, a subtype of apelin, plays an important role in regulating blood glucose levels. However, the role of apelin-13 in diabetic nephropathy remains unclear. In the present study, a rat model of diabetic nephropathy was constructed by the injection of streptozocin (STZ). During this process, these rats were injected with apelin-13. The blood glucose, urine protein and insulin levels were determined weekly. Next, the expression of angiotensin domain type 1 receptor-associated protein (APJ), endothelial nitric oxide synthase (eNOS), E-cadherin and α-smooth muscle actin (α-SMA) in the kidney tissues was determined with western blotting. Then, the endothelial cells of glomerular vessels were cultured with high glucose medium. These cells were treated with apelin-13 for 24 h. Finally, cell viability of these cells and the expression of APJ, eNOS, E-cadherin and α-SMA in these cells were determined with western blotting. As a result, treatment of apelin-13 induced the lower levels of blood glucose and urine protein. In addition, application of apelin-13 promoted the production of insulin and alleviated the insulin resistance. Treatment with apelin-13 promoted the expression of APJ, eNOS and E-cadherin while it suppressed the expression of α-SMA in kidney tissues of rats and endothelial cells of glomerular vessels. Furthermore, application of apelin-13 also promoted the cell viability of these cells. In conclusion, apelin-13 relieved diabetic nephropathy by promoting the production of nitric oxide (NO) and alleviating the fibrosis of kidney tissues.

Early Renoprotective Effect of Ruxolitinib in a Rat Model of Diabetic Nephropathy.

Diabetic kidney disease (DKD) is still one of the unresolved major complications of diabetes mellitus, which leads ultimately to end-stage renal disease in both type 1 and type 2 diabetes patients. Available drugs that suppress the renin–angiotensin system have partially minimized the disease impact. Yet, there is an unmet need for new therapeutic interventions to protect the kidneys of diabetic patients. In DN, glomerular sclerosis and tubulointerstitial fibrosis are mediated through several pathways, of which JAK/STAT is a key one. The current study explored the potential renoprotective effect of the JAK1/JAK2 inhibitor ruxolitinib (at doses of 0.44, 2.2, and 4.4 mg·kg−1) compared to that of enalapril at a dose of 10 mg·kg−1, in a rat model of streptozotocin-induced diabetes mellitus over 8 weeks. The effect of ruxolitinib was assessed by determining urinary albumin/creatinine ratio, serum level of cystatin, and levels of TGF-β1, NF-κB, and TNF-α in renal tissue homogenates by biochemical assays, the glomerular sclerosis and tubulointerstitial fibrosis scores by histological analysis, and fibronectin, TGF-β1, and Vimentin levels by immunohistochemical staining with the respective antibodies. Our results revealed a significant early favorable effect of a two-week ruxolitinib treatment on the renal function, supported by a decline in the proinflammatory biomarkers of DKD. This pre-clinical study suggests that the renoprotective effect of ruxolitinib in the long term should be investigated in animals, as this drug may prove to be a potential option for the treatment of diabetic kidney disease.

Stabilized-chitosan selenium nanoparticles efficiently reduce renal tissue injury and regulate the expression pattern of aldose reductase in the diabetic-nephropathy rat model

One of the global alarming prevalent metabolic diseases is Type 2 diabetes mellitus (T2DM) than other diabetes and sustains a substantial burden on public and healthcare systems. This study attempts to endeavor the beneficial effect of chitosan stabilized nanoparticles Ch-SeNPs on combating diabetic nephropathy (DN) after induction of T2DM in rats (DN.STZ-induced T2D). High-fat diet (HFD) and STZ were used for the induction of T2DM in rats, and then they were treated with either metformin alone (MEF) (500 mg/kg b.wt.) or combined with (Ch-SeNPs) (2 mg Se/kg b.wt.) for eight weeks. The microvascular complications in renal tissue of diabetic rats were pronounced by the prevalence of microalbuminuria and elevated levels of urea, creatinine, and BUN. Pronounced oxidative stress with enhanced inflammatory response. In the urine of diabetic rats, a marked increase in Kim 1, β2-microglobulin, and urinary albumin. Renal morphological alterations were observed in all groups upon induction of T2DM, except for the Ch-SeNPs/MEF group showed noticeable improvements. The expression levels of Aldo-keto reductase AKr1B1, profibrotic protein transforming growth factor-β1 (TGF-β1), nestin, desmin, and vimentin, were up-regulated in the diabetic group. Significant down-regulation of their expression and restored antioxidant capacity was observed in the combined-treated group than single treated ones. Ch-SeNPs helped limit the prevalence of TNF-α, IL-6, and IL-1β while used after T2DM induction by STZ and HFD. Ch-SeNPs/MEF co-therapy could effectively guard the kidneys and reduce the renal tissue injury via inhibiting oxidative stress and restoring glucose hemostasis, which indicates a promising line for treating T2DM nephropathy.

Fabrication of All-Trans Retinoic Acid loaded Chitosan/Tripolyphosphate Lipid Hybrid Nanoparticles as a Novel Oral Delivery Approach for Management of Diabetic Nephropathy in Rats.

The present study aims to formulate all-trans retinoic acid (ATRA) loaded chitosan/tripolyphosphate lipid hybrid nanoparticles (CTLHNs) for enhancing its solubility and oral delivery. This is to improve ATRA therapeutic effect on diabetic nephropathy (DN). CTLHNs were prepared by o/w homogenization, employing stearic acid, to form lipid nanoparticles coated with chitosan that is stabilized against acidic pH via sodium tripolyphosphate crosslinking. Chitosan coated (F7) and naked lipid nanoparticles (F6) were also prepared for comparison with CTLHNs. In vitro characterization for the prepared formulations was performed comprising entrapment efficiency, particle size, zeta potential, transmission electron microscopy, FT-IR spectroscopy and x-ray diffraction. Stability of chitosan coat in GI fluid revealed that CTLHNs were more stable than F7. In vitro release indicated an enhanced release of ATRA from the developed formulations. In vitro mucoadhesion study proved a notable mucoadhesive property for CTLHNs. In DN rat model, serum levels of creatinine and urea were elevated, over expression of tumor necrosis factor alpha (TNF-α), granulocyte macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) were observed. In addition, adenosine monophosphate activated protein kinase (AMPK) and liver kinase B1 (LKB1) expressions were decreased in DN rats. Treatment with free ATRA and the selected formulations led to a significant amelioration of DN by reducing of creatinine, urea, TNF-α, ICAM-1, GM-CSF, VEGF levels as well as elevating AMPK and LKB1 levels. The order of activity was: CTLHNs > F7 > F6 > free ATRA, as proved by histopathological examination.

Combined Melatonin and Extracorporeal Shock Wave Therapy Enhances Podocyte Protection and Ameliorates Kidney Function in a Diabetic Nephropathy Rat Model.

(1) Background: Diabetic nephropathy (DN) is common complication of diabetes. Current therapy for DN does not include promotion of podocyte protection. Therefore, we investigated the therapeutic effect of melatonin (Mel) combined extracorporeal shock wave (SW) therapy on a DN rat model. (2) Methods: The DN rats were treated with Mel (5 mg/kg) twice a week for 6 weeks and SW treatment once a week (0.13 mJ/mm2) for 6 weeks. We assessed urine microalbumin, albumin to creatinine ratio (ACR), glomerular hypertrophy, glomerular fibrosis, podocyte markers (Wilm’s tumor protein-1, synaptopodin and nephrin), cell proliferation, cell survival, cell apoptosis, renal inflammation and renal oxidative stress. (3) Results: The Mel combined SW therapy regimen significantly reduced urine microalbumin excretion (3.3 ± 0.5 mg/dL, p < 0.001), ACR (65.2 ± 8.3 mg/g, p < 0.001), glomerular hypertrophy (3.1 ± 0.1 × 106 μm3, p < 0.01) and glomerular fibrosis (0.9 ± 0.4 relative mRNA fold, p < 0.05). Moreover, the Mel combined SW therapy regimen significantly increased podocyte number (44.1 ± 5.0% area of synaptopodin, p < 0.001) in the Mel combined SW group. This is likely primarily because Mel combined with SW therapy significantly reduced renal inflammation (753 ± 46 pg/mg, p < 0.01), renal oxidative stress (0.6 ± 0.04 relative density, p < 0.05), and apoptosis (0.3 ± 0.03 relative density, p < 0.001), and also significantly increased cell proliferation (2.0 ± 0.2% area proliferating cell nuclear antigen (PCNA), p < 0.01), cell survival, and nephrin level (4.2 ± 0.4 ng/mL, p < 0.001). (4) Conclusions: Mel combined SW therapy enhances podocyte protection and ameliorates kidney function in a DN rat model. Mel combined SW therapy may serve as a novel noninvasive and effective treatment of DN.

The role of transcription factor Ap1 in the activation of theNrf2/ARE pathway through TET1 in diabetic nephropathy.

TET1mediates demethylation in tumors, but its role in diabetic nephropathy (DN), a prevalent diabetic complication, is unclear. We attempted to probe the possible mechanism of TET1 in DN. A DN rat model was established and verified by marker detection and histopathological observation. The in vitro model was established on human mesangial cells (HMCs) induced by high glucose (HG), and verified by evaluation of fibrosis and inflammation. The differentially expressed mRNA was screened out by microarray analysis. The most differentially expressed mRNA (TET1) was reduced in DN rats and HG-HMCs. The upstream and downstream factors of TET1 were verified, and their roles in DN were analyzed by gain- and loss-function assays. TET1 was decreased in DN rats and HG-HMCs. High expression of TET1 decreased biochemical indexes and renal injury of DN rats and hampered the activity, fibrosis, and inflammation of HG-HMCs. Ap1 lowered TET1 expression, and enhanced inflammation in HG-HMCs, and accentuated renal injury in DN rats. TET1 overexpression inhibited the effect of Ap1 on DN. TET1 promoted the transcription of Nrf2. The Ap1/TET1 axis mediated the Nrf2/ARE pathway activity. Overall, TET1 overexpression weakened the inhibitory effect of Ap1 on the Nrf2/ARE pathway, thus alleviating inflammation and renal injury in DN.

Combination CTLA-4 immunoglobulin treatment and ultrasound microbubble-mediated exposure improve renal function in a rat model of diabetic nephropathy.

Objective: This study explored the therapeutic impact of combined cytotoxic T lymphocyte-associated antigen 4 immunoglobulin (CTLA-4-Ig) treatment and microbubble-mediated exposure in a rat model of diabetic nephropathy (DN).Method: We treated rats using CTLA-4-Ig and/or microbubble exposure. At 8 weeks post-intervention, key parameters were evaluated including blood biochemistry, damage to renal tissue, renal parenchymal elasticity, ultrastructural changes in podocytes, and renal parenchymal expression of CD31, CD34, IL-6, Fn, Collagen I, Talin, Paxillin, α3β1, podocin, nephrin, and B7-1.Result: We found that renal function in the rat model of DN can be significantly improved by CTLA-4-Ig and CTLA-4-Ig + ultrasound microbubble treatment. Treatment efficacy was associated with reductions in renal parenchymal hardness, decreases in podocyte reduction, decreased IL-6, Fn and Collagen I expression, increased Talin, Paxillin and α3β1 expression, elevated podocin and nephrin expression, and decreased B7-1 expression. In contrast, these treatments did not impact CD31 or CD34 expression within the renal parenchyma.Conclusion: These findings clearly emphasize that CTLA-4-Ig can effectively prevent podocyte damage, inhibiting inflammation and fibrosis, and thereby treating and preventing DN. In addition, ultrasound microbubble exposure can improve the ability of CTLA-4-Ig to pass through the glomerular basement membrane in order to access podocytes such that combination CTLA-4-Ig + microbubble exposure treatment is superior to treatment with CTLA-4-Ig only.

Emodin Ameliorates Renal Damage and Podocyte Injury in a Rat Model of Diabetic Nephropathy via Regulating AMPK/mTOR-Mediated Autophagy Signaling Pathway.

PurposeThe activation of autophagy has potential protective effect on diabetic nephropathy (DN) podocyte injury, and the AMPK/mTOR signaling pathway is an important regulatory pathway of autophagy. Emodin has been reported to effectively delay DN progression; however, the therapeutic mechanisms involved in vivo remain ambiguous. The present study aimed to elucidate the mechanism of emodin in improving renal tissue and podocyte injury in DN by regulating the AMPK/mTOR-autophagy signaling pathway.MethodsAll rats were divided into 4 groups: a Sham group, a Vehicle group, a low-dose emodin (LD-Emo) group (20 mg/kg/day) and a high-dose emodin (HD-Emo) group (40 mg/kg/day). The different doses of Emo and distilled water were daily administrated for 8 weeks after the induction of DN by the unilateral nephrectomy combined with intraperitoneal injections of streptozotocin (STZ). The rats' general status, blood glucose, biochemical parameters, urinary protein excretion, renal histological changes and cell apoptosis in renal tissue, as well as the key protein expressions in the AMPK/mTOR signaling pathway and apoptosis-related proteins were examined, respectively.ResultsEmodin ameliorated the general condition, kidney weight and urinary protein excretion of the rats, but has little influence on serum biochemical parameters and did not lower blood glucose; emodin attenuated renal fibrosis including the cell numbers, extracellular matrix rate and collagen area in glomerulus, simultaneously relieved podocyte foot process fusion, up-regulated the expression of nephrin protein and suppressed glomerular and tubular epithelial cell apoptosis. In addition, emodin can induce and enhance autophagy in podocytes including increased expression of LC3-II/I, Beclin-1, p-AMPK protein and decreased expression of p62, p-mTOR protein, as well as increased autophagosomes in podocytes.ConclusionWe have demonstrated that emodin, as a natural regulator in vivo, reduced proteinuria and alleviated renal fibrosis without affecting hyperglycemia in DN rats. The potential mechanisms by which emodin exerts its renoprotective effects in vivo are through suppressing cell apoptosis and enhancing autophagy of podocytes via the AMPK/mTOR signaling pathway in the kidney.

Role of Angiotensin II and Renal Nerves on TGF-b/SmadPathway in Diabetic Nephropathy Rat Model

AbstractBackground: Renal nerves and Renin-Angiotensin Aldos-terone System (RAAS) are involved in the early renal patho-logical changes occurring during the development of DiabeticNephropathy (DN). Bilateral renal nerve denervation (BRD)and angiotensin II (AngII) blockade have renoprotectiveeffects by retarding the progression of renal fibrosis throughTransforming growth factor b 1 (TGF-b 1) signaling. This study aimed to compare therole of AngII and renal nerves on TGF-b/Smadpathway in diabetic nephropathy rat model.Material and Methods: Eightymale Sprague-Dawley ratsdivided into 4 groupswere used: Group 1 (normal controlgroup), group II (untreated diabetic nephropathy group), group III (diabetic nephropathytreated by valsartan), group IV (diabetic nephropathytreated by renal denervation). Rats wereassessed by measuring Blood Pressure (BP), blood glucose,body and kidney weights, fluid and food intake and urinevolume/24h, renal function tests, mRNA expression andactivity of TGF-b 1 and Smad3 and histopathological changes in all groups at the end of fourth week of valsartan administration and BRD operation.Results: Valsartan and BRD treatment significantlyim-proved renal functionand reduced ABP, blood glucose level,histopathological score and TGF-b 1 and Smad3 and theirmRNA expression with significant difference between themand the control and untreated groups.Conclusion: Valsartan appeared to alleviate DN by sup-pressing TGF-b 1 and ph-Smad3. This also occurs in case of renal denervation but to a lesser degree.

Ginkgo biloba leaf extract prevents diabetic nephropathy through the suppression of tissue transglutaminase.

The present study aimed to investigate the preventive effects of Ginkgo biloba leaf extract (GBE) against extracellular matrix (ECM) accumulation in a streptozotocin (STZ)-induced rat model of diabetic nephropathy (DN), and to determine its underlying molecular mechanism. In vivo, a rat model of DN was established by intraperitoneal injection of STZ, and the rats were subsequently administered GBE. The results demonstrated that GBE significantly decreased blood glucose, the urine protein excretion rate and ECM accumulation in DN rats. In addition, the development of DN significantly induced tissue transglutaminase (tTG) protein expression, which was detected by immunohistochemistry, western blotting and PCR analyses, while GBE administration decreased tTG expression in the diabetic kidney. In vitro, rat glomerular mesangial cells (HBZY-1 cells) cultured with high glucose were also treated with GBE. The concentrations of tTG, fibronectin, type IV collagen, transforming growth factor (TGF)-β and connective tissue growth factor (CTGF) were detected via ELISA. The results demonstrated that GBE notably decreased the concentration of these proteins, and tTG expression was positively associated with TGF-β. GBE also suppressed tTG expression of high glucose-treated HBZY-1 cells in a concentration-dependent manner. Furthermore, tTG protein expression was detected in high glucose-treated HBZY-1 cells transfected with small interfering RNA (siRNA) oligonucleotides against TGF-β and CTGF to investigate a possible mechanism of GBE-mediated inhibition of tTG. The results demonstrated that the tTG levels remained unchanged in CTGF siRNA-transfected cells, but were decreased in the GBE + CTGF siRNA group compared with the control siRNA group, suggesting that tTG may not be regulated by CTGF, and the inhibitory effect of GBE on tTG may not be associated with the direct inhibition of CTGF. However, tTG expression was decreased following the transfection with TGF-β siRNA, in which levels of tTG were similar compared with both the GBE group and GBE + TGF-β siRNA group, indicating that tTG may be regulated by TGF-β, and that the GBE-induced repression of tTG expression may be associated with the downregulation of TGF-β. Taken together, the results of the present study suggest that GBE prevented ECM accumulation by suppressing tTG expression in DN, which was predominantly mediated by TGF-β.

Galangin protects against oxidative damage and attenuates inflammation and apoptosis via modulation of NF-κB p65 and caspase-3 signaling molecules in a rat model of diabetic nephropathy.

Oxidative tissue injury and inflammatory response are the main regulators of diabetic nephropathy (DN). The potential protective effect of galangin (Gal), a powerful flavonoid with several promising bioactivities, on hyperglycemia-induced kidney injury in a rat model of DN has been investigated in this study. A rat model of diabetes was induced by intraperitoneal injection of 50 mg kg⃛1 streptozotocin (STZ). Rats were treated orally with Gal (15 mg kg⃛1 d⃛1) for 8 weeks. Diabetic animals demonstrated elevated levels of glucose and glycosylated hemoglobin along with reduced insulin levels. Hyperglycemia was associated with a remarkable increase in malondialdehyde and protein carbonyl along with a significant decrease in reduced glutathione, superoxide dismutase and catalase in the kidney of rats. Diabetic rats showed a remarkable increase in blood creatinine and blood urea nitrogen (BUN) and urine albumin. Additionally, diabetic rats demonstrated increased nuclear factor kappaB (NF-κB) p65 expression and pro-inflammatory cytokines (tumor necrosis factor-α, interleukin 1β and interleukin 6) levels in the renal tissue. Gal ameliorated hyperglycemia, oxidative stress and inflammation and increased antioxidants in the kidney of diabetic rats. In addition, Gal decreased Bax and caspase-3 and increased Bcl-2 in the kidney of diabetic animals. In conclusion, Gal improved renal function and ameliorated oxidative stress, inflammation and apoptosis in the kidney of diabetic rats. Gal might have therapeutic potential for the treatment of DN, which deserves exploration in upcoming studies.

Sanguinarine Ameliorates Diabetic Nephropathy in Rats through Nuclear Factor-Kappa B and Nuclear-Factor Erythroid 2-Related Factor 2/Heme Oxygenase-1 Pathways

Alkaloids - derived from natural plants - were widely used for therapy in diabetes or diabetes-related complications. Sanguinarine, a benzophenanthridine alkaloid derived from Sanguinaria canadensis, has been identified as a potential drug for type 2 diabetes. However, the role of sanguinarine on diabetes-related complication, diabetic nephropathy, has not been reported yet. In a rat model of diabetic nephropathy we have demonstrated increased levels of 24 h urinary proteins, serum creatinine, and blood urea nitrogen, as well as series of degenerative changes in the kidney tissues. Oral administration with sanguinarine to diabetic rats diminished kidney injury markers and improved the tissue morphology. Furthermore, sanguinarine attenuated increase in the levels of tumor necrosis factor-α and interleukin-6 through downregulation of phosphonuclear factor-kappa B and phosphorylated inhibitor of nuclear factor kappa-B. Lastly, sanguinarine reversed the effects of streptozotocin on levels of reactive oxygen species, malonaldehyde, superoxide dismutase, and glutathione peroxidase through upregulation of nuclear factor erythropoietin-2-related factor 2, heme oxygenase 1 and NAD(P)H quinone dehydrogenase 1 in kidney of rats. In conclusion, sanguinarine ameliorates diabetic nephropathy in rats through inactivation of nuclear factor-kappa B and activation of nuclear-factor erythroid 2-related factor 2 pathways.

Effect of Salviae Miltiorrhizae Radix et Rhizoma on diversity of intestinal flora in diabetic nephropathy rats

This study aimed to explore the effect of Salviae Miltiorrhizae Radix et Rhizoma, its stems and leaves on the diversity of intestinal microflora in rats with diabetic kidney injury. Diabetic rats model was established by feeding high glucose and high fat diet and 5% glucose solution with intraperitoneal injection of 30 mg·kg~(-1) streptozocin(STZ). The rats were randomly divided into normal group, model group, irbesartan control group, Huangkui Capsules control group, as well as low, middle and high dose groups of Sal-viae Miltiorrhizae Radix et Rhizoma, its stems and leaves. After administration for 2 weeks, 16 S rRNA technique was used to analyze the diversity of intestinal microflora in the feces of each group. The results showed rats in the model group developed renal tubular epithelial vacuole degeneration and a large amount of inflammatory cell infiltration in the renal interstitium. A small amount of inflammatory cell infiltration was seen in each administration group. The kidney structure of rats in irbesartan group, Huangkui Capsules group, high-dose group of Salviae Miltiorrhizae Radix et Rhizoma and its stem water extract, as well as high dose group of Salviae Miltiorrhizae Radix et Rhizoma and its stem ethnol extract group was close to the normal group. The diversity and structure of intestinal flora in the model group were significantly different from those in the normal group. Each administration group improved the fecal flora diversity in rats with diabetic kidney injury to a certain extent, especially the high dose of Salviae Miltiorrhizae Radix et Rhizoma and its stems water extract. Different flora were found in feces of diabetic nephropathy model rats on class, order, family and genus levels. On families and genera levels, the relative abundance of Bifidobacterium, Turicibacter, Peptostreptococcaceae, Desulfovibrio, and SMB53 showed an upward trend in model group, but that of Lactobacillus, Clostridium, Rikenella, Rumen fungi showed a downward trend. The administration groups can improve the relative abundance of the above intestinal flora in the model rats to a normal-like level. The results of this study provide a reference for resource utilization and further development of Salviae Miltiorrhizae Radix et Rhizoma.

Salidroside from Rhodiola rosea L. attenuates diabetic nephropathy in STZ induced diabetic rats via anti-oxidative stress, anti-inflammation, and inhibiting TGF-β1/Smad pathway

Salidroside from Rhodiola rosea L. has hypoglycemic effects, and has anti-osteoporosis effect in diabetic rats. Whether it has beneficial effects on diabetic nephropathy (DN) has not been fully reported. Here, a DN rat model was established by streptozotocin (STZ). Salidroside (10, and 20 mg kg−1 d−1) were orally giving for eight weeks. The purity of salidroside was 99%. The results showed that eight weeks salidroside supplementation dose-dependently decreased blood glucose, serum insulin, serum creatinine, blood urea nitrogen (BUN), as well as urinary albumin of DN rats, repaired the pathological changes of kidney tissue, the renal sclerosis and fibrosis in the kidney of DN rats were improved, and the activities of oxidative defense system associated enzyme such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were also improved. Serum inflammatory cytokines (including tumor necrosis factor-α, monocyte chemoattractant protein-1, interleukin-1β, and interleukin-6) were decreased significantly in DN rats after eight weeks salidroside supplementation. Immunohistochemical results showed that fibrosis related proteins such as transforming growth factor-β1 (TGF-β1), phospho-Smad2 (p-Smad2), and phospho-Smad3 (p-Smad3) expression levels were decreased significantly in the kidney of salidroside treated group. Our results indicate that daily salidroside consumption could alleviate DN in rats, the main mechanisms are anti-inflammatory, anti-oxidative stress, and inhibition of the TGF-β1/Smad2/3 pathway. This study suggested that salidroside could be used as a nutrient against DN, as well as diabetes.

MicroRNA-30/Cx43 axis contributes to podocyte injury by regulating ER stress in diabetic nephropathy.

BackgroundThe microRNA-30 family plays a critical role in the pathogenesis of podocyte injury. Cx43 plays an essential role in intercellular communication, which is essential for coordinated kidney function. This study was conducted to explore the function of microRNA-30s/Cx43 in podocyte injury in diabetic nephropathy (DN), both in vivo and in vitro.MethodsSD rats were given streptozotocin (STZ) injections to induce DN. Podocytes were incubated in the medium in the presence or absence of high glucose (HG). The effects of the microRNA-30/Cx43 axis on DN and its underlying mechanisms were investigated by TUNEL assay, PAS, immunohistochemical staining, immunofluorescence staining, Western blot, RT-qPCR, RNA interference, and luciferase reporter assay. Podocytes were transfected with microRNA-30 family mimics, microRNA-30 family inhibitors, Cx43 siRNA, and negative controls to detect the effect of the microRNA-30/Cx43 axis. MicroRNA-30 family mimic AAVs, and microRNA-30 family inhibitor AAVs applied to regulate microRNA-30 family expression in the kidneys of the STZ-induced DN model rats to reveal the underlying mechanisms of the microRNA-30/Cx43 axis in DN.ResultsMicroRNA-30 family member expression was downregulated in HG-treated podocytes and the glomeruli of STZ-induced DN rats. Luciferase reporter assays confirmed Cx43 is a directed target of microRNA-30s. The overexpression of microRNA-30 family members attenuated the HG-induced podocyte injury and protected against podocyte apoptosis and endoplasmic reticulum stress (ERS) both in vivo and in vitro. Also, silencing Cx43 expression eased podocyte apoptosis, injury, and ERS induced by a HG+microRNA-30 family inhibitor. Double-immunofluorescence staining assays proved the co-localization of caspase12 and Cx43.ConclusionsThe overexpression of microRNA-30 family members prevents HG-induced podocyte injury and attenuates ERS by modulating Cx43 expression. The microRNA-30/Cx43/ERS axis might be a potential therapeutic target to treat DN.

Amygdalin alleviates renal injury by suppressing inflammation, oxidative stress and fibrosis in streptozotocin-induced diabetic rats

AimsTo explore the protective efficacies and potent mechanism of amygdalin on high glucose-cultured renal cell HBZY-1 in vitro and streptozotocin (STZ)-induced diabetic nephropathy (DN) rat in vivo. Main methodsThe cellar proliferation and generation of ROS in high-glucose cultured HBZY-1 cell were assessed by MTT and DCFH-DA assay, respectively. The fasting blood glucose levels, renal function and inflammation indexes as well as oxidative stress markers in STZ-induced diabetic rats were all measured. The histologic renal section was stained with Mason and periodic acid-Schiff (PAS) method. Immunohistochemistry and western blotting methods were applied to assess expression levels of extracellular matrix (ECM), epithelial-mesenchymal transition (EMT)-related as well as TGF-β1/Smad signaling pathway-related proteins. Key findingsFirstly, amygdalin significantly suppressed the excessive cell proliferation and ROS generation in HBZY-1 cells cultured with high glucose. The hyperglycemia, 24 h-UP excretion, BUN and Scr of DN rats were significantly attenuated after the chronic treatment of amygdalin. Moreover, MDA, SOD, IFN-γ and IL-12 levels in kidney tissues were all effectively reduced. Besides, amygdalin can suppress the ECM accumulation and EMT transformation by inhibiting Smad/TGF-β pathway to alleviate the renal fibrosis in renal tissues of DN model rats. SignificanceAmygdalin ameliorates excessive oxidative stress, inflammation and renal tissue fibrosis of DN mainly by suppressing TGF-β1/Smad signaling pathway and regulating the key enzymes of ECM degradation.

The Novel Phosphate and Bile Acid Sequestrant Polymer SAR442357 Delays Disease Progression in a Rat Model of Diabetic Nephropathy.

As a gut-restricted, nonabsorbed therapy, polymeric bile acid sequestrants (BAS) play an important role in managing hyperlipidemia and hyperglycemia. Similarly, nonabsorbable sequestrants of dietary phosphate have been used for the management of hyperphosphatemia in end-stage renal disease. To evaluate the potential utility of such polymer sequestrants to treat type 2 diabetes (T2D) and its associated renal and cardiovascular complications, we synthesized a novel polymeric sequestrant, SAR442357, possessing optimized bile acid (BA) and phosphate sequestration characteristics. Long-term treatment of T2D obese cZucker fatty/Spontaneously hypertensive heart failure F1 hybrid (ZSF1) with SAR442357 resulted in enhanced sequestration of BAs and phosphate in the gut, improved glycemic control, lowering of serum cholesterol, and attenuation of diabetic kidney disease (DKD) progression. In comparison, colesevelam, a BAS with poor phosphate binding properties, did not prevent DKD progression, whereas losartan, an angiotensin II receptor blocker that is widely used to treat DKD, showed no effect on hyperglycemia. Analysis of hepatic gene expression levels of the animals treated with SAR442357 revealed upregulation of genes responsible for the biosynthesis of cholesterol and BAs, providing clear evidence of target engagement and mode of action of the new sequestrant. Additional hepatic gene expression pathway changes were indicative of an interruption of the enterohepatic BA cycle. Histopathological analysis of ZSF1 rat kidneys treated with SAR442357 further supported its nephroprotective properties. Collectively, these findings reveal the pharmacological benefit of simultaneous sequestration of BAs and phosphate in treating T2D and its associated comorbidities and cardiovascular complications. SIGNIFICANCE STATEMENT: A new nonabsorbed polymeric sequestrant with optimum phosphate and bile salt sequestration properties was developed as a treatment option for DKD. The new polymeric sequestrant offered combined pharmacological benefits including glucose regulation, lipid lowering, and attenuation of DKD progression in a single therapeutic agent.