Intercellular adhesion molecule-1-deficient mice are resistant against renal injury after induction of diabetes

Diabetic nephropathy is a leading cause of end-stage renal failure. Several mechanisms, including activation of protein kinase C, advanced glycation end products, and overexpression of transforming growth factor (TGF)-beta, are believed to be involved in the pathogenesis of diabetic nephropathy. However, the significance of inflammatory processes in the pathogenesis of diabetic microvascular complications is poorly understood. Accumulation of macrophages and overexpression of leukocyte adhesion molecules and chemokines are prominent in diabetic human kidney tissues. We previously demonstrated that intercellular adhesion molecule (ICAM)-1 mediates macrophage infiltration into the diabetic kidney. In the present study, to investigate the role of ICAM-1 in diabetic nephropathy, we induced diabetes in ICAM-1-deficient (ICAM-1(-/-)) mice and ICAM-1(+/+) mice with streptozotocin and examined the renal pathology over a period of 6 months. The infiltration of macrophages was markedly suppressed in diabetic ICAM-1(-/-) mice compared with that of ICAM-1(+/+) mice. Urinary albumin excretion, glomerular hypertrophy, and mesangial matrix expansion were significantly lower in diabetic ICAM-1(-/-) mice than in diabetic ICAM-1(+/+) mice. Moreover, expressions of TGF-beta and type IV collagen in glomeruli were also suppressed in diabetic ICAM-1(-/-) mice. These results suggest that ICAM-1 is critically involved in the pathogenesis of diabetic nephropathy.     

The role of protein kinase C activation in diabetic nephropathy

Diabetic nephropathy is the leading cause of end-stage renal disease worldwide and an independent risk factor for all-cause and cardiovascular mortalities in diabetic patients. New insights into the molecular mechanisms that underlie the development and progression of microvascular complications of diabetes including nephropathy are emerging rapidly from experimental and clinical studies. Chronic hyperglycemia is a major initiator of diabetic microvascular complications. Activation of diacylglycerol (DAG)-protein kinase C (PKC) pathway, enhanced polyol pathway, increased oxidative stress, and overproduction of advanced glycation end products have all been proposed as potential cellular mechanisms by which hyperglycemia induces diabetic vascular complications. The DAG-PKC pathway contributes to vascular function in many ways such as the regulation of endothelial permeability, vasoconstriction, extracellular matrix synthesis/turnover, cell growth, angiogenesis, cytokine activation, and leukocyte adhesion. We will briefly review the current knowledge base regarding the pathogenic role for the activation of DAG-PKC pathway in diabetic nephropathy and other microvascular complications of diabetes. The results from animal studies and key clinical studies investigating specific effects of the PKC isoforms on the renal and other vascular tissues to induce diabetic complications are also reviewed.     

Toll-like receptor 4 promotes tubular inflammation in diabetic nephropathy

Inflammation contributes to the tubulointerstitial lesions of diabetic nephropathy. Toll-like receptors (TLRs) modulate immune responses and inflammatory diseases, but their role in diabetic nephropathy is not well understood. In this study, we found increased expression of TLR4 but not of TLR2 in the renal tubules of human kidneys with diabetic nephropathy compared with expression of TLR4 and TLR2 in normal kidney and in kidney disease from other causes. The intensity of tubular TLR4 expression correlated directly with interstitial macrophage infiltration and hemoglobin A1c level and inversely with estimated glomerular filtration rate. The tubules also upregulated the endogenous TLR4 ligand high-mobility group box 1 in diabetic nephropathy. In vitro, high glucose induced TLR4 expression via protein kinase C activation in a time- and dose-dependent manner, resulting in upregulation of IL-6 and chemokine (C-C motif) ligand 2 (CCL-2) expression via IκB/NF-κB activation in human proximal tubular epithelial cells. Silencing of TLR4 with small interfering RNA attenuated high glucose-induced IκB/NF-κB activation, inhibited the downstream synthesis of IL-6 and CCL-2, and impaired the ability of conditioned media from high glucose-treated proximal tubule cells to induce transmigration of mononuclear cells. We observed similar effects using a TLR4-neutralizing antibody. Finally, streptozotocin-induced diabetic and uninephrectomized TLR4-deficient mice had significantly less albuminuria, renal dysfunction, renal cortical NF-κB activation, tubular CCL-2 expression, and interstitial macrophage infiltration than wild-type animals. Taken together, these data suggest that a TLR4-mediated pathway may promote tubulointerstitial inflammation in diabetic nephropathy.     

Expression of receptors for advanced glycosylated end-products in renal disease

BACKGROUND: Advanced glycation endproducts (AGEs) are believed to mediatelong-term complications in diabetes mellitus. In this contextwe studied the expression of the receptor for AGEs (RAGE) inthe kidney of patients with a variety of different renal diseases. METHODS: RAGE was detected by immunocytochemistry in renal biopsies.We compared the staining for RAGE in nine patients with diabeticnephropathy, 20 with inflammatory and/or immune complex and10 with non-inflammatory renal diseases. Normal renal tissuefrom seven patients with tumour nephrectomies served as controls. RESULTS: In controls the only cells expressing RAGE constitutively wereinterstitial cells and vascular smooth muscle cells (6/7), whiledistal tubular cells were rarely positive (1/7). Endothelialcells of arteries/arterioles, glomerular endothelial cells,podocytes, and capsular epithelial cells were consistently negative. In diabetic nephropathy, inflammatory and/or immune complex,and non-inflammatory renal diseases, all cell types mentionedabove became positive for RAGE. Whilst the distribution of RAGEin the tissue was quite similar, staining intensity in inflammatoryand/or immune complex diseases was higher than in diabetic nephropathy. CONCLUSION: RAGE induction in the kidney is not specific for diabetic nephropathyand occurs in other types of renal diseases as well.     

Heparanase-1 gene expression and regulation by high glucose in renal epithelial cells: a potential role in the pathogenesis of proteinuria in diabetic patients

The molecular mechanisms of heparan sulfate proteoglycan downregulation in the glomerular basement membrane (GBM) of the kidneys with diabetic nephropathy remain controversial. In the present study, we showed that the expression of heparanase-1 (HPR1), a heparan sulfate-degrading endoglycosidase, was upregulated in the renal epithelial cells in the kidney with diabetic nephropathy. Urinary HPR1 levels were elevated in patients with diabetic nephropathy. In vitro cell culture studies revealed that HPR1 promoter-driven luciferase reporter gene expression, HPR1 mRNA, and protein were upregulated in renal epithelial cells under high glucose conditions. Induction of HPR1 expression by high glucose led to decreased cell surface heparan sulfate expression. HPR1 inhibitors were able to restore cell surface heparan sulfate expression. Functional analysis revealed that renal epithelial cells grown under high glucose conditions resulted in an increase of basement membrane permeability to albumin. Our studies suggest that loss of heparan sulfate in the GBM with diabetic nephropathy is attributable to accelerated heparan sulfate degradation by increased HPR1 expression.     

The effects of adenosine A2B receptor inhibition on VEGF and nitric oxide axis-mediated renal function in diabetic nephropathy

Diabetic nephropathy (DN) is the most common cause of end-stage renal disease worldwide. The pathophysiologic mechanisms of diabetic nephropathy are incompletely understood but include overproduction of various growth factors and cytokines. Upregulation of vascular endothelial growth factor (VEGF) is a pathogenic event occurring in most forms of podocytopathy; however, the mechanisms that regulate this growth factor induction are not clearly identified. A_2B receptors have been found to regulate VEGF expression under hypoxic environment in different tissues. One proposed hypothesis in mediating diabetic nephropathy is the modulation of VEGF-NO balance in renal tissue. We determined the role of adenosine A_2B receptor in mediating VEGF overproduction and nitrite in diabetic nephropathy. The renal content of A_2B receptors and VEGF was increased after 8 weeks of diabetes induction. The renal and plasma nitrite levels were also reduced in these animals. In vivo administration of A_2B adenosine receptor antagonist (MRS1754) inhibited the renal over expression of VEGF and adverse renal function parameters. The antagonist administration also improved the kidney tissue nitrite levels. In conclusion, we demonstrated that VEGF induction via adenosine signaling might be the critical event in regulating VEGF-NO axis in diabetic nephropathy.     

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.     

Chemotactic factors and renal inflammation

The mechanisms of leukocyte entry into the kidney during inflammatory renal disease have recently received considerable attention. Chemotactic factors appear to play a central role in this process, not only by inducing leukocyte movement but also by enhancing endothelial and leukocyte adhesiveness and endothelial permeability. The evidence supporting the role of chemotactic factors in renal inflammation comes from three types of studies. (1) Cell culture studies have shown that renal parenchymal cells produce chemotactic factors in response to proinflammatory stimuli. (2) Immunohistochemical and in situ hybridization analyses of renal tissue from patients or experimental animals have demonstrated local renal expression of chemotactic factors in association with inflammatory disease. (3) Experiments designed to neutralize the chemoattractant activity of specific chemotactic factors in leukocyte-dependent models of renal injury have shown an attenuation of inflammatory infiltrates and a decrease in indices of renal damage. In this article, these data are reviewed for complement-derived chemotactic factors, the leukocyte-specific chemokines, and the interstitial chemoattractant osteopontin, and the possibilities of therapeutic interventions based on abrogating chemoattractant expression or function in human renal disease are considered.     

Hypertension in diabetic nephropathy: epidemiology, mechanisms, and management

Hypertension is highly prevalent in patients with diabetic nephropathy. Diabetic nephropathy is the leading cause of CKD and end-stage kidney disease in the United States. The etiology of hypertension in diabetic nephropathy involves mechanisms with multiple inter-related mediators that result in renal sodium reabsorption and peripheral vasoconstriction. The management of hypertension in these patients is focused on treatments that target these mediators. Clinical trials have established that drugs that inhibit the renin-angiotensin-aldosterone system should be used as first-line agents on the basis of their ability to slow down progression of kidney disease and lower albuminuria. There is further interest into how the combination of drugs that inhibit this pathway at multiple steps will contribute further to the management of hypertension and diabetic nephropathy. This article presents an updated review of the mechanisms involved in hypertension in patients with diabetic nephropathy. It also reviews the past clinical trials using single agents as therapeutics and the more recent trials involving novel drugs or drug combinations used to treat these patients. Retrospective analyses of multiple studies are included to better examine the significance of the currently proposed blood pressure targets for patients with diabetic nephropathy.     

Renin-angiotensin system activation and interstitial inflammation in human diabetic nephropathy

BACKGROUND: The molecular mechanisms of renal injury in diabetic nephropathy (DN) are not completely understood, although inflammatory cells play a key role. The renin-angiotensin system (RAS) is involved in kidney damage; however, few studies have examined the localization of RAS components in human DN. Our aim was to investigate in renal biopsies the expression of RAS and their correlation with proinflammatory parameters and renal injury. METHODS: The biopsies from 10 patients with type 2 diabetes mellitus and overt nephropathy were studied for the expression of RAS components by immunohistochemistry (IH). In addition, by Southwestern histochemistry we studied the in situ detection of the activated nuclear factor kappa B (NFkappaB), and by IH and/or in situ hybridization (ISH), the expression of monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation, normal T cell expressed and secreted (RANTES), whose genes are regulated by NFkappaB. RESULTS: Angiotensin-converting enzyme (ACE) immunostaining was elevated in tubular cells and appeared in interstitial cells. Elevated levels of angiotensin II (Ang II) immunostaining were observed in tubular and infiltrating interstitial cells. There was also a down-regulation of AT1 and up-regulation of AT2 receptors. An activation of NFkappaB and a marked up-regulation of NFkappaB-dependent chemokines mainly in tubular cells was observed. Elevated levels of NFkappaB, chemokines, and Ang II in tubules were correlated with proteinuria and interstitial cell infiltration. CONCLUSIONS: Our results show that in human DN, RAS components are modified in renal compartments, showing elevated local Ang II production, activation of tubular cells, and induction of proinflammatory parameters. These data suggest that Ang II contributes to the renal inflammatory process, and may explain the molecular mechanisms of the beneficial effect of RAS blockade.     

MCP-1、ICAM-1在糖尿病肾病大鼠肾脏损害中作用及厄贝沙坦干预的影响

目的：探讨MCP-1、ICAM-1在糖尿病肾病大鼠肾脏损害中作用及厄贝沙坦对二者的影响.方法：采用高糖高脂饮食合并链脲佐菌素腹腔注射的方法建立糖尿病肾病大鼠模型.将大鼠随机分为正常对照NC 组、糖尿病肾病DN组、厄贝沙坦DI组,检测各组大鼠24 h尿量、24 h尿白蛋白定量（24 h UTP）、血糖（BG）、血肌酐（Scr）、尿素氮（BUN）、肾重指数（KI）;行HE染色观察各组大鼠病理学形态,免疫组化观察MCP-1、ICAM-1蛋白的表达,RT-PCR观察MCP-1 mRNA、ICAM-1mRNA的表达.结果：与NC组比较,DN组大鼠肾脏病理改变加重,24 h尿量、24 h UTP、KI、BG、Scr、BUN、肾脏组织中MCP-1mRNA和ICAM-1mRNA及蛋白水平均显著增加,差异均有统计学意义（P＆lt;0.01）;与DN组比较,DI组大鼠BG、BUN、Scr有所改善,差异无统计学意义;肾脏病理改变减轻,其余指标明显降低,差异有统计学意义（P＆lt;0.05）.结论：MCP-1、ICAM-1在糖尿病肾病肾脏损害过程中可能起重要作用;厄贝沙坦能够减轻糖尿病肾病肾组织MCP-1、ICAM-1的表达,缓解了肾脏病理损伤.     

The key role of the transforming growth factor-beta system in the pathogenesis of diabetic nephropathy

Progressive renal injury in diabetes mellitus leads to major morbidity and mortality. The manifestations of diabetic nephropathy may be a consequence of the actions of certain cytokines and growth factors. Prominent among these is transforming growth factor-beta (TGF-beta) because it promotes renal cell hypertrophy and stimulates extracellular matrix accumulation, the two hallmarks of diabetic renal disease. In cell culture, high ambient glucose increases TGF-beta mRNA and protein in proximal tubular, glomerular epithelial, and mesangial cells. Neutralizing anti-TGF-beta antibodies prevent the hypertrophic and matrix stimulatory effects of high glucose in these cells. In experimental and human diabetes mellitus, several reports describe overexpression of TGF-beta in the glomeruli and tubulointerstitium. We demonstrate that short-term treatment of diabetic mice with neutralizing monoclonal antibodies against TGF-beta significantly reduces kidney weight and glomerular hypertrophy and attenuates the increase in extracellular matrix mRNAs. Long-term treatment of diabetic mice further improves the renal pathology and also ameliorates the functional abnormalities of diabetic nephropathy. Finally, we provide evidence that the renal TGF-beta system is significantly up-regulated in human diabetes. The kidney of a diabetic patient actually elaborates TGF-beta1 protein into the circulation whereas the kidney of a non-diabetic subject extracts TGF-beta1 from the circulation. The data we review here strongly support the hypothesis that elevated production or activity of the TGF-beta system mediates diabetic renal hypertrophy and extracellular matrix expansion.     

Monocyte chemoattractant protein-1 promotes the development of diabetic renal injury in streptozotocin-treated mice

Diabetic nephropathy involves a renal inflammatory response induced by the diabetic milieu. Macrophages accumulate in diabetic kidneys in association with the local upregulation of monocyte chemoattractant protein-1 (MCP-1); however, the contribution of macrophages to renal injury and the importance of MCP-1 to their accrual are unclear. Therefore, we examined the progression of streptozotocin (STZ)-induced diabetic nephropathy in mice deficient in MCP-1 in order to explore the role of MCP-1-mediated macrophage accumulation in the development of diabetic kidney damage. Renal pathology was examined at 2, 8, 12 and 18 weeks after STZ treatment in MCP-1 intact (+/+) and deficient (-/-) mice with equivalent blood glucose and hemoglobin A1c levels. In MCP-1(+/+) mice, the development of diabetic nephropathy was associated with increased kidney MCP-1 production, which occurred mostly in tubules, consistent with our in vitro finding that elements of the diabetic milieu (high glucose and advanced glycation end products) directly stimulate tubular MCP-1 secretion. Diabetes of 18 weeks resulted in albuminuria and elevated plasma creatinine in MCP-1(+/+) mice, but these aspects of renal injury were largely suppressed in MCP-1(-/-) mice. Protection from nephropathy in diabetic MCP-1(-/-) mice was associated with marked reductions in glomerular and interstitial macrophage accumulation, histological damage and renal fibrosis. Diabetic MCP-1(-/-) mice also had a smaller proportion of kidney macrophages expressing markers of activation (inducible nitric oxide synthase or sialoadhesin) compared to diabetic MCP-1(+/+) mice. In conclusion, our study demonstrates that MCP-1-mediated macrophage accumulation and activation plays a critical role in the development of STZ-induced mouse diabetic nephropathy.     

The role of the renal kallikrein-kinin system in diabetic nephropathy

PURPOSE OF REVIEW: Diabetic nephropathy is one of the most common complications in diabetes mellitus. Multiple pathogenic mechanisms are now believed to contribute to this disease, including inflammatory cytokines, autacoids and oxidative stress. Numerous studies have shown that the kallikrein-kinin system may be involved in these mechanisms. This review focuses on recent research advance on the potential role of the kallikrein-kinin system in the development of diabetic nephropathy, and its clinical relevance. RECENT FINDINGS: A collection of recent studies has shown that angiotensin-converting enzyme inhibitors, which inhibit angiotensin II formation and degradation of bradykinin, and vasopeptidase inhibitors attenuated the development of diabetic nephropathy in experimental animals and clinical settings. The role of the kallikrein-kinin system in diabetes is further supported by findings that diabetic nephropathy is worsened in diabetic mice lacking bradykinin B2 receptors. Although long-acting bradykinin B2 receptor agonists have been shown to have renal protective effects, their therapeutic benefits have not been well studied. SUMMARY: Current experimental investigations demonstrated that pharmacological intervention of the kallikrein-kinin system improved renal conditions in diabetes mellitus. These findings suggest that the kallikrein-kinin system may be a therapeutic target in preventing and treating diabetic nephropathy.     

The NLRP3 inflammasome in kidney disease and autoimmunity

The NLRP3 inflammasome is an intracellular platform that converts the pro‐inflammatory cytokines interleukin (IL)‐1β and IL‐18 to their active forms in response to ‘danger’ signals, which can be either host or pathogen derived, and mediates a form of inflammatory cell death called pyroptosis. This component of the innate immune system was initially discovered because of its role in rare autoinflammatory syndromes called cryopyrinopathies, but it has since been shown to mediate injurious inflammation in a broad range of diseases. Inflammasome activation occurs in both immune cells, primarily macrophages and dendritic cells, and in some intrinsic kidney cells such as the renal tubular epithelium. The NLRP3 inflammasome has been implicated in the pathogenesis of a number of renal conditions, including acute kidney injury, chronic kidney disease, diabetic nephropathy and crystal‐related nephropathy. The inflammasome also plays a role in autoimmune kidney disease, as IL‐1β and IL‐18 influence adaptive immunity through modulation of T helper cell subsets, skewing development in favour of Th17 and Th1 cells that are important in the development of autoimmunity. Both IL‐1 blockade and two recently identified specific NLRP3 inflammasome blockers, MCC950 and β‐hydroxybutyrate, have shown promise in the treatment of inflammasome‐mediated conditions. These targeted therapies have the potential to be of benefit in the growing number of kidney diseases in which the NLRP3 inflammasome has been implicated.     

Fcγ receptor deficiency attenuates diabetic nephropathy

Among patients with diabetes, increased production of immunoglobulins against proteins modified by diabetes is associated with proteinuria and cardiovascular risk, suggesting that immune mechanisms may contribute to the development of diabetes complications, such as nephropathy. We investigated the contribution of IgG Fcγ receptors to diabetic renal injury in hyperglycemic, hypercholesterolemic mice. We used streptozotocin to induce diabetes in apolipoprotein E-deficient mice and in mice deficient in both apolipoprotein E and γ-chain, the common subunit of activating Fcγ receptors. After 15 weeks, the mice lacking Fcγ receptors had significantly less albuminuria and renal hypertrophy, despite similar degrees of hyperglycemia and hypercholesterolemia, immunoglobulin production, and glomerular immune deposits. Moreover, diabetic Fcγ receptor-deficient mice had less mesangial matrix expansion, inflammatory cell infiltration, and collagen and α-smooth muscle actin content in their kidneys. Accordingly, expression of genes involved in leukocyte infiltration, fibrosis, and oxidative stress was significantly reduced in diabetic kidneys and in mesangial cells cultured from Fcγ receptor-deficient mice. In summary, preventing the activation of Fcγ receptors alleviates renal hypertrophy, inflammation, and fibrosis in hypercholesterolemic mice with diabetes, suggesting that modulating Fcγ receptor signaling may be renoprotective in diabetic nephropathy.     

Imatinib attenuates diabetic nephropathy in apolipoprotein E-knockout mice

In the diabetic kidney, clinical as well as experimental observations have shown an upregulation of growth factors such as PDGF. These studies, however, were not designed to address whether upregulation of PDGF is merely a manifestation of diabetic renal injury or whether PDGF plays an active role in the pathophysiology of diabetic nephropathy. The objectives of this study were first to assess whether PDGF-dependent pathways are involved in the development of diabetic nephropathy and second to determine the effects of PDGF receptor antagonism on this disorder and associated molecular and cellular processes. This study used the diabetic apolipoprotein E-knockout (apoE-KO) mouse, a recently described model of accelerated diabetic nephropathy. Diabetes was induced by injection of streptozotocin in 6-wk-old apoE-KO mice. Diabetic animals received treatment with a tyrosine kinase inhibitor that inhibits PDGF action, imatinib (STI-571, 10 mg/kg per d orally) or no treatment for 20 wk. Nondiabetic apoE-KO mice served as controls. This model of accelerated renal disease with albuminuria as well as glomerular and tubulointerstitial injury was associated with increased renal expression of PDGF-B, proliferating cells, and alpha-smooth muscle actin-positive cells. Furthermore, there was increased accumulation of type I and type IV collagen as well as macrophage infiltration. Imatinib treatment ameliorated both renal functional and structural parameters of diabetes as well as overexpression of a number of growth factors, collagens, proliferating cells, alpha-smooth muscle actin-positive cells, and macrophage infiltration within the kidney. Tyrosine kinase inhibition with imatinib seems to retard the development of experimental diabetic nephropathy.     

Diabetic nephropathy: the proteinuria hypothesis

BACKGROUND/AIMS: Proteinuria, nearly a universal finding in progressive kidney disease, has been the subject of frequent recent analyses in the renal literature. Proteinuria is a hallmark of diabetic nephropathy: microalbuminuria is the principal early predictor for progression of diabetic glomerulopathy, and proteinuria may be viewed as a measure of the severity and promoter of progression of nephropathy. METHODS: This article critically reviews for the first time the full scope of diabetic proteinuria--complex molecular mechanisms, natural history, and analysis of treatment trials--in order to address the validity of 'the proteinuria hypothesis', i.e., that diabetic proteinuria is a modifiable determinant of renal progression. This hypothesis is analyzed in detail, including recent studies on the primary therapy of diabetic nephropathy, renin-angiotensin blockade. RESULTS: As fully developed, this hypothesis consists of three postulates: that higher amounts of proteinuria predict progressive loss of function, that proteinuria reduction correlates with slowing progression, and that proteinuria is a surrogate endpoint for clinical trials. The latter postulate has not before been adequately linked to growing information about the first two postulates as they apply to diabetic kidney disease. CONCLUSION: While diabetic nephropathy is a disease model for the potential use of proteinuria as a surrogate marker for renal progression, this shift in perspective will require prospective data from additional clinical trials, particularly of non-renin-angiotensin blocking drugs, to be complete.     

益肾胶囊对糖尿病肾病大鼠肾组织JAK/STAT信号通路的影响

目的：观察益肾胶囊对糖尿病肾病（DN）大鼠肾组织JAK/STAT信号通路影响,探讨益肾胶囊对DN大鼠肾脏保护作用的可能机制。方法：将Wistar大鼠制备成DN模型。随机分为4组,即正常对照组（N组）、DN模型组（DN组）、益肾胶囊治疗组（625mg·kg-1.d-1）、氯沙坦钾治疗组（30mg·kg-1.d-1）。实验周期12周。期间检测大鼠血糖和24h尿蛋白定量,通过光镜及电镜观察肾脏组织病理形态学的变化;采用免疫组化方法检测肾组织磷酸化JAK2（p-JAK2）、磷酸化STAT3（p-STAT3）表达及转化生长因子β1（TGF-β1）表达变化。结果：12周末,DN组大鼠肾组织中p-JAK2、p-STAT3、TGF-β1表达显著高于同期正常对照组（P〈0.05）。益肾胶囊治疗组和氯沙坦钾治疗组肾组织中p-JAK2、p-STAT3、TGF-β1表达显著低于同期DN组（P〈0.05）;24h尿蛋白定量显著低于同期DN组（P〈0.05）;病理损伤较同期DN组改善。结论：益肾胶囊可能部分通过抑制DN大鼠肾组织JAK/STAT通路调节肾组织TGF-β1表达,发挥对DN大鼠肾脏的保护作用。