Effect of multi-glycosides of Tripterygium wilfordii on renal injury in diabetic kidney disease rats through NLRP3/caspase-1/GSDMD pyroptosis pathway / 中国中药杂志

This study investigated the effect of multi-glycosides of Tripterygium wilfordii(GTW) on renal injury in diabetic kidney disease(DKD) rats through Nod-like receptor protein 3(NLRP3)/cysteine-aspartic acid protease-1(caspase-1)/gsdermin D(GSDMD) pyroptosis pathway and the mechanism. To be specific, a total of 40 male SD rats were randomized into the normal group(n=8) and modeling group(n=34). In the modeling group, a high-sugar and high-fat diet and one-time intraperitoneal injection of streptozotocin(STZ) were used to induce DKD in rats. After successful modeling, they were randomly classified into model group, valsartan(Diovan) group, and GTW group. Normal group and model group were given normal saline, and the valsartan group and GTW group received(ig) valsartan and GTW, respectively, for 6 weeks. Blood urea nitrogen(BUN), serum creatinine(Scr), alanine ami-notransferase(ALT), albumin(ALB), and 24 hours urinary total protein(24 h-UTP) were determined by biochemical tests. The pathological changes of renal tissue were observed based on hematoxylin and eosin(HE) staining. Serum levels of interleukin-1β(IL-1β) and interleukin-18(IL-18) were detected by enzyme-linked immunosorbent assay(ELISA). Western blot was used to detect the expression of pyroptosis pathway-related proteins in renal tissue, and RT-PCR to determine the expression of pyroptosis pathway-related genes in renal tissue. Compared with the normal group, the model group showed high levels of BUN, Scr, ALT, and 24 h-UTP and serum levels of IL-1β and IL-18(P<0.01), low level of ALB(P<0.01), severe pathological damage to kidney, and high protein and mRNA levels of NLRP3, caspase-1, and GSDMD in renal tissue(P<0.01). Compared with the model group, valsartan group and GTW group had low levels of BUN, Scr, ALT, and 24 h-UTP and serum levels of IL-1β and IL-18(P<0.01), high level of ALB(P<0.01), alleviation of the pathological damage to the kidney, and low protein and mRNA levels of NLRP3, caspase-1, and GSDMD in renal tissue(P<0.01 or P<0.05). GTW may inhibit pyroptosis by decreasing the expression of NLRP3/caspase-1/GSDMD in renal tissue, thereby relieving the inflammatory response of DKD rats and the pathological injury of kidney.

Role of TGF-β/Smad signaling pathway in diabetic kidney disease and research progress of traditional Chinese medicine intervention / 中国中药杂志

Diabetic kidney disease is an important microvascular complication of diabetes and the leading cause of end-stage renal disease. Its pathological characteristics mainly include epithelial mesenchymal transition(EMT) in glomerulus, podocyte apoptosis and autophagy, and damage of glomerular filtration barrier. Transforming growth factor-β(TGF-β)/Smad signaling pathway is specifically regulated by a variety of mechanisms, and is a classic pathway involved in physiological activities such as apoptosis, proliferation and differentiation. At present, many studies have found that TGF-β/Smad signaling pathway plays a key role in the pathogenesis of diabetic kidney disease. Traditional Chinese medicine has significant advantages in the treatment of diabetic kidney disease for its multi-component, multi-target and multi-pathway characteristics, and some traditional Chinese medicine extracts, traditional Chinese medicines and traditional Chinese medicine compound prescription improve the renal injury of diabetic kidney disease by regulating TGF-β/Smad signaling pathway. This study clarified the mechanism of TGF-β/Smad signaling pathway in diabetic kidney disease by expounding the relationship between the key targets of the pathway and diabetic kidney disease, and summarized the research progress of traditional Chinese medicine in the treatment of diabetic kidney disease by interfering with TGF-β/Smad signaling pathway in recent years, to provide reference for drug research and clinical treatment of diabetic kidney disease in the future.

The A allele of the rs759853 single nucleotide polymorphism in the AKR1B1 gene confers risk for diabetic kidney disease in patients with type 2 diabetes from a Brazilian population

ABSTRACT Objective: The AKR1B1 gene encodes an enzyme that catalyzes the reduction of glucose into sorbitol. Chronic hyperglycemia in patients with diabetes mellitus (DM) leads to increased AKR1B1 affinity for glucose and, consequently, sorbitol accumulation. Elevated sorbitol increases oxidative stress, which is one of the main pathways related to chronic complications of diabetes, including diabetic kidney disease (DKD). Accordingly, some studies have suggested the rs759853 polymorphism in the AKR1B1 gene is associated with DKD; however, findings are still contradictory. The aim was to investigate the association of the rs759853 polymorphism in the AKR1B1 gene and DKD. Materials and methods: The sample comprised 695 patients with type 2 DM (T2DM) and DKD (cases) and 310 patients with T2DM of more than 10 years' duration, but no DKD (controls). The polymorphism was genotyped by real-time PCR. Results: Allelic and genotype frequencies of this polymorphism did not differ significantly between groups. However, the A/A genotype was associated with risk for DKD after adjustment for gender, triglycerides, BMI, presence of hypertension and diabetic retinopathy, and duration of DM, under both recessive (P = 0.048) and additive (P = 0.037) inheritance models. Conclusion: Our data suggest an association between the AKR1B1 rs759853A/A genotype and risk for DKD in Brazilians T2DM patients.

Protective effects of Moutan Cortex polysaccharides components on renal injury in diabetic nephropathy rats / 中国中药杂志

This study investigated the protective effects of Moutan Cortex polysaccharides components(MCPC) on the renal tissues of diabetic nephropathy(DN) rats and explored their regulation effect on inflammatory response and oxidative stress. The DN rat model was induced by high-glucose and high-fat diet combined with streptozotocin(STZ), and then the rats were randomly divided into control group, model group, positive group and MCPC high(120 mg·kg~(-1)·d~(-1)), low(60 mg·kg~(-1)·d~(-1)) dose groups. After 12 weeks treatment, blood was taken from the orbit of the rats, and then they were sacrificed before the kidney tissues were collected. The serum and tissues were detected for related biochemical indicators and pathological changes of the kidney. Immunohistochemical methods were used to determine the expression of FN and ColⅣ in the kidney tissue of DN rats. Compared with the model group, blood glucose, serum creatinine, blood urea nitrogen and 24 h urine protein in the MCPC high-dose group were significantly reduced(P<0.01). The results of HE, PAS, Masson staining showed that glomerular basement membrane thickening, Bowman's capsule narrowing and inflammatory cell infiltration in DN rats were improved in the MCPC high-dose group; the activity of T-SOD and GSH-Px in serum significantly increased(P<0.001), and the expression level of FN significantly decreased(P<0.001). The high-dose MCPC treatment could effectively inhibit the abnormal expression of Col Ⅳ(P<0.001) and significantly reduce the levels of AGEs and RAGE in serum(P<0.001), the content of VCAM-1 and IL-1β in serum(P<0.001), and the levels of IL-1β mRNA in kidney tissue(P<0.001), but failed to effectively reduce VCAM-1 mRNA levels in kidney tissues. The high-dose MCPC could significantly improve pathological injury of renal tissue and related renal indicators in DN rats, and achieve renal protection in DN rats mainly by regulating oxidative stress and inflammatory factors.

PK2/PKR1 signaling pathway participates in geniposide protection against diabetic nephropathy in mice / 中国中药杂志

This study aimed to investigate the effects of geniposide(GP) on the expression of prokineticin(PK2) and prokineticin receptor 1(PKR1) in db/db mice with diabetic nephropathy(DN), so as to explore how the PK2 signaling pathway participated in the pathological changes of DN and whether GP exerted the therapeutic effect through this signaling pathway. Male mice were randomly divided into four groups, namely db/m, db/db, db/db+GP, and db/m+GP groups, with five in each group. The mice in the db/db+GP and db/m+GP groups were gavaged with 150 mg·kg~(-1) GP for eight successive weeks. Afterwards, all the mice were sacrificed and the renal tissues were embedded. The morphological changes in glomerulus and renal tubules were observed by Masson and PAS staining. The expression levels of PK2, PKR1, and Wilm's Tumor Protein 1(WT_1) in podocytes were detected by immunohistochemistry, and the protein expression levels of PK2 and PKR1 in mouse kidney by Western blot. The morphological results showed serious glomerular and tubular fibrosis(Masson), high glomerular and tubular injury score(PAS), increased glomerular mesangial matrix, thickened basement membrane, exfoliated brush border of renal tubules, decreased WT_1 in glomerular podocytes, and massive loss of podocytes in the db/db group. After administration with GP, the glomerular and tubular fibrosis was alleviated, accompanied by improved glomerular basement membrane and renal tubule brush edge, and up-regulated WT_1. As revealed by further protein detection, in the db/db group, the expression levels of PK2 and PKR1 and p-Akt/Akt ratio declined, whereas the ratio of Bax/Bcl-2 rose. Ho-wever, PKR2 and p-ERK/ERK ratio did not change significantly. After administration with GP, the PK2 and PKR1 expression was elevated, and p-Akt/Akt ratio was increased. There was no obvious change in PKR2, Bax/Bcl-2 ratio, or p-ERK/ERK ratio. All these have demonstrated that GP improves the renal damage in DN mice, and PK2/PKR1 signaling pathway may be involved in such protection, which has provided reference for clinical treatment of DN with GP.

Influence of long non-coding RNA Gm15645 on the podocyte injury in diabetic nephropathy / 中华医学遗传学杂志

OBJECTIVE@#To explore the influence of long non-coding (lnc) RNA Gm15645 on the podocyte injury in mice with diabetic nephropathy.@*METHODS@#Male db/db mice (with Type 2 diabetes) with a genetic background of C57BLKs/J and db/m mice (healthy) born in littermates were randomly divided into three groups. db/db group was injected with lncRNAGm15645 shRNA lentivirus with a podocyte-specific marker NPHS2; db/db blank group was injected with saline, and db/db control group was injected withnon-sense lentivirus. The results of PAS staining, pathological changes of renal tissue, relative expression of GSK-3beta, and podocin expression were compared.@*RESULTS@#lncRNAGm15 645 was overexpressed and podocin was down-regulated in the lentivirus overexpressed group. Mesangial cell proliferation, mesangial matrix hyperplasia, thickened basement membrane, widely fused foot process, and podocyte injury were observed by PAS staining. The expression of Gm15645 in the db/db group was significantly lower than that of the db/db blank group and db/db control group (P< 0.05), while the expression of podocin was higher (P< 0.05). Gm15645 was co-stained with podocin in renal tissue, and the target gene was GSK-3beta.@*CONCLUSION@#lncRNAGm15645 may provide an early biomarker for the occurrence of podocyte injury in diabetic nephropathy. The mechanism may be related to the feedback regulation of GSK-3beta gene.

Study on network pharmacological mechanism of "treating different diseases with same method" of Notoginseng Radix et Rhizoma in treating diabetic nephropathy, diabetic encephalopathy and diabetic cardiomyopathy / 中国中药杂志

Pharmacology network was used to investigate the common key target and signaling pathway of Notoginseng Radix et Rhizoma in the protection against diabetic nephropathy(DN), diabetic encephalopathy(DE) and diabetic cardiomyopathy(DCM). The chemical components of Notoginseng Radix et Rhizoma were obtained through TCMSP database and literature mining, and SwissTargetPrediction database was used to predict potential targets of Notoginseng Radix et Rhizoma. The disease targets of DN, DE and DCM were obtained through OMIM and GeneCards databases. The overlapped targets of component targets and disease targets of DN, DE and DCM were obtained, and the network of "chemical component-target-disease" was established. The enriched GO and KEGG of the overlapped genes were investigated by using ClueGo plug-in with Cytoscape. At the same time, the PPI network was constructed through STRING database, and the common key targets for the treatment of three diseases by Notoginseng Radix et Rhizoma were obtained through topological parametric mathematical analysis by Cytoscape. A total of 166 chemical components and 835 component targets were screened out from Notoginseng Radix et Rhizoma. Briefly, 216, 194 and 230 disease targets of DN, DE and DCM were collected, respectively. And 54, 45 and 57 overlapped targets were identified when overlapping these disease targets with component targets of Notoginseng Radix et Rhizoma, respectively. Enrichment analysis indicated that the AGE-RAGE signaling pathway and FoxO signaling pathway were the common pathways in the protection of Notoginseng Radix et Rhizoma against DN, DE and DCM. Network analysis of the overlapped targets showed that TNF, STAT3, IL6, VEGFA, MAPK8, CASP3 and SIRT1 were identified as key targets of Notoginseng Radix et Rhizoma against DN, DE and DCM, the selected key targets were verified by literature review, and it was found that TNF, IL6, VEGFA, CASP3 and SIRT1 had been reported in the literature. In addition, there were the most compounds corresponding to the commom core target STAT3, indicating that more compounds in Notoginseng Radix et Rhizoma could regulate STAT3. This study indicated that Notoginseng Radix et Rhizoma potentially protected against DN, DE and DCM through regulating AGE-RAGE signaling pathway and FoxO signaling pathway and 7 common targets including TNF, STAT3, IL6, VEGFA, MAPK8, CASP3 and SIRT1. This study provided a reference for the research of "different diseases with same treatment" and also elucidated the potential mechanism of Notoginseng Radix et Rhizoma against DN, DE and DCM.

lncRNA ZEB1-AS1 inhibits high glucose-induced EMT and fibrogenesis by regulating the miR-216a-5p/BMP7 axis in diabetic nephropathy

Diabetic nephropathy (DN) is one of the leading causes of mortality in diabetic patients. Long non-coding RNA zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) plays a crucial role in the development of various diseases, including DN. However, the molecular mechanism of ZEB1-AS1 in DN pathogenesis remains elusive. An in vitro DN model was established by treating HK-2 cells with high glucose (HG). Quantitative polymerase chain reaction (qRT-PCR) was utilized to detect the expression levels of ZEB1-AS1, microRNA-216a-5p (miR-216a-5p), and bone morphogenetic protein 7 (BMP7). Western blot assay was used to evaluate the protein levels of BMP7, epithelial-to-mesenchymal transition (EMT)-related proteins, and fibrosis markers. Additionally, the interaction among ZEB1-AS1, miR-216a-5p, and BMP7 was predicted by MiRcode (http://www.mircode.org) and starBase 2.0 (omics_06102, omicX), and confirmed by luciferase reporter assay. ZEB1-AS1 and BMP7 were down-regulated, while miR-216a-5p was highly expressed in kidney tissues of DN patients. Consistently, HG treatment decreased the levels of ZEB1-AS1 and BMP7, whereas HG increased miR-216a-5p expression in HK-2 cells in a time-dependent manner. ZEB1-AS1 upregulation inhibited HG-induced EMT and fibrogenesis. Furthermore, ZEB1-AS1 directly targeted miR-216a-5p, and overexpression of miR-216a-5p restored the inhibitory effects of ZEB1-AS1 overexpression on EMT and fibrogenesis. BMP7 was negatively targeted by miR-216a-5p. In addition, ZEB1-AS1 suppressed HG-induced EMT and fibrogenesis by regulating miR-216a-5p and BMP-7. lncRNA ZEB1-AS1 inhibited high glucose-induced EMT and fibrogenesis via regulating miR-216a-5p/BMP7 axis in diabetic nephropathy, providing a potential target for DN therapy.

MicroRNAs: new biomarkers and promising therapeutic targets for diabetic kidney disease / MicroRNAs: novos biomarcadores e alvos terapêuticos promissores da doença renal do diabetes

Abstract Diabetic kidney disease (DKD) is a chronic complication of diabetes mellitus associated with significant morbidity and mortality regarded as a global health issue. MicroRNAs - small RNA molecules responsible for the post-transcriptional regulation of gene expression by degradation of messenger RNA or translational repression of protein synthesis - rank among the factors linked to the development and progression of DKD. This study aimed to offer a narrative review on investigations around the use of microRNAs in the diagnosis, monitoring, and treatment of DKD. Various microRNAs are involved in the pathogenesis of DKD, while others have a role in nephroprotection and thus serve as promising therapeutic targets for DKD. Serum and urine microRNAs levels have also been considered in the early diagnosis and monitoring of individuals with DKD, since increases in albuminuria, decreases in the glomerular filtration rate, and progression of DKD have been linked to changes in the levels of some microRNAs.

Resumo A doença renal do diabetes (DRD) é uma complicação crônica do diabetes mellitus associada à elevada morbidade e mortalidade, considerada um problema de saúde mundial. Dentre os fatores associados ao desenvolvimento e à progressão da DRD, destacam-se os microRNAs, que consistem em pequenas moléculas de RNA que regulam a expressão gênica por meio da degradação pós-transcricional do RNA mensageiro ou inibição translacional da síntese proteica. Este estudo teve como objetivo realizar uma revisão narrativa buscando investigar os microRNAs como auxiliares no diagnóstico, monitoramento e tratamento da DRD. Vários microRNAs estão envolvidos na patogênese da DRD, enquanto que outros têm papel nefroprotetor, consistindo assim em alvos terapêuticos promissores para o tratamento da DRD. A dosagem laboratorial dos microRNAs no soro e na urina também é muito promissora para o diagnóstico precoce e o monitoramento da DRD, já que os níveis de alguns microRNAs se alteram antes do aumento da albuminúria e da diminuição da taxa de filtração glomerular e podem ainda se alterar com a progressão da DRD.

Searching for mutations in the HNF1B gene in a Brazilian cohort with renal cysts and hyperglycemia

ABSTRACT Objective To verify the presence of variants in HNF1B in a sample of the Brazilian population selected according to the presence of renal cysts associated with hyperglycemia. Subjects and methods We evaluated 28 unrelated patients with clinical suspicion of HNF1B mutation because of the concomitant presence of diabetes mellitus (DM) or prediabetes and renal cysts. Genotyping was accomplished using Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA). In positive cases, available relatives were recruited. Results We found two patients with HNF1B mutations. The first presented the variant p.Pro328Leufs*48(c.983delC) and had DM, renal cysts, and hypomagnesemia. The second presented a heterozygous whole gene deletion in HNF1B, DM, renal cysts, body and tail pancreatic agenesis, and hypomagnesemia; this alteration was also found in his two siblings and his father. Conclusion The recruitment of suspected cases of HNF1B gene mutations in Brazilians due to hyperglycemia and renal cysts presents two positive cases. Our cases contribute to the annotation of clinical and biochemical phenotypes of this rare form of maturity-onset diabetes of the young (MODY).

Vascular endothelial growth factor insertion/deletion gene polymorphism in West Indian patients of type 2 diabetes and diabetic nephropathy.

Diabetic nephropathy (DN) is a major cause of morbidity and mortality in diabetes. Vascular endothelial growth factor (VEGF) is a potent multi-functional cytokine which plays a key role in the pathogenesis of DN. In this study, we evaluated the possible association of the VEGF gene (I/D) polymorphisms with DN in type 2 diabetes patients in West Indian population. Genotyping (I/D) of the VEGF gene polymorphism was done by the polymerase chain reaction. A total of 103 patients with type 2 diabetes, 102 patients with DN, 108 patients with non-diabetic nephropathy and 143 healthy controls were genotyped. The frequency of VEGF genotype distribution and biochemical parameters like creatinine and HbA1c were compared in diabetic, diabetic nephropathy, non diabetic nephropathy and control groups. We found significant difference in creatinine level in DN and NDN groups on comparison with control group. Our study suggests that I/D polymorphism in the promoter region of the VEGF gene is not associated with DN in type 2 diabetes patients, but might have a role in development of non-diabetic nephropathy.

Small ubiquitin-like modifier 4 M55V polymorphism is not associated with diabetic nephropathy in Iranian type 2 diabetes patients.

INTRODUCTION: We studied the impact of small ubiquitin-like modifier 4 (SUMO4) M55V polymorphism on susceptibility to diabetic nephropathy in Iranian type 2 diabetes patients. MATERIALS AND METHODS: The patient group consisted of 50 Iranian type 2 diabetes patients with nephropathy, and the control group consisted of 50 Iranian type 2 diabetes patients without nephropathy. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism method for the M55V. RESULTS: The frequency of SUMO4 AA, AG, and GG genotypes were 23%, 18%, and 9% in the patient group and 10%, 22%, and 18% in the control group. There was no significant difference in frequency of SUMO4 genotypes in patients compared to controls. CONCLUSION: These findings indicate that SUMO4 M55V polymorphism is not associated with diabetic nephropathy in Iranian type 2 diabetes patients.

Relação dos polimorfismos funcionais -509C>t e 869T>C no gene do TGFß1 com a retinopatia e nefropatia diabéticas em pacientes com diabetes mellitus tipo 2 / Relationship of functional polymorphisms -509C>T and 869T>C in the TGFß1 gene with diabetic retinopathy and nephropathy in patients with type 2 diabetes mellitus

Introdução: O fator de crescimento transformante beta-1 (TGFß1) é uma citocina multifuncional que regula a proliferação, a diferenciação e a formação da matriz extracelular de vários tipos de células. Existem evidências de que os polimorfismos -509C>T e 869T>C no gene do TGFß1 alteram a sua expressão gênica e podem estar envolvidos na patogênese das complicações crônicas do diabetes mellitus tipo 2 (DM2). O objetivo deste estudo foi analisar o papel dos polimorfismos funcionais -509C>T e 869T>C no gene do TGFß1 na patogênese da retinopatia (RD) e da nefropatia (ND) diabéticas, em pacientes com DM2. Métodos: Foi realizado um estudo de caso-controle aninhado a um estudo transversal. Foram selecionados pacientes caucasoides com DM2 que realizaram exames clínicos, laboratoriais e uma entrevista com questionário padronizado. A genotipagem dos polimorfismos foi realizada por meio de PCR. Resultados: As frequências genotípicas e alélicas obtidas para o polimorfismo -509C>T nos pacientes com RD ou ND não diferiram daquelas observadas nos pacientes sem estas complicações. Mas quando a gravidade das complicações foi analisada, observou-se que o alelo C foi menos frequente entre os pacientes com insuficiência renal crônica não tratada com diálise, assim como a frequência de homozigotos para o alelo C foi maior nos pacientes dialíticos. Conclusão: Após a análise multivariada, o genótipo CC permaneceu como um fator de risco associado com a progressão da ND (RC = 2,68, IC 95% 1,08-6,68). Assim, os resultados sugerem que o polimorfismo 869T>C no gene do TGFß1 está associado com a progressão da ND em pacientes com DM2 (AU)

Introduction: The transforming growth factor-beta 1 (TGFß1) is a multifunctional cytokine that regulates proliferation, differentiation and extracellular matrix formation of multiple cell types. There is evidence that polymorphisms -509C> T and 869T> C in the TGFß1 gene alter its gene expression and may be involved in the pathogenesis of chronic complications of diabetes mellitus type 2 (DM2). The aim of this study was to analyze the role of functional polymorphisms -509C> T and 869T> C in the TGFß1 gene in the pathogenesis of diabetic retinopathy (DR) and diabetic nephropathy (DN) in patients with DM2. Methods: We conducted a case-control study nested in a cross-sectional study. We selected Caucasian patients with DM2 who underwent clinical and laboratory tests and an interview with a standardized questionnaire. Polymorphism genotyping was performed by PCR. Results: The allele and genotype frequencies obtained for polymorphism -509C> T in patients with DR or DN did not differ from those observed in patients without these complications. But when the severity of complications was analyzed, the C allele was found to be less frequent among patients with chronic renal failure untreated with dialysis, and the frequency of homozygous for the C allele was higher in dialysis patients. Conclusion: After multivariate analysis, the CC genotype remained a risk factor associated with progression of DN (OR = 2.68, 95% CI 1.08 to 6.68). Thus, the results suggest that polymorphism 869T> C in THE TGFß1 gene is associated with progression of DN in patients with DM2 (AU)

The role of ecto-nucleotide pyrophosphatase/phosphodiesterase 1 in diabetic nephropathy / Papel da ectonucleotídeo pirofosfatase/fosfodiesterase 1 (ENPP1) na nefropatia diabética

The increased prevalence of diabetes mellitus has caused a rise in the occurrence of its chronic complications, such as diabetic nephropathy (DN), which is associated with elevated morbidity and mortality. Familial aggregation studies have demonstrated that besides the known environmental risk factors, DN has a major genetic component. Therefore, it is necessary to identify genes associated with risk for or protection against DN. Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is expressed in several tissues, including the kidneys. Increased levels of ENPP1 expression inhibit tyrosine-kinase activity of the insulin receptor in several cell types, leading to insulin resistance. K121Q polymorphism of the ENPP1 gene seems to be associated with insulin resistance and DN development. The elucidation of genetic factors and their associations will provide better understanding of the pathogenesis of DN and, may consequently, lead to a more effective approach to prevention and treatment.

A crescente prevalência do diabetes melito tem causado aumento na ocorrência das suas complicações crônicas, como a nefropatia diabética (ND), a qual está associada com elevada morbidade e mortalidade. Estudos de agregação familiar demonstram que a ND tem um importante componente genético, além dos conhecidos fatores de risco ambientais. Portanto, existe a necessidade de se identificarem genes associados ao risco ou proteção à ND. A ectonucleotide pyrophosphatase/phosphodiesterase 1(ENPP1) é expressa em vários tecidos, incluindo nos rins. Foi encontrado que níveis aumentados de expressão da ENPP1 inibem a atividade tirosino-quinase do receptor da insulina em vários tipos celulares, causando resistência à insulina. O polimorfismo K121Q do gene ENNP1parece estar associado com resistência à insulina e com o desenvolvimento da ND. A elucidação dos fatores genéticos e de suas associações permitirá um melhor entendimento da patogênese da ND e, consequentemente, poderemos ter uma abordagem mais efetiva em sua prevenção e tratamento.

Null genetic risk of ACE gene polymorphisms with nephropathy in type 1 diabetes among Egyptian population

Reported to date, strong evidence exists in multiple studies for genetic predisposing in the development of diabetic nephropathy, and no studies addressed this issue among Egyptian population. The results of angiotensin converting enzyme gene [ACE] in the susceptibility to nephropathy in type 1 diabetes with nephropathy are conflicting. We aim to identify the associations of two ACE gene polymorphisms [PstI, A > G substitution and a 287-bp insertion/deletion] with nephropathy in type 1 diabetes in Egyptian children/adolescents. Our case-control study contained 140 diabetic individuals; 80 diabetic with nephropathy as cases, and 60 diabetic subjects without nephropathy as control group. Amplified DNA from peripheral leucocytes/buccal mucosa was genotyped for using polymerase chain reaction and enzymatic assay. We found no significant differences in the distribution of ACE insertion/deletion and PstI genotypes or allele frequencies were observed between the examined groups. Frequencies of PstI-indel haplotypes were similar in all of our study groups. In both cases and control subjects, ACE activity and microalbuminuria were highest among D/D homozygotes and lowest in I/I homozygotes, while a dissimilar result was seen in PstI polymorphism. Our findings in Egyptian population strongly conclude that there is no association between the ACE gene I/D and PstI polymorphisms with nephropathy in type 1 diabetes

Null association between ACE gene I/D polymorphism and diabetic nephropathy among multiethnic Malaysian subjects.

BACKGROUND: Wide inter-ethnic allelic variations of the Angiotensin Converting Enzyme (ACE) i nsertion-deletion (I/D) gene polymorphism were thought to be responsible for the conflicting gene–diabetic nephropathy disease association worldwide. We have investigated the genetic susceptibility of the ACE gene to diabetic nephropathy in the multiethnic Malaysian population. MATERIALS AND METHODS: A total of 137 healthy (control) and 256 diabetic subjects were recruited. The diabetic subjects were further subdivided according to their nephropathy status based on urinary albumin-creatinine ratio (ACR) and glomerular filtration rate (GFR). Triple primer polymerase chain reaction (PCR) was used for ACE I/D genotyping. Subsequently, populationwide genetic analysis and gene-disease association studies were performed. RESULTS: The genotype frequencies in all subgroups were in Hardy-Weinberg equilibrium. Similar allelic and genotypic frequency of ACE I/D gene polymorphism was observed between healthy controls versus pooled type 2 diabetes mellitus (T2DM) subjects, and normoalbuminuria versus microalbuminuria, macroalbuminuria and End Stage Renal Failure (ESRF) (P > 0.05). Neither ethnicity nor gender exerted any influence on the ACE I/D gene polymorphism (P > 0.05), with the exception of the Chinese ethnic group which exhibited a higher frequency of ID genotype (P = 0.042). A multinomial logistic regression model showed that predictive factors including age, systolic blood pressure (SBP), high density lipoprotein (HDL) and glycosylated hemoglobin (HbA1C) were independently associated with diabetic nephropathy, in that order. CONCLUSION: The I/D polymorphism of the ACE gene is not significantly associated with both T2DM and/or diabetic nephropathy in this Malaysian population regardless of ethnicity and gender.

Effect of GSTM1 and GSTT1 double deletions in the development of oxidative stress in diabetic nephropathy patients.

Association of diabetic nephropathy (DN) with the deletion of GSTT1 and GSTM1 genes is well reported. Oxidative stress (OS) has also been associated with the development of DN. The present study was conducted to find out, whether these deletions had any contributory role in the development of OS in patients with DN. Pre-dialysis venous blood samples were obtained from 60 patients with diabetic end-stage renal disease (stages 4 and 5). Reduced-glutathione (GSH), glutathione S-transferase (GST) activity and malondialdehyde (MDA) levels were measured for the assessment of OS. Genetic polymorphism analysis of DN patients revealed the following distribution pattern: GSTM1 null 46.7%; GSTT1 null 55%; both null 30% and both positive 28.3%. Patients with both null genotypes were found to have significantly increased levels of MDA and low GST activity as compared to other genotypic groups. Lower GSH levels were observed in all the genotypic groups as compared to both positives. Double deletions involving GSTT1 and GSTM1 may result in decreased GST levels, leading to increased OS as reflected by increased MDA levels. As GST is a multi-functional enzyme involved in xenobiotic metabolism, this double null genotype population has a greater risk of development of DN. Further studies using increased sample size to find out the allelic distribution and their role in the development of DN are in progress.

Genetics of diabetic nephropathy / Bases genéticas da nefropatia diabética

The increasing prevalence of diabetes mellitus has led to a growing number of chronic complications including diabetic nephropathy (DN). In addition to its high prevalence, DN is associated with high morbidity and mortality especially due to cardiovascular diseases. It is well established that genetic factors play a role in the pathogenesis of DN and genetically susceptible individuals can develop it after being exposed to environmental factors. DN is probably a complex, polygenic disease. Two main strategies have been used to identify genes associated to DN: analysis of candidate genes, and more recently genome-wide scan. Great efforts have been made to identify these main genes, but results are still inconsistent with different genes associated to a small effect in specific populations. The identification of the main genes would allow the detection of those individuals at high risk for DN and better understanding of its pathophysiology as well.

A crescente elevação na prevalência do diabetes melito (DM) acarretou em um aumento de suas complicações crônicas, entre elas a nefropatia diabética (ND). Além da elevada prevalência, a ND está associada à importante morbidade e mortalidade, principalmente por doenças cardiovasculares. É notória a contribuição genética na patogênese da ND, em que, na presença de fatores ambientais propícios, aqueles indivíduos geneticamente predispostos desenvolverão a doença. Trata-se de uma doença com provável transmissão genética do tipo poligênica e complexa. Duas estratégias principais têm sido utilizadas na busca dos genes associados à ND: a avaliação de genes candidatos e, mais recentemente, a utilização de genoma wide scan. Grande empenho tem sido realizado para identificar os principais genes associados à ND, mas os resultados ainda são heterogêneos com diferentes genes apresentando um efeito pequeno em populações específicas. A identificação dos principais genes permitiria prever os indivíduos de maior risco para o desenvolvimento da ND, além de possibilitar um melhor entendimento fisiopatológico da doença.

Papel dos lipídeos da dieta na nefropatia diabética: [revisão] / Role of dietary lipids in diabetic nephropathy: [review]

O objetivo do presente manuscrito foi revisar o possível papel dos lipídeos dietéticos na nefropatia diabética (ND), considerando as alterações do perfil lipídico associadas e a interação entre aspectos dietéticos e genéticos. Os lipídeos dietéticos podem ter um papel importante no desenvolvimento e na progressão da ND. A composição das gorduras da dieta tem sido associada com a ND, particularmente à microalbuminúria e às anormalidades lipídicas e de função endotelial. Entretanto, ainda não está comprovado o benefício da modificação da ingestão de gorduras em pacientes com ND, em especial sobre desfechos definitivos, como incidência e progressão da ND, insuficiência renal e morte. Além disso, a resposta do perfil lipídico à ingestão de gorduras pode ser influenciada por fatores genéticos. A identificação de polimorfismos genéticos específicos associados a essa interação poderá permitir a individualização de estratégias nutricionais na ND.

The aim of the present study was to review the possible role of dietary lipids in diabetic nephropathy (DN), taking into account associated abnormalities of serum lipids and interaction of dietary and genetic aspects. Dietary lipids may have an important role in the development and progression of DN. The fat diet composition has been associated with DN, particularly with microalbuminuria, serum lipids abnormalities, and endothelial function. However, the beneficial effect of fat intake modification for these patients is not fully established, especially regarding hard outcomes, such as DN incidence and progression, kidney failure, and death. Moreover, genetic factors may influence the response of serum lipids to fat intake. The identification of specific genetic polymorphisms associated with this interaction could allow adoption of individual nutritional strategies in DN.

Proteinuria in cystic fibrosis: a possible correlation between genotype and renal phenotype / Proteinúria na fibrose cística: possível correlação entre genótipo e fenótipo renal

Objective: To assess proteinuria in patients with cystic fibrosis (CF), and to correlate proteinuria with genotype, CF-related diabetes and disease severity. Methods: A prospective study was carried out over a six-month period and involving 22 CF patients. After the collection and analysis of 24-h urine samples, the patients were divided into two subgroups: protein excretion < 150 mg/day (low-proteinuria); and protein excretion ≥ 150 mg/day (highproteinuria). Patient charts were reviewed to obtain data on genotype and CF-related diabetes. Disease severity was assessed based on acute exacerbations in the last six months and FEV1 measured during the study period. To assess the correlation between genotype and proteinuria, the two main mutations (ΔF508 and R334W) were evaluated. Due to the existence of genotype ΔF508/R334W, two categories were created to enable statistical analysis, ΔF508 being evaluated in category 1 and R334W being evaluated in category 2. Results: The ΔF508 mutation tended to be associated with normal protein excretion: 100% of the low-proteinuria subgroup patients were consideredΔF508 in category 1, compared with 86.7% in category 2. Protein excretion tended to be higher in patients withthe R334W mutation: 60.0% of the high-proteinuria subgroup patients were considered R334W in category 1, compared with 80.0% in category 2 (p = 0.009 and p = 0.014, respectively). No significant association was foundfor any of the other variables. Conclusions: The results suggest that genotype is associated with renal phenotype, depending on the mechanism by which the genotype alters the function of the cystic fibrosis transmembrane conductance regulator gene.

Objetivo: Avaliar a proteinúria em pacientes com fibrose cística (FC) e correlacioná-la com o genótipo, com adiabetes relacionada à FC e com a gravidade da doença. Métodos: Estudo prospectivo realizado num período deseis meses com 22 pacientes com FC. Efetuada proteinúria de 24 h com a divisão dos pacientes em dois subgrupos:proteinúria < 150 mg/dia (proteinúria-baixa); e proteinúria ≥ 150 mg/dia (proteinúria-alta). Revisamos os prontuários clínicos para a coleta de informações sobre o genótipo e a presença de diabetes relacionada à FC. A gravidade da doença foi avaliada pelas exacerbações agudas no último semestre e pelo VEF1 durante o período de estudo. Para avaliar a correlação entre genótipo e proteinúria, consideraram-se as duas principais mutações, ΔF508 e R334W. Dada a existência do genótipo ΔF508/R334W, foram criadas duas categorias para se proceder à avaliação estatística, sendo esse genótipo considerado ΔF508 na categoria 1 e R334W na categoria 2. Resultados: A mutação ΔF508 se associou com valores normais de proteinúria: 100% dos pacientes do subgrupo proteinúria-baixa foram considerados ΔF508 na categoria 1, comparados a 86,7% na categoria 2. Em pacientes com a mutação R334W, osvalores de proteinuria foram mais elevados: 60,0% dos pacientes do subgrupo proteinúria-alta foram considerados R334W na categoria 1, comparados a 80,0% na categoria 2 (p = 0,009 e p = 0,014, respectivamente). Para as outras variáveis, não houve associação significativa. Conclusões: Os resultados sugerem que há uma associação entre o genótipo e o fenótipo renal, dependendo do mecanismo pelo qual o genótipo altera a função do generegulador de condutância transmembrana da fibrose cística.