Empagliflozin attenuates the renal tubular ferroptosis in diabetic kidney disease through AMPK/NRF2 pathway

Renal tubular damage plays a key role in the pathogenesis of diabetic kidney disease (DKD), and one of the main pathological process associated with DKD in diabetic mice is the ferroptosis, a novel form of cell death caused by iron-dependent lipid peroxidation. Several researches suggested that empagliflozin may treat renal injury, but its effects on diabetic-related ferroptosis and underlying mechanisms were not fully elucidated. In this study, the influence of empagliflozin on renal injury was evaluated in vivo and in vitro in a mouse model and in high-glucose (HG) or Erastin-stimulated renal HK-2 cell line, respectively. Ferroptosis-related markers were assessed, including GSH, labile iron levels, and ferroptosis regulators by Western blot, qRT-PCR, immunohistochemistry, and immunofluorescence. The level of malondialdehyde (MDA) and the fluorescence intensity of BODIPY probe indicated the level of lipid peroxidation. It was demonstrated that solute carrier family 7, member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) were less expressed in renal biopsy samples from patients affected by DKD than in those from non-diabetic renal disease patients (NDRD), proving the ferroptosis of tubular epithelial cells in case of DKD. Furthermore, empagliflozin markedly decreased the ferroptosis impairment in DKD mice, as well as in HG model of HK-2 cells. Our investigations showed the ability of empagliflozin to suppress ferroptosis was partially countered by AMP-activated protein kinase (AMPK) inhibitor, which led to a reduction of the nuclear translocation of the antioxidant transcription factor NFE2-related factor 2 (NRF2) and downregulation of target genes such as GPX4, ferritin heavy chain 1 (FTH1), and SLC7A11, while AMPK agonists were responsible for the enhancement of the protective effects of empagliflozin. Taken together, our findings showed that empagliflozin may prevent the development of ferroptosis by promoting the AMPK-mediated NRF2 activation pathway, providing important insights for possible novel treatment approaches for DKD.

Cinacalcet attenuated bone loss via inhibiting parathyroid hormone-induced endothelial-to-adipocyte transition in chronic kidney disease rats

Background

Recently, cinacalcet (CINA) has been shown to be effective for attenuating bone loss in the treatment of secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD), which might be associated with the reduction in serum parathyroid hormone (PTH) levels. However, the exact mechanism is largely unclear. Emerging studies have revealed that an increased number of bone marrow adipocytes (BMAs) are involved in bone loss and the endothelial-to-adipocyte transition via the endothelial-to-mesenchymal transition (EndMT) might play a key role in this pathological process. Here, we assessed whether CINA could attenuate bone loss via inhibiting endothelial-to-adipocyte transition in CKD rats.

Methods

A rat model of CKD was induced by adenine and a high phosphorus diet. CINA was orally administrated to CKD animals (10 mg/kg once a day). Dual energy X-ray absorptiometry, micro-computed tomography, bone histomorphometry, and bone mechanical tests were used to determine the skeletal changes. The bone marrow expression of EndMT markers was also examined. The effect of elevated PTH levels on the endothelial-to-adipocyte transition was studied in endothelial cells (ECs).

Results

Elevation of serum PTH levels, remarkable bone loss and increased numbers of BMAs were observed in rats with CKD compared with the controls, and these changes were attenuated after treatment with CINA. Furthermore, the CINA treatment abolished the upregulation of mesenchymal markers (FSP1 and α-SMA) and the downregulation of an endothelial marker (CD31) in bone tissues from rats with CKD. The serum PTH concentrations were correlated with the bone marrow protein levels of these EndMT-related proteins. An in vitro treatment in ECs demonstrated that PTH induced the EndMT in a concentration- and time-dependent manner. Accordingly, ECs treated with PTH exhibited adipogenic potential following growth in adipogenic culture medium.

Conclusions

Our study indicated CINA treatment attenuated bone loss in CKD rats, which might be associated with inhibiting PTH-induced endothelial-to-adipocyte transition in CKD rats.

Efficacy and safety of cinacalcet and active vitamin D in the treatment of secondary hyperparathyroidism in patients with chronic kidney disease: a network meta-analysis

Background

We conducted a network meta-analysis (NMA) to evaluate the efficacy and safety of cinacalcet, active vitamin D and cinacalcet plus active vitamin D in the treatment of secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD).

Methods

A systematic literature search was performed using the Cochrane Library, PubMed, EMBASE, Web of Science, Google Scholar, China National Knowledge Internet (CNKI) and Wanfang databases. In total, eight randomized controlled trials (RCTs) with 1,443 patients were eligible for this meta-analysis. Pairwise meta-analysis was performed to evaluate the compliance of intact parathyroid hormone (iPTH), Ca, P, etc., and the mortality and safety of cinacalcet plus active vitamin D and active vitamin D alone. Then, NMA was used to estimate the safety and efficacy of the administration of active vitamin D and different drugs in the control group.

Results

The results of the pairwise meta-analysis revealed that compared with active vitamin D monotherapy, cinacalcet plus active vitamin D did not improve the survival of patients but significantly improved the blood calcium compliance rate [relative risk (RR) =1.82, 95% confidence interval (CI): 1.51-2.21, P<0.00001]. Furthermore, it is worth noting that compared with the corresponding incidence with other treatments, the incidence of vomiting was significantly increased with cinacalcet plus active vitamin D treatment (RR =2.07, 95% CI: 1.18-3.65, P=0.01). Through direct and indirect comparisons, the NMA revealed the following results: (I) compared with oral or intravenous (IV) administration of vitamin D, the solely oral administration of active vitamin D increased mortality, and (II) cinacalcet monotherapy increased the risk of hypocalcemia, and that risk was even higher for cinacalcet plus active vitamin D. However, the results should be treated with caution because the prediction interval (PrI) crossed the invalid line.

Conclusions

This pairwise meta-analysis and NMA provided a comprehensive analysis of the currently utilized CKD-SHPT treatment interventions. This network identified some highly ranked interventions through analyses that were included in a small number of trials; these interventions merit further examination on a larger scale in the context of well-designed RCTs.

FK506 prevented bone loss in streptozotocin-induced diabetic rats via enhancing osteogenesis and inhibiting adipogenesis

Background

Type 1 diabetes mellitus (DM) is associated with severe osteoporosis, which is still a great challenge in the clinic. This work aimed to investigate the skeletal effects of FK506 in a rat model of streptozocin induced type 1 DM.

Methods

Rats were divided into three groups: control (CTL), DM rats and DM rats treated with FK506. Dual energy X-ray absorption, micro-computed tomography, bone mechanics and bone histology were used for skeletal analysis. Bone marrow adipocytes infiltrations were detected by oil red O stain and H&E stain. In addition, the protein expression of adipocyte-specific makers (PPAR-γ, C/EBP-αβ), osteoblast-specific markers (Runx2, Osterix) and nuclear translocation of β-catenin in femurs were determined by western blot.

Results

In the study, bone mineral density of femurs and lumbar vertebras in diabetic rats were increased after FK506 administration. FK506 treatment resulted in higher cancellous bone volume but had no significant effect on cortical bones in diabetic rats. The ultimate force and work to failure were increased in DM+FK506 group, while they were reduced in the DM group. Compared with the CTL, the infiltration of bone marrow adipocytes was significantly increased in the DM group, which was reduced after the treatment of FK506. Besides, the expression levels of Runx2 and Osterix were up-regulated, and that of PPAR-γ and C/EBP-α were down-regulated in diabetic rats after FK506 treatment. In addition, the nuclear translocation of β-catenin protein levels were increased in diabetic rats after the treatment of FK506.

Conclusions

Our study indicated that FK506 could alleviate bone loss in diabetic rats. This effects could be due to the results of enhancing osteogenesis and inhibiting adipogenesis, which might be regulated by activation the nuclear translocation of β-catenin.

Bioinformatics-based discovery of the urinary BBOX1 mRNA as a potential biomarker of diabetic kidney disease

Background

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD) in the world. Emerging evidence has shown that urinary mRNAs may serve as early diagnostic and prognostic biomarkers of DKD. In this article, we aimed to first establish a novel bioinformatics-based methodology for analyzing the “urinary kidney-specific mRNAs” and verify their potential clinical utility in DKD.

Methods

To select candidate mRNAs, a total of 127 Affymetrix microarray datasets of diabetic kidney tissues and other tissues from humans were compiled and analyzed using an integrative bioinformatics approach. Then, the urinary expression of candidate mRNAs in stage 1 study (n = 82) was verified, and the one with best performance moved on to stage 2 study (n = 80) for validation. To avoid potential detection bias, a one-step Taqman PCR assay was developed for quantification of the interested mRNA in stage 2 study. Lastly, the in situ expression of the selected mRNA was further confirmed using fluorescent in situ hybridization (FISH) assay and bioinformatics analysis.

Results

Our bioinformatics analysis identified sixteen mRNAs as candidates, of which urinary BBOX1 (uBBOX1) levels were significantly upregulated in the urine of patients with DKD. The expression of uBBOX1 was also increased in normoalbuminuric diabetes subjects, while remained unchanged in patients with urinary tract infection or bladder cancer. Besides, uBBOX1 levels correlated with glycemic control, albuminuria and urinary tubular injury marker levels. Similar results were obtained in stage 2 study. FISH assay further demonstrated that BBOX1 mRNA was predominantly located in renal tubular epithelial cells, while its expression in podocytes and urothelium was weak. Further bioinformatics analysis also suggested that tubular BBOX1 mRNA expression was quite stable in various types of kidney diseases.

Conclusions

Our study provided a novel methodology to identify and analyze urinary kidney-specific mRNAs. uBBOX1 might serve as a promising biomarker of DKD. The performance of the selected urinary mRNAs in monitoring disease progression needs further validation.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1818-2) contains supplementary material, which is available to authorized users.

Which neoadjuvant chemotherapy regimen should be recommended for patients with advanced nasopharyngeal carcinoma?: A network meta-analysis

BACKGROUND

The clinical application has widespread disagreement on the different regimens of neoadjuvant chemotherapy (NCT) in the treatment of locoregionally advanced nasopharyngeal carcinoma (NPC). We conducted a network meta-analysis (NMA) to evaluate the efficacy of the different NCT regimens in the treatment of NPC.

METHODS

A systematic literature search was performed using PubMed, Embase, and Cochran Library. Totally, 31 randomized controlled trials (RCTs) (n = 4062) met study selection criteria and were incorporated in this NMA study.

RESULTS

Our study showed that certain NCT regimens improved the prognosis of patients, and found out the relative best solution for each endpoint, such as paclitaxel, carboplatin, and gemcitabine for 1-year overall survival (OS) rate, cisplatin, calcium folinate, and 5-fluorouracil for 2-year OS rate, vinorelbine and cisplatin (NP) for 3-year OS rate, cyclophosphamide, cisplatin, and 5-fluorouracil for 5-year OS rate, NP for complete remission rate, cisplatin and gemcitabine for overall remission rate of the primary tumor. In addition, for certain grade 3 and above toxicity, the results of the NMA reflected certain NCT regimens can reduce toxicity of chemoradiotherapy (CRT) to a minimum, such as NP for anemia, mucositis, and thrombocytopenia, paclitaxel, epirubicin, and cisplatin for neutropenia and skin toxicity.

CONCLUSION

Our NMA showed that certain cisplatin-based NCT regimens improved the prognosis of patients with NPC and reduced the toxicity of CRT. However, in view of survival rate and response rate, the best NCT regimen is not entirely consistent. Therefore, which NCT regimen will benefit most patients will need further explored.

A rat model of SHPT with bone abnormalities in CKD induced by adenine and a high phosphorus diet

The study of parathyroid hyperplasia with bone disease as a critical manifestation of chronic kidney disease-mineral and bone disorders (CKD-MBDs) is challenging due to the lack of a suitable research model. Here, we established a rat model with secondary hyperparathyroidism (SHPT) and bone disease induced by adenine and a high phosphorous diet and analyzed the skeletal characteristics. We performed blood analysis, emission computed tomography (ECT), dual energy X-ray absorptiometry (DEXA), micro-computed tomography (micro-CT), bone histomorphometry, and bone mechanical tests. The CKD rats with SHPT induced by adenine and a high phosphorus diet showed severe abnormalities in calcium and phosphorus metabolism and exhibited parathyroid hyperplasia. The bone mineral density (BMD) of femurs and lumbar vertebrae was significantly lower in the CKD rats than in the control (CTL) rats. The cortical and trabecular bone parameters of femurs showed significant bone loss. In addition, we found decreases in ultimate force, work to failure, stiffness, and elastic modulus in the CKD rats. In conclusion, our findings demonstrated that the CKD rats with SHPT induced by adenine and a high phosphorus diet may serve as a useful model for skeletal analysis in CKD with SHPT.

Cetuximab versus nimotuzumab for the treatment of advanced nasopharyngeal carcinoma: A network meta-analysis

PURPOSE

We conducted a network meta-analysis to evaluate the efficacy and toxicity of cetuximab and nimotuzumab in the treatment of advanced nasopharyngeal carcinoma (NPC).

METHODS

A systematic literature search was performed though Pubmed, Embase, Cochran Library, China National Knowledge Infrastructure (CNKI), Chinese Biomedical (CBM) and Wanfang databases. Totally, 19 randomized controlled trials (RCTs) (n=1201) met the study selection criteria and were incorporated in this network meta-analysis.

RESULTS

Compared with cetuximab, the results of network meta-analysis indicated that nimotuzumab may achieve higher complete remission rate (CRR) or overall remission rate (ORR) of the primary tumor, but no difference was noticed in 1- and 2-year overall survival (OS) rate and certain toxicities such as myelosuppression, radiodermatitis, mucositis and gastrointestinal reactions. Although nimotuzumab increased the 3-year OS rate, compared with cetuximab, this result needs to be interpreted cautiously because of the studies' heterogeneity.

CONCLUSION

Even though we didn't find significant difference between cetuximab and nimotuzumab in terms of survival outcomes, nimotuzumab is more advantageous in short-term efficacy.

No association of TNF-α-308G/A polymorphisms with head and neck cancer risk: A PRISMA-compliant meta-analysis

BACKGROUND

A number of studies had reported the association between tumor necrosis factor-alpha (TNF-α) gene polymorphisms and head and neck cancer (HNC) risk. However, the results remained controversial. Therefore, we performed a meta-analysis to derive a more precise evaluation of the association between TNF-α-308G/A polymorphism and overall HNC risk and evaluated influence of cancer types and ethnicities.

METHODS

A systematic literature search was performed using Pubmed, Embase, Cochrane Library, and Web of science. In total, we identified 15 studies including 2005 cancer cases and 2876 controls to evaluate the association of TNF-α-308G/A polymorphism with risk for HNC.

RESULTS

Overall, there was no significant association between TNF-α-308G/A polymorphism and the risk of HNC. Furthermore, subgroup analyses were performed according to the types of tumor and the ethnicities, we also found there was no significant association between TNF-α-308G/A polymorphism and the risk of NPC and OC, and European and Asian populations had no statistically significant difference in the relationship of TNF-α-308G/A polymorphism and HNC susceptibility.

CONCLUSION

This meta-analysis indicates that the TNF-α-308G/A polymorphism is not associated with HNC risk. In the future, large and well-designed case-control studies are needed to validate our findings.

Low expression of nm23-H1 associates with poor survival of nasopharyngeal carcinoma patients: A prisma-compliant meta-analysis

BACKGROUND

Developing a new reliable prognostic marker to predict the prognosis and supply better and more suitable therapy for patients with nasopharyngeal carcinoma (NPC) is urgent. Therefore, we performed this systematic review of the literature with meta-analysis to clarify and explore the associate expression of nm23-H1 with prognosis of NPC patients.

METHODS

Literature research in Cochrane Library, PubMed, and EMBASE was performed up to July 2016. Eligible case-control studies of associate expression of nm23-H1 with prognosis of NPC patients were included.

RESULTS

Nine studies met our inclusion criteria and were finally included for the analysis, involving 861 participants. Our meta-analysis revealed that the low expression of nm23-H1 in NPC was: RR = 2.13, 95% CI 1.15-3.95 and R = 2.56, 95% CI 2.03-3.22; and poorer overall survival (OS) rate was 3-year OS rate: RR: 0.55; 95% CI: 0.45-0.67 and 5-year OS rate: RR: 0.60; 95% CI: 0.52-0.69. Furthermore, the statistical significance was constant irrespective of different NPC subtypes.

CONCLUSION

The low expression of nm23-H1 is associated with poorer prognosis in patients with NPC, suggesting that it is a prognostic factor and potential biomarker for survival in NPC.

Radiation therapy outcomes in muscle invasive urinary bladder cancer: A single institution experience

INTRODUCTION

To audit the survival outcomes and loco-regional control in muscle invasive urinary bladder cancer patients treated with external beam radiation therapy (RT).

MATERIALS AND METHODS

From November 2008 through December 2011, 50 consecutively diagnosed muscle invasive urinary bladder carcinoma (T2-4a N0-2, M0) patients were included in this retrospective study. All these patients received external beam RT to a median dose of 60 Gy (range 30-66 Gy), and were not suitable for radical surgery due to patients' preference or medical comorbidities. A stepwise procedure using proportional hazard regression was used to identify prognostic factors with respect to survival.

RESULTS

Completion trans-urethral resection of bladder tumor was done in 38 (76%) patients of the cohort and 47 (94%) had transitional cell carcinoma on histopathology. Clinical stage T2 was diagnosed in 40 (80%) patients. The median follow-up for the entire cohort was 14 ± 8.9 months (range 1-36 months). In conclusion, 24 patients (48%) were free of disease, 5 patients (10%) had residual disease, and 13 patients (26%) had died of disease. Two-year and 3 year overall survival of intact bladder for the entire cohort was 58% and 43.6%, respectively. Cox regression modeling strongly suggested clinical stage (P = 0.01) and RT dose (P = 0.001) as being predictors for overall survival.

CONCLUSION

RT shows reliable outcomes and excellent compliance in this advanced disease. Prescribing a higher RT dose could potentially correlate to better intact bladder control rates while maintaining good quality of life in selected patients.