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Diabetic nephropathy (DN) is considered the primary causes of end-stage renal disease (ESRD) and is related to abnormal glycolipid metabolism, hemodynamic abnormalities, oxidative stress and chronic inflammation. Antagonism of vascular endothelial growth factor B (VEGF-B) could efficiently ameliorate DN by reducing renal lipotoxicity. However, this pharmacological strategy is far from satisfactory, as it ignores numerous pathogenic factors, including anomalous reactive oxygen species (ROS) generation and inflammatory responses. We found that the upregulation of VEGF-B and downregulation of interleukin-22 (IL-22) among DN patients were significantly associated with the progression of DN. Thus, we hypothesized that a combination of a VEGF-B antibody and IL-22 could protect against DN not only by regulating glycolipid metabolism but also by reducing the accumulation of inflammation and ROS. To meet these challenges, a novel anti-VEGFB/IL22 fusion protein was developed, and its therapeutic effects on DN were further studied. We found that the anti-VEGFB/IL22 fusion protein reduced renal lipid accumulation by inhibiting the expression of fatty acid transport proteins and ameliorated inflammatory responses via the inhibition of renal oxidative stress and mitochondrial dysfunction. Moreover, the fusion protein could also improve diabetic kidney disease by increasing insulin sensitivity. Collectively, our findings indicate that the bifunctional VEGF-B antibody and IL-22 fusion protein could improve the progression of DN, which highlighted a novel therapeutic approach to DN., Graphical abstract The expression of VEGF-B was increased and that of IL-22 was decreased in diabetic nephropathy (DN) patients. Anti-VEGFB/IL22 fusion protein combining VEGF-B antibody and IL22 ameliorated DN by alleviating ectopic lipid accumulation, inflammatory responses and insulin resistance.Image 1

Acetaminophen (APAP) overdose can lead to acute, severe kidney injury, which has recently attracted considerable attention among researchers and clinicians. Unfortunately, there are no well-established treatments for APAP-induced renal injury, and the molecular mechanism of APAP-induced kidney injury is still unclear. Herein, we explored the protective effects of interleukin (IL)-22 on APAP-induced renal injury and the underlying molecular basis. We found that IL-22 could significantly alleviate the accumulation of reactive oxygen species (ROS) and ameliorate mitochondrial dysfunction, reducing APAP-induced renal tubular epithelial cell (TEC) death in vitro and in vivo. Furthermore, IL-22 could downregulate the APAP-induced NLRP3 inflammasome activation and mature IL-1β release in kidney injury. Additionally, the APAP-mediated upregulation of the serum levels of IL-18, TNF-α, IL-6, and IL-1β was obviously decreased, suggesting IL-22 has inhibitory effects on inflammatory responses. Conclusively, our study demonstrated that IL-22 exerted ameliorative effects on APAP-induced kidney injury by alleviating mitochondrial dysfunction and NLRP3 inflammasome activation, suggesting that IL-22 represents a potential therapeutic approach to treat APAP-induced kidney injury. KEY POINTS: • IL-22 could ameliorate APAP that triggered oxidative stress and mitochondrial dysfunction. • IL-22 could reduce APAP that caused inflammatory responses. Graphical abstract.

Oxalate-induced crystalline kidney injury is one of the most common types of crystalline nephropathy. Unfortunately, there is no effective treatment to reduce the deposition of calcium oxalate crystals and alleviate kidney damage. Thus, proactive therapeutic is urgently needed to alleviate the suffering it causes to patient. Here, we investigated whether IL-22 exerted nephroprotective effects to sodium oxalate-mediated kidney damage and its potential mechanism. Crystalline kidney injury models were developed in vitro and in vivo that was often observed in clinic. We provided evidence that IL-22 could effectively decrease the accumulation of ROS and mitochondrial damage in cell and animal models and reduce the death of TECs. Moreover, IL-22 decreased the expression of the NLRP3 inflammasome and mature IL-1β in renal tissue induced by sodium oxalate. Further studies confirmed that IL-22 could play an anti-inflammatory role by reducing the levels of cytokines such as IL-1β, IL-18, and TNF-α in serum. In conclusion, our study confirmed that IL-22 has protective effects on sodium oxalate-induced crystalline kidney injury by reducing the production of ROS, protecting mitochondrial membrane potential, and inhibiting the inflammatory response. Therefore, IL-22 may play a potential preventive role in sodium oxalate-induced acute renal injury. KEY POINTS: • IL-22 could reduce sodium oxalate-mediated cytotoxicity and ameliorate renal injury. • IL-22 could alleviate oxidative stress and mitochondrial dysfunction induced by sodium oxalate. • IL-22 could inhibit inflammatory response of renal injury caused by sodium oxalate.

Kidney damage initiates the deteriorating metabolic states in tubule cells that lead to the development of end‐stage renal disease (ESTD). Interleukin‐22 (IL‐22) is an effective therapeutic antidote for kidney injury via promoting kidney recovery, but little is known about the underlying molecular mechanisms. Here, we first provide evidence that IL‐22 attenuates kidney injury via metabolic reprogramming of renal tubular epithelial cells (TECs). Specifically, our data suggest that IL‐22 regulates mitochondrial function and glycolysis in damaged TECs. Further observations indicate that IL‐22 alleviates the accumulation of mitochondrial reactive oxygen species (ROS) and dysfunctional mitochondria via the induction of AMPK/AKT signaling and PFBFK3 activities. In mice, amelioration of kidney injury and necrosis and improvement of kidney functions via regulation of these metabolism relevant signaling and mitochondrial fitness of recombinant IL‐22 are certificated in cisplatin‐induced kidney damage and diabetic nephropathy (DN) animal models. Taken together, our findings unravel new mechanistic insights into protective effects of IL‐22 on kidneys and highlight the therapeutic opportunities of IL‐22 and the involved metabolic regulators in various kidney diseases., IL‐22 attenuates kidney injury via metabolic reprogramming of renal TECs, regulates mitochondrial function and glycolysis in damaged TECs, and alleviates the accumulation of mitochondrial ROS and dysfunctional mitochondria via the induction of AMPK/AKT and PFBFK3 activities. Ameliorating kidney injury of IL‐22 via regulation of metabolism relevant signaling is certificated in cisplatin‐induced kidney damage and diabetic nephropathy animal models.

Kidney damage initiates the deteriorating metabolic states in tubule cells that lead to the development of end-stage renal disease (ESTD). Interleukin 22 (IL-22) is an effective therapeutic antidote for kidney injury via promoting kidney recovery, but little is known about the underlying molecular mechanisms. Here we first provide evidence that IL-22 attenuates kidney injury via metabolic reprogramming of renal tubular epithelial cells (TECs). Specifically, our data suggest that IL-22 regulates mitochondrial function and glycolysis in damaged TECs. Further observations indicate that IL-22 alleviates the accumulation of mitochondrial reactive oxygen species (ROS) and dysfunctional mitochondria via the induction of AMPK/AKT signaling and PFBFK3 activities. In mice, amelioration of kidney injury and necrosis and improvement of kidney functions via regulation of these metabolism relevant signaling and mitochondrial fitness of recombinant IL-22 are certificated in cisplatin induced kidney damage and diabetic nephropathy (DN) animal models. Taken together, our findings unravel new mechanistic insights into protective effects of IL-22 on kidney and highlight the therapeutic opportunities of IL-22 and the involved metabolic regulators in various kidney diseases.

Acetaminophen (APAP) overdose can lead to acute, severe kidney injury, which has recently attracted considerable attention among researchers and clinicians. Unfortunately, there are no well-established treatments for APAP-induced renal injury, and the molecular mechanism of APAP-induced kidney injury is still unclear. Herein, we explored the protective effects of interleukin (IL)-22 on APAP-induced renal injury and the underlying molecular basis. We found that IL-22 could significantly alleviate the accumulation of reactive oxygen species (ROS) and ameliorate mitochondrial dysfunction, reducing APAP-induced renal tubular epithelial cell (TEC) death in vitro and in vivo. Furthermore, IL-22 could downregulate the APAP-induced NLRP3 inflammasome activation and mature IL-1β release in kidney injury. Additionally, the APAP-mediated upregulation of the serum levels of IL-18, TNF-α, IL-6, and IL-1β was obviously decreased, suggesting IL-22 has inhibitory effects on inflammatory responses. Conclusively, our study demonstrated that IL-22 exerted ameliorative effects on APAP-induced kidney injury by alleviating mitochondrial dysfunction and NLRP3 inflammasome activation, suggesting that IL-22 represents a potential therapeutic approach to treat APAP-induced kidney injury. KEY POINTS: • IL-22 could ameliorate APAP that triggered oxidative stress and mitochondrial dysfunction. • IL-22 could reduce APAP that caused inflammatory responses. Graphical abstract.

Background Diabetic nephropathy (DN), the leading cause of end-stage renal disease, is acknowledged as an independent risk factor for cardiovascular disease, which underlines the urgent need for new medications to DN. Dihydroquercetin (DHQ), an important natural dihydroflavone, exerts significant antioxidant, anti-inflammatory, and antifibrotic properties, but its effects on DN have not been investigated yet. Purpose We aimed to explore the kidney protection effects of DHQ on DN rats induced by high-fat diet/streptozotocin in vivo and the underlying mechanisms of DHQ on renal cells including HBZY-1 and HK2 exposed to high glucose in vitro. Methods Major biochemical indexes were measured including urine microalbumin, fasting serum glucose, serum levels of creatinine, total cholesterol and low density lipoprotein cholesterol. Renal histologic sections were stained with hematoxylin-eosin, periodic acid-Schiff and Masson. The cell proliferation was assessed by MTT assay. Reactive oxygen species (ROS) generation was detected by DCFH-DA assay and laser scanning confocal microscope. Expression of all proteins was examined by western-blot. Results In high-fat diet/streptozotocin-induced DN rats, DHQ at the dose of 100 mg/kg/day significantly attenuated the increasing urine microalbumin excretion, hyperglycemia and lipid metabolism disorders, and mitigated renal histopathological lesions. In in vitro studies, DHQ significantly suppressed cell proliferation and the excessive ROS generation, and alleviated the activation of nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome and the expression of renal fibrosis-associated proteins in renal cells exposed to high glucose. Conclusion The results revealed that DHQ possesses kidney protection effects including attenuating urine microalbumin excretion, hyperglycemia and lipid metabolism disorders, and mitigating renal histopathological lesions on DN, and one of the possible renal-protective mechanisms is suppressing ROS and NLRP3 inflammasome.

Background/Aims: Overproliferation of mesangial cells was believed to play an important role in the progress of diabetic nephropathy, one of the primary complications of diabetes. Hydrogen sulfide (H2S), a well-known and pungent gas with the distinctive smell of rotten eggs, was discovered to play a protective role in diabetic nephropathy. Methods: MTT assay was used to examine the viability of mesangial cells. Small interfering RNA was used to knock down the expression of TLR4 while specific inhibitor LY294002 to suppress the function of PI3K. H2S generation rate was determined by a H2S micro-respiration sensor. Results: Glucose of 25mM induced significant mesangial cells proliferation, which was accomplished by significantly inhibited endogenous H2S synthesis. And exogenous H2S treatment by NaHS markedly mitigated the overproliferation of mouse mesangial cells. Furthermore, it was found that H2S deficiency could result in TLR4 activation. And H2S supplementation remarkably inhibited TLR4 expression and curbed the mesangial cell overproliferation. Besides, PI3K/Akt pathway inhibition also significantly ameliorated the cell overproliferation. Conclusion: High glucose (HG) induces mouse mesangial cell overproliferation via inhibition of hydrogen sulfide synthesis in a TLR-4-dependent manner. And PI3K/Akt pathway might also play a vital part in the HG-induced mesangial cell overproliferation.

Background Inhibitors targeting VEGF and VEGFR are commonly used in the clinic, but only a subset of patients could benefit from these inhibitors and the efficacy was limited by multiple relapse mechanisms. In this work, we aimed to investigate the role of innate immune response in anti-angiogenic therapy and explore efficient therapeutic strategies to enhance efficacy of anti-angiogenic therapy against non-small cell lung cancer (NSCLC). Methods Three NSCLC tumor models with responses to VEGF inhibitors were designed to determine innate immune-related underpinnings of resistance to anti-angiogenic therapy. Immunofluorescence staining, fluorescence-activated cell sorting and immunoblot analysis were employed to reveal the expression of immune checkpoint regulator CD47 in refractory NSCLC. Metastatic xenograft models and VEGFR1-SIRPα fusion protein were applied to evaluate the therapeutic effect of simultaneous disruption of angiogenetic axis and CD47-SIRPα axis. Results Up-regulation of an innate immunosuppressive pathway, CD47, the ligand of the negative immune checkpoint regulator SIRPα (signal regulatory protein alpha), was observed in NSCLC tumors during anti-angiogenic therapy. Further studies revealed that CD47 upregulation in refractory lung tumor models was mediated by TNF-α/NF-κB1 signal pathway. Targeting CD47 could trigger macrophage-mediated elimination of the relapsed NSCLC cells, eliciting synergistic anti-tumor effect. Moreover, simultaneously targeting VEGF and CD47 by VEGFR1-SIRPα fusion protein induced macrophages infiltration and sensitized NSCLC to angiogenesis inhibitors and CD47 blockade. Conclusions Our research provided evidence that CD47 blockade could sensitize NSCLC to anti-angiogenic therapy and potentiate its anti-tumor effects by enhancing macrophage infiltration and tumor cell destruction, providing novel therapeutics for NSCLC by disrupting CD47/SIRPα interaction and angiogenetic axis.

Nonalcoholic fatty liver disease (NAFLD) is now a leading cause of chronic liver disease, and there is currently no available treatment strategy. Interleukin-22 (IL-22) has been recognized as a promising agent for alleviating NAFLD, but the efficacy of IL-22 is far from satisfactory because safe dose of IL-22 elicited limited improvement, whereas higher concentration might induce serious side effects and off-target toxicities. Thus, targeted and sustained expression of IL-22 in the liver is necessary. To meet the challenge, we elaborately developed a novel polymetformin carrier by conjugating biguanide to chitosan, termed chitosan-metformin (CM), which could exert advanced gene delivery efficiency and possess intrinsic therapeutic efficacy from metformin for NAFLD. CM accompanied with penetratin and DSPE-PEG2000 could self-assemble to form stable nanocomplexes with IL-22 gene via electrostatic interaction. This nanoparticle (CDPIA) exerted desirable particle size at ∼100 nm, fine morphology, and efficient cellular internalization. Furthermore, CDPIA also demonstrated a unique superiority in endosomal escape capacity and satisfactory biocompatibility as well as predominant liver accumulation. Most importantly, CDPIA distinctly alleviated hepatic steatosis, restored insulin sensitivity, and improved metabolic syndrome in high-fat-diet-fed mice model. This liver-targeted delivery of IL-22 activated STAT3/Erk1/2 and Nrf2/SOD1 signaling transductions as well as modulated lipid-metabolism-related gene expression. These findings altogether demonstrated that the polymetformin and penetratin-based hybrid nanoparticles could be exploited as a novel safe and efficient strategy for the improvement of NAFLD.

Additional file 9: Figure S9. (a) FACS analysis was employed to sort CD68+ macrophages from LLC tumor and the VEGFA level in CD68+ macrophage was measured. SIRPα-Fc enhanced macrophage infiltration without significant VEFGA production in the tumors. (b) CD11c was used as a marker to detect dendritic cells in LLC tumor treated with SIRPα-Fc or VEGFR1-SIRPα.

B-cell non-Hodgkin's lymphoma (B-NHL) is one of the most common types of cancer in the world, with half of the patients dying due to the resistance or tolerance against the treatment. Thus, a novel therapeutic approach for B-NHL treatment was urgently needed. In this study, we investigated the potential of co-inhibition of Hedgehog signaling pathway (Hh) and autophagy in B-NHL therapy. We reported that vismodegib, an inhibitor of Hedgehog signaling pathway, could block the Hh pathway and induce cytotoxicity and apoptosis in B-NHL Raji cells. During this process, autophagy was activated as a response to Hh inhibition. Importantly, inhibition of autophagy potentiated the cytotoxicity and caspase 3-dependent apoptosis induced by vismodegib in B-NHL cells. Furthermore, clearance of ROS generation caused a decreased activity of autophagy and attenuated cytotoxicity in vismodegib-treated cells, while inhibition of autophagy accelerated the formation of ROS, indicating that ROS was required for vismodegib-induced autophagy and cytotoxicity in B-NHL cells. Our results demonstrated that co-inhibition of Hh pathway and autophagy could potently kill B-NHL cells and highlighted a novel approach for B-NHL therapy by co-inhibition of Hh pathway and cytoprotective autophagy.

Recombinant human arginase (rhArg) is an arginine-degrading enzyme that has been evaluated as effective therapeutics for varieties of malignant tumors and is in clinical trials for hepatocellular carcinoma (HCC) treatment nowadays. Our previous studies have reported that rhArg could induce autophagy and apoptosis in lymphoma cells and inhibiting autophagy could enhance the efficacy of rhArg on lymphoma. However, whether rhArg could induce autophagy and what roles autophagy plays in leukemia cells are unclear. In this study, we demonstrated that rhArg treatment could lead to the formation of autophagosomes and the upregulation of microtubule-associated protein light chain 3 II (LC3-II) in human promyelocytic leukemia HL-60 cells and human acute T cell leukemia Jurkat cells. Furthermore, inhibiting autophagy using 3-methyladenine (3-MA) or chloroquine (CQ) could significantly enhance rhArg-induced cell growth inhibition and apoptosis. Taken together, these findings indicated that rhArg induced autophagy in leukemia cells and inhibiting autophagy enhanced anti-leukemia effect of rhArg, which might encourage the treatment of leukemia by targeting arginine depletion and autophagy in clinics.

Diabetic nephropathy (DN) is one of the most lethal complications of diabetes mellitus with metabolic disorders and chronic inflammation. Although the cytokine IL-22 was initially implicated in the pathogenesis of chronic inflammatory diseases, recent studies suggested that IL-22 could suppress inflammatory responses and alleviate tissue injury. Herein, we examined the role of IL-22 in DN. We found that serum levels of IL-22 were significantly downregulated in both patients and mice with DN. The expression of IL-22 was further decreased with the progression of DN, whereas IL-22 gene therapy significantly ameliorated renal injury and mesangial matrix expansion in mice with established nephropathy. IL-22 could also markedly reduce high glucose-induced and TGF-β1-induced overexpression of fibronectin and collagen IV in mouse renal glomerular mesangial cells in a dose-dependent manner, suggesting the potential role of IL-22 to inhibit the overproduction of ECM in vitro. Simultaneously, IL-22 gene therapy drastically alleviated renal fibrosis and proteinuria excretion in DN. In addition, IL-22 gene therapy markedly attenuated hyperglycemia and metabolic disorders in streptozotocin-induced experimental diabetic mice. Notably, IL-22 drastically reversed renal activation of NLRP3, cleavage of caspase-1, and the maturation of IL-1β in DN, suggesting unexpected anti-inflammatory function of IL-22 via suppressing the activation of NLRP3 inflammasome in vivo. Moreover, IL-22 markedly downregulated high glucose-induced activation of NLRP3 inflammasome in renal mesangial cells in a dose-dependent manner, indicating that the effects of IL-22 on NLRP3 inflammasome activation was independent of improved glycemic control. These results suggested that nephroprotection by IL-22 in DN was most likely associated with reduced activation of NLRP3 inflammasome. In conclusion, our finding demonstrated that IL-22 could exert favorable effects on DN via simultaneously alleviating systemic metabolic syndrome and downregulating renal NLRP3/caspase-1/IL-1β pathway, suggesting that IL-22 might have therapeutic potential for the treatment of DN.

The Pro12Ala and C161T polymorphisms in peroxisome proliferator-activated receptor γ (PPARγ) have been shown to be associated with carotid artery atherosclerosis. It remains unclear whether these two polymorphisms are associated with risk factors for cardiovascular disease (CVD) in hemodialysis (HD) patients. Therefore, the PPARγ genotypes in 99 HD patients and 149 controls were determined, and clinical characteristics among the different genotypes were compared. We found that the frequency of the Pro12Ala and C161T polymorphisms in HD patients was similar to that in healthy controls, but C161T polymorphism and T allele frequencies in HD patients with CVD were lower than that in HD patients without CVD. Carotid artery plaque (CAP) and carotid intima-media thickness (CIMT) in HD patients with CT + TT or Pro12Ala genotypes were also less than that in patients with CCor Pro12Pro genotypes, respectively. HD patients with CT + TT genotype had lower serum C reactive protein (CRP) levels, as well as higher triceps skin fold (TSF) thickness, mid arm circumference (MAC) and mean mid arm circumference (MMAC) than HD patients with CC genotype (P

To investigate the role of cyclin kinase inhibitor p27 on proliferation of mesangial cell (MC) induced by tumor necrosis factor-alpha (TNF-alpha).p27 protein of MC lysate was detected with Western blotting analysis. The degree of MC proliferation was estimated through [(3)H] thymidine incorporation. The effect of reducing p27 expression on MC proliferation was analysed with p27 antisense oligodeoxynucleotide (ODN) phosphorothioate.TNFalpha (200 000 U/L) decreased p27 level to 0.6 +/- 0.1 from 1.1 +/- 0.1 of MC lysate cultured in serum-free DMEM for 24 hours (P0.01) and increased [(3)H] thymidine incorporation to 2 060 +/- 112 from 685 +/- 53 cpm/well (P0.01). p27 antisense ODN transfection decreased p27 level of MC stimulated by TNF-alpha for 24 hours (0.3 +/- 0.1 vs 0.6 +/- 0.1, P0.01) and increased [(3)H] thymidine incorporation (2 420 +/- 130 vs 2 060 +/- 112 cpm/well, P0.05) in 24 hours of culture.The decline of p27 protein may play an important role in MC proliferation induced by TNF-alpha. Because the cell cycle is controlled by the interplay between the positive cell cycle regulatory proteins (CCRP) and negative CCRP, further research is needed to study the expression of the positive and negative CCRP in MC in order to understand better the role of CCRP in MC proliferation.