Thrombomodulin domain 1 ameliorates diabetic nephropathy in mice via anti-NF-κB/NLRP3 inflammasome-mediated inflammation, enhancement of NRF2 antioxidant activity and inhibition of apoptosis

Dapagliflozin ameliorated retinal vascular permeability in diabetic retinopathy rats by suppressing inflammatory factors

BACKGROUND

Diabetic retinopathy is a common microvascular complication of diabetes and one of the major causes of blindness in the working-age population. Emerging evidence has elucidated that inflammation drives the key mechanism of diabetes-mediated retinal disturbance. As a new therapeutic drug targeting diabetes, whether dapagliflozin could improve vascular permeability from the perspective of anti-inflammatory effect need to be further explored.

METHODS

Type 2 diabetic retinopathy rat model was established and confirmed by fundus fluorescein angiography (FFA). ELISA detected level of plasma inflammatory factors and C-peptide. HE staining, immunohistochemistry and western blot detected histopathology changes of retina, expression of retinal inflammatory factors and tight junction proteins.

RESULTS

Dapagliflozin exhibited hypoglycemic effect comparable to insulin, but did not affect body weight. By inhibiting expression of inflammatory factors (NLRP3, Caspase-1, IL-18, NF-κB) in diabetic retina and plasma, dapagliflozin reduced damage of retinal tight junction proteins and improved retinal vascular permeability. The anti-inflammatory effect of dapagliflozin was superior to insulin.

CONCLUSIONS

Dapagliflozin improved retinal vascular permeability by reducing diabetic retinal and plasma inflammatory factors. The anti-inflammatory mechanism of dapagliflozin is independent of hypoglycemic effect and superior to insulin.

Downregulation of ARNTL in renal tubules of diabetic db/db mice reduces kidney injury by inhibiting ferroptosis

BACKGROUND

The prevalence of ferroptosis in diabetic kidney tubules has been documented, yet the underlying mechanism remains elusive. The aim of this study was to ascertain the pivotal gene linked to ferroptosis and establish a novel target for the prevention and management of diabetic kidney disease (DKD).

METHODS

Transcriptomics data (GSE184836) from DKD mice (C57BLKS/J) were retrieved from the GEO database and intersected with ferroptosis-related genes from FerrDb. Then, differentially expressed genes associated with ferroptosis in the glomeruli and tubules were screened. Gene ontology analysis and protein-protein interaction network construction were used to identify key genes. Western blotting and real-time quantitative polymerase chain reaction were employed to validate the expression in the same model. Aryl hydrocarbon receptor nuclear translocator-like protein 1 (ARNTL) expression in patients and mice with DKD was assessed using immunohistochemistry staining. ARNTL knockdown in C57BLKS/J mice was established and plasma malonaldehyde, superoxide dismutase, and renal pathology were analyzed. The efficacy of ARNTL knockdown was evaluated using proteomics analysis. Mitochondrial morphology was observed using transmission electron microscopy.

RESULTS

ARNTL was screened by bioinformatics analysis and its overexpression verified in patients and mice with DKD. ARNTL knockdown reduced oxidative stress in plasma. Kidney proteomics revealed that ferroptosis was inhibited. The reduction of the classic alteration in mitochondrial morphology associated with ferroptosis was also observed. Gene set enrichment analysis demonstrated that the downregulation of the TGFβ pathway coincided with a decrease in collagen protein and TGFβ1 levels.

CONCLUSIONS

The ferroptosis-associated gene ARNTL is a potential target for treating DKD.

Nrf2 signaling in diabetic nephropathy, cardiomyopathy and neuropathy: Therapeutic targeting, challenges and future prospective

Western lifestyle contributes to an overt increase in the prevalence of metabolic anomalies including diabetes mellitus (DM) and obesity. Prevalence of DM is rapidly growing worldwide, affecting many individuals in both developing and developed countries. DM is correlated with the onset and development of complications with diabetic nephropathy (DN), diabetic cardiomyopathy (DC) and diabetic neuropathy being the most devastating pathological events. On the other hand, Nrf2 is a regulator for redox balance in cells and accounts for activation of antioxidant enzymes. Dysregulation of Nrf2 signaling has been shown in various human diseases such as DM. This review focuses on the role Nrf2 signaling in major diabetic complications and targeting Nrf2 for treatment of this disease. These three complications share similarities including the presence of oxidative stress, inflammation and fibrosis. Onset and development of fibrosis impairs organ function, while oxidative stress and inflammation can evoke damage to cells. Activation of Nrf2 signaling significantly dampens inflammation and oxidative damage, and is beneficial in retarding interstitial fibrosis in diabetic complications. SIRT1 and AMPK are among the predominant pathways to upregulate Nrf2 expression in the amelioration of DN, DC and diabetic neuropathy. Moreover, certain therapeutic agents such as resveratrol and curcumin, among others, have been employed in promoting Nrf2 expression to upregulate HO-1 and other antioxidant enzymes in the combat of oxidative stress in the face of DM.

Human Umbilical Cord Mesenchymal Stem Cells Inhibit Pyroptosis of Renal Tubular Epithelial Cells through miR-342-3p/Caspase1 Signaling Pathway in Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the microvascular complications of diabetes. Recent studies suggest that the pyroptosis of renal tubular epithelial cell plays a critical role in DN. Currently, effective therapeutic strategies to counteract and reverse the progression of DN are lacking. Mesenchymal stem cells (MSCs) represent an attractive therapeutic tool for tissue damage and inflammation owing to their unique immunomodulatory properties. However, the underlying mechanisms remain largely unknown. In the present study, we found that human umbilical cord MSCs (UC-MSCs) can effectively ameliorate kidney damage and reduce inflammation in DN rats. Importantly, UC-MSC treatment inhibits inflammasome-mediated pyroptosis in DN. Mechanistically, we performed RNA sequencing and identified that miR-342-3p was significantly downregulated in the kidneys of DN rats. Furthermore, we found that miR-342-3p was negatively correlated with renal injury and pyroptosis in DN rats. The expression of miR-342-3p was significantly increased after UC-MSC treatment. Moreover, miR-342-3p decreased the expression of Caspase1 by targeting its 3 $\prime$ -UTR, which was confirmed by double-luciferase assay. Using miRNA mimic transfection, we demonstrated that UC-MSC-derived miR-342-3p inhibited pyroptosis of renal tubular epithelial cells through targeting the NLRP3/Caspase1 pathway. These findings would provide a novel intervention strategy for the use of miRNA-modified cell therapy for kidney diseases.

Glycyrrhizin mitigates acute lung injury by inhibiting the NLRP3 inflammasome in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza glabra L. is a widely used traditional Chinese medicine with antipyretic, detoxification, antibacterial and therapeutic effects against various diseases, including liver diseases. Glycyrrhizin (GL), the most significant active ingredient of Glycyrrhiza glabra L., exerts anti-inflammatory activity. However, the anti-inflammatory effect of GL remains to be determined.

AIM OF THIS STUDY

Consequently, this research was carried out to discover the effects and mechanism of action of GL on ALI.

MATERIALS AND METHODS

Cell experiments established an in vitro model of LPS-induced RAW 264.7 macrophages to verify the mechanism. The levels of NO, PEG₂, and inflammatory cytokines were estimated by ELISA. The expression levels of proteins related to the NF-κB signalling pathway and NLRP3 inflammasome were determined by Western blotting. The nuclear translocation of NF-κB p65 and ASC was tested through immunofluorescence analysis. The inhibitory effect of NLRP3 inhibitor MCC950 on macrophage was evaluated. Male BALB/C mice were selected to establish the ALI model. The experiment was randomly divided into five groups: control, ALI, GLL, GLH, and DEX. Pathological alterations were explored by H&E staining. The weight ratios of lung W/D, MPO, and inflammatory cytokines were evaluated by ELISA. The expression levels of proteins related to the NF-κB signalling pathway or NLRP3 inflammasome were analysed by Western blotting.

RESULTS

Here, we demonstrate that GL attenuates inflammation, nitric oxide, IL-18, IL-1β, TNF-α, IL-6, and PGE₂ levels and alveolar epithelial barrier permeability in macrophages and mice challenged with LPS. In addition, GL inhibits NLRP3 inflammasome initiation and activation and NF-κB signalling pathway activation.

CONCLUSION

This research demonstrates that GL may alleviate ALI inflammation by interfering with the NF-κB/NLRP3 inflammasome signalling pathway.

Thrombomodulin activation driven by LXR agonist attenuates renal injury in diabetic nephropathy

Objective

Inflammation and thrombosis are recognized as interrelated biological processes. Both thrombomodulin (TM) and factor XIII-A (FXIII-A) are involved in inflammation and coagulation process. However, their role in the pathogenesis of diabetic nephropathy (DN) remains unclear. In vitro study, the liver X receptor (LXR) agonist T0901317 can up-regulate the expression of TM in glomerular endothelial cells. Now we evaluated the interaction between TM activation and FXIII-A and their effects against renal injury.

Methods

We first evaluated the serum levels of FXIII-A and TM and the expression of TM, LXR-α and FXIII-A in renal tissues of patients with biopsy-proven DN. We then analyzed the expression of TM, LXR-α and FXIII-A in renal tissues of db/db DN mice after upregulating TM expression via T0901317 or downregulating its expression via transfection of TM shRNA-loaded adenovirus. We also investigated the serum levels of Tumor necrosis factor (TNF)-α, Interleukin (IL)-6, creatinine, and urinary microalbumin level in db/db mice.

Results

Our study showed that elevations in serum levels of FXIII-A positively correlated to the serum levels of TM and were also associated with end-stage kidney disease in patients with DN. The number of TM⁺ cells in the renal tissues of patients with DN negatively correlated with the number of FXIII-A⁺ cells and positively correlated with the number of LXR-α⁺ cells and estimated glomerular filtration rate (eGFR), whereas the number of FXIII-A⁺ cells negatively correlated with the eGFR.

Conclusion

Thrombomodulin activation with T0901317 downregulated FXIII-A expression in the kidney tissue and alleviated renal injury in db/db mice.

Nanocurcumin combined with insulin alleviates diabetic kidney disease through P38/P53 signaling axis

Treatments for diabetic kidney disease (DKD) mainly focus on managing hyperglycemia and hypertension, but emerging evidence suggests that inflammation also plays a role in the pathogenesis of DKD. This 10-week study evaluated the efficacy of daily oral nanoparticulate-curcumin (nCUR) together with long-acting insulin (INS) to treat DKD in a rodent model. Diabetic rats were dosed with unformulated CUR alone, nCUR alone or together with INS, or INS alone. The progression of diabetes was reflected by increases in plasma fructosamine, blood urea nitrogen, creatinine, bilirubin, ALP, and decrease in albumin and globulins. These aberrancies were remedied by nCUR+INS or INS but not by CUR or nCUR. Kidney histopathological results revealed additional abnormalities characteristic of DKD, such as basement membrane thickening, tubular atrophy, and podocyte cytoskeletal impairment. nCUR and nCUR+INS mitigated these lesions, while CUR and INS alone were far less effective, if not ineffective. To elucidate how our treatments modulated inflammatory signaling in the liver and kidney, we identified hyperactivation of P38 (MAPK) and P53 with INS and CUR, whereas nCUR and nCUR+INS deactivated both targets. Similarly, the latter interventions led to significant downregulation of renal NLRP3, IL-1β, NF-ĸB, Casp3, and MAPK8 mRNA, indicating a normalization of inflammasome and apoptotic pathways. Thus, we show therapies that reduce both hyperglycemia and inflammation may offer better management of diabetes and its complications.

A novel fusion protein consisting of anti-ANGPTL3 antibody and interleukin-22 ameliorates diabetic nephropathy in mice

Introduction

The pathogenic mechanisms of diabetic nephropathy (DN) include podocyte injury, inflammatory responses and metabolic disorders. Although the antagonism of Angiopoietin-like protein 3 (ANGPTL3) can alleviate proteinuria symptoms by inhibiting the activation of integrin αvβ3 on the surface of podocytes, it can not impede other pathological processes, such as inflammatory responses and metabolic dysfunction of glucolipid. Interleukin-22 (IL-22) is considered to be a pivotal molecule involved in suppressing inflammatory responses, initiating regenerative repair, and regulating glucolipid metabolism.

Methods

Genes encoding the mIL22IgG2aFc and two chains of anti-ANGPTL3 antibody and bifunctional protein were synthesized. Then, the DN mice were treated with intraperitoneal injection of normal saline, anti-ANGPTL3 (20 mg/kg), mIL22Fc (12 mg/kg) or anti-ANGPTL3 /IL22 (25.3 mg/kg) and irrigation of positive drug losartan (20mg/kg/d) twice a week for 8 weeks.

Results

In this research, a novel bifunctional fusion protein (anti-ANGPTL3/IL22) formed by the fusion of IL-22 with the C-terminus of anti-ANGPTL3 antibody exhibited favorable stability and maintained the biological activity of anti-ANGPTL3 and IL-22, respectively. The fusion protein showed a more pronounced attenuation of proteinuria and improved dysfunction of glucolipid metabolism compared with mIL22Fc or anti-ANGPTL3. Our results also indicated that anti-ANGPTL3/IL22 intervention significantly alleviated renal fibrosis via inhibiting the expression of the inflammatory response-related protein nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) p65 and NOD-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome. Moreover, transcriptome analysis revealed the downregulation of signaling pathways associated with injury and dysfunction of the renal parenchymal cell indicating the possible protective mechanisms of anti-ANGPTL3/IL22 in DN.

Conclusion

Collectively, anti-ANGPTL3/IL22 bifunctional fusion protein can be a promising novel therapeutic strategy for DN by reducing podocyte injury, ameliorating inflammatory response, and enhancing renal tissue recovery.

Effects of the uremic toxin indoxyl sulphate on human microvascular endothelial cells

Indoxyl sulphate (IS) is a uremic toxin accumulating in the plasma of chronic kidney disease (CKD) patients. IS accumulation induces side effects in the kidneys, bones and cardiovascular system. Most studies assessed IS effects on cell lines by testing higher concentrations than those measured in CKD patients. Differently, we exposed a human microvascular endothelial cell line (HMEC-1) to the IS concentrations measured in the plasma of healthy subjects (physiological) or CKD patients (pathological). Pathological concentrations reduced cell proliferation rate but did not increase long-term oxidative stress level. Indeed, total protein thiols decreased only after 24 h of exposure in parallel with an increased Nrf-2 protein expression. IS induced actin cytoskeleton rearrangement with formation of stress fibres. Proteomic analysis supported this hypothesis as many deregulated proteins are related to actin filaments organization or involved in the endothelial to mesenchymal transition. Interestingly, two proteins directly linked to cardiovascular diseases (CVD) in in vitro and in vivo studies underwent deregulation: COP9 signalosome complex subunit 9 and thrombomodulin. Future experiments will be needed to investigate the role of these proteins and the signalling pathways in which they are involved to clarify the possible link between CKD and CVD.

The VEGF Inhibitor Soluble Fms-like Tyrosine Kinase 1 Does Not Promote AKI-to-CKD Transition

(1) Background: Soluble Fms-like tyrosine kinase 1 (sFLT1) is an endogenous VEGF inhibitor. sFLT1 has been described as an anti-inflammatory treatment for diabetic nephropathy and heart fibrosis. However, sFLT1 has also been related to peritubular capillary (PTC) loss, which promotes fibrogenesis. Here, we studied whether transfection with sFlt1 aggravates experimental AKI-to-CKD transition and whether sFLT1 is increased in human kidney fibrosis. (2) Methods: Mice were transfected via electroporation with sFlt1. After confirming transfection efficacy, mice underwent unilateral ischemia/reperfusion injury (IRI) and were sacrificed 28 days later. Kidney histology and RNA were analyzed to study renal fibrosis, PTC damage and inflammation. Renal sFLT1 mRNA expression was measured in CKD biopsies and control kidney tissue. (3) Results: sFlt1 transfection did not aggravate renal fibrosis, PTC loss or macrophage recruitment in IRI mice. In contrast, higher transfection efficiency was correlated with reduced expression of pro-fibrotic and pro-inflammatory markers. In the human samples, sFLT1 mRNA levels were similar in CKD and control kidneys and were not correlated with interstitial fibrosis or PTC loss. (4) Conclusion: As we previously found that sFLT1 has therapeutic potential in diabetic nephropathy, our findings indicate that sFLT1 can be administered at a dose that is therapeutically effective in reducing inflammation, without promoting maladaptive kidney damage.

Activated Protein C Ameliorates Tubular Mitochondrial Reactive Oxygen Species and Inflammation in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is an emerging pandemic, paralleling the worldwide increase in obesity and diabetes mellitus. DKD is now the most frequent cause of end-stage renal disease and is associated with an excessive risk of cardiovascular morbidity and mortality. DKD is a consequence of systemic endothelial dysfunction. The endothelial-dependent cytoprotective coagulation protease activated protein C (aPC) ameliorates glomerular damage in DKD, in part by reducing mitochondrial ROS generation in glomerular cells. Whether aPC reduces mitochondrial ROS generation in the tubular compartment remains unknown. Here, we conducted expression profiling of kidneys in diabetic mice (wild-type and mice with increased plasma levels of aPC, APC^high mice). The top induced pathways were related to metabolism and in particular to oxidoreductase activity. In tubular cells, aPC maintained the expression of genes related to the electron transport chain, PGC1-α expression, and mitochondrial mass. These effects were associated with reduced mitochondrial ROS generation. Likewise, NLRP3 inflammasome activation and sterile inflammation, which are known to be linked to excess ROS generation in DKD, were reduced in diabetic APC^high mice. Thus, aPC reduces mitochondrial ROS generation in tubular cells and dampens the associated renal sterile inflammation. These studies support approaches harnessing the cytoprotective effects of aPC in DKD.

Diabetic Kidney Disease: From Pathogenesis to Novel Treatment Possibilities

One of the microvascular complications of diabetes is diabetic kidney disease (DKD), often leading to end stage renal disease (ESRD) in which patients require costly dialysis or transplantation. The silent onset and irreversible progression of DKD are characterized by a steady decline of the estimated glomerular filtration rate, with or without concomitant albuminuria. The diabetic milieu allows the complex pathophysiology of DKD to enter a vicious cycle by inducing the synthesis of excessive amounts of reactive oxygen species (ROS) causing oxidative stress, inflammation, and fibrosis. As no cure is available, intensive research is required to develop novel treatments possibilities. This chapter provides an overview of the important pathomechanisms identified in diabetic kidney disease, the currently established therapies, as well as recently developed novel therapeutic strategies in DKD.

Podocyte-specific Nlrp3 inflammasome activation promotes diabetic kidney disease

Efficient therapies for diabetic kidney disease (DKD), now the leading cause of kidney failure, are lacking. One hallmark of DKD is sterile inflammation (inflammation in absence of microorganisms), but the underlying molecular mechanisms remain poorly understood. The NLRP3 inflammasome (innate immune system receptors and sensors regulating activation of caspase-1) is a mechanism of sterile inflammation known to be activated by metabolic stimuli and reactive metabolites associated with DKD, including inflammasome activation in podocytes. However, whether NLRP3 inflammasome activation in podocytes contributes to sterile inflammation and glomerular damage in DKD remains unknown. Here, we found that kidney damage, as reflected by increased albuminuria, glomerular mesangial expansion and glomerular basement membrane thickness was aggravated in hyperglycemic mice with podocyte-specific expression of an Nlrp3 gain-of-function mutant (Nlrp3A350V). In contrast, hyperglycemic mice with podocyte-specific Nlrp3 or Caspase-1 deficiency showed protection against DKD. Intriguingly, podocyte-specific Nlrp3 deficiency was fully protective, while podocyte-specific caspase-1 deficiency was only partially protective. Podocyte-specific Nlrp3, but not caspase-1 deficiency, maintained glomerular autophagy in hyperglycemic mice, suggesting that podocyte Nlrp3 exerts both canonical and non-canonical effects. Thus, podocyte NLRP3 inflammasome activation is both sufficient and required for DKD and supports the concept that podocytes exert some immune cell-like functions. Hence, as podocyte NLRP3 exerts non-canonical and canonical effects, targeting NLRP3 may be a promising therapeutic approach in DKD.

Novel insights into NOD-like receptors in renal diseases

Nucleotide-binding oligomerization domain-like receptors (NLRs), including NLRAs, NLRBs (also known as NAIPs), NLRCs, and NLRPs, are a major subfamily of pattern recognition receptors (PRRs). Owing to a recent surge in research, NLRs have gained considerable attention due to their involvement in mediating the innate immune response and perpetuating inflammatory pathways, which is a central phenomenon in the pathogenesis of multiple diseases, including renal diseases. NLRs are expressed in different renal tissues during pathological conditions, which suggest that these receptors play roles in acute kidney injury, obstructive nephropathy, diabetic nephropathy, IgA nephropathy, lupus nephritis, crystal nephropathy, uric acid nephropathy, and renal cell carcinoma, among others. This review summarises recent progress on the functions of NLRs and their mechanisms in the pathophysiological processes of different types of renal diseases to help us better understand the role of NLRs in the kidney and provide a theoretical basis for NLR-targeted therapy for renal diseases.

TLR9 regulates NLRP3 inflammasome activation via the NF-kB signaling pathway in diabetic nephropathy

BACKGROUND

Toll-like receptors (TLRs) are critical sensors for the conservation of bacterial molecules and play a key role in host defense against pathogens. The effect of TLRs on the maintenance of diabetic nephropathy (DN) and resistance to infection has been investigated; however, the detailed effects of TLR9 on DN development remain elusive.

METHODS

We performed quantitative reverse transcription-polymerase chain reaction and western blotting to detect TLR9 expression levels in the kidneys of experimental mice (db/db) and high-glucose-treated mouse mesangial cell strains (MCs).

RESULTS

TLR9 expression was found to be remarkably upregulated in the kidneys of experimental mice (db/db) and MCs cultivated under hyperglycemic conditions. Moreover, knockdown of TLR9 could restrain NF-kB viability and downregulate the NLRP3 inflammasome in high glucose-treated MCs. TLR9 inhibition also alleviated inflammation and apoptosis, which was reversed by the addition of the NF-κB activator, betulinic acid. Furthermore, depleted TLR9 levels restrained NF-κB viability and NLRP3 expression and reduced kidney inflammation, microalbuminuria discharge, blood sugar level, and glomerular damage in experimental mice (db/db) kidneys. Conclusions These findings offer novel insights into the regulation of TLR9 via the nuclear factor-kB/NOD-, LRR-, and pyrin domain-containing protein 3 inflammasome inflammation pathways in DN progression.

Adverse renal effects of NLRP3 inflammasome inhibition by MCC950 in an interventional model of diabetic kidney disease

Activation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome has been reported in diabetic complications including diabetic kidney disease (DKD). However, it remains unknown if NLRP3 inhibition is renoprotective in a clinically relevant interventional approach with established DKD. We therefore examined the effect of the NLRP3-specific inhibitor MCC950 in streptozotocin-induced diabetic mice to measure the impact of NLRP3 inhibition on renal inflammation and associated pathology in DKD. We identified an adverse effect of MCC950 on renal pathology in diabetic animals. Indeed, MCC950-treated diabetic animals showed increased renal inflammation and macrophage infiltration in association with enhanced oxidative stress as well as increased mesangial expansion and glomerulosclerosis when compared with vehicle-treated diabetic animals. Inhibition of the inflammasome by MCC950 in diabetic mice led to renal up-regulation of markers of inflammation (Il1β, Il18 and Mcp1), fibrosis (Col1, Col4, Fn1, α-SMA, Ctgf and Tgfβ1) and oxidative stress (Nox2, Nox4 and nitrotyrosine). In addition, enhanced glomerular accumulation of pro-inflammatory CD68 positive cells and pro-oxidant factor nitrotyrosine was identified in the MCC950-treated diabetic compared with vehicle-treated diabetic animals. Collectively, in this interventional model of established DKD, NLRP3 inhibition with MCC950 did not show renoprotective effects in diabetic mice. On the contrary, diabetic mice treated with MCC950 exhibited adverse renal effects particularly enhanced renal inflammation and injury including mesangial expansion and glomerulosclerosis.

NAD(P)H: quinone oxidoreductase 1 attenuates oxidative stress and apoptosis by regulating Sirt1 in diabetic nephropathy

Background

Diabetic nephropathy (DN) is one of the main complications of diabetes, and oxidative stress plays an important role in its progression. NAD(P)H: quinone oxidoreductase 1 (NQO1) protects cells from oxidative stress and toxic quinone damage. In the present study, we aimed to investigate the protective effects and underlying mechanisms of NQO1 on diabetes-induced renal tubular epithelial cell oxidative stress and apoptosis.

Methods

In vivo, the kidneys of db/db mice, which are a type 2 diabetes model, were infected with adeno-associated virus to induce NQO1 overexpression. In vitro, human renal tubular epithelial cells (HK-2 cells) were transfected with NQO1 pcDNA3.1(+) and cultured in high glucose (HG). Gene and protein expression was assessed by quantitative real-time PCR, western blotting, immunofluorescence analysis, and immunohistochemical staining. Reactive oxygen species (ROS) were examined by MitoSox red and flow cytometry. TUNEL assays were used to measure apoptosis.

Result

In vivo, NQO1 overexpression reduced the urinary albumin/creatinine ratio (UACR) and blood urea nitrogen (BUN) level in db/db mice. Our results revealed that NQO1 overexpression could significantly increase the ratio of NAD+/NADH and silencing information regulator 1 (Sirt1) expression and block tubular oxidative stress and apoptosis in diabetic kidneys. In vitro, NQO1 overexpression reduced the generation of ROS, NADPH oxidase 1 (Nox1) and Nox4, the Bax/Bcl-2 ratio and the expression of Cleaved Caspase-3 and increased NAD+/NADH levels and Sirt1 expression in HK-2 cells under HG conditions. However, these effects were reversed by the Sirt1 inhibitor EX527.

Conclusions

All these data suggest that NQO1 has a protective effect against oxidative stress and apoptosis in DN, which may be mediated by the regulation of Sirt1 through increasing intracellular NAD+/NADH levels. Therefore, NQO1 may be a new therapeutic target for DN.

Involvement of Inflammasome Components in Kidney Disease

Inflammasomes are multiprotein complexes with an important role in the innate immune response. Canonical activation of inflammasomes results in caspase-1 activation and maturation of cytokines interleukin-1β and -18. These cytokines can elicit their effects through receptor activation, both locally within a certain tissue and systemically. Animal models of kidney diseases have shown inflammasome involvement in inflammation, pyroptosis and fibrosis. In particular, the inflammasome component nucleotide-binding domain-like receptor family pyrin domain containing 3 (NLRP3) and related canonical mechanisms have been investigated. However, it has become increasingly clear that other inflammasome components are also of importance in kidney disease. Moreover, it is becoming obvious that the range of molecular interaction partners of inflammasome components in kidney diseases is wide. This review provides insights into these current areas of research, with special emphasis on the interaction of inflammasome components and redox signalling, endoplasmic reticulum stress, and mitochondrial function. We present our findings separately for acute kidney injury and chronic kidney disease. As we strictly divided the results into preclinical and clinical data, this review enables comparison of results from those complementary research specialities. However, it also reveals that knowledge gaps exist, especially in clinical acute kidney injury inflammasome research. Furthermore, patient comorbidities and treatments seem important drivers of inflammasome component alterations in human kidney disease.

Tanshinone IIA sodium sulfonate attenuates inflammation by upregulating circ-Sirt1 and inhibiting the entry of NF-κB into the nucleus

Inflammation is a biological process that exists in a large number of diseases. NF-κB has been proven to play a pivotal role in the development of inflammation. New drugs aimed at inhibiting the expression of NF-κB have gained attention from researchers. Sirt1 has an anti-inflammatory function, and the circRNA encoded by the Sirt1 gene may also play roles in the anti-inflammatory reaction of Sirt1. In the present study, LPS-treated RAW264.7 cells were used as an inflammatory cell model, and tanshinone IIA sodium sulfonate (TSS) was used as a therapeutic drug. We found that TSS downregulated LPS-induced TNF-α and IL-1β expression nearly threefold. LPS reduced Circ-sirt1 mRNA expression by one-third, while TSS started this phenomenon. In addition, overexpression/knockdown of Circ-sirt1 neutralized the function of TSS by regulating the translocation of NF-κB. Thus, we proved that TSS has an anti-inflammatory function by upregulating circ-Sirt1 and subsequently inhibiting the translocation of NF-κB. An in vivo experiment was also performed to confirm the protective function of TSS on inflammation. These results indicated that TSS is a potential treatment for inflammation.

TRIM32 Inhibition Attenuates Apoptosis, Oxidative Stress, and Inflammatory Injury in Podocytes Induced by High Glucose by Modulating the Akt/GSK-3β/Nrf2 Pathway

Hyperglycemia-induced oxidative stress in podocytes exerts a major role in the pathological process of diabetic nephropathy. Tripartite motif-containing protein 32 (TRIM32) has been reported to be a key protein in the modulation of cellular apoptosis and oxidative stress under various pathological processes. However, whether TRIM32 participates in the regulation of high glucose (HG)-induced injury in podocytes has not been investigated. This work aimed to assess the possible role of TRIM32 in mediating HG-induced apoptosis, oxidative stress, and inflammatory response in podocytes in vitro. Our results showed a marked increase in TRIM32 expression in HG-exposed podocytes and the glomeruli of diabetic mice. Loss-of-function experiments showed that TRIM32 knockdown improves the viability of HG-stimulated podocytes and suppresses HG-induced apoptosis, oxidative stress, and inflammatory responses in podocytes. Further investigation revealed that TRIM32 inhibition enhances the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, which is associated with the modulation of the Akt/glycogen synthase kinase-3β (GSK-3β) axis in podocytes following HG exposure. However, Akt suppression abrogated the TRIM32 knockdown-mediated activation of Nrf2 in HG-exposed podocytes. Nrf2 knockdown also markedly abolished the protective effects induced by TRIM32 inhibition o in HG-exposed podocytes. In summary, this work demonstrated that TRIM32 inhibition protects podocytes from HG-induced injury by potentiating Nrf2 signaling through modulation of Akt/GSK-3β signaling. The findings reveal the potential role of TRIM32 in mediating podocyte injury during the progression of diabetic nephropathy.

Recombinant soluble thrombomodulin accelerates epithelial stem cell proliferation in mouse intestinal organoids and promotes the mucosal healing in colitis

BACKGROUND AND AIM

Epithelial regeneration, a critical step for the mucosal healing in inflammatory bowel disease, is tightly regulated by stem cells. Therefore, identification of the specific factors that induce stem cell proliferation could contribute to the development of effective strategies for treating inflammatory bowel disease. Recombinant soluble thrombomodulin (rsTM) has previously been shown to promote cell proliferation in skin and corneal wound healing in murine models, but its effects on intestinal epithelial cell proliferation remains unclear.

METHODS

Mouse intestinal organoids and dextran sulfate sodium (DSS)-induced colitis mouse model were used to assess the effects of rsTM on proliferation of intestinal epithelial cells. The size and budding morphologies of organoids were studied by confocal microscopy. The gene expression levels were analyzed by quantitative real-time polymerase chain reaction and immunofluorescence analysis. The effects of rsTM on DSS-induced colitis were investigated by evaluating body weight changes, colon length, histological score, and survival rate.

RESULTS

The rsTM markedly stimulated the growth of intestinal organoids, thereby increasing the surface areas and budding phenotypes of the organoids. rsTM also significantly upregulated the gene expression of intestinal stem cell-specific and epithelial cell-specific markers in a dose-dependent manner. Furthermore, the treatment with high concentrations of rsTM significantly improved the recovery of body weight, histological outcomes, colon length shortening, and prolonged the survival of mice with colitis.

CONCLUSIONS

The rsTM promotes intestinal stem cell proliferation in intestinal organoids and enhances the mucosal healing during recovery phase in DSS-induced colitis.

Targeting NLRP3 Inflammasome in the Treatment Of Diabetes and Diabetic Complications: Role of Natural Compounds from Herbal Medicine

Diabetes, a common metabolic disease with various complications, is becoming a serious global health pandemic. So far there are many approaches in the management of diabetes; however, it still remains irreversible due to its complicated pathogenesis. Recent studies have revealed that nucleotide-binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome plays a vital role in the progression of diabetes and many of its complications, making it a promising therapeutic target in pharmaceutical design. Natural derived herbal medicine, known for its utilization of natural products such as herbs or its bioactive ingredients, is shown to be able to ameliorate hyperglycemia-associated symptoms and to postpone the progression of diabetic complications due to its anti-inflammatory and anti-oxidative properties. In this review, we summarized the role of NLRP3 inflammasome in diabetes and several diabetic complications, as well as 31 active compounds that exert therapeutic effect on diabetic complications via inhibiting NLRP3 inflammasome. Improving our understanding of these promising candidates from natural compounds in herbal medicine targeting NLRP3 inflammasome inspires us the relationship between inflammation and metabolic disorders, and also sheds light on searching potential agents or therapies in the treatment of diabetes and diabetic complications.

Protective Effect of Yi Shen Pai Du Formula against Diabetic Kidney Injury via Inhibition of Oxidative Stress, Inflammation, and Epithelial-to-Mesenchymal Transition in db/db Mice

OBJECTIVE

Diabetic kidney disease (DKD) is one of the most common chronic microvascular complications of diabetes; however, there remains a lack of effective therapeutic strategies. Yi Shen Pai Du Formula (YSPDF), a traditional Chinese medicine preparation, has been clinically used in treating chronic kidney disease (CKD) for more than 20 years. However, whether YSPDF has a therapeutic effect on DKD has not been studied.

METHODS

This study was conducted to investigate the effect of YSPDF administration on db/db mice, a model of type 2 diabetes that develops DKD, and reveal its underlying mechanism of action through a high glucose- (HG-) induced renal injury cell model.

RESULTS

We found that YSPDF significantly improved numerous biochemical parameters (fasting blood glucose, serum creatinine, blood urea nitrogen, 24 h urine total protein, total cholesterol, and total triglycerides) and ameliorated the abnormal histology and fibrosis of renal tissue. Moreover, the status of oxidative stress and levels of inflammatory cytokines (TNF-α, IL-6, IL-1β, and MCP-1) were markedly inhibited by YSPDF treatment. YSPDF treatment significantly mitigated renal fibrosis, with evidence suggesting that this was by inhibiting epithelial-to-mesenchymal transition (EMT) via suppression of the TGF-β1/Smad pathway. Interestingly, the expression of Nrf2, HO-1, and NQO1, proteins known to be associated with oxidative stress, were significantly increased upon administration of YSPDF. The levels of NLRP3 inflammasome proteins, including NLRP3, ASC, caspase-1, and cleaved caspase-1 were decreased in the YSPDF-treated group. Cell experiments showed that YSPDF inhibited EMT and the NLRP3 inflammasome in HG-exposed HK-2 cells, possibly via activation of Nrf2.

CONCLUSION

Our study indicates that YSPDF may ameliorate renal damage in db/db mice via inhibition of oxidative stress, inflammation, and EMT, with the mechanism potentially being related to the activation of the Nrf2 pathway.

Protective Role of Recombinant Human Thrombomodulin in Diabetes Mellitus

Diabetes mellitus is a global threat to human health. The ultimate cause of diabetes mellitus is insufficient insulin production and secretion associated with reduced pancreatic β-cell mass. Apoptosis is an important and well-recognized mechanism of the progressive loss of functional β-cells. However, there are currently no available antiapoptotic drugs for diabetes mellitus. This study evaluated whether recombinant human thrombomodulin can inhibit β-cell apoptosis and improve glucose intolerance in a diabetes mouse model. A streptozotocin-induced diabetes mouse model was prepared and treated with thrombomodulin or saline three times per week for eight weeks. The glucose tolerance and apoptosis of β-cells were evaluated. Diabetic mice treated with recombinant human thrombomodulin showed significantly improved glucose tolerance, increased insulin secretion, decreased pancreatic islet areas of apoptotic β-cells, and enhanced proportion of regulatory T cells and tolerogenic dendritic cells in the spleen compared to counterpart diseased mice treated with saline. Non-diabetic mice showed no changes. This study shows that recombinant human thrombomodulin, a drug currently used to treat patients with coagulopathy in Japan, ameliorates glucose intolerance by protecting pancreatic islet β-cells from apoptosis and modulating the immune response in diabetic mice. This observation points to recombinant human thrombomodulin as a promising antiapoptotic drug for diabetes mellitus.

Plantamajoside Ameliorates Inflammatory Response of Chondrocytes via Regulating NF-κB/NLRP3 Inflammasome Pathway

The damage of articular cartilage in osteoarthritis involves the oxidative stress and inflammation. The aim of the present study was to explore the role of plantamajoside (PM) in chondrocytes and elucidate the underlying mechanism. The cell viability following treatment with PM or lipopolysac-charide (LPS) was assessed by cell counting kit-8 (CCK-8). Enzyme-Linked Immunosorbent Assay (ELISA) was supplied to determine the levels of pro-inflammatory cytokines. Moreover, the oxidative stress-related markers were evaluated via assay kits. TUNEL assay was employed to stain the apoptotic cells. The components of nuclear factor-κB (NF-κB) pathway and NLRP3 inflammasome were estimated by western blot analysis. LPS-insulted cell viability of ATDC5 was restored by PM. PM alleviated the inflammatory response and oxidative stress of ATDC5 cells induced by LPS. Furthermore, it was found that the apoptotic cells were reduced following PM treatment. The protein levels of NF-κB, IκB kinase β (IKKβ) and NLRP3 inflammasome were decreased by PM. These results suggested that PM protected the ATDC5 cells from LPS stimulation, alleviated the inflammatory response may through regulating the NF-κB and NLRP3 inflammasome.

Thrombomodulin is upregulated in the kidneys of women with pre-eclampsia

The endothelial glycoprotein thrombomodulin regulates coagulation, vascular inflammation and apoptosis. In the kidney, thrombomodulin protects the glomerular filtration barrier by eliciting crosstalk between the glomerular endothelium and podocytes. Several glomerular pathologies are characterized by a loss of glomerular thrombomodulin. In women with pre-eclampsia, serum levels of soluble thrombomodulin are increased, possibly reflecting a loss from the glomerular endothelium. We set out to investigate whether thrombomodulin expression is decreased in the kidneys of women with pre-eclampsia and rats exposed to an angiogenesis inhibitor. Thrombomodulin expression was examined using immunohistochemistry and qPCR in renal autopsy tissues collected from 11 pre-eclamptic women, 22 pregnant controls and 11 hypertensive non-pregnant women. Further, kidneys from rats treated with increasing doses of sunitinib or sunitinib in combination with endothelin receptor antagonists were studied. Glomerular thrombomodulin protein levels were increased in the kidneys of women with pre-eclampsia. In parallel, in rats exposed to sunitinib, glomerular thrombomodulin was upregulated in a dose-dependent manner, and the upregulation of glomerular thrombomodulin preceded the onset of histopathological changes. Selective ETAR blockade, but not dual ETA/BR blockade, normalised the sunitinib-induced increase in thrombomodulin expression and albuminuria. We propose that glomerular thrombomodulin expression increases at an early stage of renal damage induced by antiangiogenic conditions. The upregulation of this nephroprotective protein in glomerular endothelial cells might serve as a mechanism to protect the glomerular filtration barrier in pre-eclampsia.

Inhibition of miRNA-155 Alleviates High Glucose-Induced Podocyte Inflammation by Targeting SIRT1 in Diabetic Mice

OBJECTIVE

Microinflammation plays a crucial role in podocyte dysfunction in diabetic nephropathy, but its regulatory mechanism is still unclear. This study is aimed at discussing the mechanisms underlying the effect of miRNA-155 on podocyte injury to determine its potential as a therapeutic target.

METHODS

Cultured immortalized mouse podocytes and diabetic KK-Ay mice models were treated with a miR-155 inhibitor. Western blotting, real-time PCR, ELISA, immunofluorescence, and Luciferase reporter assay were used to analyze markers of inflammation cytokines and podocyte injury.

RESULTS

miRNA-155 was found to be highly expressed in serum and kidney tissue of mice with diabetic nephropathy and in cultured podocytes, accompanied by elevated levels of inflammatory factors. Inhibition of miRNA-155 can reduce proteinuria and ACR levels, diminish the secretion of inflammatory molecules, improve kidney function, inhibit podocyte foot fusion, and reverse renal pathological changes in diabetic nephropathy mice. Overexpression of miRNA-155 in vitro can increase inflammatory molecule production in podocytes and aggravates podocyte injury, while miRNA-155 inhibition suppresses inflammatory molecule production in podocytes and reduces podocyte injury. A luciferase assay confirmed that miRNA-155 could selectively bind to 3'-UTR of SIRT1, resulting in decreased SIRT1 expression. In addition, SIRT1 siRNA could offset SIRT1 upregulation and enhance inflammatory factor secretion in podocytes, induced by the miRNA-155 inhibitor.

CONCLUSIONS

These findings strongly support the hypothesis that miRNA-155 inhibits podocyte inflammation and reduces podocyte injury through SIRT1 silencing. miRNA-155 suppression therapy may be useful for the management of diabetic nephropathy.

Reduced Glomerular Endothelial Thrombomodulin Is Associated with Glomerular Macrophage Infiltration in Diabetic Nephropathy

The endothelial glycoprotein thrombomodulin regulates coagulation, inflammation, and apoptosis. In diabetic mice, reduced thrombomodulin function results in diabetic nephropathy (DN). Furthermore, thrombomodulin treatment reduces renal inflammation and fibrosis. Herein, thrombomodulin expression was examined in human kidney samples to investigate the possibility of targeting thrombomodulin in patients with DN. Glomerular thrombomodulin was analyzed together with the number of glomerular macrophages in 90 autopsied diabetic cases with DN, 55 autopsied diabetic cases without DN, and 37 autopsied cases without diabetes or kidney disease. Thrombomodulin mRNA was measured in glomeruli microdissected from renal biopsies from patients with DN and nondiabetic controls. Finally, glomerular thrombomodulin was measured in diabetic mice following treatment with the selective endothelin A receptor (ET_AR) blocker, atrasentan. In diabetic patients, glomerular thrombomodulin expression was increased at the mRNA level, but decreased at the protein level, compared with nondiabetic controls. Reduced glomerular thrombomodulin was associated with an increased glomerular influx of macrophages. Blocking the ET_AR with atrasentan restored glomerular thrombomodulin protein levels in diabetic mice to normal levels. The reduction in glomerular thrombomodulin in diabetes likely serves as an early proinflammatory step in the pathogenesis of DN. Thrombomodulin protein may be cleaved under diabetic conditions, leading to a compensatory increase in transcription. The nephroprotective effects of ET_AR antagonists in diabetic patients may be attributed to the restoration of glomerular thrombomodulin.

Perilipin 5 ameliorates high-glucose-induced podocyte injury via Akt/GSK-3β/Nrf2-mediated suppression of apoptosis, oxidative stress, and inflammation

Hyperglycemia-induced podocyte damage contributes to the onset of diabetic nephropathy, a severe complication of diabetes. Perilipin 5 (Plin5) exerts a vital role in numerous pathological conditions via affecting cell apoptosis, oxidative stress, and inflammation. However, whether Plin5 plays a role in regulating podocyte damage of diabetic nephropathy has not been fully determined. This work aimed to explore the role of Plin5 in mediating high glucose (HG)-induced injury of podocytes in vitro. Our results demonstrated that Plin5 expression was markedly decreased in mouse podocytes challenged with HG. Plin5 overexpression markedly suppressed HG-induced apoptosis, reactive oxygen species (ROS) production, and the pro-inflammatory response in podocytes. On the contrary, Plin5 silencing produced the opposite effects. Further mechanistic analysis demonstrated that Plin5 upregulation remarkably increased the levels of phospho-Akt and phospho-glycogen synthase kinase-3β (GSK-3β) in HG-exposed podocytes. Moreover, Plin5 overexpression increased the levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and enhanced the activation of Nrf2 signaling. Akt inhibition markedly blocked Plin5-mediated activation of Nrf2, while GSK-3β inhibition reversed Plin5-silencing-induced suppressive effects on Nrf2 activation. Notably, Nrf2 suppression significantly blocked Plin5-mediated protective effects against HG-induced podocyte injury. In summary, our work indicates a vital role for Plin5 in protecting against HG-induced apoptosis, oxidative stress, and inflammation in podocytes via modulation of Akt/GSK-3β/Nrf2 signaling. This study suggests that Plin5 may participate in modulating podocyte damage in diabetic nephropathy.

Functional crosstalk between Long non-coding RNAs and the NLRP3 inflammasome in the regulation of diseases

Emerging evidence has indicated that long noncoding RNAs (lncRNAs) are involved in various pathophysiological processes of disease, such as cancer occurrence, viral invasion, and inflammatory damage. The main inflammatory body component, nod-like receptor protein 3 (NLRP3), is the trigger point of inflammatory reactions and inflammation-related diseases and coordinates the body's response to inflammation. At present, increasing evidence shows that the interaction of lncRNAs and the NLRP3 inflammasome plays an important role in the inflammatory response and different diseases. This may be involved in the development and progression of various diseases by activating signalling pathways and a variety of molecular regulatory mechanisms-this article reviews progress in research on the relationship between lncRNAs and the NLRP3 inflammasome under different conditions.

VEGF-B antibody and interleukin-22 fusion protein ameliorates diabetic nephropathy through inhibiting lipid accumulation and inflammatory responses

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.

Vinpocetine Attenuates Ischemic Stroke Through Inhibiting NLRP3 Inflammasome Expression in Mice

ABSTRACT

Ischemic stroke is the leading cause of globe death and permanent disability, but its therapeutic strategies are limited. Over the past decades, multiprotein complexes called inflammasomes have been shown as promising targets in ischemic stroke. Here, we examined vinpocetine (Vinp), a synthetic drug, playing a neuroprotective role against ischemic stroke in mice through regulating NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation. Middle cerebral artery occlusion/reperfusion (MCAO/R) was applied to mimic ischemic stroke in vivo. Vinp was administrated by intraperitoneal injection with different dose (5 or 10 mg/kg) 1 hour after reperfusion. Then, neurological assessment and infarct size were performed, and interleukin-1β (IL-1β) and IL-18 levels were evaluated using ELISA. The levels of NLRP3 inflammasome components and its upstream nuclear factor-κB (NF-κB) were determined using real-time PCR or Western blot. The experimental results indicated that posttreatment with Vinp decreased cerebral infarct size, improved behavior recover, reduced NLRP3 inflammasome expression, and suppressed the transfer of NF-κB to nucleus and proinflammatory cytokine release in middle cerebral artery occlusion/reperfusion mice. In conclusion, this study demonstrates that Vinp alleviates ischemic stroke by regulating levels of NLRP3 inflammasome, NF-κB, and proinflammatory cytokines in vivo, offering an alternative medication for ischemic stroke associated with inflammation.

A Comprehensive Analysis of Unique and Recurrent Copy Number Variations in Alzheimer's Disease and its Related Disorders

BACKGROUND

Copy number variations (CNVs) play an important role in the genetic etiology of various neurological disorders, including Alzheimer's disease (AD). Type 2 diabetes mellitus (T2DM) and major depressive disorder (MDD) were shown to have share mechanisms and signaling pathways with AD.

OBJECTIVE

We aimed to assess CNVs regions that may harbor genes contributing to AD, T2DM, and MDD in 67 Saudi familial and sporadic AD patients, with no alterations in the known genes of AD and genotyped previously for APOE.

METHODS

DNA was analyzed using the CytoScan-HD array. Two layers of filtering criteria were applied. All the identified CNVs were checked in the Database of Genomic Variants (DGV).

RESULTS

A total of 1086 CNVs (565 gains and 521 losses) were identified in our study. We found 73 CNVs harboring genes that may be associated with AD, T2DM or MDD. Nineteen CNVs were novel. Most importantly, 42 CNVs were unique in our studied cohort existing only in one patient. Two large gains on chromosomes 1 and 13 harbored genes implicated in the studied disorders. We identified CNVs in genes that encode proteins involved in the metabolism of amyloid-β peptide (AGRN, APBA2, CR1, CR2, IGF2R, KIAA0125, MBP, RER1, RTN4R, VDR and WISPI) or Tau proteins (CACNAIC, CELF2, DUSP22, HTRA1 and SLC2A14).

CONCLUSION

The present work provided information on the presence of CNVs related to AD, T2DM, and MDD in Saudi Alzheimer's patients.

Thrombomodulin ameliorates transforming growth factor-β1-mediated chronic kidney disease via the G-protein coupled receptor 15/Akt signal pathway

Kidney fibrosis is the common consequence of chronic kidney diseases that inexorably progresses to end-stage kidney disease with organ failure treatable only with replacement therapy. Since transforming growth factor-β1 is the main player in the pathogenesis of kidney fibrosis, we posed the hypothesis that recombinant thrombomodulin can ameliorate transforming growth factor-β1-mediated progressive kidney fibrosis and failure. To interrogate our hypothesis, we generated a novel glomerulus-specific human transforming growth factor-β1 transgenic mouse to evaluate the therapeutic effect of recombinant thrombomodulin. This transgenic mouse developed progressive glomerular sclerosis and tubulointerstitial fibrosis with kidney failure. Therapy with recombinant thrombomodulin for four weeks significantly inhibited kidney fibrosis and improved organ function compared to untreated transgenic mice. Treatment with recombinant thrombomodulin significantly inhibited apoptosis and mesenchymal differentiation of podocytes by interacting with the G-protein coupled receptor 15 to activate the Akt signaling pathway and to upregulate the expression of anti-apoptotic proteins including survivin. Thus, our study strongly suggests the potential therapeutic efficacy of recombinant thrombomodulin for the treatment of chronic kidney disease and subsequent organ failure.

Thrombomodulin as a Physiological Modulator of Intravascular Injury

Thrombomodulin (TM), which is predominantly expressed on the endothelium, plays an important role in maintaining vascular homeostasis by regulating the coagulation system. Intravascular injury and inflammation are complicated physiological processes that are induced by injured endothelium-mediated pro-coagulant signaling, necrotic endothelial- and blood cell-derived damage-associated molecular patterns (DAMPs), and DAMP-mediated inflammation. During the hypercoagulable state after endothelial injury, TM is released into the intravascular space by proteolytic cleavage of the endothelium component. Recombinant TM (rTM) is clinically applied to patients with disseminated intravascular coagulation, resulting in protection from tissue injury. Recent studies have revealed that rTM functions as an inflammatory regulator beyond hemostasis through various molecular mechanisms. More specifically, rTM neutralizes DAMPs, including histones and high mobility group box 1 (HMGB1), suppresses excessive activation of the complement system, physiologically protects the endothelium, and influences both innate and acquired immunity. Neutrophil extracellular traps (NETs) promote immunothrombosis by orchestrating platelets to enclose infectious invaders as part of the innate immune system, but excessive immunothrombosis can cause intravascular injury. However, rTM can directly and indirectly regulate NET formation. Furthermore, rTM interacts with mediators of acquired immunity to resolve vascular inflammation. So far, rTM has shown good efficacy in suppressing inflammation in various experimental models, including thrombotic microangiopathy, sterile inflammatory disorders, autoimmune diseases, and sepsis. Thus, rTM has the potential to become a novel tool to regulate intravascular injury via pleiotropic effects.

Ropivacaine Prevents the Activation of the NLRP3 Inflammasome Caused by High Glucose in HUVECs

Endothelial dysfunction caused by high glucose is recognized as an important event in the pathogenesis of diabetes-related vascular complications. Ropivacaine is considered to have the best safety profile among the commonly used amide local anesthetics, but the extent of its actions remains incompletely understood. Here, we used human umbilical vein endothelial cells exposed to high glucose to explore the effects of ropivacaine on oxidative stress and markers of inflammation. Ropivacaine treatment exerted significant beneficial effects by rescuing oxidative stress and downregulating interleukin (IL)-1β and IL-18. We also found that ropivacaine could inhibit the secretion of the high-mobility group box 1 protein and improve cell viability. Importantly, sirtuin-1 (SIRT1) knockdown experiments show that the inhibitory effects of ropivacaine against NLRP3 inflammasome activation are dependent on SIRT1. Taken together, these results demonstrate the potential of ropivacaine as a promising therapy against diabetic endothelial dysfunction.

Targeting NLRP3 inflammasome as a promising approach for treatment of diabetic nephropathy: Preclinical evidences with therapeutic approaches

Diabetes mellitus is an increasingly prevalent disease around the globe. The epidemic of diabetes mellitus and its complications pretenses the foremost health threat globally. Diabetic nephropathy is the notable complication in diabetes, leading to end-stage renal disease (ESRD) and premature death. Abundant experimental evidence indicates that oxidative stress and inflammation are the important mediators in diabetic kidney diseases and interlinked with various signal transduction molecular mechanisms. Inflammasomes are the critical components of innate immunity and are recognized as a critical mediator of inflammation and autoimmune disorders. NOD-like receptor protein 3 (NLRP3) inflammasome is the well-characterized protein and it exhibits the sterile inflammation through the regulation of pro-inflammatory cytokines interleukin (IL)-1β and IL-18 production in tissues. In recent years, the role of NLRP3 inflammasome in the pathophysiology of diabetic kidney diseases in both clinical and experimental studies has generated great interest. In the current review, we focused on and discussed the role of NLRP3 inflammasome in diabetic nephropathy. A literature review was performed using online databases namely, PubMed, Scopus, Google Scholar and Web of science to explore the possible pharmacological interventions that blunt the NLRP3 inflammasome-caspase-1-IL-1β/IL-18 axis and shown to have a beneficial effect in diabetic kidney diseases. This review describes the inhibition of NLRP3 inflammasome activation as a promising therapeutic target for drug discovery in future.

Expression of Pinopodes in the Endometrium from Recurrent Pregnancy Loss Women. Role of Thrombomodulin and Ezrin

BACKGROUND

Pinopode expression has been suggested as a marker of endometrial receptivity.

METHODS

We set up an experimental study comparing endometrial tissue from recurrent pregnancy loss (RPL, n = 30) and fertile control (CTR, n = 20) women in terms of pinopode expression/morphology; expression of thrombomodulin (TM) and ezrin; cytoskeletal organization. Endometrial samples were collected during implantation window and evaluated by scanning electron microscopy, western blot, and immunofluorescence.

RESULTS

We found that RPL endometrial tissue showed: (i) increased pinopodes density (* p < 0.05); (ii) a reduced diameter of pinopodes (* p < 0.05); (iii) a decreased TM and ezrin expression (p < 0.05). Additionally, confocal images showed a significantly reduced expression of phosphorylated (p)-ezrin, confirming the results obtained through immunoblot analysis. Immunofluorescence staining showed that in CTR samples, junctions between cells are intact and clearly visible, whereas actin filaments appear completely lost in RPL endometrial samples; this suggests that, due to the impaired expression and activity of TM and ezrin, actin does not bind to plasma membrane in order to orchestrate the cytoskeletal actin filaments.

CONCLUSIONS

Our findings suggest that an impaired expression of TM and expression/activation of ezrin may affect the connection between the TM and actin cytoskeleton, impairing the organization of cytoskeleton and, eventually, the adequate pinopode development.

Compound K inhibits priming and mitochondria-associated activating signals of NLRP3 inflammasome in renal tubulointerstitial lesions

BACKGROUND

Renal tubulointerstitial lesions (TILs), a key pathological hallmark for chronic kidney disease to progress to end-stage renal disease, feature renal tubular atrophy, interstitial mononuclear leukocyte infiltration and fibrosis in the kidney. Our study tested the renoprotective and therapeutic effects of compound K (CK), as described in our US patent (US7932057B2), on renal TILs using a mouse unilateral ureteral obstruction (UUO) model.

METHODS

Renal pathology was performed and renal draining lymph nodes were subjected to flow cytometry analysis. Mechanism-based experiments included the analysis of mitochondrial dysfunction, a model of tubular epithelial cells (TECs) under mechanically induced constant pressure (MICP) and tandem mass tags (TMT)-based proteomics analysis.

RESULTS

Administration of CK ameliorated renal TILs by reducing urine levels of proinflammatory cytokines, and preventing mononuclear leukocyte infiltration and fibrosis in the kidney. The beneficial effects clearly correlated with its inhibition of: (i) NF-κB-associated priming and the mitochondria-associated activating signals of the NLRP3 inflammasome; (ii) STAT3 signalling, which in part prevents NLRP3 inflammasome activation; and (iii) the TGF-β-dependent Smad2/Smad3 fibrotic pathway, in renal tissues, renal TECs under MICP and/or activated macrophages, the latter as a major inflammatory player contributing to renal TILs. Meanwhile, TMT-based proteomics analysis revealed downregulated renal NLRP3 inflammasome activation-associated signalling pathways in CK-treated UUO mice.

CONCLUSIONS

The present study, for the first time, presents the potent renoprotective and therapeutic effects of CK on renal TILs by targeting the NLRP3 inflammasome and STAT3 signalling.

The Inflammasome in Chronic Complications of Diabetes and Related Metabolic Disorders

Diabetes mellitus (DM) ranks seventh as a cause of death worldwide. Chronic complications, including cardiovascular, renal, and eye disease, as well as DM-associated non-alcoholic fatty liver disease (NAFLD) account for most of the morbidity and premature mortality in DM. Despite continuous improvements in the management of late complications of DM, significant gaps remain. Therefore, searching for additional strategies to prevent these serious DM-related conditions is of the utmost importance. DM is characterized by a state of low-grade chronic inflammation, which is critical in the progression of complications. Recent clinical trials indicate that targeting the prototypic pro-inflammatory cytokine interleukin-1β (IL-1 β) improves the outcomes of cardiovascular disease, which is the first cause of death in DM patients. Together with IL-18, IL-1β is processed and secreted by the inflammasomes, a class of multiprotein complexes that coordinate inflammatory responses. Several DM-related metabolic factors, including reactive oxygen species, glyco/lipoxidation end products, and cholesterol crystals, have been involved in the pathogenesis of diabetic kidney disease, and diabetic retinopathy, and in the promoting effect of DM on the onset and progression of atherosclerosis and NAFLD. These metabolic factors are also well-established danger signals capable of regulating inflammasome activity. In addition to presenting the current state of knowledge, this review discusses how the mechanistic understanding of inflammasome regulation by metabolic danger signals may hopefully lead to novel therapeutic strategies targeting inflammation for a more effective treatment of diabetic complications.

Role of the Nox4/AMPK/mTOR signaling axe in adipose inflammation-induced kidney injury

Diabetic kidney disease is one of the most serious complications of diabetes worldwide and is the leading cause of end-stage renal disease. While research has primarily focused on hyperglycemia as a key player in the pathophysiology of diabetic complications, recently, increasing evidence have underlined the role of adipose inflammation in modulating the development and/or progression of diabetic kidney disease. This review focuses on how adipose inflammation contribute to diabetic kidney disease. Furthermore, it discusses in detail the underlying mechanisms of adipose inflammation, including pro-inflammatory cytokines, oxidative stress, and AMPK/mTOR signaling pathway and critically describes their role in diabetic kidney disease. This in-depth understanding of adipose inflammation and its impact on diabetic kidney disease highlights the need for novel interventions in the treatment of diabetic complications.

Therapeutic Potential of Thrombomodulin in Renal Fibrosis of Nephrotoxic Serum Nephritis in Wistar-Kyoto Rats

BACKGROUND

Recombinant human soluble thrombomodulin (rhTM) was approved in 2008 and has been used for treatment of disseminated intravascular coagulation in Japan. The antifibrotic effects of rhTM in acute exacerbation of idiopathic pulmonary fibrosis are well established, but the therapeutic potential of rhTM in renal fibrosis remains poorly understood.

METHODS

Nephrotoxic serum nephritis (NTS-N) was induced in 22 female Wistar-Kyoto (WKY) rats on day 0. Rats were administered either rhTM or vehicle intraperitoneally, every day from day 4 to day 55. Rats were sacrificed on day 56 when renal fibrosis was established and renal morphological investigations were performed. In vitro, rat renal fibroblasts (NRK-49F) were pretreated with rhTM or saline, and expression levels of profibrogenic gene induced by thrombin were analyzed by real-time reverse transcription polymerase chain reaction.

RESULTS

Compared to WKY-GN-vehicle rats, the body weights of WKY-GN-rhTM rats were significantly greater on day 55. By day 56, rhTM had significantly reduced serum creatinine levels in NTS-N. On the other hand, urinary protein excretion was comparable between the two treatment groups throughout the study. The percentage of Masson trichrome-positive areas in WKY-GN-rhTM rats was significantly lower compared to that in WKY-GN-vehicle rats. Glomerular fibrin deposition was significantly reduced in WKY-GN-rhTM rats. In addition, rhTM significantly reduced the renal cortical mRNA expression levels of TNF-α, Toll-like receptor 4, MYD88, TGF-β, αSMA, collagen I, collagen III, fibronectin, and protease-activated receptor 1 (PAR1), a thrombin receptor. In vitro, thrombin stimulation of NRK-49F cells significantly enhanced the mRNA expression levels of αSMA and PAR1, and these upregulations were significantly reduced by pretreatment with rhTM.

CONCLUSIONS

Administration of rhTM after establishment of crescentic glomerulonephritis (GN) attenuated the subsequent development of renal fibrosis in NTS-N, possibly in part by inhibiting thrombin-mediated fibrogenesis. Our results suggest that rhTM may offer a therapeutic option for limiting the progression of chronic kidney disease in crescentic GN.

Filtering through the role of NRF2 in kidney disease

Kidney disease affects ~ 10% of the population worldwide, resulting in millions of deaths each year. Mechanistically, oxidative stress is a major driver of various kidney diseases, and promotes the progression from acute to chronic injury, as well as renal cancer development. NRF2, the master regulator of redox balance, has been shown to protect against kidney disease through its negation of reactive oxygen species (ROS). However, many kidney diseases exhibit high levels of ROS as a result of decreased NRF2 protein levels and transcriptional activity. Many studies have tested the strategy of using NRF2 inducing compounds to alleviate ROS to prevent or slow down the progression of kidney diseases. Oppositely, in specific subsets of renal cancer, NRF2 is constitutively activated and contributes to tumor burden and overall poor prognosis; therefore, there has been a recent interest in studies investigating the benefits of NRF2 inhibition. In this review, we summarize recent literature investigating the role of NRF2 and oxidative stress in various kidney diseases, and how pharmacological modification of NRF2 signaling could play a protective role.

Nrf2 in early vascular ageing: Calcification, senescence and therapy

Under normal physiological conditions, free radical generation and antioxidant defences are balanced, and reactive oxygen species (ROS) usually act as secondary messengers in a plethora of biological processes. However, when this balance is impaired, oxidative stress develops due to imbalanced redox homeostasis resulting in cellular damage. Oxidative stress is now recognized as a trigger of cellular senescence, which is associated with multiple chronic 'burden of lifestyle' diseases, including atherosclerosis, type-2 diabetes, chronic kidney disease and vascular calcification; all of which possess signs of early vascular ageing. Nuclear factor erythroid 2-related factor 2 (Nrf2), termed the master regulator of antioxidant responses, is a transcription factor found to be frequently dysregulated in conditions characterized by oxidative stress and inflammation. Recent evidence suggests that activation of Nrf2 may be beneficial in protecting against vascular senescence and calcification. Both natural and synthetic Nrf2 agonists have been introduced as promising drug classes in different phases of clinical trials. However, overexpression of the Nrf2 pathway has also been linked to tumorigenesis, which highlights the requirement for further understanding of pathways involving Nrf2 activity, especially in the context of cellular senescence and vascular calcification. Therefore, comprehensive translational pre-clinical and clinical studies addressing the targeting capabilities of Nrf2 agonists are urgently required. The present review discusses the impact of Nrf2 in senescence and calcification in early vascular ageing, with focus on the potential clinical implications of Nrf2 agonists and non-pharmacological Nrf2 therapeutics.

Metformin rescues Parkin protein expression and mitophagy in high glucose-challenged human renal epithelial cells by inhibiting NF-κB via PP2A activation

Our preliminary research revealed that metformin, a classic anti-diabetic drug, could rescue Parkin protein expression and mitophagy in high glucose-challenged human renal epithelial cells in vitro, but the molecular mechanism remains to be explored. In the study, Human Renal Cortical Epithelial Cells (HRCEpiC) and Human Renal Proximal Tubular Epithelial Cells (HRPTEpic) were challenged with high glucose with or without metformin pre-treatment to monitor Parkin mRNA and protein expression level change. PRKN gene knockdown was performed by lentiviral-based shRNA delivery. Cell viability, apoptosis and mitophagy were monitored after treatment. Mitochondrial damage was evaluated by analyzing mitochondrial permeability transition pore opening, membrane potential change, mitochondrial superoxide accumulation and cytochrome C release. Protein levels of activating transcription factor 4 (ATF4), p53 phospho-Ser15, IκBα phosphor-Ser32, IKKα phosphor-Ser176/180 in whole cell lysate and nuclear entry of p50/p65 were assessed by western blot. Okadaic acid was used to inhibit protein phosphatase 2A (PP2A). The data suggested high glucose challenge significantly reduced PRKN gene expression, mitophagy, mitochondria integrity and cell viability in vitro, which was rescued by metformin co-treatment. The effects of metformin were crippled by PRKN gene knockdown. Metformin increased PRKN gene transcription while reducednuclear factor kappa B (NF-κB) activation but not that of p53 or ATF4. Inhibiting PP2A weakened NF-κB inhibition and PRKN induction by metformin in high glucose-challenged cells, reducing its mitochondrial protective and cytoprotective effect. So, we concluded thatmetformin protects human renal epithelial cells from high glucose-induced apoptosis by restoring Parkin protein expression and mitophagy via PP2A activation and NF-κB inhibition.

Isomangiferin Attenuates Renal Injury in Diabetic Mice via Inhibiting Inflammation

AIM

Renal injury induced by diabetes is reported to be associated with inflammation. Isomangiferin (ISO), a xanthone C-glucoside from the Cyclopia subfamily, exhibits many pharmacological properties. This study aimed to evaluate the protection of ISO against renal damage in diabetic mice.

METHODS

Serum glucose, insulin, uric acid, creatinine, total cholesterol (TC), triglyceride (TG), and inflammatory cytokines in serum and the kidney of db/db diabetes model mice were detected. The components of high mobility group protein B1 (HMGB1)/NACHT leucine-rich repeat- and PYD-containing 3 (NLRP3)/nuclear factor kappa-B (NF-κB) pathway in the kidney were detected by Western blot and immunohistochemical analysis.

RESULTS

ISO improved lipid profile and glucose tolerance, and inhibited the production of inflammatory cytokines in a db/db model mice. Moreover, ISO decreased biochemical indexes in the serum and inhibited the activation of HMGB1/NLRP3/NF-κB signaling in the kidney of db/db model mice.

CONCLUSION

ISO provides protection against renal injury via inhibiting HMGB1/NLRP3/NF-κB signaling in a diabetic mouse model.

Accelerated and Severe Lupus Nephritis Benefits From M1, an Active Metabolite of Ginsenoside, by Regulating NLRP3 Inflammasome and T Cell Functions in Mice

Chinese herbal medicines used in combination have long-term been shown to be mild remedies with “integrated effects.” However, our study provides the first demonstration that M1, an active metabolite of ginsenoside, exerted its dramatic therapeutic effects on accelerated and severe lupus nephritis (ASLN) mice, featuring acute renal function impairment, heavy proteinuria, high serum levels of anti-dsDNA, and high-grade, diffuse proliferative renal lesions. In the present study, NZB/WF1 mice were given injections of lipopolysaccharide to induce the ASLN model. M1 (30 mg/kg) was then administered to the mice by gavage daily, and the mice were sacrificed on week 3 and week 5 after the induction of disease. To identify the potential mechanism of action for the pure compound, levels of NLRP3 inflammasome activation in bone marrow-derived dendritic cells (BMDCs), podocytes and macrophages, and antigen-specific T cell activation in BMDCs were determined in addition to mechanistic experiments in vivo. Treatment with M1 dramatically improved renal function, albuminuria and renal lesions and reduced serum levels of anti-dsDNA in the ASLN mice. These beneficial effects with M1 treatment involved the following cellular and molecular mechanistic events: [1] inhibition of NLRP3 inflammasome associated with autophagy induction, [2] modulation of T help cell activation, and [3] induction of regulatory T cell differentiation. M1 improved the ASLN mice by blunting NLRP3 inflammasome activation and differentially regulating T cell functions, and the results support M1 as a new therapeutic candidate for LN patients with a status of abrupt transformation of lower-grade (mesangial) to higher-grade (diffuse proliferative) nephritis.

Glucosamine inhibits IL-1β expression by preserving mitochondrial integrity and disrupting assembly of the NLRP3 inflammasome

The NLRP3 inflammasome promotes the pathogenesis of metabolic, neurodegenerative and infectious diseases. Increasing evidences show that the NLRP3 inflammasome is a promising therapeutic target in inflammatory diseases. Glucosamine is widely used as a dietary supplement to promote the health of cartilage tissue and is expected to exert anti-inflammatory activity in joint inflammation, which is a nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome-associated complication. Here, we investigated whether GlcN inhibits the NLRP3 inflammasome and dissected the underlying molecular mechanisms. We found that GlcN suppressed the NLRP3 inflammasome in mouse and human macrophages. A mechanistic study revealed that GlcN inhibited the expression of NLRP3 and IL-1β precursor by reducing reactive oxygen species generation and NF-κB activation in lipopolysaccharide-activated macrophages. GlcN also suppressed mitochondrial reactive oxygen species generation and mitochondrial integrity loss in NLRP3-activated macrophages. Additionally, GlcN disrupted NLRP3 inflammasome assembly by inhibiting NLRP3 binding to PKR, NEK7 and ASC. Furthermore, oral administration of GlcN reduced peritoneal neutrophils influx and lavage fluids concentrations of IL-1β, IL-6 MCP-1 and TNF-α in uric acid crystal-injected mice. These results indicated that GlcN might be a novel dietary supplement for the amelioration of NLRP3 inflammasome-associated complications.