Wogonin upregulates SOCS3 to alleviate the injury in Diabetic Nephropathy by inhibiting TLR4-mediated JAK/STAT/AIM2 signaling pathway.

BACKGROUND: Diabetic nephropathy (DN) is a life-threatening renal disease and needs urgent therapies. Wogonin is renoprotective in DN. This study aimed to explore the mechanism of how wogonin regulated high glucose (HG)-induced renal cell injury. METHODS: Diabetic mice (db/db), control db/m mice, and normal glucose (NG)- or HG-treated human tubule epithelial cells (HK-2) were used to evaluate the levels of suppressor of cytokine signaling 3 (SOCS3), Toll-like receptor 4 (TLR4), inflammation and fibrosis. Lentivirus was used to regulate SOCS3 and TLR4 expressions. After oral gavage of wogonin (10 mg/kg) or vehicle in db/db mice, histological morphologies, blood glucose, urinary protein, serum creatinine values (Scr), blood urea nitrogen (BUN), superoxide dismutase (SOD), glutathione (GSH), and reactive oxygen species (ROS) were assessed. RT-qPCR and Western blot evaluated inflammation and fibrosis-related molecules. RESULTS: HG exposure induced high blood glucose, severe renal injuries, high serumal Src and BUN, low SOD and GSH, and increased ROS. HG downregulated SOCS3 but upregulated TLR4 and JAK/STAT, fibrosis, and inflammasome-related proteins. Wogonin alleviated HG-induced renal injuries by decreasing cytokines, ROS, Src, and MDA and increasing SOD and GSH. Meanwhile, wogonin upregulated SOCS3 and downregulated TLR4 under HG conditions. Wogonin-induced SOCS3 overexpression directly decreased TLR4 levels and attenuated JAK/STAT signaling pathway-related inflammation and fibrosis, but SOCS3 knockdown significantly antagonized the protective effects of wogonin. However, TLR4 knockdown diminished SOCS3 knockdown-induced renal injuries. CONCLUSION: Wogonin attenuates renal inflammation and fibrosis by upregulating SOCS3 to inhibit TLR4 and JAK/STAT pathway.

Time-Dependent Factors Influencing Cardiocerebral Vascular Events in Chronic Hemodialysis Patients: Insights from a Longitudinal Study.

BACKGROUND Cardiocerebral vascular events (CVCs) are significant complications in patients undergoing hemodialysis (HD). Given the increased morbidity and mortality associated with CVCs in this population, understanding the factors influencing CVC occurrence over time is crucial. This study aimed to investigate these time-dependent factors in HD patients. MATERIAL AND METHODS A total of 228 HD patients from 2 dialysis centers, with at least 3 months of treatment between 2017 and 2021, were included. Annual clinical data were collected, and patients were monitored until CVC development. Kaplan-Meier analysis and a time-dependent Cox regression model were used for data analysis. RESULTS The mean age of 228 patients was 55.0±15.0 years, and 64.76% were male. For 5 years of monitoring, the mean follow-up interval was 3.1±1.0 years for patients to develop CVCs. The 1-year, 3-year, and 5-year CVC-free rates were 97.47%, 81.31%, and 70.71%, respectively. Time-dependent Cox regression revealed that C-reactive protein was an independent time-dependent risk factor in HD patients and blood flow rate was an independent time-dependent protective factor. The male subgroup and non-diabetic subgroup had these same results. The following were was the independent time-dependent risk factors: white blood cell count for the female subgroup; blood flow rate for the non-elderly subgroup; and C-reactive protein for the diabetic subgroup. None were risk factors for the elderly subgroup. CONCLUSIONS It took an average of 3.1±1.0 years for patients with HD to develop CVCs. C-reactive protein and blood flow rate emerged as key time-dependent influencing factors for CVCs in this population.

Implementing Assisted Peritoneal Dialysis in Renal Care: a Chinese-German Perspective.

Assisted PD (assPD) is an option of home dialysis treatment for dependent end-stage renal patients and worldwide applied in different countries since more than 40 years. China and Germany shares similar trends in demographic development with a growing proportion of elderly referred to dialysis treatment. So far number of patients treated by assPD is low in both countries. We analyze experiences in the implementation process, barriers, and benefits of ass PD in the aging population to provide a model for sustainable home dialysis treatment with PD in both countries. Differences and similarities of different factors (industrial, patient and facility based) which affect utilization of assPD are discussed. AssPD should be promoted in China and Germany to realize the benefits of home dialysis for the aging population by providing a structured model of implementation and quality assurance.

LncRNA SNHG16 regulates RAS and NF-κB pathway-mediated NLRP3 inflammasome activation to aggravate diabetes nephropathy through stabilizing TLR4.

AIMS: LncRNA SNHG16 and Toll-like receptor-4 (TLR4) participate in diabetes nephropathy. This study investigated whether SNHG16 regulates diabetic renal injury (DRI) via TLR4 and its related mechanism. METHODS: Diabetic mice and high glucose (HG)-induced HRMCs were used to examine the expressions of SNHG16 and TLR4. The SNHG16 expression, cytokines, reactive oxygen species, MDA, SOD, GSH, and fibrosis-related proteins were evaluated in HG-induced HRMCs transfected with sh-NC or sh-SHNG16. RNA immunoprecipitation and RNA pull-down determined the interaction between SNHG16 and EIF4A3 or TLR4 and EIF4A3. We used HG-treated HRMCs or diabetic mice to investigate the roles of TLR4 or SNHG16 in renal injuries. RESULTS: Both SNHG16 and TLR4 were upregulated in diabetic conditions. HG increased serum Scr and BUN, led to significant fibrosis, increased inflammation- and renal fibrosis-related proteins in mice, and increased ROS, MDA, and decreased SOD and GSH in HRMCs. SNHG16 silencing diminished HG-upregulated SNHG16, decreased HG-increased cytokines secretion, ROS, MDA, and fibrosis but increased SOD and GSH. RIP and RNA pull-down confirmed that SNHG16 recruits EIF4A3 to stabilize TLR4 mRNA. TLR4 knockdown alleviated HG-induced renal injuries by suppressing RAS and NF-κB-mediated activation of NLRP3 inflammasomes. SNHG16 knockdown alleviated HG-induced renal injuries in HG-induced HRMCs or diabetic mice. Interestingly, TLR4 overexpression reversed the effects of SNHG16 knockdown. Mechanistically, SNHG16 knockdown alleviated HG-induced renal injuries by suppressing TLR4. CONCLUSION: SNHG16 accelerated HG-induced renal injuries via recruiting EIF4A3 to enhance the stabilization of TLR4 mRNA. The SNGHG16/ELF4A3/TLR4 axis might be a novel target for treating DRI.

C5a-C5aR1 induces endoplasmic reticulum stress to accelerate vascular calcification via PERK-eIF2α-ATF4-CREB3L1 pathway.

AIMS: Vascular calcification (VC) predicts the morbidity and mortality in cardiovascular diseases. Vascular smooth muscle cells (VSMCs) osteogenic transdifferentiation is the crucial pathological basis for VC. To date, the molecular pathogenesis is still largely unclear. Notably, C5a-C5aR1 contributes to the development of cardiovascular diseases, and its closely related to physiological bone mineralization which is similar to VSMCs osteogenic transdifferentiation. However, the role and underlying mechanisms of C5a-C5aR1 in VC remain unexplored. METHODS AND RESULTS: A cross-sectional clinical study was utilized to examine the association between C5a and VC. Chronic kidney diseases mice and calcifying VSMCs models were established to investigate the effect of C5a-C5aR1 in VC, evaluated by changes in calcium deposition and osteogenic markers. The cross-sectional study identified that high level of C5a was associated with increased risk of VC. C5a dose-responsively accelerated VSMCs osteogenic transdifferentiation accompanying with increased the expression of C5aR1. Meanwhile, the antagonists of C5aR1, PMX 53, reduced calcium deposition, and osteogenic transdifferentiation both in vivo and in vitro. Mechanistically, C5a-C5aR1 induced endoplasmic reticulum (ER) stress and then activated PERK-eIF2α-ATF4 pathway to accelerated VSMCs osteogenic transdifferentiation. In addition, cAMP-response element-binding protein 3-like 1 (CREB3L1) was a key downstream mediator of PERK-eIF2α-ATF4 pathway which accelerated VSMCs osteogenic transdifferentiation by promoting the expression of COL1α1. CONCLUSIONS: High level of C5a was associated with increased risk of VC, and it accelerated VC by activating the receptor C5aR1. PERK-eIF2α-ATF4-CREB3L1 pathway of ER stress was activated by C5a-C5aR1, hence promoting VSMCs osteogenic transdifferentiation. Targeting C5 or C5aR1 may be an appealing therapeutic target for VC.

Abnormal Calcium Metabolism Mediated Increased Risk of Cardiovascular Events Estimated by High Ankle-Brachial Index in Patients on Peritoneal Dialysis.

Cardiovascular disease (CVD) is the leading cause of death in peritoneal dialysis (PD) patients. But the relationship between regular PD and the risk of major adverse cardiovascular events (MACE) remains controversial. The possible risk factors are not fully elucidated. This study aims to investigate the possible factors affecting the risk of MACE estimated by high ankle-brachial index (ABI) in PD patients. A total of 243 patients were enrolled and divided into chronic kidney diseases (CKD) stage 1, non-dialyzed CKD stages 2-5, and PD groups. The prevalence of high ABI, indicating increased MACE, was elevated with CKD progression but not further increased in PD patients. Systolic blood pressure was closely correlated with high ABI in non-dialyzed CKD patients (ß = 0.059, P = 0.001). But in PD patients, serum calcium had a crucial effect on high ABI (ß = -9.853, P < 0.001). Additionally, PD patients with high ABI tended to dialyze inadequately (Kt/V <1.7) compared to those with normal ABI (29.0 vs. 13.3%, P = 0.031). Further mediation analysis revealed that ~86.2% of the relationship between Kt/V and high ABI was mediated by serum calcium in PD patients (mediation effect = 86.2%, ab = -0.220, 95% CI: -0.381 to -0.059, P = 0.008), especially in those starting PD before 55 years of age and with normal body mass index. This present study indicated that improvement of PD adequacy by maintaining calcium balance might be a promising method to reduce the risk of MACE estimated by high ABI for PD patients.

SIRT6 protects vascular smooth muscle cells from osteogenic transdifferentiation via Runx2 in chronic kidney disease.

Vascular calcification (VC) is regarded as an important pathological change lacking effective treatment and associated with high mortality. Sirtuin 6 (SIRT6) is a member of the Sirtuin family, a class III histone deacetylase and a key epigenetic regulator. SIRT6 has a protective role in patients with chronic kidney disease (CKD). However, the exact role and molecular mechanism of SIRT6 in VC in patients with CKD remain unclear. Here, we demonstrated that SIRT6 was markedly downregulated in peripheral blood mononuclear cells (PBMCs) and in the radial artery tissue of patients with CKD with VC. SIRT6-transgenic (SIRT6-Tg) mice showed alleviated VC, while vascular smooth muscle cell-specific (VSMC-specific) SIRT6 knocked-down mice showed severe VC in CKD. SIRT6 suppressed the osteogenic transdifferentiation of VSMCs via regulation of runt-related transcription factor 2 (Runx2). Coimmunoprecipitation (co-IP) and immunoprecipitation (IP) assays confirmed that SIRT6 bound to Runx2. Moreover, Runx2 was deacetylated by SIRT6 and further promoted nuclear export via exportin 1 (XPO1), which in turn caused degradation of Runx2 through the ubiquitin-proteasome system. These results demonstrated that SIRT6 prevented VC by suppressing the osteogenic transdifferentiation of VSMCs, and as such targeting SIRT6 may be an appealing therapeutic target for VC in CKD.

ALKBH1-demethylated DNA N6-methyladenine modification triggers vascular calcification via osteogenic reprogramming in chronic kidney disease.

Vascular calcification (VC) predicts cardiovascular morbidity and mortality in chronic kidney disease (CKD). To date, the underlying mechanisms remain unclear. We detected leukocyte DNA N6-methyladenine (6mA) levels in patients with CKD with or without aortic arch calcification. We used arteries from CKD mice infected with vascular smooth muscle cell-targeted (VSMC-targeted) adeno-associated virus encoding alkB homolog 1 (Alkbh1) gene or Alkbh1 shRNA to evaluate features of calcification. We identified that leukocyte 6mA levels were significantly reduced as the severity of VC increased in patients with CKD. Decreased 6mA demethylation resulted from the upregulation of ALKBH1. Here, ALKBH1 overexpression aggravated whereas its depletion blunted VC progression and osteogenic reprogramming in vivo and in vitro. Mechanistically, ALKBH1-demethylated DNA 6mA modification could facilitate the binding of octamer-binding transcription factor 4 (Oct4) to bone morphogenetic protein 2 (BMP2) promoter and activate BMP2 transcription. This resulted in osteogenic reprogramming of VSMCs and subsequent VC progression. Either BMP2 or Oct4 depletion alleviated the procalcifying effects of ALKBH1. This suggests that targeting ALKBH1 might be a therapeutic method to reduce the burden of VC in CKD.

Silencing of Central (Pro)renin Receptor Ameliorates Salt-Induced Renal Injury in Chronic Kidney Disease.

Aims: A high-salt diet can aggravate oxidative stress, and renal fibrosis via the brain and renal renin-angiotensin system (RAS) axis in chronic kidney disease (CKD) rats. (Pro)renin receptor (PRR) plays a role in regulating RAS and oxidative stress locally. However, whether central PRR regulates salt-induced renal injury in CKD remains undefined. Here, we hypothesized that the reduction of central PRR expression could ameliorate central lesions and thereby ameliorate renal injury in high-salt-load CKD rats. Results: We investigated RAS, sympathetic nerve activity, oxidative stress, inflammation, and tissue injury in subfornical organs and kidneys in high-salt-load 5/6 nephrectomy CKD rats after the silencing of central PRR expression by intracerebroventricular lentivirus-RNAi. We found that the sympathetic nerve activity was reduced, and the levels of inflammation and oxidative stress were decreased in both brain and kidney. Renal injury and fibrosis were ameliorated. To explore the mechanism by which central inhibition of PRR expression ameliorates kidney damage, we blocked central MAPK/ERK1/2 and PI3K/Akt signaling pathways as well as angiotensin converting enzyme 1-angiotensin II-angiotensin type 1 receptors (ACE1-Ang II-AT1R) axis. Salt-induced overexpression of renal RAS, inflammation, oxidative stress, and fibrosis in CKD rats were prevented by central blockade of the pathways. Innovation: This study provides new insights into the mechanisms underlying salt-induced kidney damage. Targeting central PRR or PRR-mediated signaling pathway may be a novel strategy for the treatment of CKD. Conclusions: These results suggested that the silencing of central PRR expression ameliorates salt-induced renal injury in CKD through Ang II-dependent and -independent pathways.

Hydrophilic Porous Poly(l-Lactic Acid) Nanomembranes: Self-Assembly, and Anti-Biofouling and Anti-Thrombosis Effects.

Hydrophilic PEGylated porous self-assembled nanomembranes (PSANMs) with average thickness and pore diameter of ca. 10 and 20-24 nm were successfully prepared by an emulsification-induced programmable self-assembly strategy. The hydrophilicity, anti-biofouling, and anti-thrombosis properties of PEGylated PSANMs were largely improved in comparison with the nonfunctionalized PSANMs, which could transform into hydrophilic (PEGylated PSANMs, minimum water contact angle: 38.8°) from hydrophobic units (PSANMs, maximum water contact angle: 137.5°) with increasing PEG density and length. The total protein adsorption of PEGylated PSANMs was about six times lower than that of the PSANMs, while the thrombosis of the PEGylated PSANMs (maximum R-time: 5.37 min) was also greatly relieved in comparison with the PSANMs (minimum R-time: 2.93 min). Such PEG-modified PSANMs may have applications in drug delivery and tissue and organ repair in vivo.

Kidney-targeted triptolide-encapsulated mesoscale nanoparticles for high-efficiency treatment of kidney injury.

Bad water solubility and undesired toxicity of triptolide (TP) still restrict its clinical applications in renal diseases. In this work, well-defined, monodispersed, and uniform-sized TP-encapsulated mesoscale nanoparticles (TP-MNPs) were fabricated through a nanoprecipitation method, which possesses special kidney-targeting capacity, slow-release property, and high-efficiency treatment for renal ischaemia-reperfusion injury (IRI). The TP-MNPs had good cytocompatibility in wide TP concentration (0-500 ng ml-1) and time ranges (6-24 h). Ex vivo organ fluorescence imaging and pharmacokinetic analysis suggested that TP-MNPs possessed excellent kidney-targeting capability with long retention time (7 days). The TP-MNPs with a very low dose of TP (0.01 mg kg-1) could effectively protect the kidney against IRI, while 0.01 mg kg-1 TP was completely ineffective. After treatment with TP-MNPs, the serum creatine, blood urea nitrogen, expression of C3 complement, and phospho-extracellular signal-regulated kinase of renal IRI mice were estimated to be 5.9-, 2.0-, 5.4-, and 2.8-fold lower than those of the mice treated with TP, respectively. Compared with TP, the TP-MNPs exhibited ignorable hepatotoxicity, reproductive toxicity, and immunotoxicity, such as lower alanine aminotransferase (0.5 fold) and aspartate aminotransferase (0.2 fold), and a higher ratio of CD4+/CD8+ (2.2 fold). Thus, the monodispersed and uniform-sized TP-MNPs with special kidney-targeting and slow-release property may pave an avenue for designing a new therapeutic strategy for renal diseases.

Hydroxychloroquine-induced renal phospholipidosis resembling Fabry disease in undifferentiated connective tissue disease: A case report.

BACKGROUND: Fabry disease is a kind of lysosomal storage disease resulting from deficient activity of the lysosomal hydrolase alpha-galactosidase A (GLA). A mutation in the GLA gene leads to a loss of activity of alpha-galactosidase A. Some drugs, such as hydroxychloroquine, can cause pathological changes similar to those usually seen in Fabry disease. CASE SUMMARY: We report the case of a 41-year-old female patient who was diagnosed with undifferentiated connective tissue disease in 2008. Hydroxychloroquine treatment started 2 years ago, and proteinuria and hematuria increased. Renal biopsy demonstrated renal phospholipidosis. Zebra bodies and myelin figures were found by renal electron microscopy and were initially thought to be indicators of Fabry disease. A genetic analysis of the patient and her family members did not reveal mutations in the GLA gene, supporting a diagnosis of hydroxychloroquine-induced renal phospholipidosis. CONCLUSION: This report reveals one of the adverse effects of hydroxychloroquine. We should pay more attention to hydroxychloroquine-induced renal phospholipidosis.

Renal and cerebral RAS interaction contributes to diabetic kidney disease.

The diabetes mellitus has posed a grave threat on human health, and is bound to result in renal trauma by uncertain mechanisms. Increasing evidences indicated that the activation of the renin-angiotensin system plays a pivotal role during the progression of diabetic kidney disease. In streptozotocin (STZ)-induced type 1 diabetic rat model, the losartan (a selective angiotensin II type 1 (AT1) receptor antagonist) and tempol (4-Hydroxy-TEMPO, reactive oxygen species scavenger) were administrated through intracerebroventricular injection or intragastric gavage. Intracerebroventricular administration of clonidine or renal denervation was carried out to block sympathetic nerve traffic. Compared with non-diabetic rats, the reno-cerebral axis was over-activated, including activity of renin-angiotensin system (RAS), oxidative stress, and sympathetic activity in diabetic rats. Central blockade of RAS inhibited the central oxidative stress and sympathetic activity, which led to decrease of intrarenal RAS activity and oxidative stress. Meanwhile, central administration of tempol reduced brain RAS, thus downregulated renal RAS activity and oxidative stress. Importantly, oral administration by intragastric gavage of high dose of losartan and tempol achieved the same effect. The results suggested that there is a cross-talk between renal and cerebral RAS/reactive oxygen species, contributing to the progression of diabetic kidney disease. The subfornical organ, paraventricular nucleus, and supraoptic nucleus in the forebrain also play a key role in development and progression of renal trauma through reno-cerebral reflex axis.

A stimuli-responsive drug release nanoplatform for kidney-specific anti-fibrosis treatment.

The renoprotective effects of hypoxia inducible-factor (HIF) activators have been demonstrated by improving renal hypoxia in chronic kidney disease. Cobalt chloride is one of the most widely used HIF activators in biomedicine; however, poor kidney targeting and undesirable side effects greatly limit its clinical applications. Here, we report a novel stimuli-responsive drug release nanoplatform in which glutathione (GSH)-modified Au nanoparticles (GLAuNPs) and Co2+ self-assemble into nanoassemblies (GLAuNPs-Co) through coordination interactions between empty orbitals of Co2+ and lone pairs of GSH. The GLAuNPs, when used as a drug carrier, demonstrated high drug loading capacity and pH-triggered drug release after assembling with Co2+. The acidic environment of lysosomes in renal fibrosis tissues could disassemble GLAuNPs-Co and release Co2+. Moreover, encapsulation of the Co2+ ions in the GLAuNPs greatly lowered the cytotoxicity of Co2+ in kidney tubule cells. Tissue fluorescence imaging showed that GLAuNPs-Co specifically accumulated in the kidneys, especially in the renal proximal tubules. After GLAuNPs-Co was intraperitoneally injected into ureter-obstructed mice, significant attenuation of interstitial fibrosis was exhibited. The beneficial effects can be mainly ascribed to miR-29c expression restored by HIF-α activation. These findings revealed that GLAuNPs-Co have pH-responsive drug release and renal targeting capabilities; thus, they are a promising drug delivery platform for treating kidney disease.

Small-Sized Cationic miRi-PCNPs Selectively Target the Kidneys for High-Efficiency Antifibrosis Treatment.

Small-sized cationic miRi (microRNA-21 inhibitor)-PCNPs (low molecular weight chitosan (LMWC)-modified polylactide-co-glycoside (PLGA) nanoparticles (PLNPs)) with special kidney-targeting and high-efficiency antifibrosis treatment are fabricated through coupling miRi, PLGA, and LMWC. In the miRi-PCNPs, easily degraded miRi is encapsulated in PCNPs and thus prevented from degradation by nuclease. Cytotoxicity, immunotoxicity, and systemic toxicity assays and in vitro and ex vivo fluorescence imaging suggest that PCNPs possess excellent biocompatibility, higher cellular uptake efficiency, and selective kidney-targeting capacity. Western blotting, pathological staining, and real-time polymerase chain reaction analyses show that the therapeutic effect of miRi-PCNPs on kidney fibrosis is much higher than that of miRi, which is mainly through suppressing transforming growth factor beta-1/drosophila mothers against decapentaplegic protein 3 (TGF-ß1/Smad3) and extracellular signal-regulated kinases/mitogen-activated protein kinase signaling pathway by inhibiting the expression of microRNA-21. For example, the tubule damage index and tubulointerstitial fibrosis area in the miRi-PCNPs group are ≈2.5-fold lower than those in the saline and bare miRi groups. The miRi-PCNPs with special kidney-targeting and high-efficiency antifibrosis treatment may represent a promising strategy for designing and developing a therapeutic treatment for kidney fibrosis.

Targeted Ablation of Distal Cerebrospinal Fluid-Contacting Nucleus Alleviates Renal Fibrosis in Chronic Kidney Disease.

The potential function of distal cerebrospinal fluid-contacting nucleus (dCSF-CNs) in chronic kidney disease (CKD) development is poorly understood. We hypothesized that dCSF-CNs might affect the renin-angiotensin system (RAS) in kidney injury progression, with dCSF-CNs ablation potentially alleviating local RAS and renal fibrosis in rats after five-sixths nephrectomy (5/6Nx). Part of rats were randomly administered artificial cerebrospinal fluid (aCSF) intracerebroventricularly (icv), followed by 5/6Nx or sham operation; and other part of rats were administered Cholera toxin B subunit conjugated with saporin (CB-SAP) for dCSF-CNs lesion before 5/6Nx. The effect of CB-SAP on dCSF-CNs ablation was confirmed by double immunofluorescence staining. RAS component, NOX2 and c-fos levels in the subfornical organ (SFO), hypothalamic paraventricular nucleus (PVN) and hippocampus, as well as tyrosine hydroxylase (TH) and c-fos positive cells in rostral ventrolateral medulla (RVLM) were assessed. Next, the levels of RAS components (angiotensinogen [AGT], angiotensin-converting enzyme [ACE], Ang II type 1 receptor [AT1R], angiotensin-converting enzyme 2 [ACE2], and Mas receptor), NADPH oxidases (NOX2 and catalase), inflammatory cytokines (monocyte chemotactic protein 1 [MCP-1] and IL-6), and fibrotic factors (fibronectin and collagen I) were assessed. Less CB-labeled neurons were found in dCSF-CNs of CB-SAP-treated rats compared with 5/6Nx animals. Meanwhile, CB-SAP downregulated AGT, Ang II, AT1R, NOX2, catalase, MCP-1, IL-6, fibronectin, and collagen I, and upregulated ACE2 and Mas receptor, compared with CKD rats. More TH and c-fos positive cells were found in RVLM of 5/6Nx rats but the number decreased after dCSF-CNs ablation. Targeted dCSF-CNs ablation could alleviate renal inflammation and fibrosis in chronic kidney injury by inhibiting cerebral and renal RAS/NADPH oxidase.

Music stimuli lead to increased levels of nitrite in unstimulated mixed saliva.

Concentration of salivary nitrate is approximately 10-fold to that of serum. Many circumstances such as acute stress could promote salivary nitrate secretion and nitrite formation. However, whether other conditions can also be used as regulators of salivary nitrate/nitrite has not yet been explored. The present study was designed to determine the influence of exposure to different music on the salivary flow rate and nitrate secretion and nitrite formation. Twenty-four undergraduate students (12 females and 12 males) were exposed to silence, rock music, classical music or white noise respectively on four consecutive mornings. The unstimulated salivary flow rate and stimulated salivary flow rate were measured. Salivary ionic (Na+, Ca2+ Cl-, and PO43-) content and nitrate/nitrite levels were detected. The unstimulated salivary flow rate was significantly increased after classical music exposure compared to that after silence. Salivary nitrite levels were significantly higher upon classical music and white noise stimulation than those under silence in females. However, males were more sensitive only to white noise with regard to the nitrite increase. In conclusion, this study demonstrated that classical music stimulation promotes salivary nitrite formation and an increase in saliva volume was observed. These observations may play an important role in regulating oral function.

Salt-induced phosphoproteomic changes in the hypothalamic paraventricular nucleus in rats with chronic renal failure.

Hypothalamic paraventricular nucleus (PVN) is a cardiovascular regulating center within the brain, which plays a critical role in high salt-induced progression of chronic renal failure (CRF). However, the phosphoproteomic changes in the PVN caused by CRF remain unclear. This study aimed to perform large-scale phosphoproteomic analysis of PVN induced by CRF and high salt intake. In this study, eight weeks post 5/6 nephrectomy (CRF model) or sham operation, Sprague-Dawley rats were fed a high-salt (4%) or normal-salt (0.4%) diet for 3weeks. TiO2 enrichment, iTRAQ labeling, and liquid chromatography tandem mass spectrometry were applied for phosphoproteomic profiling of PVN. A total of 3723 unique phosphopeptides corresponding to 1530 phosphoproteins were identified. Compared with sham group, 133 upregulated and 141 downregulated phosphopeptides were identified in CRF group during normal-salt feeding. However, with a high-salt diet, 160 phosphopeptides were upregulated and 142 downregulated in the CRF group. Gene Ontology analysis revealed that these phosphoproteins were involved in binding, catalytic, transporter, and other molecular functions. Search Tool for the Retrieval of Interacting Genes protein-protein analysis showed direct or indirect functional links among 25 differentially expressed phosphoproteins in CRF rats compared with sham group. However, 24 differentially phosphorylated proteins induced by high salt intake were functionally linked in CRF animals. The altered phosphorylation levels of dynamin 1, TPPP and Erk1/2 were validated. Phosphoproteomic changes of PVN triggered by CRF and high salt-load have been investigated. It will provide new insight into pathogenetic mechanisms of development of chronic kidney disease and salt sensitivity.

Increased Apoptosis in the Paraventricular Nucleus Mediated by AT1R/Ras/ERK1/2 Signaling Results in Sympathetic Hyperactivity and Renovascular Hypertension in Rats after Kidney Injury.

Background: The central nervous system plays a vital role in the development of hypertension, but the molecular regulatory mechanisms are not fully understood. This study aimed to explore signaling in the paraventricular nucleus (PVN) which might contribute to renal hypertension. Methods: Renal hypertension model was established by five-sixth nephrectomy operation (5/6Nx) in male Sprague Dawley rats. Ten weeks afterwards, they were random assigned to no treatment, or intracerebroventricular injection (ICV) with artificial cerebrospinal fluid, losartan [angiotensin II receptor type 1 (AT1R) antagonist], farnesylthiosalicylic acid (Ras inhibitor), PD98059 (MEK inhibitor), or SB203580 (p38 inhibitor) and Z-DEVD-FMK (caspase-3 inhibitor). Before and after treatment, physiological and biochemical indices were measured. Immunohistochemistry, western blot and RT-PCR were applied to quantify key components of renin-angiotensin system, apoptosis-related proteins, Ras-GTP, and MAPKs in the PVN samples. TUNEL assay was used to measure the situ apoptosis in PVN. Results: The 5/6Nx rats showed significantly elevated systolic blood pressure, urinary protein excretion, serum creatinine, and plasma norepinephrine (p < 0.05) compared to sham rats. The expression of angiotensinogen, Ang II, AT1R, p-ERK1/2, or apoptosis-promoting protein Bax were 1.08-, 2.10-, 0.74-, 0.82-, 0.83-fold higher in the PVN of 5/6Nx rats, than that of sham rats, as indicated by immunohistochemistry. Western blot confirmed the increased levels of AT1R, p-ERK1/2 and Bax; meanwhile, Ras-GTP and p-p38 were also found higher in the PVN of 5/6Nx rats, as well as the apoptosis marker cleaved caspase-3 and TUNEL staining. In 5/6Nx rats, ICV infusion of AT1R antagonist, Ras inhibitor, MEK inhibitor or caspase-3 inhibitor could lower systolic blood pressure (20.8-, 20.8-, 18.9-, 14.3%-fold) together with plasma norepinephrine (53.9-, 57.8-,63.3-, 52.3%-fold). Western blot revealed that blocking the signaling of AT1R, Ras, or MEK/ERK1/2 would significantly reduce PVN apoptosis as indicated by changes of apoptosis-related proteins (p < 0.05). AT1R inhibition would cause reduction in Ras-GTP and p-ERK1/2, but not vice versa; such intervention with corresponding inhibitors also suggested the unidirectional regulation of Ras to ERK1/2. Conclusion: These findings demonstrated that the activation of renin-angiotensin system in PVN could induce apoptosis through Ras/ERK1/2 pathway, which then led to increased sympathetic nerve activity and renal hypertension in 5/6Nx rats.