C1q/tumor necrosis factor‐related protein‐3 improves renal fibrosis via inhibiting notch signaling pathways

Reno-protective effect of nicorandil and pentoxifylline against potassium dichromate-induced acute renal injury via modulation p38MAPK/Nrf2/HO-1 and Notch1/TLR4/NF-κB signaling pathways

BACKGROUND

Occupational and environmental exposure to chromium compounds such as potassium dichromate (PDC) (K2Cr2O7) has emerged as a potential aetiologic cause for renal disease through apoptotic, and inflammatory reactions. The known potent antioxidants such as nicorandil (NIC) and/or pentoxifylline (PTX) were studied for their possible nephroprotective effect in PDC-treated rats.

METHODS

Forty male Wistar rats were divided into five groups; control, PDC group, NIC+PDC, PTX+PDC group, and combination+PDC group. Nephrotoxicity was evaluated histopathologically and biochemically. Invasive blood pressure, renal function parameters urea, creatinine, uric acid and albumin, glomerular filtration rate markers Cys-C, Kim-1 and NGAL, inflammatory markers IL-1β, IL-6, TNF-α, TGF-β, COX-II, p38MAPK, NF-κB and TLR4, oxidative stress SOD, GSH, MDA, MPO, HO-1 and Nrf2 and apoptotic mediators Notch1 and PCNA were evaluated. Besides, renal cortical histopathology was assayed as well.

RESULTS

PDC led to a considerable increase in indicators for kidney injury, renal function parameters, invasive blood pressure, oxidative stress, and inflammatory markers. They were markedly reduced by coadministration of PDC with either/or NIC and PTX. The NIC and PTX combination regimen showed a more significant improvement than either medication used alone. Our results demonstrated the nephroprotective effect of NIC, PTX, and their combined regimen on PDC-induced kidney injury through suppression of oxidative stress, apoptosis, and inflammatory response.

CONCLUSION

Renal recovery from PDC injury was achieved through enhanced MAPK/Nrf2/HO-1 and suppressed Notch1/TLR4/NF-κB signaling pathways. This study highlights the role of NIC and PTX as effective interventions to ameliorate nephrotoxicity in patients undergoing PDC toxicity.

Plasma proteomics of acute tubular injury

The kidney tubules constitute two-thirds of the cells of the kidney and account for the majority of the organ's metabolic energy expenditure. Acute tubular injury (ATI) is observed across various types of kidney diseases and may significantly contribute to progression to kidney failure. Non-invasive biomarkers of ATI may allow for early detection and drug development. Using the SomaScan proteomics platform on 434 patients with biopsy-confirmed kidney disease, we here identify plasma biomarkers associated with ATI severity. We employ regional transcriptomics and proteomics, single-cell RNA sequencing, and pathway analysis to explore biomarker protein and gene expression and enriched biological pathways. Additionally, we examine ATI biomarker associations with acute kidney injury (AKI) in the Kidney Precision Medicine Project (KPMP) (n = 44), the Atherosclerosis Risk in Communities (ARIC) study (n = 4610), and the COVID-19 Host Response and Clinical Outcomes (CHROME) study (n = 268). Our findings indicate 156 plasma proteins significantly linked to ATI with osteopontin, macrophage mannose receptor 1, and tenascin C showing the strongest associations. Pathway analysis highlight immune regulation and organelle stress responses in ATI pathogenesis.

Secreted frizzled-related protein 5 protects against renal fibrosis by inhibiting Wnt/β-catenin pathway

Renal fibrosis (RF) is an important pathogenesis for renal function deterioration in chronic kidney disease. Secreted frizzled-related protein 5 (SFRP5) is an anti-fibrotic adipokine but its direct role on RF remains unknown. It was aimed to study the protective effect of SFRP5 against RF and interference with Wnt/β-catenin signaling pathway for the first time. First, the therapeutic efficacy of SFRP5 was evaluated by adenovirus overexpression in rats with unilateral ureteral obstruction (UUO) in vivo. Thirty-six rats were randomly divided into the sham, UUO, and SFRP5 (UUO + Ad-SFRP5) groups. Half rats in each group were selected at random for euthanasia at 7 days and the others until 14 days. Then, the transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) was established in HK-2 cells in vitro. The cells were divided into four groups: the control group, the TGF-β1 group, the TGF-β1 + SFRP5 group, and the TGF-β1 + SFRP5 + anti-SFRP5 group. The makers of EMT and Wnt/β-catenin pathway proteins were investigated. In the UUO model, expression of SFRP5 showed compensatory upregulation, and adenoviral-mediated SFRP5 over-expression remarkably attenuated RF, as demonstrated by maintenance of E-cadherin and suppression of α-smooth muscle actin (SMA). In vitro, SFRP5 was shown to inhibit TGF-β1-mediated positive regulation of α-SMA, fibronectin, collagen I but negative regulation of E-cadherin. Furthermore, SFRP5 abrogated activation of Wnt/β-catenin, which was the essential pathway in EMT and RF pathogenesis. The changes after a neutralizing antibody to SFRP5 confirmed the specificity of SFRP5 for inhibition. These findings suggest that SFRP5 can directly ameliorate EMT and protect against RF by inhibiting Wnt/β-catenin pathway.

CTRP3 attenuates inflammation, oxidative and cell death in cisplatin induced HK-2 cells

Cisplatin has been widely studied and found to be a highly effective anti-tumor drug. It has several side effects, including acute kidney injury (AKI). Cisplatin-induced AKI can be primarily attributed to oxidative stress, inflammation, and apoptosis. The CTRP3 adipokine is a new adipokine that exhibits antioxidant, anti-inflammatory, and antiapoptotic properties. Despite this, the role of CTRP3 in AKI remain unclear. In cisplatin-induced AKI models, our findings demonstrated that CTRP3 expression was decreased in human proximal tubule epithelial cells (HK-2). In the in vitro experiments, HK-2 cells were first transfected with an overexpression plasmid of CTRP3 (pcDNA-CTRP3) or a small interfering RNA for CTRP3 (si-CTRP3) and induced by cisplatin; and cell oxidative stress, inflammation, proliferation, and apoptosis were found to be present. Overexpressing CTRP3 inhibited oxidative stress through decreasing malondialdehyde (MDA) levels and increasing the activity of SOD and CAT. The mRNA levels of SOD1 and SOD2 were increased in response to CTRP3 overexpression. Additionally, CTRP3 decreased TNF-α and MCP-1 levels. Moreover, CTRP3 overexpression increased cisplatin-induced cell activity and decreased cell apoptosis, as indicated by the elevated numbers of EdU positive cells and decreased numbers of apoptotic cells. Consistent with these results, the overexpression of CTRP3 effectively elevated the mRNA levels of Bcl-2 and reduced the mRNA levels of Bax. In contrast, inhibition of CTRP3 expression by si-CTRP3 reversed the cisplatin-induced indices. Mechanistically, we found that the overexpression of CTRP3 can increase expression of Nrf2 and inhibit the activation of MAPK phosphorylation (ERK, JNK, and p38). Furthermore, inhibition of ERK, JNK and p38 activity eliminated aggravation of cisplatin-induced inflammation and apoptosis caused by CTRP3 knockdown. Additionally, the cisplatin-induced oxidative stress and activation of MAPK phosphorylation (ERK, JNK, and p38) in HK-2 cells were reversed by Nrf2 suppression by siRNA. Collectively, these results indicated that CTRP3 may identify as a novel target for AKI treatment and protect against cisplatin-induced AKI through the Nrf2/MAPK pathway.

C1q/TNF-related protein 3 alleviates heart failure via attenuation of oxidative stress in myocardial infarction rats

C1q-tumor necrosis factor-related protein 3 (CTRP3), an adipokine, has been reported to be closely related to cardiovascular diseases (CVDs). However, the effect of CTRP3 on heart failure (HF) remains dimness. This study was to explore the role of CTRP3 in HF and its potential interaction mechanism. Heart failure model was established by inducing ischemia myocardial infarction (MI) through ligation of the left anterior descending artery in Sprague-Dawley rats. Four weeks later, the rats were detected by transthoracic echocardiography and masson staining. Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), cardiac troponin I (cTnI) levels, creatine kinase-MB (CK-MB) and oxidative stress levels were recorded. The level of CTRP3 was reduced in the cardiomyocytes (CMs) treated with oxygen-glucose deprivation (OGD) and in the heart of MI rats. CTRP3 overexpression alleviated cardiac dysfunction, attenuated the cardiac fibrosis, and inhibited the increases of ANP, BNP, cTnI and CK-MB in the serum of MI rats. The increases of ANP and BNP in the CMs, and the collagen I and collagen III in the cardiac fibroblasts (CFs) induced by OGD were inhibited by CTRP3 overexpression. The enhancement of oxidative stress in the heart of MI rats was inhibited by CTRP3 overexpression. These results indicated that overexpression of CTRP3 could improve cardiac function and the related cardiac fibrosis in MI-induced HF rats via inhibition of oxidative stress. Upregulation of CTRP3 may be a strategy for HF therapy in the future.

Obesity, chronic kidney disease progression and the role of the adipokine C1q/TNF related protein-3

INTRODUCTION AND AIMS

Obesity is a risk factor for incident chronic kidney disease (CKD). C1q/TNF related protein 3 (CTRP3) is an adipokine with multiple effects and may modulate the association between obesity and vascular diseases. The aim of the study is to explore potential links between obesity, CTRP3 levels and CKD progression.

METHODS

Patients with stage 3 and 4 CKD without previous cardiovascular events were enrolled and divided into groups according to body mass index (BMI) and sex. Demographic, clinical, analytical data and CTRP3 levels were collected at baseline. During follow-up, renal events (defined as dialysis initiation, serum creatinine doubling or a 50% decrease in estimated glomerular filtration rate were registered).

RESULTS

81 patients were enrolled. 27 were obese and 54 non-obese. Baseline CTRP3 was similar between both groups (90.1±23.8 vs 84.5±6.2; p=0.28). Of the sum, 54 were men and 27 women, with higher CTRP3 in women (81.4±24.7 vs 106±24.7;p<0.01). During a mean follow-up of 68 months, 15 patients had a renal event. Patients in the higher CTRP3 tertile had less events but without statistical significance (p=0.07). Obese patients in the higher CTRP3 tertile significantly had less renal events (p=0.049). By multiple regression analysis CTRP3 levels could not predict renal events (HR 0.98; CI95% 0.96-1.06).

CONCLUSIONS

CTRP3 levels are higher in woman than men in patients with CKD, with similar levels between obese and non obese. Higher CTRP3 levels at baseline were associated with better renal outcomes in obese patients.

Keloid Core Factor CTRP3 Overexpression Significantly Controlled TGF-β1-Induced Propagation and Migration in Keloid Fibroblasts

Purpose

Keloid is a type of benign fibrous proliferative tumor characterized by excessive scarring. C1q/TNF-related protein 3 (CTRP3) has been proven to possess antifibrotic effect. Here, we explored the role of CTRP3 in keloid. In the current research, we examined the influence of CTRP3 on keloid fibroblasts (KFs) and investigated the potential molecular mechanism.

Methods

KF tissue specimens and adjacent normal fibroblast (NF) tissues were collected cultured from 10 keloid participants. For the TGF-β1 stimulation group, KFs were processed with human recombinant TGF-β1. Cell transfection of pcDNA3.1-CTRP3 or pcDNA3.1 was performed. The siRNA of CTRP3 (si-CTRP3) or negative control siRNA (si-scramble) was transfected into KFs.

Results

CTRP3 was downregulated in keloid tissues and KFs. CTRP3 overexpression significantly controlled TGF-β1-induced propagation and migration in KFs. Col I, α-SMA, and fibronectin mRNA and protein levels were enhanced by TGF-β1 stimulation, whereas they were inhibited by CTRP3 overexpression. In contrast, CTRP3 knockdown exhibited the opposite effect. In addition, CTRP3 attenuated TGF-β receptors TRI and TRII in TGF-β1-induced KFs. Furthermore, CTRP3 prevented TGF-β1-stimulated nuclear translocation of smad2 and smad3 and suppressed the expression levels of p-smad2 and p-smad3 in KFs.

Conclusion

CTRP3 exerted an antifibrotic role through inhibiting proliferation, migration, and ECM accumulation of KFs via regulating TGF-β1/Smad signal path.

C1q/tumour necrosis factor-related protein-3 alleviates high-glucose-induced lipid accumulation and necroinflammation in renal tubular cells by activating the adenosine monophosphate-activated protein kinase pathway

Lipid accumulation and progressive necroinflammation play pivotal roles in the development of diabetic nephropathy. C1q tumour necrosis factor-related protein-3 (CTRP3) is an adipokine with pleiotropic functions in cell proliferation, glucose and lipid metabolism, and inflammation. However, the mechanism and involvement of CTRP3 in lipid metabolism and the necroinflammation of renal tubular cells remain unclear. Here, we report that CTRP3 expression decreased in a time- and concentration-dependent manner in high glucose-stimulated HK-2 cells. We noted that the overexpression of CTRP3 or recombinant CTRP3 (rCTRP3) treatment prevented high glucose-induced lipid accumulation by inhibiting the expression of sterol regulatory element-binding protein-1 and increasing the expression of peroxisome proliferator-activated receptor-α and ATP-binding cassette A1. Moreover, the nucleotide-binding oligomerisation domain-like receptor protein 3-mediated inflammatory response and mixed lineage kinase domain-like protein-dependent necroinflammation were inhibited by CTRP3 overexpression or rCTRP3 treatment in HK-2 cells cultured in high glucose. Furthermore, lipotoxicity-induced by palmitic acid was found to be involved in necroinflammation in HK-2 cells, and CTRP3 displayed the same protective effect. CTRP3 also activated the adenosine monophosphate-activated protein kinase (AMPK) pathway, whereas adenine 9-β-D-arabinofuranoside, an AMPK inhibitor, replicated the protective effects of CTRP3. Besides, using kidney biopsies from patients with diabetes, we found that decreased CTRP3 expression was accompanied by increased lipid deposition, as well as the structural and functional injury of renal tubular cells. Our findings demonstrate that CTRP3 affects lipid metabolism and necroinflammation in renal tubular cells via the AMPK signalling pathway. Thus, CTRP3 may be a potential therapeutic target in diabetic renal injury.

C1q inhibits differentiation of oligodendrocyte progenitor cells via Wnt/β-catenin signaling activation in a cuprizone-induced mouse model of multiple sclerosis

Multiple sclerosis (MS) is a chronic central nervous system demyelinating disease of autoimmune originate. Complement C1q, a complex glycoprotein, mediates a variety of immunoregulatory functions considered important in the prevention of autoimmunity. Although we found that the increased serum C1q level was highly associated with the Fazekas scores and T2 lesion volume of MS patients, the effect and mechanism of C1q on demyelination remains unclear. Cluster analysis and protein array results showed that serum Wnt receptors Frizzled-6 and LRP-6 levels in MS patients were both increased, we proposed that C1q may be involved in demyelination via Wnt signaling. The increased C1q protein levels in the serum and brain tissue were confirmed in a cuprizone (CPZ)-induced demyelination mice model. Moreover, CPZ treatment induced significant increase of LRP-6 and Frizzled-6 protein in mice corpus callosum. LRP-6 extra-cellular domain (LRP-6-ECD) level in the serum and cerebrospinal fluid (CSF) of CPZ mice also significantly increased. Knockdown of the subunit C1s of C1 not only substantially attenuated demyelination, promoted M2 microglia polarization and improved neurological function, but inhibited β-catenin expression and its nuclear translocation in oligodendrocyte progenitor cells (OPCs). In vitro, C1s silence reversed the increased level of LRP-6-ECD in the medium and β-catenin expression in OPCs induced by C1q treatment. Meanwhile, inhibition of C1s also markedly lowered the number of EDU positive OPCs, but enhanced the number of CNPase positive oligodendrocyte and the protein of MBP. The present study indicated that C1q was involved in demyelination in response to CPZ in mice by preventing OPC from differentiating into mature oligodendrocyte via Wnt/β-catenin signaling activation.

Cr(VI) promotes tight joint and oxidative damage by activating the Nrf2/ROS/Notch1 axis

This study aimed to investigate whether Cr(VI) induced tight joint and oxidative damage in the small intestine, as mediated by the nuclear factor erythroid 2-related factor 2 (Nrf2)/reactive oxygen species (ROS)/Notch1 axis crosstalk. Thirty-two ICR mice were obtained and subjected to Cr(VI) via intragastric administration daily for 5 days. Western blot (WB) analysis, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC) staining, and immunofluorescence (IF) staining were applied to detect small intestinal damage, Nrf2, Notch1, and respective downstream targets in this research. Results showed that Cr(VI) led to the tight joint and oxidative damage in the small intestine of mice. Nrf2 was stimulated, and Notch1 (Notch intracellular domain, NICD1) was activated to translocate into the nucleus and activate an antioxidant action. These findings were validated by WB analysis and IF staining. ROS levels increased as the Cr(VI) concentration increased. The colocalization analysis of Nrf2 and NICD1 implied that a crosstalk between Nrf2 and Notch1 existed. Therefore, this study indicated that the Nrf2/ROS/Notch1 axis crosstalk could aggravate the tight joint and oxidative damage in the small intestine after Cr(VI) treatment.

CTRP3 protects hippocampal neurons from oxygen-glucose deprivation-induced injury through the AMPK/Nrf2/ARE pathway

OBJECTIVE

C1q/TNF-related protein 3 (CTRP3), a member of CTRP family, has been found to have neuroprotective effect. In the current study, we investigated the protective role of CTRP3 in hippocampal neurons exposed to oxygen-glucose deprivation/reperfusion (OGD/R).

MATERIALS AND METHODS

The mRNA and protein levels of CTRP3 in OGD/R-stimulated hippocampal neurons were measured using qRT-PCR and western blot analysis, respectively. CCK-8 assay was performed to assess cell viability. ROS production was measured using the fluorescence probe 2',7'-dichlorofluorescein diacetate (H₂DCFDA). The activities of SOD and GPx were determined using ELISA. Cell apoptosis was assessed. Luciferase reporter assay was carried out to assess the activation of ARE). The levels of p-AMPK and Nrf2 were measured using western blot.

RESULTS

Our results showed that the expression of CTRP3 was significantly downregulated in hippocampal neuronal cells exposed to OGD/R. Overexpression of CTRP3 improved cell viability of OGD/R-induced hippocampal neurons. In addition, overexpression of CTRP3 attenuated the OGD/R-caused oxidative stress with decreased ROS production and increased activities of SOD and GPx. Moreover, CTRP3 caused a significant increase in bcl-2 expression and decreases in bax expression and caspase-3 activity. Furthermore, CTRP3 overexpression significantly upregulated the levels of p-AMPK and Nrf2, as well induced the activation of ARE in OGD-R-induced hippocampal neurons. CTRP3 upregulated the mRNA expression levels of HO-1, NQO-1 and GPx-3. Additionally, treatment with the inhibitor of AMPK partially reversed the neuroprotective effect of CTRP3 in OGD/R-exposed neurons.

CONCLUSION

CTRP3 exerted protective effect on OGD/R-induced cerebral injury, which was regulated by AMPK/Nrf2/ARE pathway.

Isolation and identification of goose skeletal muscle satellite cells and preliminary study on the function of C1q and tumor necrosis factor-related protein 3 gene

Objective

Skeletal muscle satellite cells (SMSCs) are significant for the growth, regeneration, and maintenance of skeletal muscle after birth. However, currently, few studies have been performed on the isolation, culture and inducing differentiation of goose muscle satellite cells. Previous studies have shown that C1q and tumor necrosis factor-related protein 3 (CTRP3) participated in the process of muscle growth and development, but its role in the goose skeletal muscle development is not yet clear. This study aimed to isolate, culture, and identify the goose SMSCs in vitro. Additionally, to explore the function of CTRP3 in goose SMSCs.

Methods

Goose SMSCs were isolated using 0.25% trypsin from leg muscle (LM) of 15 to 20 day fertilized goose eggs. Cell differentiation was induced by transferring the cells to differentiation medium with 2% horse serum and 1% penicillin streptomycin. Immunofluorescence staining of Desmin and Pax7 was used to identify goose SMSCs. Quantitative realtime polymerase chain reaction and western blot were applied to explore developmental expression profile of CTRP3 in LM and the regulation of CTRP3 on myosin heavy chains (MyHC), myogenin (MyoG) expression and Notch signaling pathway related genes expression.

Results

The goose SMSCs were successfully isolated and cultured. The expression of Pax7 and Desmin were observed in the isolated cells. The expression of CTRP3 decreased significantly during leg muscle development. Overexpression of CTRP3 could enhance the expression of two myogenic differentiation marker genes, MyHC and MyoG. But knockdown of CTRP3 suppressed their expression. Furthermore, CTRP3 could repress the mRNA level of Notch signaling pathway-related genes, notch receptor 1, notch receptor 2 and hairy/enhancer-of-split related with YRPW motif 1, which previously showed a negative regulation in myoblast differentiation.

Conclusion

These findings provide a useful cell model for the future research on goose muscle development and suggest that CTRP3 may play an essential role in skeletal muscle growth of goose.