C1q/tumor Necrosis Factor-related Protein-3 Research Articles

GCTRP3 inhibits oophorectomy‑induced osteoporosis by activating the AMPK/SIRT1/Nrf2 signaling pathway in mice.

C1q/tumor necrosis factor‑related protein 3 (CTRP3) expression is markedly reduced in the serum of patients with osteoporosis. The present study aimed to investigate whether CTRP3 reduces bone loss in oophorectomy (OVX)‑induced mice via the AMP‑activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/nuclear factor E2‑related factor 2 (Nrf2) signaling pathway. Female C57BL/6J mice and MC3T3‑E1 cells were used to construct in vivo and in vitro models of osteoporosis, respectively. The left femurs of mice were examined using micro‑computed tomography scans and bone‑related quantitative morphological evaluation was performed. Pathological changes and the number of osteoclasts in the left femurs of mice were detected using hematoxylin and eosin, and tartrate‑resistant acid phosphatase (TRAP) staining. Runt‑related transcription factor‑2 (RUNX2) expression in the left femurs was detected using immunofluorescence analysis, and the serum levels of bone resorption markers (C‑telopeptide of type I collagen and TRAP) and bone formation markers [osteocalcin (OCN) and procollagen type 1 N‑terminal propeptide] were detected. In addition, osteoblast differentiation and calcium deposits were examined in MC3T3‑E1 cells using alkaline phosphatase (ALP) and Alizarin red staining, respectively. Moreover, RUNX2, ALP and OCN expression levels were detected using reverse transcription‑quantitative PCR, and the expression levels of proteins associated with the AMPK/SIRT1/Nrf2 signaling pathway were detected using western blot analysis. The results revealed that globular CTRP3 (gCTRP3) alleviated bone loss and promoted bone formation in OVX‑induced mice. gCTRP3 also facilitated the osteogenic differentiation of MC3T3‑E1 cells through the AMPK/SIRT1/Nrf2 signaling pathway. The addition of an AMPK inhibitor (Compound C), SIRT1 inhibitor (EX527) or Nrf2 inhibitor (ML385) reduced the osteogenic differentiation of MC3T3‑E1 cells via inhibition of gCTRP3. In conclusion, gCTRP3 inhibits OVX‑induced osteoporosis by activating the AMPK/SIRT1/Nrf2 signaling pathway.

C1q/Tumor Necrosis Factor-Related Protein-9 Enhances Macrophage Cholesterol Efflux and Improves Reverse Cholesterol Transport via AMPK Activation.

Cholesterol efflux from foam cells in atherosclerotic plaques is crucial for reverse cholesterol transport (RCT), an important antiatherogenic event. ATP-binding cassette (ABC) transporters, ABCA1 and ABCG1, are key receptors in the cholesterol efflux pathway. C1q/tumor necrosis factor-related protein-9 (CTRP9) is a newly discovered adipokine and exhibits an atheroprotective activity. However, the role of CTRP9 in RCT still remains unknown. In this work, we investigated the effect of subcutaneous administration of CTRP9 protein on RCT and atherosclerotic lesion formation in ApoE-/- mice fed with a high-fat diet. CTRP9-dependent regulation of cholesterol efflux and ABC transporters in RAW 264.7 foam cells was determined. Our results showed that CTRP9 protein decreased atherosclerotic lesions, increased cholesterol efflux, and upregulated liver ABCA1 and ABCG1 expression in ApoE-/- mice. CTRP9 treatment dose-dependently increased mRNA and protein expression of ABCA1, ABCG1, and LXR-α in RAW 264.7 foam cells. Moreover, the expression and phosphorylation of AMPK was potentiated upon CTRP9 treatment. Notably, CTRP9-induced cholesterol efflux and upregulation of ABCA, ABCG1, and LXR-α were impaired when AMPK was knocked down. AMPK depletion restored cholesterol accumulation in CTRP9-treated RAW 264.7 cells. Taken together, subcutaneous injection is an effective novel delivery route for CTRP9 protein, and exogenous CTRP9 can facilitate cholesterol efflux and promote RCT in an animal model of atherosclerosis. The atheroprotective activity of CTRP9 is mediated through the activation of AMPK signaling.

CTRP3 alleviates mitochondrial dysfunction and oxidative stress injury in pathological cardiac hypertrophy by activating UPRmt via the SIRT1/ATF5 axis

Pathological cardiac hypertrophy is an independent risk factor for heart failure. Disruption of mitochondrial protein homeostasis plays a key role in pathological cardiac hypertrophy; however, the mechanism of maintaining mitochondrial homeostasis in pathological cardiac hypertrophy remains unclear. In this study, we investigated the regulatory mechanisms of mitochondrial protein homeostasis in pathological cardiac hypertrophy. Wildtype (WT) mice, knockout mice, and mice transfected with lentivirus overexpressing mouse C1q-tumor necrosis factor-related protein-3 (CTRP3) underwent transverse aortic constriction or sham surgery. After 4 weeks, cardiac function, mitochondrial function, and oxidative stress injury were examined. For mechanistic studies, neonatal rat cardiomyocytes were treated with small interfering RNA or overexpression plasmids for the relevant genes. CTRP3 overexpression attenuated transverse aortic constriction (TAC) induced pathological cardiac hypertrophy, mitochondrial dysfunction, and oxidative stress injury compared to that in WT mice. TAC or Ang II resulted in compensatory activation of UPRmt, but this was not sufficient to counteract pathologic cardiac hypertrophy. CTRP3 overexpression further induced activation of UPRmt during pathologic cardiac hypertrophy and thereby alleviated pathologic cardiac hypertrophy, whereas CTRP3 knockout or knockdown inhibited UPRmt. ATF5 was a key regulatory molecule of UPRmt, as ATF5 knockout prevented the cardioprotective effect of CTRP3 in TAC mice. In vitro, SIRT1 was identified as a possible downstream CTRP3 effector molecule, and SIRT1 knockout blocked the cardioprotective effects of CTRP3. Our results also suggest that ATF5 may be regulated by SIRT1. Our study demonstrates that CTRP3 activates UPRmt via the SIRT1/ATF5 axis under pathological myocardial hypertrophy, thus attenuating mitochondrial dysfunction and oxidative stress injury.

Clinical Significance of Serum CTRP3 Level in the Prediction of Cardiac and Intestinal Mucosal Barrier Dysfunction in Patients with Severe Acute Pancreatitis.

C1q/tumor necrosis factor-related protein 3 (CTRP3) has been demonstrated to play a protective role in mice with severe acute pancreatitis (SAP). However, its clinical significance in SAP remains unknown. This study was conducted to explore the clinical values of serum C1q/tumor necrosis factor-related protein 3 (CTRP3) level in the diagnosis of cardiac dysfunction (CD) and intestinal mucosal barrier dysfunction (IMBD) in SAP. Through RT-qPCR, we observed decreased CTRP3 level in the serum of SAP patients. Serum CTRP3 level was correlated with C-reactive protein, procalcitonin, creatine, modified computed tomography severity index score, and Acute Physiology and Chronic Health Evaluation II score. The receiver-operating characteristic curve revealed that CTRP3 serum level < 1.005 was conducive to SAP diagnosis with 72.55% sensitivity and 60.00% specificity, CTRP3 < 0.8400 was conducive to CD diagnosis with 80.49% sensitivity and specificity 65.57%, CTRP3 < 0.8900 was conducive to IMBD diagnosis with 94.87% sensitivity and 63.49% specificity, and CTRP3 < 0.6250 was conducive to the diagnosis of CD and IMBD co-existence with 65.22% sensitivity and 89.87% specificity. Generally, CTRP3 was downregulated in the serum of SAP patients and served as a candidate biomarker for the diagnosis of SAP and SAP-induced CD and IMBD.

Hypermethylation of the CTRP9 promoter region promotes Hcy induced VSMC lipid deposition and foam cell formation via negatively regulating ER stress

To provide a theoretical basis for the prevention and treatment of atherosclerosis (As), the current study aimed to investigate the mechanism underlying the effect of homocysteine (Hcy) on inducing the lipid deposition and foam cell formation of the vascular smooth muscle cell (VSMC) via C1q/Tumor necrosis factor-related protein9 (CTRP9) promoter region Hypermethylation negative regulating endoplasmic reticulum stress (ERs). Therefore, apolipoprotein E deficient (ApoE−/−) mice were randomly divided into the control [ApoE−/− + normal diet (NC)] and high methionine [ApoE−/− + (normal diet supplemented with 1.7% methionine (HMD)] groups (n = 6 mice/group). Following feeding for 15 weeks, the serum levels of Homocysteine (Hcy), total cholesterol (TC), and triglyceride (TG) were measured using an automatic biochemical analyzer. HE and oil red O staining were performed on the aorta roots to observe the pathological changes. Additionally, immunofluorescence staining was performed to detect the protein expression levels of CTRP9, glucose-regulated protein 78 kD (GRP78), phosphorylated protein kinase RNA-like ER kinase (p-PERK), activating transcription factor 6a (ATF6a), phosphorylated inositol-requiring enzyme-1α (p-IRE1α), sterol regulatory element binding proteins-1c (SREBP1c) and sterol regulatory element binding proteins-2 (SREBP2) in VSMC derived from murine aortic roots. In vitro, VSMC was stimulated with 100 μmol/l Hcy. After transfection of plasmids with overexpression and interference of CTRP9, ERs agonist (TM) and inhibitor (4-PBA) were given to stimulate VSMC cells. HE staining and oil red O staining were used to observe the effect of Hcy stimulation on lipid deposition in VSMC. Additionally, The mRNA and protein expression levels of CTRP9, GRP78, PERK, ATF6a, IRE1α, SREBP1c, and SREBP2 in VSMC were detected by RT-qPCR and western blot analysis, respectively. Finally, The methylation modification of the CTRP9 promoter region has been studied. The NCBI database was used to search the promoter region of the CTRP9 gene, and CpG Island was used to predict the methylation site. After Hcy stimulation of VSMC, overexpression of DNMT1, and intervention with 5-Azc, assess the methylation level of the CTRP9 promoter through bisulfite sequencing PCR (BSP). The results showed that the serum levels of Hcy, TC, and TG in the ApoE−/− + HMD group were significantly increased compared with the ApoE−/− + NC group. In addition, HE staining and oil red O staining showed obvious AS plaque formation in the vessel wall, and a large amount of fat deposition in VSMC, thus indicating that the hyperhomocysteinemia As an animal model was successfully established. Furthermore, CTRP9 were downregulated, while GRP78, p-PERK, ATF6a, p-IRE1α, SREBP1c, SREBP2 was upregulated in aortic VSMC in the ApoE−/− + HMD group. Consistent with the in vivo results, Hcy can inhibit the expression of CTRP9 in VSMC and induce ERs and lipid deposition in VSMC. Meanwhile, the increased expression of CTRP9 can reduce ERs and protect the lipid deposition in Hcy induced VSMC. Furthermore, ERs can promote Hcy induced VSMC lipid deposition, inhibition of ERs can reduce Hcy induced VSMC lipid deposition, and CTRP9 may play a protective role in Hcy induced VSMC lipid deposition and foam cell transformation through negative regulation of ERs. In addition, The CTRP9 promoter in the Hcy group showed hypermethylation. At the same time as Hcy intervention, overexpression of DNMT1 increases the methylation level of the CTRP9 promoter, while 5-Azc can reduce the methylation level of the CTRP9 promoter. Finally, Hcy can up-regulate the expression of DNMT1 and down-regulate the expression of CTRP9. After overexpression of DNMT1, the expression of CTRP9 is further decreased. After 5-Azc inhibition of DNMT1, the expression of DNMT1 decreases, while the expression of CTRP9 increases. It is suggested that the molecular mechanism of Hcy inhibiting the expression of CTRP9 is related to the hypermethylation of the CTRP9 promoter induced by Hcy and regulated by DNMT1. 5-Azc can inhibit the expression of DNMT1 and reverse the regulatory effect of DNMT1 on CTRP9. Overall, the results of the present study suggested that Hcy induces DNA hypermethylation in the CTRP9 promoter region by up-regulating DNMT1 expression, and negatively regulates ERs mediated VSMC lipid deposition and foam cell formation. CTRP9 may potentially be a therapeutic target in the treatment of hyperhomocysteinemia and As.

Association of serum 25-hydroxyvitamin D3, fibroblast growth factor-23, and C1q/tumor necrosis factor-related protein-3 with coronary artery calcification in nondialysis chronic kidney disease patients

Objective To assess serum 25-hydroxyvitamin D3 (25(OH)D3), fibroblast growth factor 23 (FGF23), and C1q/tumor necrosis factor-related protein-3 (CTRP3) levels in nondialysis chronic kidney disease (CKD) patients and their relationship with coronary artery calcification (CAC). Methods One hundred and twenty-eight patients diagnosed with CKD were selected and all underwent cardiac computed tomography. CAC was assessed using the Agatston score, and coronary artery calcification score (CACs) >10 was identified as CAC. The differences in serum 25(OH)D3, FGF23, and CTRP3 levels between the CAC and non-CAC groups were analyzed. Their correlation with CACs was assessed by Spearman’s analysis, and logistic regression analysis was used to find risk factors for CAC. Results Compared to the non-CAC group, the CAC group was older (64.21 ± 9.68 years), with a higher percentage of hypertension (93.10%) and diabetes (63.80%) and higher levels of serum CTRP3 [1079.20 (644.4–1567.2) ng/mL]. However, there was no significant difference in serum 25(OH)D3 and FGF23 between these two groups. The high level CTRP3 group had a higher prevalence of CAC (61.5%). Logistic regression results showed that age, diabetes, decreased 25(OH)D3 (odds ratio (OR) = 0.95, p = .030) and high levels of CTRP3 (OR = 3.19, p = .022) were risk factors for CAC in nondialysis CKD patients. Conclusions Serum CTRP3 levels progressively increased with the progression of kidney disease, while 25(OH)D3 levels progressively decreased. Decreased 25(OH)D3 and high levels of CTRP3 are associated with CAC in patients with nondialysis CKD.

C1q/tumor necrosis factor-related protein-9 exerts antioxidant and anti-inflammatory effects on oxygen-glucose deprivation/reoxygenation-stimulated neurons by modulating the Akt-GSK-3β-Nrf2 cascade via AdipoR1

C1q/tumor necrosis factor-related protein-9 (CTRP9) is linked to diverse pathological conditions via the effects on cell apoptosis, inflammatory response, and oxidative stress. However, its functional relevance in ischemic brain injury is not well determined. The present work aimed to evaluate the role of CTRP9 in ischemia/reperfusion-associated neuronal injury using an in vitro model. The cultured cortical neurons were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to simulate ischemia/reperfusion in vitro. CTRP9 level was lowered in cultured neurons exposed to OGD/R. Neurons with overexpressed CTRP9 were resistant to OGD/R-elicited injuries, including neuronal apoptosis, oxidative stress, and pro-inflammatory response. Mechanism research revealed that CTRP9 could boost the activation of the nuclear factor erythroid 2-related factor (Nrf2) pathway associated with modulation of the Akt-glycogen synthase kinase-3β (GSK-3β) axis. CTRP9 regulated the transduction of the Akt-GSK-3β-Nrf2 cascade via adiponectin receptor 1 (AdipoR1). Restraining Nrf2 could diminish CTRP9-mediated neuroprotective effects in OGD/R-injured neurons. Altogether, these results confirmed that CTRP9 exerts a protective effect on OGD/R-injured neurons by modulating Akt-GSK-3β-Nrf2 cascade via AdipoR1. This work suggests a possible link between CTRP9 and ischemic brain injury.

Bone marrow-mesenchymal stem cells alleviate microglial Pyroptosis after intracerebral hemorrhage in rat by secreting C1q/tumor necrosis factor-related protein 3

BackgroundThere are no specific treatment methods for intracerebral hemorrhage (ICH). Neuroinflammation triggered by microglial pyroptosis plays an important role in ICH pathophysiology. Bone marrow mesenchymal stem cells (BMSCs) are widely used in the treatment of neurological diseases because of their paracrine function. In this study, we aimed to clarify whether BMSCs can alleviate microglial pyroptosis after ICH by secreting C1q/tumor necrosis factor-related protein 3 (CTRP3), a adiponectin paralog with established metabolic regulatory properties and neuroprotective effects. MethodsIn an in vitro study, microglia were stimulated with hemin for pyroptosis and then co-cultured with BMSCs, CTRP3, or CTRP3-small interfering RNA (siRNA)-BMSC; in an in vivo study, intracerebroventricular transplantation of BMSCs or siRNA-CTRP3-BMSCs was performed after ICH surgery. The expression of inflammation-related factors was detected by qRT-PCR and ELISA. Western blotting and immunofluorescence staining were performed to detect the expression of pyroptotic protein, and western blotting was used to detect the activation of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT) and splenic tyrosine kinase (Syk). Behavioral changes were detected 7 days after transplantation. ResultsELISA and qRT-PCR results showed that the production of inflammatory cytokines in hemin-stimulated microglia was significantly downregulated following pretreatment with BMSCs or CTRP3. The Caspase-1 activity assay kit and western blotting results showed that BMSCs attenuated microglial pyroptosis by secreting CTRP3. Furthermore, the modulation functions of BMSCs or CTRP3 involve the promotion of PI3K/AKT and inhibition of Syk signaling pathway activation. Neurological deficits, edema, and disruption of tight junction protein were completely alleviated, while inflammation-related factors and microglial pyroptosis after ICH were significantly downregulated after BMSCs administration. ConclusionBMSCs can inhibit neuroinflammation by inhibiting microglial pyroptosis, thus alleviate ICH symptoms, likely by suppressing the Syk signaling pathway while promoting the PI3K/AKT signaling pathway activation through producing CTRP3.

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.

Angiogenic adipokine C1q-TNF-related protein 9 ameliorates myocardial infarction via histone deacetylase 7-mediated MEF2 activation.

C1q/tumor necrosis factor-related protein 9 (CTRP9) is an adipokine and has high potential as a therapeutic target. However, the role of CTRP9 in cardiovascular disease pathogenesis remains unclear. We found CTRP9 to induce HDAC7 and p38 MAPK phosphorylation via tight regulation of AMPK in vascular endothelial cells, leading to angiogenesis through increased MEF2 activity. The expression of CTRP9 and atheroprotective MEF2 was decreased in plaque tissue of atherosclerotic patients and the ventricle of post-infarction mice. CTRP9 treatment inhibited the formation of atherosclerotic plaques in ApoE KO and CTRP9 KO mice. In addition, CTRP9 induced significant ischemic injury prevention in the post-MI mice. Clinically, serum CTRP9 levels were reduced in patients with MI compared with healthy controls. In summary, CTRP9 induces a vasoprotective response via the AMPK/HDAC7/p38 MAPK pathway in vascular endothelial cells, whereas its absence can contribute to atherosclerosis and MI. Hence, CTRP9 may represent a valuable therapeutic target and biomarker in cardiovascular diseases.

Correlation analysis of serum CTRP3 and PGC-1α expression with traumatic fracture healing

To investigate the relationship between serum C1q/tumor necrosis factor-related protein-3(CTRP3) and peroxisome proliferator-activated receptor γ coactivator-1α(PGC-1α) on predictive value of expression level on fracture healing. From January 2019 to January 2020, 80 patients with traumatic tibial plateau fractures were treated by internal fixation with support plates through the posterior approach of the knee joint. The patients were followed up for 12 months. According to the criteria for delayed fracture healing, the patients were divided into two groups:54 patients in fracture healing group included 24 males and 30 females, aged 29 to 75 years old with an average of (52.36±13.17) years;In the delayed healing group, there were 26 cases, 13 males and 13 females, aged from 29 to 75 with an average od (53.82±13.52) years. The serum levels of CTRP3, PGC-1αand 25 hydroxyvitamin D3[25(OH)D3] in patients with traumatic fracture were detected by enzyme-linked immunosorbent assay(ELISA);Blood phosphorus and calcium levels were measured by automatic biochemical analyzer, and the product of calcium and phosphorus was calculated;Pearson's method was used to analyze the correlation between serum CTRP3, PGC-1αand bone biochemical indexes in patients with delayed union one week after operation;The predictive value of serum levels of CTRP3 and PGC-1αon traumatic fracture healing was analyzed by receiver operating characteristic curve(ROC curve). PGC-1α, calcium phosphorus product and 25(OH)D3 in the fracture healing group were higher than those in the delayed healing group at 1 and 4 weeks after operation(P<0.05). Serum CTRP3 was positively correlated with PGC-1α(r=0.637, P<0.05) and positively correlated with calcium phosphorus product and 25(OH)D3(P<0.05). The areas under the curve(AUC) of serum ctrp3 and PGC-1α levels in predicting traumatic fracture healing were 0.845 and 0.855, respectively. The cutoff values were 188.678 pg/ml and 2.697 ng/ml, respectively. The specificity was 96.2% and 80.8%, and the sensitivity was 53.7% and 77.8%;The predicted AUC was 0.904, the specificity was 88.5%, and the sensitivity was 81.5%. The serum levels of CTRP3 and PGC-1 in patients with delayed union of traumatic fracture at 1 and 4 weeks after operation α The expression level is of certain reference value to predict the fracture healing status of patients.

Characteristics of the post-infarction period in obese patients after percutaneous coronary intervention

Annotation. The study on the metabolic profile in the long-term period after myocardial infarction with comorbidity is relevant. The aim of the work was to examine metabolic profile and echocardiographic parameters in patients with ST-elevation myocardial infarction (STEMI) and obesity following percutaneous coronary intervention (PCI) after a 1-year follow-up. A total of 60 patients with STEMI and obesity were examined. The first subgroup consisted of 20 patients with medicamentous therapy, and the second group – 38 patients with PCI. Adropin, irisin, fatty acid-binding protein 4 (FABP4), C1q/tumor necrosis factor-related protein-3 (CTRP3) were measured by the enzyme-linked immunosorbent assay. The statistical processing of the study results obtained was carried out using the software package “IBM SPPS Statistics 27.0”. The following parameters were increased in patients who received combined medicamentous and PCI therapy before and after the treatment (p&lt;0.05): end-diastolic size (EDS) (by 16.83% and 10.89%, respectively), end-diastolic volume (EDV) (by 45.95% and 18.92% respectively), end-systolic volume (ESV) (by 40.0% and 27.69%, respectively), stroke volume (SV) (by 33.85% and 18.46%, respectively), left ventricular myocardial mass index (LVMMI) (by 18.93% and 10.06%, respectively), adropin (by 27.13% and 47.21%, respectively), irisin (by 2.07 times and 2.75 times, respectively) and CTRP3 (by 15.98 % and 31.96%, respectively), while the following parameters were decreased: systolic blood pressure (by 16.0% and 16.67%, respectively), diastolic blood pressure (by 15.56% and 14.44%, respectively), insulin (by 40 .38% and 48.59%, respectively), glucose (by 10.97% and 15.74%, respectively), atherogenic index (by 6.03% and 12.33%, respectively). Thus, patients with post-infarction cardiosclerosis and obesity have been revealed with increased echocardiographic parameters and imbalanced energy and adipokine metabolism.

Astragaloside IV Regulates Insulin Resistance and Inflammatory Response of Adipocytes via Modulating CTRP3 and PI3K/AKT Signaling.

Emerging evidence showed that adipocytes are important regulators in controlling insulin resistance in type 2 diabetes mellitus (T2DM). So far, compounds isolated from natural plants have been widely studied for their roles in alleviating T2DM-associated complications. This work evaluated the actions of astragaloside IV (AS-IV) on insulin resistance and inflammatory biomarker expression in adipocytes and explored the potential mechanisms. Glucose consumption of the adipocytes was determined by a glucose assay kit; the mRNA expression levels of glucose transporter type 4 (GLUT-4), interleukin-6 (IL-6), TNF-α and C1q tumor necrosis factor-related protein 3 (CTRP3) were measured by quantitative real-time PCR (qRT-PCR); the protein levels were determined by western blot assay and enzyme-linked immunosorbent assay. AS-IV concentration-dependently increased glucose consumption in the insulin resistance adipocytes. Further qRT-PCR results showed that AS-IV concentration-dependently reduced adipocyte IL-6 and TNF-α expression. Moreover, GLUT-4 expression in adipocytes was also significantly upregulated by AS-IV. Furthermore, we found that AS-IV concentration-dependently increased CTRP3 expression in adipocytes. CTRP3 silence decreased glucose consumption, upregulated IL-6 and TNF-α expression and downregulated GLUT-4 mRNA expression in 200µM AS-IV-treated adipocytes. Moreover, AS-IV treatment enhanced the activity of phosphoinositide 3-kinase (PI3K)/AKT signaling in adipocytes, which was markedly attenuated by CTRP3 silencing. Importantly, inhibition of PI3K/AKT signaling also attenuated AS-IV induced an increase in glucose consumption and GLUT-4 expression and a decrease in IL-6 and TNF-α expression of adipocytes. Collectively, our data indicated that AS-IV attenuated insulin resistance and inflammation in adipocytes via targeting CTRP3/PI3K/Akt signaling.

Circulating CTRP9 Is Associated With Severity of Systemic Sclerosis-Associated Interstitial Lung Disease.

While interstitial lung disease (ILD) is the leading cause of morbidity and mortality in systemic sclerosis (SSc), there remains a paucity of predictive markers to assess disease progression. We previously demonstrated that adipose tissue metabolism and adipokine homeostasis is dysregulated in SSc. The present study was undertaken to determine the association and predictive ability of the novel adipokine C1q/tumor necrosis factor-related protein 9 (CTRP9) for SSc-associated ILD. We performed a retrospective longitudinal study utilizing the Northwestern Scleroderma Program Patient Registry and Biorepository. Serum levels of CTRP9 were measured in 110 SSc patients at baseline, and demographic, clinical, and pulmonary function test data were collected in 12-month intervals to 48 months. Longitudinal trajectory of forced vital capacity percent predicted (FVC%) was used as a primary outcome measure. We utilized a mixed model to compare trajectories of lung function by CTRP9 groups and performed latent trajectory analysis to accommodate for heterogeneity. In cross-sectional analysis, elevated circulating CTRP9 was associated with significantly lower FVC% at baseline (72% ± 17 versus 80% ± 18; P=0.02) and 48 months (68 ± 19 versus 84 ± 18; P=0.001). In mixed model analysis, high CTRP9 was associated with worse lung function but not with a different trajectory (P=0.23). In contrast, low CTRP9 identified patients with stability of lung disease with reasonable accuracy (sensitivity 73%). Latent trajectory analysis confirmed the association of lower CTRP9 with higher FVC%. Higher circulating CTRP9 associated with worse pulmonary function, while low CTRP9 identified patients with lung disease stability over time. These findings suggest that CTRP9 may be a potential biomarker in SSc-associated ILD.

Expression of Serum Omentin, CTRP9, and Vaspin in Patients with Polycystic Ovary Syndrome.

Objective To explore the relationship between serum omentin, C1q/tumor necrosis factor-related protein-9 (CTRP9), and visceral fat-specific serine protease inhibitor (vaspin) levels in different phenotypes in patients with polycystic ovary syndrome (PCOS). Methods One hundred PCOS patients treated at our hospital's clinic of reproductive medicine were chosen and included into the research group, and 100 healthy women who came for physical examination during the same time period were included into the control group. According to the definition of obesity by the WHO (body mass index (BMI) ≥25 kg/m2), 100 patients with PCOS were equally divided into obese (study group A) and nonobese (study group B) groups. 100 healthy women were also divided into obese (control group A) and nonobese (control group B) groups with 50 patients each. Comparison among the 4 groups was performed in factors/indicators including the serum omentin, CTRP9, and vaspin levels and biochemical indexes (triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), fasting insulin (FINS), total testosterone, and homeostasis model assessment of insulin resistance (HOMA-IR) levels), and the correlation analysis was conducted with omentin, CTRP9, and vaspin. Results There was no significant difference in age, TG, TC, and LDL-C among the 4 groups (P > 0.05). The BMI, WHR, HDL-C, and omentin of the obese phenotype were significantly different from those of the nonobese phenotype (P < 0.05). Among the four groups, FINS, HOMA-IR, and vaspin in group A (obesity) was the highest, and the control group B (nonobese) was the lowest. There was no significant difference in the levels of study group B (nonobese) and control group A (obesity). The level of CTRP9 in the study group was significantly lower than that in the control group (P < 0.05). Taking serum omentin, CTRP9, and vaspin levels of patients in the study group as dependent variables, Pearson correlation analysis showed that the omentin level was negatively correlated with BMI, WHR, FINS, TG, TC, LDL-C, HOMA-IR, and TT levels (P < 0.05) and was positively correlated with the HDL-C level (P < 0.05); CTRP9 level was negatively correlated with BMI, TC, and HOMA-IR (P < 0.05) and was not correlated with age, WHR, FINS, TG, HDL-C, LDL-C, HOMA-IR, and TT levels. The vaspin level was positively correlated with BMI, WHR, FINS, TG, TC, LDL-C, HOMA-IR, and TT levels (P < 0.05) and negatively correlated with HDL-C levels (P < 0.05) and was not correlated with age. Conclusion When compared with healthy people, PCOS patients have higher serum vaspin levels and lower CTRP9 levels; BMI, TC, LDL-C, FINS, TG, total testosterone, HDL-C levels, waist-to-hip ratio, and HOMA-IR are all closely related to serum vaspin and CTRP9 levels; increasing serum CTRP9 levels and decreasing vaspin levels help to slow progress and promote prognosis of the disease. Serum omentin level is connected with the obesity index but not with PCOS.

Adipokines, adiposity, and atherosclerosis.

Characterized by a surplus of whole-body adiposity, obesity is strongly associated with the prognosis of atherosclerosis, a hallmark of coronary artery disease (CAD) and the major contributor to cardiovascular disease (CVD) mortality. Adipose tissue serves a primary role as a lipid-storage organ, secreting cytokines known as adipokines that affect whole-body metabolism, inflammation, and endocrine functions. Emerging evidence suggests that adipokines can play important roles in atherosclerosis development, progression, as well as regression. Here, we review the versatile functions of various adipokines in atherosclerosis and divide these respective functions into three major groups: protective, deteriorative, and undefined. The protective adipokines represented here are adiponectin, fibroblast growth factor 21 (FGF-21), C1q tumor necrosis factor-related protein 9 (CTRP9), and progranulin, while the deteriorative adipokines listed include leptin, chemerin, resistin, Interleukin- 6 (IL-6), and more, with additional adipokines that have unclear roles denoted as undefined adipokines. Comprehensively categorizing adipokines in the context of atherosclerosis can help elucidate the various pathways involved and potentially pave novel therapeutic approaches to treat CVDs.

Relationship between Coronary VH-IVUS Plaque Characteristics and CTRP9, SAA, and Hcy in Patients with Coronary Heart Disease.

Coronary heart disease is a common disease threatening human health. In recent years, the incidence of coronary heart disease in China has only increased. It is the most common type of organ disease caused by coronary atherosclerosis, which is observed in the aorta, carotid artery, and femoral artery. The main clinical treatments for coronary heart disease include coronary artery bypass grafting and drug treatment. To investigate the relationship of serum adipocytokine C1q/tumor necrosis factor-related protein 9 (CTRP9), amyloid A (SAA), and plasma homocysteine (Hcy) with coronary artery plaque characteristics in patients with coronary heart disease. Overall, 143 patients with coronary heart disease admitted to our hospital are selected as research participants. The proportion of plaque necrosis core volume is higher in group A than in group B, and the differences are statistically significant (P < 0.05). In group A, necrotic core volume percentage is negatively correlated with CTRP9 levels and positively correlated with SAA and Hcy levels (P < 0.05). Logistic regression analysis revealed that increased systolic blood pressure, increased number of coronary artery lesions, decreased CTRP9 levels, and increased Hcy levels are independent risk factors for thin fibrous cap atherosclerosis in patients with coronary heart disease (P < 0.05). Decreased CTRP9 levels and increased Hcy levels are independent risk factors for coronary heart disease patients with thin fibrous cap atherosclerosis.

C1q/Tumor Necrosis Factor-Related Protein 9: Basics and Therapeutic Potentials.

C1q/tumor necrosis factor-related protein 9 (CTRP9) is a newly discovered adipokine that is the closest paralog of adiponectin. Proteolytic cleavage of CTRP9 leads to the release of the globular domain (gCTRP9), which serves as the major circulating subtype. After binding with adiponectin receptor 1 (AdipoR1) and N-cadherin, CTRP9 activates various signaling pathways to regulate glucose and lipid metabolism, vasodilation and cell differentiation. Throughout human development and adult life, CTRP9 controls many biological phenomena. simultaneously, abnormal gene or protein expression of CTRP9 is accompanied by a wide range of human pathological phenomena. In this review, we briefly introduce CTRP9 and its associated signaling pathways and physiological functions, which may be helpful in the understanding of the occurrence of diseases. Moreover, we summarize the broader research prospects of CTRP9 and advances in therapeutic intervention. In recent years, CTRP9 has attracted extensive attention due to its role in the pathogenesis of various diseases, providing further avenues for its exploitation as a potential biomarker or therapeutic target.

Serum CTRP9 Reflects Coronary Collateralization in Nondiabetic Patients with Obstructive Coronary Artery Disease

Aim To explore the association between the serum C1q/tumor necrosis factor-related protein 9 (CTRP9) and the formation of coronary collateral circulation in obstructive coronary artery disease (CAD). Methods A total of 206 patients who underwent coronary angiography at Beijing Anzhen Hospital and had epicardial arteries with at least 95% stenotic lesion were enrolled. Blood samples were taken after an overnight fasting before the coronary angiography. Serum CTRP9 level was measured using commercial enzyme linked immunosorbent assay (ELISA) kit. The development of coronary collateralization was determined according to the Rentrop classification system. Rentrop score 0-1 was graded as impaired or less-developed coronary collateralization (n = 54) while the Rentrop score 2-3 was defined as well-developed collateralization (n = 152). Results Serum CTRP9 level was significantly higher in well-developed collateralization and diabetes groups (P < 0.001). To further explore the association between the CTRP9 level and coronary collateralization, the enrolled participants were divided into 3 tertiles according to the serum CTRP9 level. The prevalence of impaired coronary collateralization decreased stepwise with the increasing CTRP9 tertiles (P for trend <0.001). Multivariate regression analysis showed that the serum CTRP9 is independently associated with well-developed collateralization, with an OR (95% CI) of 4.49 (1.75-11.55) and 8.98 (2.75-29.35) in the tertiles 2 and 3, respectively. The following subgroup and receiver-operating characteristic (ROC) analysis also indicated that the diagnostic value of serum CTRP9 level for detecting the formation of collateralization persisted only in nondiabetic participants. Lastly, adding the serum CTRP9 into the baseline model could increase the diagnostic value of established model consisting of relevant factor for the discrimination of well-developed collateralization only in the nondiabetic group (P = 0.046). Conclusions Serum CTRP9 reflects well-developed coronary collateralization in nondiabetic patients with obstructive CAD, and CTRP9 level ≥ 1.217 indicated a greater chance to forming well-developed coronary collaterals.

CTRP3 alleviates myocardial ischemia/reperfusion injury in mice through activating LAMP1/JIP2/JNK pathway

Myocardial ischemia reperfusion (I/R) injury is an important complication of myocardial infarction reperfusion therapy, and no effective treatment has been identified. Based on preexisting evidence, C1q/tumor necrosis factor-related protein 3 (CTRP3) has been reported to be closely associated with myocardial dysfunction. In this study, we found that CTRP3 was downregulated in acute coronary syndrome (ACS) patients and myocardial I/R mice. Silence of CTRP3 aggravated cardiac systolic function due to I/R of mice, while CTRP3 overexpression ameliorated cardiac function. Moreover, overexpression of CTRP3 improved I/R inhibitory effects on the levels of creatinine phosphokinase (CPK), lactate dehydrogenase (LDH) and cardiac troponin-I (cTn-I), myocardial infarction area, the intensity of the 3-nitrotyrosine (3-NT), apoptosis and protein levels of LAMP1, JNK-Interacting Protein-2 (JIP-2) and JNK, while these effects could be exacerbated by downregulation of CTRP3. Co-IP experiments could identify physical interactions between CTRP3 and lysosomal-associated membrane protein 1 (LAMP1) and Numb and JIP2. LAMP1 silence aggravated the inhibition effects of I/R on JIP2 and JNK protein expression, CPK, LDH and cTn-I levels and caspase-3 activity, while overexpression of LAMP1 recovered these inhibition effects of I/R. JNK inhibitor (SP600125) could reverse the inhibitory effects of CTRP3 overexpression on CPK, LDH, cTn-I, myocardial infarction, strong positive staining for 3-NT and apoptosis. These findings demonstrated that CTRP3 protected against injury caused by myocardial I/R through activating LAMP1/JIP2/JNK pathway to attenuate myocardial injury, improve left ventricular function, decrease myocardial infarction, and reduce myocardial apoptosis.