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

Photosymbiosis shaped animal genome architecture and gene evolution as revealed in giant clams

Symbioses are major drivers of organismal diversification and phenotypic innovation. However, how long-term symbioses shape whole genome evolution in metazoans is still underexplored. Here, we use a giant clam (Tridacna maxima) genome to demonstrate how symbiosis has left complex signatures in an animal's genome. Giant clams thrive in oligotrophic waters by forming a remarkable association with photosymbiotic dinoflagellate algae. Genome-based demographic inferences uncover a tight correlation between T. maxima global population change and major paleoclimate and habitat shifts, revealing how abiotic and biotic factors may dictate T. maxima microevolution. Comparative analyses reveal genomic features that may be symbiosis-driven, including expansion and contraction of immunity-related gene families and a large proportion of lineage-specific genes. Strikingly, about 70% of the genome is composed of repetitive elements, especially transposable elements, most likely resulting from a symbiosis-adapted immune system. This work greatly enhances our understanding of genomic drivers of symbiosis that underlie metazoan evolution and diversification.

The Potential Role of Cardiokines in Heart and Kidney Diseases

As the engine that maintains blood circulation, the heart is also an endocrine organ that regulates the function of distant target organs by secreting a series of cardiokines. As endocrine factors, cardiokines play an indispensable role in maintaining the homeostasis of the heart and other organs. Here, we summarize some of the cardiokines that have been defined thus far and explore their roles in heart and kidney diseases. Finally, we propose that cardiokines may be a potential therapeutic target for kidney diseases.

Cardiac-derived CTRP9 mediates the protection of empagliflozin against diabetes-induced male subfertility in mice

Previous studies have shown beneficial effects of empagliflozin (Empa), a selective inhibitor of the sodium-glucose cotransporter 2 (SGLT2), on diabetes and cardiovascular outcomes in patients with diabetes. However, whether Empa could ameliorate diabetes mellitus (DM)-induced male spermatogenesis dysfunction remains unclear. Our study aimed to investigate the effect of Empa in the development of DM-induced male spermatogenesis dysfunction and to reveal the molecular mechanisms. DM mice were orally treated with Empa to investigate the effects of Empa on DM-induced male mice spermatogenesis dysfunction. We employed a cardiac-specific C1q/tumor necrosis factor-related protein 9 (CTRP9)-deficient mouse model and a cardiac-specific CTRP9 overexpression mouse model to investigate its role in the protection of Empa against diabetes-induced male subfertility. We found that Empa treatment could improve DM-induced male mice subfertility. Interestingly, we discovered that cardiac-derived CTRP9 was decreased in DM mice and this decrease was prevented by Empa treatment. A CTRP9 blocking antibody or cardiac-specific depletion of CTRP9 abolished the protection of Empa on DM-induced male subfertility. Cardiac-specific CTRP9 overexpression ameliorated DM-induced male subfertility. Mechanistically, we identified that cardiac-derived CTRP9 increased steroidogenesis in mice with diabetes in a PKA-dependent manner. We also provided direct evidence that activation of AMP activated protein kinase α (AMPKα)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signalling pathway by CTRP9 was responsible for the attenuation of ferroptosis in Leydig cells. In conclusions, we supposed that Empa was a potential therapeutic agent against DM-induced male mice spermatogenesis dysfunction.

CTRP9: An Anti-Atherosclerotic Factor in ApoE Knockout Mice through Oxidative Stress Inhibition

BACKGROUND

C1q/tumor necrosis factor-related protein-9 (CTRP9) is critically involved in the pathophysiology of metabolic and cardiovascular disorders. This investigation aimed to clarify the mechanism underlying the role of CTRP9 in atherosclerosis in apolipoprotein E (ApoE) knockout (KO) mice.

METHODS

ApoE KO mice were fed a Western diet and injected with a virus which resulted in CTRP9 overexpression or knockdown for 12 weeks. The plasma lipid levels and atherosclerotic plaque areas were measured after the mice were euthanized. Aortas were isolated, and RNA sequencing was performed to identify the differentially expressed genes and related signaling pathways. Finally, plasma oxidative stress factors were measured to demonstrate the reliability of the RNA sequencing results.

RESULTS

The plasma lipid levels in the CTRP9 overexpression group did not significantly differ from those in the green fluorescence protein (GFP) group. Markablely, CTRP9 overexpression inhibited atherosclerotic plaque formation in ApoE KO mice, whereas CTRP9 knockdown promoted plaque formation. RNA sequencing analysis identified 3485 differentially expressed genes that were prominently enriched across 55 signaling pathways. Additionally, plasma oxidative stress factors were significantly reduced after CTRP9 overexpression, whereas these factors were increased after CTRP9 knockdown, which was consistent with the results of the RNA sequencing analysis.

CONCLUSIONS

These findings demonstrated that CTRP9 alleviated inflammation and cholesterol metabolism, which reduced oxidative stress in an atherosclerotic animal model. These beneficial effects may mediate the suppression of lesion development in the aorta.

Effects of 12-weeks resistance training and vitamin E supplementation on aminotransferases, CTRP-2, and CTRP-9 levels in males with nonalcoholic fatty liver disease: a double-blind, randomized trial

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) involves excessive liver fat accumulation and is closely linked to oxidative stress, which contributes to liver inflammation and damage. This study aimed to evaluate how interventions such as resistance training (RT) and vitamin E supplementation (VES) can modulate markers of NAFLD and key proteins regulating glucose and lipid metabolism, such as C1Q/TNF-related proteins (CTRPs).

METHODS

Forty participants with NAFLD (mean age: 32.4 ± 8.2 years) were randomly assigned to one of four groups for 12 weeks: placebo (PLB), VES, PLB + RT, and VES + RT. VES was administered at 800 IU/day in a double-blind manner. The RT regimen included eight exercises at 60-80% of one-repetition maximum (1RM), with three sets of 8-12 repetitions, performed three times per week. Pre- and post-intervention assessments included body composition, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lipid profile, glycemic control, CTRP-2, CTRP-9, and 1RM evaluations.

RESULTS

Following the interventions, there was a significant improvement in body composition, lipid profile, glycemic control, and 1RM indices in the exercise groups compared to non-exercise groups (p < 0.05). AST and ALT levels decreased in all groups (p < 0.05) compared to the PLB group. There was also a significant difference between the VES + RT group and both the VES and PLB + RT groups (p < 0.05). CTRP-2 and CTRP-9 levels decreased in the exercise groups compared to non-exercise groups (p < 0.05), and their changes showed a marked correlation with body composition, lipid profile, and glycemic control indices (p < 0.05).

CONCLUSIONS

This study highlights the benefits of RT on various health parameters among NAFLD patients. While adding VES to RT resulted in greater decreases in aminotransferases, it did not provide further improvements in other variables. Additionally, enhancements in body composition, lipid profile, and glycemic control indices were possibly associated with decreased levels of CTRPs.

TRIAL REGISTRATION

Registered retrospectively in the Iranian Registry of Clinical Trials (IRCT20220601055056N1) on December 21, 2023. Access at https://irct.behdasht.gov.ir/trial/69231 .

Knockout of C1q/tumor necrosis factor-related protein-9 aggravates cardiac fibrosis in diabetic mice by regulating YAP-mediated autophagy

Introduction

Diabetic cardiomyopathy (DCM) is predominantly distinguished by impairment in ventricular function and myocardial fibrosis. Previous studies revealed the cardioprotective properties of C1q/tumor necrosis factor-related protein 9 (CTRP9). However, whether CTRP9 affects diabetic myocardial fibrosis and its underlying mechanisms remains unclear.

Methods

We developed a type 1 diabetes (T1DM) model in CTRP9-KO mice via streptozotocin (STZ) induction to examine cardiac function, histopathology, fibrosis extent, Yes-associated protein (YAP) expression, and the expression of markers for autophagy such LC3-II and p62. Additionally, we analyzed the direct impact of CTRP9 on high glucose (HG)-induced transdifferentiation, autophagic activity, and YAP protein levels in cardiac fibroblasts.

Results

In diabetic mice, CTRP9 expression was decreased in the heart. The absence of CTRP9 aggravated cardiac dysfunction and fibrosis in mice with diabetes, alongside increased YAP expression and impaired autophagy. In vitro, HG induced the activation of myocardial fibroblasts, which demonstrated elevated cell proliferation, collagen production, and α-smooth muscle actin (α-SMA) expression. CTRP9 countered these adverse effects by restoring autophagy and reducing YAP protein levels in cardiac fibroblasts. Notably, the protective effects of CTRP9 were negated by the inhibition of autophagy with chloroquine (CQ) or by YAP overexpression through plasmid intervention. Notably, the protective effect of CTRP9 was negated by inhibition of autophagy caused by chloroquine (CQ) or plasmid intervention with YAP overexpression.

Discussion

Our findings suggest that CTRP9 can enhance cardiac function and mitigate cardiac remodeling in DCM through the regulation of YAP-mediated autophagy. CTRP9 holds promise as a potential candidate for pharmacotherapy in managing diabetic cardiac fibrosis.

Putative therapeutic impacts of cardiac CTRP9 in ischaemia/reperfusion injury

Recently, cytokines belonging to C1q/tumour necrosis factor‐related proteins (CTRPs) superfamily have attracted increasing attention due to multiple metabolic functions and desirable anti‐inflammatory effects. These various molecular effectors exhibit key roles upon the onset of cardiovascular diseases, making them novel adipo/cardiokines. This review article aimed to highlight recent findings correlated with therapeutic effects and additional mechanisms specific to the CTRP9, particularly in cardiac ischaemia/reperfusion injury (IRI). Besides, the network of the CTPR9 signalling pathway and its possible relationship with IRI were discussed. Together, the discovery of all involved underlying mechanisms could shed light to alleviate the pathological sequelae after the occurrence of IRI.