CCN1 triggers adaptive autophagy in cardiomyocytes to curb its apoptotic activities

Hypoxia-initiated Cysteine-rich protein 61 secretion promotes chemoresistance of acute B lymphoblastic leukemia cells

The drug resistance is a major obstacle in acute B-lymphoblastic leukemia (B-ALL) treatment. Our previous study has indicated that increased levels of Cysteine-rich protein 61 (Cyr61) in the bone marrow can mitigate the chemosensitivity of B-ALL cells, though the specific source of Cyr61 in the bone marrow remains unknown. In this study, we aimed to investigate whether hypoxia can induce Cyr61 production in B-ALL cells, delineates the underlying mechanisms, and evaluates the effect of Cyr61 on the chemosensitivity of B-ALL cells under hypoxia conditions. The results indicate that hypoxia promotes Cyr61 production in B-ALL cells by activating the NF-κB pathway. Increased Cyr61 expression appears to reduce the chemosensitivity of B-ALL cell to vincristine (VCR) and daunorubicin (DNR) through autophagy under hypoxia. Notably, inhibition of Cyr61 restores the chemosensitivity of B-ALL cells to both chemotherapeutic agents. This study is the first time to report that hypoxia decreases the chemosensitivity of B-ALL cells by inducing Cyr61 production, suggesting that targeting Cyr61 or its associated pathways could potentially improve the clinical response of B-ALL patients.

Targeting HDAC6 to treat heart failure with preserved ejection fraction in mice

Heart failure with preserved ejection fraction (HFpEF) poses therapeutic challenges due to the limited treatment options. Building upon our previous research that demonstrates the efficacy of histone deacetylase 6 (HDAC6) inhibition in a genetic cardiomyopathy model, we investigate HDAC6's role in HFpEF due to their shared mechanisms of inflammation and metabolism. Here, we show that inhibiting HDAC6 with TYA-018 effectively reverses established heart failure and its associated symptoms in male HFpEF mouse models. Additionally, in male mice lacking Hdac6 gene, HFpEF progression is delayed and they are resistant to TYA-018's effects. The efficacy of TYA-018 is comparable to a sodium-glucose cotransporter 2 (SGLT2) inhibitor, and the combination shows enhanced effects. Mechanistically, TYA-018 restores gene expression related to hypertrophy, fibrosis, and mitochondrial energy production in HFpEF heart tissues. Furthermore, TYA-018 also inhibits activation of human cardiac fibroblasts and enhances mitochondrial respiratory capacity in cardiomyocytes. In this work, our findings show that HDAC6 impacts on heart pathophysiology and is a promising target for HFpEF treatment.

Decrease of Cellular Communication Network Factor 1 (CCN1) Attenuates PTZ-Kindled Epilepsy in Mice

To investigate the molecular mechanism of communication network factor 1 (CCN1) regulating pentylenetetrazol (PTZ)-induced epileptogenesis, deepen the understanding of epilepsy seizure pathogenesis, and provide new drug action targets for its clinical prevention and treatment. Differentially expressed genes (DEGs) on microarrays GSE47516 and GSE88992 were analyzed online using GEO2R. Pathway enrichment and protein-protein interaction network (PPI) analysis of DEGs were carried out using Metascape. Brain tissue samples of severe traumatic brain injury patients (named Healthy group) and refractory epilepsy patients (named Epilepsy group) were obtained and analyzed by qRT-PCR and immunohistochemistry (IHC) staining. A PTZ-induced epilepsy mouse model was established and verified. Morphological changes of neurons in mouse brain tissue were detected using hematoxylin and eosin (HE) staining. qRT-PCR was conducted to detect the mRNA expressions of apoptosis-associated proteins Bax, Caspase-3 and bcl2. TUNEL staining was performed to detect brain neuron apoptosis. The levels of myocardial enzymology, GSH, MDA and ROS in blood of mouse were detected by biochemical assay. CCN1 expression was increased in epilepsy brain tissue samples. CCN1 decreasing effectively prolongs seizure incubation period and decreases seizure duration. Silencing of CCN1 also reduces neuronal damage and apoptosis, decreases mRNA and protein expression of proapoptotic proteins Bax and Caspase-3, increases mRNA expression of antiapoptotic protein Bcl2. Moreover, decrease of CCN1 decreases myocardial enzymatic indexes CK and CK-MB levels, reduces myocardial tissue hemorrhage, and relieves oxidative stress response in hippocampal and myocardial tissue. CCN1 expression is increased in epileptic samples. CCN1 decreasing protects brain tissue by attenuating oxidative stress and inhibiting neuronal apoptosis triggered by PTZ injection, which probably by regulating Nrf2/HO-1 pathway.

A 4D transcriptomic map for the evolution of multiple sclerosis-like lesions in the marmoset brain

Single-time-point histopathological studies on postmortem multiple sclerosis (MS) tissue fail to capture lesion evolution dynamics, posing challenges for therapy development targeting development and repair of focal inflammatory demyelination. To close this gap, we studied experimental autoimmune encephalitis (EAE) in the common marmoset, the most faithful animal model of these processes. Using MRI-informed RNA profiling, we analyzed ~600,000 single-nucleus and ~55,000 spatial transcriptomes, comparing them against EAE inoculation status, longitudinal radiological signals, and histopathological features. We categorized 5 groups of microenvironments pertinent to neural function, immune and glial responses, tissue destruction and repair, and regulatory network at brain borders. Exploring perilesional microenvironment diversity, we uncovered central roles of EAE-associated astrocytes, oligodendrocyte precursor cells, and ependyma in lesion formation and resolution. We pinpointed imaging and molecular features capturing the pathological trajectory of WM, offering potential for assessing treatment outcomes using marmoset as a platform.

The regulation and functions of the matricellular CCN proteins induced by shear stress

Shear stress is a frictional drag generated by the flow of fluid, such as blood or interstitial fluid, and plays a critical role in regulating cellular gene expression and functional phenotype. The matricellular CCN family proteins are dynamically regulated by shear stress of different flow patterns, and their expression significantly alters the microenvironment of cells. Secreted CCN proteins mainly bind to several cell surface integrin receptors to mediate their diverse functions in regulating cell survival, function, and behavior. Gene-knockout studies indicate major functions of CCN proteins in the cardiovascular and skeletal systems, the two primary systems in which CCN expressions are regulated by shear stress. In the cardiovascular system, the endothelium is directly exposed to vascular shear stress. Unidirectional laminar blood flow generates laminar shear stress, which promotes a mature endothelial phenotype and upregulates anti-inflammatory CCN3 expression. In contrast, disturbed flow generates oscillatory shear stress, which induces endothelial dysfunction through the induction of CCN1 and CCN2. Shear-induced CCN1 binds to integrin α6β1 and promotes superoxide production, NF-κB activation, and inflammatory gene expression in endothelial cells. Although the interaction between shear stress and CCN4-6 is not clear, CCN 4 exhibits a proinflammatory property and CCN5 inhibits vascular cell growth and migration. The crucial roles of CCN proteins in cardiovascular development, homeostasis, and disease are evident but not fully understood. In the skeletal system, mechanical loading on bone generates shear stress from interstitial fluid in the lacuna-canalicular system and promotes osteoblast differentiation and bone formation. CCN1 and CCN2 are induced and potentially mediate fluid shear stress mechanosensing in osteocytes. However, the exact roles of interstitial shear stress-induced CCN1 and CCN2 in bone are still not clear. In contrast to other CCN family proteins, CCN3 inhibits osteoblast differentiation, although its regulation by interstitial shear stress in osteocytes has not been reported. The induction of CCN proteins by shear stress in bone and their functions remain largely unknown and merit further investigation. This review discusses the expression and functions of CCN proteins regulated by shear stress in physiological conditions, diseases, and cell culture models. The roles between CCN family proteins can be compensatory or counteractive in tissue remodeling and homeostasis.

Astragaloside IV improves pulmonary arterial hypertension by increasing the expression of CCN1 and activating the ERK1/2 pathway

The aim of the present study was to investigate the underlying mechanism of AS-IV and CCN1 in PAH and to evaluate whether the protective effect of AS-IV against PAH is associated with CCN1 and its related signalling pathway. In vivo, male SD rats were intraperitoneally injected with monocrotaline (MCT, 60 mg/kg) or exposed to hypoxia (10% oxygen) and gavaged with AS-IV (20, 40 and 80 mg/kg/day) to create a PAH model. In vitro, human pulmonary artery endothelial cells (hPAECs) were exposed to hypoxia (3% oxygen) or monocrotaline pyrrole (MCTP, 60 μg/mL) and treated with AS-IV (10, 20 and 40 μM), EGF (10 nM, ERK agonist), small interfering CCN1 (CCN1 siRNA) and recombinant CCN1 protein (rCCN1, 100 ng/mL). We identified the differences in the expression of genes in the lung tissues of PAH rats by proteomics. At the same time, we dynamically detected the expression of CCN1 by Western blot both in vivo and in vitro. The Western blot experimental results showed that the expression of CCN1 increased in the early stage of PAH and decreased in the advanced stage of PAH. The results showed that compared with the control group, MCT- and hypoxia-induced increased the hemodynamic parameters and apoptosis. AS-IV can improve PAH, as characterized by decreased hemodynamic parameters, vascular wall area ratio (WA%), vascular wall thickness ratio (WT%) and α-SMA expression and inhibition of cell apoptosis. Moreover, the improvement of PAH by AS-IV was accompanied by increased CCN1 expression, which activated the ERK1/2 signalling pathway. Meanwhile, CCN1 and p-ERK1/2 were inhibited by siCCN1 and promoted by rCCN1. EGF not only activated the ERK1/2 signalling pathway but also induced the expression of CCN1. In conclusion, AS-IV improves PAH by increasing the expression of CCN1 and activating the ERK1/2 signalling pathway. The results of our study provide a theoretical basis for additional study on the protective effect of AS-IV against PAH.

MOTS-c repairs myocardial damage by inhibiting the CCN1/ERK1/2/EGR1 pathway in diabetic rats

Cardiac structure remodeling and dysfunction are common complications of diabetes, often leading to serious cardiovascular events. MOTS-c, a mitochondria-derived peptide, regulates metabolic homeostasis by accelerating glucose uptake and improving insulin sensitivity. Plasma levels of MOTS-c are decreased in patients with diabetes. MOTS-c can improve vascular endothelial function, making it a novel therapeutic target for the cardiovascular complications of diabetes. We investigated the effects of MOTS-c on cardiac structure and function and analyzed transcriptomic characteristics in diabetic rats. Our results indicate that treatment with MOTS-c for 8-week repaired myocardial mitochondrial damage and preserved cardiac systolic and diastolic function. Transcriptomic analysis revealed that MOTS-c altered 47 disease causing genes. Functional enrichment analysis indicated MOTS-c attenuated diabetic heart disease involved apoptosis, immunoregulation, angiogenesis and fatty acid metabolism. Moreover, MOTS-c reduced myocardial apoptosis by downregulating CCN1 genes and thereby inhibiting the activation of ERK1/2 and the expression of its downstream EGR1 gene. Our findings identify potential therapeutic targets for the treatment of T2D and diabetic cardiomyopathy.

Cellular communication network factor 1 interlinks autophagy and ERK signaling to promote osteogenesis of periodontal ligament stem cells

OBJECTIVES

To investigate the effects of cellular communication network factor 1 (CCN1), a critical matricellular protein, on alveolar bone regeneration, and to elucidate the underlying molecular mechanism.

BACKGROUND

In the process of orthodontic tooth movement, bone deposition on the tension side of human periodontal ligament stem cells (hPDLSCs) ensured high efficiency and long-term stability of the treatment. The matricellular protein CCN1 is responsive to mechanical stimulation, exhibiting important tasks in bone homoeostasis. However, the role and mechanism of CCN1 on alveolar bone remodeling of hPDLSCs remains unclear.

METHODS

The expression and distribution of CCN1 in rat periodontal ligament were detected by immunofluorescence staining and immunohistochemical staining. ELISA verified the secretion of CCN1 triggered by stretch loading. To examine the mineralization ability of hPDLSCs induced by CCN1, Western blotting, qRT-PCR, ARS, and ALP staining were performed. CCK-8 and cell migration assay were performed to detect the cell proliferation rate and the wound healing. PI3K/Akt, MAPK, and autophagy activation were examined via Western blotting and immunofluorescence.

RESULTS

Mechanical stimuli induced the release of CCN1 into extracellular environment by hPDLSCs. Knockdown of CCN1 attenuated the osteogenesis of hPDLSCs while rhCCN1 enhanced the expression of Runx2, Col 1, ALPL, and promoted the mineralization nodule formation. CCN1 activated PI3K/Akt and ERK signaling, and blockage of PI3K/Akt signaling reversed the accelerated cell migration triggered by CCN1. The enhanced osteogenesis induced by CCN1 was abolished by ERK signaling inhibitor PD98059 or autophagy inhibitor 3-MA. Further investigation demonstrated PD98059 abrogated the activation of autophagy.

CONCLUSION

This study demonstrated that CCN1 promotes osteogenesis in hPDLSCs via autophagy and MAPK/ERK pathway.

Melatonin and verteporfin synergistically suppress the growth and stemness of head and neck squamous cell carcinoma through the regulation of mitochondrial dynamics

The prevalence of head and neck squamous cell carcinoma (HNSCC) has continued to rise for decades. However, drug resistance to chemotherapeutics and relapse, mediated by cancer stem cells (CSCs), remains a significant impediment in clinical oncology to achieve successful treatment. Therefore, we focused on analyzing CSCs in HNSCC and demonstrated the effect of melatonin (Mel) and verteporfin (VP) on SCC-25 cells. HNSCC CSCs were enriched in the reactive oxygen species-low state and in sphere-forming cultures. Combination treatment with Mel and VP decreased HNSCC viability and increased apoptosis without causing significant damage to normal cells. Sphere-forming ability and stem cell population were reduced by co-treatment with Mel and VP, while mitochondrial ROS level was increased by the treatment. Furthermore, the expression of mitophagy markers, parkin and PINK1, was significantly decreased in the co-treated cells. Mel and VP induced mitochondrial depolarization and inhibited mitochondrial function. Parkin/TOM20 was localized near the nucleus and formed clusters of mitochondria in the cells after treatment. Moreover, Mel and VP downregulated the expression of markers involved in epithelial-mesenchymal transition and metastasis. The migration capacity of cells was significantly decreased by co-treatment with Mel and VP, accompanied by the down-regulation of MMP-2 and MMP-9 expression. Taken together, these results indicate that co-treatment with Mel and VP induces mitochondrial dysfunction, resulting in the apoptosis of CSCs. Mel and VP could thus be further investigated as potential therapies for HNSCC through their action on CSCs.

Advances in Cardiotoxicity Induced by Altered Mitochondrial Dynamics and Mitophagy

Mitochondria are the most abundant organelles in cardiac cells, and are essential to maintain the normal cardiac function, which requires mitochondrial dynamics and mitophagy to ensure the stability of mitochondrial quantity and quality. When mitochondria are affected by continuous injury factors, the balance between mitochondrial dynamics and mitophagy is broken. Aging and damaged mitochondria cannot be completely removed in cardiac cells, resulting in energy supply disorder and accumulation of toxic substances in cardiac cells, resulting in cardiac damage and cardiotoxicity. This paper summarizes the specific underlying mechanisms by which various adverse factors interfere with mitochondrial dynamics and mitophagy to produce cardiotoxicity and emphasizes the crucial role of oxidative stress in mitophagy. This review aims to provide fresh ideas for the prevention and treatment of cardiotoxicity induced by altered mitochondrial dynamics and mitophagy.

CYR61, regulated by miR-22-3p and MALAT1, promotes autophagy in HK-2 cell inflammatory model

Background

Renal tubular epithelial cells play an important role in renal function and are a major site of injury from inflammation. Emerging evidence suggests that CYR61 is involved in the regulation of autophagy. However, there are few studies on CYR61 in nephropathy and associated inflammation. This study aimed to clarify how CYR61 regulates autophagy in human renal epithelial cells while in an inflammatory state and regulates the upstream pathway of CYR61 levels.

Methods

The human renal tubular epithelial cells (HK-2) cell line treated by lipopolysaccharide (LPS) was used as an inflammatory model of human epithelial cells. Short hairpin RNA (shRNA) was used to down-regulate CYR61, and the changes in the transcription and expression levels of related molecules, as well as the morphological changes of HK-2 cells, were detected by quantitative real time-PCR (qRT-PCR), western blot (WB), and transmission electron microscopy. Either CYR61 or MALAT1 were up-regulated by overexpression vectors, or MALAT1 was down-regulated by miR-22-3p mimics. Subsequently, the levels of CYR61, MALAT1, related inflammatory factors, and autophagy factors were measured by qPCR, WB, and enzyme-linked immunosorbent assay (ELISA). Cell apoptosis was detected by flow cytometry and acridine-orange assay.

Results

We observed that down-regulation of CYR61 could down-regulate 1B-light chain 3 (LC3) level and inhibit autophagy in the LPS-induced inflammation model of HK-2 cells. The expression levels of CYR61, Beclin1, Atg5, LC3, interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) were significantly increased by upregulating CYR61 or MALAT1 by overexpression vector, while the expression level of p62 was significantly decreased, intracellular reactive oxygen species (ROS) content was increased, and the proportion of autophagy and apoptosis was increased. The use of miR-22-3p mimics significantly reversed the changes induced by up-regulation of CYR61 or MALAT1 at the molecular and cellular levels.

Conclusions

Our data indicated that CYR61 positively regulates autophagy of HK-2 cells under an inflammatory state, and was negatively regulated by miR-22-3p, while miR-22-3p and MALAT1 were negatively regulated by each other.

Cellular communication network factor 1 (CCN1) knockdown exerts a protective effect for hepatic ischemia/reperfusion injury by deactivating the MEK/ERK pathway

OBJECTIVE

Hepatic ischemia/reperfusion injury (IRI) is an unsettled and intractable conundrum in clinical treatment after liver transplantation and resection. Cellular communication network factor 1 (CCN1) is upregulated in liver IRI and may play a key role in this process. The objective of this study is to investigate the regulatory mechanism of CCN1 in liver IRI, which may provide new insight into liver IRI clinical treatment.

METHODS

The hepatic ischemia/reperfusion model was established in male C57BL/6 mice by occlusion of vessels in the liver followed by reperfusion. The mice were transfected with two small interfering RNAs (siRNAs) against CCN1 for CCN1 knockdown. The hypoxia/reoxygenation (HR) model was established in vitro using mouse hepatic cells followed by transfection with a siRNA and treatment with an ERK activator TPA to confirm the effects of CCN1 on the MEK/ERK pathway in liver IRI.

RESULTS

In hepatic IRI, CCN1 was upregulated and its knockdown reduced alanine aminotransferase and aspartate transaminase levels, myeloperoxidase activity, and the levels of IL-6 and TNF-α. CCN1 downregulation alleviated inflammatory cell infiltration and apoptosis in the liver. The expressions of cleaved caspase-9, cleaved caspase-3, Bax, and CHOP were decreased with an increased Bcl-2 level after CCN1 knockdown. The phosphorylation and activation of proteins in ER stress and MEK/ERK pathway were inhibited by CCN1 knockdown. In vitro, the levels of proinflammatory cytokines, apoptosis-inducing proteins, and proteins in ER stress and MEK/ERK pathway, which were decreased by CCN1 knockdown in HR, were restored by TPA, confirming that the activation of ERK aggravated cell apoptosis after reoxygenation.

CONCLUSION

Overall, CCN1 knockdown may suppress the inflammation, apoptosis during hepatic IRI by reducing the MEK/ERK pathway activation, which may be a breakthrough point in clinical alleviation of hepatic IRI caused by liver transplantation and resection.