The role of ZFP580, a novel zinc finger protein, in TGF-mediated cytoprotection against chemical hypoxia‑induced apoptosis in H9c2 cardiac myocytes

Investigation of coagulation and proteomics profiles in symptomatic feline hypertrophic cardiomyopathy and healthy control cats

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a crucial heart disease in cats. The clinical manifestations of HCM comprise pulmonary edema, dyspnea, syncope, arterial thromboembolism (ATE), and sudden cardiac death. D-dimer and prothrombin time (PT) are powerful biomarkers used to assess coagulation function. Dysregulation in these two biomarkers may be associated with HCM in cats. This study aims to assess D-dimer levels, PT, and proteomic profiling in healthy cats in comparison to cats with symptomatic HCM.

RESULTS

Twenty-nine client-owned cats with HCM were enrolled, including 15 healthy control and 14 symptomatic HCM cats. The D-dimer concentration and PT were examined. Proteomic analysis was conducted by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In symptomatic cats, D-dimer levels were statistically significantly higher (mean ± SEM: 372.19 ng/ml ± 58.28) than in healthy cats (mean ± SEM: 208.54 ng/ml ± 10.92) with P-value of less than 0.01, while PT was statistically significantly lower in symptomatic cats (mean ± SEM: 9.8 s ± 0.15) compared to healthy cats (mean ± SEM: 11.08 s ± 0.23) with P-value of less than 0.0001. The proteomics analysis revealed upregulation of integrin subunit alpha M (ITGAM), elongin B (ELOB), and fibrillin 2 (FBN2) and downregulation of zinc finger protein 316 (ZNF316) and ectonucleoside triphosphate diphosphohydrolase 8 (ENTPD8) in symptomatic HCM cats. In addition, protein-drug interaction analysis identified the Ras signaling pathway and PI3K-Akt signaling pathway.

CONCLUSIONS

Cats with symptomatic HCM have higher D-dimer and lower PT than healthy cats. Proteomic profiles may be used as potential biomarkers for the detection and management of HCM in cats. The use of D-dimer as a biomarker for HCM detection and the use of proteomic profiling for a better understanding of disease mechanisms remain to be further studied in cats.

Protective effects of Thai silk sericins and their related mechanisms on UVA-induced phototoxicity and melanogenesis: Investigation in primary melanocyte cells using a proteomic approach

UV radiation causes excess production of melanin as a result of hyperpigmentation and skin disorders. Silk sericin exhibited bioactivities to skin and inhibited UV-induced phototoxicity and melanogenesis in skin cells; however, the mechanism related to sericin against UV-induced melanogenesis has not been investigated. This study aimed to investigate the protective effects of Thai silk sericins against UVA-induced phototoxicity and melanogenesis and their related mechanisms. Thai silk sericins exhibited cytoprotective effects against UV-induced toxicity in human primary melanocytes by attenuation of cytotoxicity, intracellular ROS generation, and mitochondrial potential impairment. Pre- and post-treatment with sericin significantly inhibited melanin synthesis and tyrosinase activity against UVA exposure. In addition, sericin S2 could reduce the basal melanin content in zebrafish embryos. The proteomic analysis demonstrated that Thai silk sericins altered the protein expression in melanocytes especially proteins related to stress, inflammatory, cytokine stimulation, cell proliferation, and cell survival processes that contribute to cytoprotective effect and inhibitory effect on melanogenesis of sericin. Moreover, we demonstrated the novel mechanism of Thai silk sericins in inhibiting UVA-induced melanogenesis via increasing BMP4 expression in MAPK/ERK signaling pathway. These evidences support the potential use of Thai silk sericins in prevention of hyperpigmentation in skin disorders especially after UVA exposure.

RNA-seq analysis reveals potential molecular mechanisms of ZNF580/ZFP580 promoting neuronal survival and inhibiting apoptosis after Hypoxic-ischemic brain damage

Neonatal hypoxic-ischemic brain damage (HIBD) is one of the main causes of neonatal acute death and chronic nervous system impairment, but still lacks effective treatments. ZNF580/ZFP580, reported in our previous studies, may be a newly identified member of the Krüppel-like factor (KLF) family, and has anti-apoptotic effects during ischemic myocardial injury. In the present study, we showed that the expression levels of both ZFP580/ZNF580 mRNA and protein increased significantly in neonatal HIBD rats and oxygen-glucose deprivation (OGD) SH-SY5Y cell models. ZNF580 overexpression promoted neuron survival and suppressed neuron apoptosis after OGD in neuron-like SH-SY5Y cells, while interference with ZNF580 resulted in the opposite results. RNA-seq analysis identified 248 differentially-expressed genes (DEGs) between ZNF580 overexpression SH-SY5Y cells and interference-expressed SH-SY5Y cells. Gene Ontology functional enrichment analysis showed that these DEGs played significant roles in the growth, development, and regeneration of axons, DNA biosynthetic processes, DNA replication, and apoptosis. Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that these DEGs were found in some pathways, including ferroptosis, glutamatergic synapses, protein processing in the endoplasmic reticulum, estrogen signaling pathways, the TGF-beta signaling pathway, and the longevity regulating pathway. The qRT-PCR validation results were consistent with RNA-seq results, which showed that HSPA5, IGFBP3, NTN4, and KLF9 increased in ZNF580-overexpressed SH-SY5Y cells and decreased in interference-expressed SH-SY5Y cells, when compared with normal cells. Together, the results suggested that ZNF580 targeted these genes to inhibit neuronal apoptosis.

MicroRNA-23a reduces lipopolysaccharide-induced cellular apoptosis and inflammatory cytokine production through Rho-associated kinase 1/sirtuin-1/nuclear factor-kappa B crosstalk

Background:

MicroRNAs are closely associated with the progression and outcomes of multiple human diseases, including sepsis. In this study, we examined the role of miR-23a in septic injury.

Methods:

Lipopolysaccharide (LPS) was used to induce sepsis in a rat model and H9C2 and HK-2 cells. miR-23a expression was evaluated in rat myocardial and kidney tissues, as well as H9C2 and HK-2 cells. A miR-23a mimic was introduced into cells to identify the role of miR-23a in cell viability, apoptosis, and the secretion of inflammatory cytokines. Furthermore, the effect of Rho-associated kinase 1 (ROCK1), a miR-23a target, on cell damage was evaluated, and molecules involved in the underlying mechanism were identified.

Results:

In the rat model, miR-23a was poorly expressed in myocardial (sham vs. sepsis 1.00 ± 0.06 vs. 0.27 ± 0.03, P < 0.01) and kidney tissues (sham vs. sepsis 0.27 ± 0.03 vs. 1.00 ± 0.06, P < 0.01). Artificial overexpression of miR-23a resulted in increased proliferative activity (DNA replication rate: Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 34.13 ± 3.12 vs. 12.94 ± 1.21 vs. 13.31 ± 1.43 vs. 22.94 ± 2.26, P < 0.05; HK-2 cells: 15.17 ± 1.43 vs. 34.52 ± 3.46 vs. 35.19 ± 3.12 vs. 19.87 ± 1.52, P < 0.05), decreased cell apoptosis (Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 11.39 ± 1.04 vs. 32.57 ± 2.29 vs. 33.08 ± 3.12 vs. 21.63 ± 2.35, P < 0.05; HK-2 cells: 15.17 ± 1.43 vs. 34.52 ± 3.46 vs. 35.19 ± 3.12 vs. 19.87 ± 1.52, P < 0.05), and decreased production of inflammatory cytokines, including interleukin-6 (Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 59.61 ± 5.14 vs. 113.54 ± 12.30 vs. 116.51 ± 10.69 vs. 87.69 ± 2.97 ng/mL; P < 0.05, F = 12.67, HK-2 cells: 68.12 ± 6.44 vs. 139.65 ± 16.62 vs. 143.51 ± 13.64 vs. 100.82 ± 9.74 ng/mL, P < 0.05, F = 9.83) and tumor necrosis factor-α (Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 103.20 ± 10.31 vs. 169.67 ± 18.84 vs. 173.61 ± 15.91 vs. 133.36 ± 12.32 ng/mL, P < 0.05, F = 12.67, HK-2 cells: 132.51 ± 13.37 vs. 187.47 ± 16.74 vs. 143.51 ± 13.64 vs. 155.79 ± 15.31 ng/mL, P < 0.05, F = 9.83) in cells. However, ROCK1 was identified as a miR-23a target, and further up-regulation of ROCK1 mitigated the protective function of miR-23a in LPS-treated H9C2 and HK-2 cells. Moreover, ROCK1 suppressed sirtuin-1 (SIRT1) expression to promote the phosphorylation of nuclear factor-kappa B (NF-κB) p65, indicating the possible involvement of this signaling pathway in miR-23a-mediated events.

Conclusion:

Our results indicate that miR-23a could suppress LPS-induced cell damage and inflammatory cytokine secretion by binding to ROCK1, mediated through the potential participation of the SIRT1/NF-κB signaling pathway.

Are activated B cells involved in the process of myocardial fibrosis after acute myocardial infarction? An in vivo experiment

BACKGROUND

Inflammatory cells infiltrate into the ischemic and hypoxic myocardial tissue after myocardial infarction. B cells gather at the site of myocardial injury and secrete cytokines to regulate immune inflammation and fiber repair processes.

METHODS

The animal experiment used ligation of the left anterior descending (LAD) artery of C57BL/6 mice to establish a mouse acute myocardial infarction (AMI) model to observe changes in activated B cells and cytokines at different time points. Twelve-week-old C57BL/6 male mice were randomly divided into the Sham group (24 mice) (thread under the LAD artery without ligation) and the AMI group (64 mice). In addition, C57BL/6 B-cell knockout (BKO) mice and C57BL/6 wild-type (WT) mice were used to establish AMI models to observe the expression levels of cardiomyocyte cytokines, such as TNF-α IL-1β, IL-6, TGF-β1, COL1-A1, COL3-AIII, TIMP, and MMP9. Moreover, pathological and collagen changes in the myocardium were analysed. One-way ANOVA and LSD method was used for comparisons of multiple and pairwise groups respectively. P < 0.05 indicated significant differences.

RESULTS

An AMI model of C57BL/6 mice was established successfully. The ratio of activated B cells and the expression of TNF-α, IL-1β, IL-6, TGF-β1, and B cell activating factor (BAFF) in the 5-day subgroup were the highest in the myocardium, spleen and peripheral blood with the most obvious myocardial inflammatory cell infiltration. The cytokines mRNA expression levels in the 5-day subgroup of the BKO group were decreased compared with those in the WT group (P < 0.05). Among the 2-week subgroups of the Sham, WT and BKO groups, the the LVEDd and LVESd of the BKO group were lower than those of the WT group (P < 0.05), and the left ventricular ejection fraction was higher than that of the WT group (P < 0.05).

CONCLUSION

Activated B cells participate in the sustained state of myocardial inflammation and immune system activation after AMI, and may affect the metabolism of myocardial collagen after AMI by secreting cytokines. Moreover, B cells promote the expression of myocardial collagen Type I and Type III and damage the left ventricular ejection function.

Thrombospondin-1 mediates Drp-1 signaling following ischemia reperfusion in the aging heart

BACKGROUND

Ischemia reperfusion (IR) injury leads to activation of dynamin-related protein (Drp-1), causing mitochondrial fission and generation of reactive oxygen species (ROS), but the molecular mechanisms that activate Drp-1 are not known. The purpose of this study was to establish a link between Thbs-1 and fission protein (Drp-1) through Pgc-1α following IR in advancing age.

METHODS

Female Fischer-344 rats were divided into four groups: Young Control, Young + IR, Old Control, and Old + IR. Heart function and coronary flow were evaluated at baseline and 72 hours after IR, hearts were explanted and mitochondrial ROS generation was measured using MitoPY1, as well as protein levels of Thbs-1, Pgc-1α, and Drp-1. In vitro, rat aortic endothelial cells (RAEC) were treated with siRNA or plasmid for Pgc-1α to evaluate Pgc-1α effect on Drp-1.

RESULTS

Mitochondrial ROS generation in heart tissue increased in both age groups following IR. Old animals exhibited diastolic dysfunction at baseline; after IR they displayed reduced systolic function and exacerbated diastolic dysfunction compared to young controls. IR increased Thbs-1 and Drp-1 expression in young and old hearts compared to control. siRNA to Pgc-1α enhanced levels of Drp-1 in RAECs and increased ROS generation after hypoxia, while Pgc-1α plasmid ameliorates Drp-1 expression in the presence of exogenous Thbs-1.

CONCLUSION

These results highlight a novel signaling pathway by which Thbs-1 regulates mitochondrial fission protein (Drp-1) and ROS generation during hypoxia, and presumably, following IR. Inhibiting Thbs-1 immediately after IR may prevent Drp-1-mediated mitochondrial fission and is likely to improve the diastolic function of the heart by reducing ROS-mediated cardiomyocyte damage in the aged population.

Propofol protects human cardiac cells against chemical hypoxiainduced injury by regulating the JNK signaling pathways

Propofol is a widely used intravenous anesthetic shown to exert a cardioprotective role against oxidative stress and ischemia/reperfusion injury in rat cardiac H9c2 cells. However, the regulatory mechanisms and functions of propofol in human cardiomyocytes remain unknown. The present study chemically induced hypoxia with cobalt chloride (CoCl₂) to mimic cardiomyocyte ischemic injury in human cardiac AC16 and HCM cells. To investigate its underlying mechanisms, propofol was added to the cells before the chemical hypoxia phase. The present results suggested that, in response to hypoxia, mitochondrial membrane potential was lost, and cardiomyocyte viability and superoxide dismutase levels decreased. However, the present results showed that reactive oxygen species and malondialdehyde levels increased. The present results suggested that these effects were significantly reversed following propofol treatment. Additionally, the present results suggested that the protective effect of propofol against CoCl₂-induced injury may be inhibited by the activation of the JNK signaling pathways. The present results indicated that propofol pre-treatment inhibited CoCl₂-induced myocardial injury by preventing mitochondrial dysfunction, which may be partially due to the activation of the JNK signaling pathways. Therefore, propofol may exert anti-oxidative effects in human cardiac cells. The present results suggested that propofol may be used as a treatment for oxidative stress-related cardiac disorders.

Telmisartan cardioprotects from the ischaemic/hypoxic damage through a miR-1-dependent pathway

The aim of this study was to investigate whether telmisartan protects the heart from the ischaemia/reperfusion damage through a local microRNA‐1 modulation. Studies on the myocardial ischaemia/reperfusion injury in vivo and on the cardiomyocyte hypoxia/reoxygenation damage in vitro were done. In vivo, male Sprague‐Dawley rats administered for 3 weeks with telmisartan 12 mg/kg/d by gastric gavage underwent ischaemia/reperfusion of the left descending coronary artery. In these rats, infarct size measurement, ELISA, immunohistochemistry (IHC) and reverse transcriptase real‐time polymerase chain reaction showed that expressions of connexin 43, potassium voltage‐gated channel subfamily Q member 1 and the protein Bcl‐2 were significantly increased by telmisartan in the reperfused myocardium, paralleled by microRNA‐1 down‐regulation. In vitro, the transfection of cardiomyocytes with microRNA‐1 reduced the expressions of connexin 43, potassium voltage‐gated channel subfamily Q member 1 and Bcl‐2 in the cells. Telmisartan (50 µmol/L) 60 minutes before hypoxia/reoxygenation, while not affecting the levels of miR‐1 in transfected cells in normoxic condition, almost abolished the increment of miR‐1 induced by the hypoxia/reoxygenation to transfected cells. All together, telmisartan cardioprotected against the myocardial damage through the microRNA‐1 modulation, and consequent modifications of its downstream target connexin 43, potassium voltage‐gated channel subfamily Q member 1 and Bcl‐2.

Terminalia arjuna extract and arjunic acid mitigate cobalt chloride-induced hypoxia stress-mediated apoptosis in H9c2 cells

Arjunic acid (AA) is one of the major active component of Terminalia arjuna known for its health benefits. In the present study, we evaluated cardioprotective potential of Terminalia arjuna extract (TAE) and AA against cobalt chloride (CoCl₂)-induced hypoxia damage and apoptosis in rat cardiomyocytes. TAE (50 μg/ml) and AA (8 μg/ml) significantly (p < 0.001) protected H9c2 cells as evidenced by cell viability assays against CoCl₂ (1.2 mM)-induced cytotoxicity. TAE and AA pretreatments protected the cells from oxidative damage by decreasing the generation of free radicals (ROS, hydroperoxide, and nitrite levels). TAE and AA pretreatments retained mitochondrial membrane potential by alleviating the rate of lipid peroxidation induced by CoCl₂ treatment. TAE and AA pretreatments elevated antioxidant status including phase II antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and total glutathione levels against CoCl₂-induced oxidative stress. Further immunoblotting studies confirmed anti-apoptotic effects of TAE and AA by alleviating the phosphorylation of JNK and c-jun and also by regulating protein expression levels of Bcl2, Bax, caspase 3, heat shock protein-70, and inducible nitric oxide synthase. Overall, our results suggest that both the extract and the active component exhibit antioxidant and anti-apoptotic defense against CoCl₂-induced hypoxic injury.