Pentraxin 3 regulates tyrosine kinase inhibitor-associated cardiomyocyte contraction and mitochondrial dysfunction via ERK/JNK signalling pathways.

BACKGROUND: Hepatocellular carcinoma (HCC) patients suffer varying degrees of heart dysfunction after tyrosine kinase inhibitor (TKI) treatment. Interestingly, HCC patients often have higher levels of pentraxin 3 (PTX3), and PTX3 inhibition was found to improve left ventricular dysfunction in animal models. OBJECTIVES: We sought to assess the therapeutic potential of PTX3 inhibition on TKI-associated cardiotoxicity. METHODS: We used a human embryonic stem cell line, RUES2, to generate cardiomyocyte cultures (RUES2-CM) for functional testing. We also assessed heart function and PTX3 expression levels in 16 HCC patients who received TKI treatment, 3 HCC patients who did not receive TKIs, and 7 healthy volunteers. RESULTS: Significantly higher PTX3 expression was noted in HCC patients with TKI treatment versus those without, and 38% of male and 33% of female patients had QTc prolongation after TKI treatment. Treatment of cardiomyocyte cultures with sorafenib also increased PTX3 expression and induced cytoskeletal remodelling, contraction reduction, sodium current inhibition, and mitochondrial respiratory dysfunction. PTX3 colocalised with CD44 in cardiomyocytes, and cardiomyocyte contraction, mitochondrial respiratory function, and regular cytoskeletal and apoptotic protein expression were restored with PTX3 inhibition. CD44 knockdown confirmed PTX3/CD44 signalling. These results suggest a possible mechanism in which sorafenib treatment increases PTX3 expression, thereby resulting in reduced extracellular signal-regulated kinase (ERK) 1/2 expression that affects cardiomyocyte contraction, while also activating c-Jun N-terminal kinase (JNK) downstream pathways to disrupt mitochondrial respiration and trigger apoptosis. CONCLUSIONS: TKI-induced cardiotoxicity may be partly mediated by the upregulation of PTX3, and thus PTX3 inhibition has potential as a therapeutic strategy.

Programmed Cell Death-1: Programmed Cell Death-Ligand 1 Interaction Protects Human Cardiomyocytes Against T-Cell Mediated Inflammation and Apoptosis Response In Vitro.

AIM: Immunological checkpoint therapy is considered a powerful method for cancer therapy and acts by re-activating autologous T cells to kill the cancer cell. Myocarditis cases have been reported in cancer patients after immunological therapy; for example, nivolumab treatment is a monoclonal antibody that blocks programmed cell death-1/programmed cell death ligand-1 ligand interaction. This project provided insight into the inflammatory response as a benchmark to investigate the potential cardiotoxic effect of T cell response to the programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) axis in regulating cardiomyocyte injury in vitro. METHODS AND RESULTS: We investigated cardiomyopathy resulted from the PD-1/PD-L1 axis blockade using the anti-PD-1 antibody in Rockefeller University embryonic stem cells-derived cardiomyocytes (RUES2-CMs) and a melanoma tumor-bearing murine model. We found that nivolumab alone did not induce inflammatory-related proteins, including PD-L1 expression, and did not induce apoptosis, which was contrary to doxorubicin, a cardiotoxic chemotherapy drug. However, nivolumab was able to exacerbate the immune response by increasing cytokine and inflammatory gene expression in RUES2-CMs when co-cultured with CD4+ T lymphocytes and induced apoptosis. This effect was not observed when RUES2-CMs were co-cultured with CD8+ T lymphocytes. The in vivo model showed that the heart function of tumor-bearing mice was decreased after treatment with anti-PD-1 antibody and demonstrated a dilated left ventricle histological examination. The dilated left ventricle was associated with an infiltration of CD4+ and CD8+ T lymphocytes into the myocardium. PD-L1 and inflammatory-associated gene expression were significantly increased in anti-PD-1-treated tumor-bearing mice. Cleaved caspase-3 and mouse plasma cardiac troponin I expressions were increased significantly. CONCLUSION: PD-L1 expression on cardiomyocytes suppressed T-cell function. Blockade of PD-1 by nivolumab enhanced cardiomyocyte inflammation and apoptosis through the enhancement of T-cell response towards cardiomyocytes.

CCAAT/enhancer-binding protein delta promotes intracellular lipid accumulation in M1 macrophages of vascular lesions.

AIMS: Lipid homeostasis is reprogrammed in the presence of inflammation, which results in excessive lipid accumulation in macrophages, and leads to the formation of lipid-laden foam cells. We aimed to link an inflammation-responsive transcription factor CCAAT/enhancer-binding protein delta (CEBPD) with polarized macrophages and dissect its contribution to lipid accumulation. METHODS AND RESULTS: We found that CEBPD protein colocalized with macrophages in human and mouse (C57BL/6, Apoe-/-) atherosclerotic plaques and that Cebpd deficiency in bone marrow cells suppressed atherosclerotic lesions in hyperlipidemic Apoe-/- mice. CEBPD was responsive to modified low-density lipoprotein (LDL) via the p38MAPK/CREB pathway, and it promoted lipid accumulation in M1 macrophages but not in M2 macrophages. CEBPD up-regulated pentraxin 3 (PTX3), which promoted the macropinocytosis of LDL, and down-regulated ATP-binding cassette subfamily A member 1 (ABCA1), which impaired the intracellular cholesterol efflux in M1 macrophages. We further found that simvastatin (a HMG-CoA reductase inhibitor) could target CEBPD to block lipid accumulation in a manner not directly related to its cholesterol-lowering effect in M1 macrophages. CONCLUSION: This study underscores how CEBPD functions at the junction of inflammation and lipid accumulation in M1 macrophages. Therefore, CEBPD-mediated lipid accumulation in M1 macrophages could represent a new therapeutic target for the treatment of cardiovascular diseases.

The neuroprotective effects of Tao-Ren-Cheng-Qi Tang against embolic stroke in rats.

BACKGROUND: Combinations of the traditional Chinese and Western medicines have been used to treat numerous diseases throughout the world, and there is a growing body of evidence showing that some of the herbs used in traditional Chinese medicine elicit significant pharmacological effects. The aim of this study was to demonstrate the neuroprotective effects of Tao-Ren-Cheng-Qi Tang (TRCQT) in combination with aspirin following middle cerebral artery occlusion (MCAO)-induced embolic stroke in rats. METHODS: A blood clot was embolized into the middle cerebral artery of rats to induce focal ischemic brain injury. After 24 h of MCAO occlusion, the rats were arbitrarily separated into five groups and subjected to different oral treatment processes with TRCQT and aspirin for 30 days before being evaluated in terms of their neurological behavior using a four-point system. The rats were sacrificed at 30 days after drug treatment and the infarct volumes were measured using a 2,3,5-triphenyltetrazolium chloride staining method. Tumor necrosis factor-α (TNF-α), c-Jun N-terminal kinases (JNK), activated caspase-3 and Bax were detected by western blot analysis. The apoptotic cells were identified by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. ROS generation was also measured by electron spin resonance spectrometry. RESULTS: Rats treated with TRCQT alone or in combination with aspirin showed a significantly reduced infarct volume (P < 0.001) and improved neurological outcome compared with those treated with distilled water. Rats treated with TRCQT alone (P = 0.021) or in combination with aspirin (P = 0.02) also showed significantly reduced MCAO-induced expression levels of TNF-α and pJNK (P < 0.001) in their ischemic regions. Rats treated with TRCQT alone or in combination with aspirin showed decreased apoptosis by a reduction in the number of TUNEL positive cells, which inhibited the expression of activated caspase-3 (P = 0.038) and Bax (P = 0.004; P = 0.003). TRCQT also led to a significant concentration-dependent reduction in the formation of hydroxyl radicals (P < 0.001). CONCLUSIONS: TRCQT reduced brain infarct volume and improved neurological outcomes by reducing apoptosis, attenuating the expression of TNF-α and p-JNK, and reducing the formation of hydroxyl radicals in MCAO-induced embolic stroke of rats.

Cyclophilin A is associated with peripheral artery disease and chronic kidney disease in geriatrics: The Tianliao Old People (TOP) study.

Cyclophilin A (CyPA), secreted by vascular smooth muscle cells in response to oxidative stress, is important in the pathogenesis of progressive peripheral arterial occlusion disease (PAOD), which is common among chronic kidney disease. We explored the prevalence of PAOD in Taiwan's elderly (≥ 65 years old) population and its association with CyPA and renal function. Residents of Tianliao District, a rural community in southern Taiwan, were surveyed. An ankle-brachial index (ABI) < 0.91 was defined as PAOD. Chronic kidney disease (CKD) was defined based on eGFR levels < 60 mL/min/1.73 m(2). Serum CyPA was measured. Of the 473 participants, 68 (14.4%) had PAOD. Multiple logistic regression analysis showed PAOD was significantly associated with lower eGFR, lower BMI, higher glycated hemoglobin and higher pulse pressure. Serum CyPA levels in participants with PAOD were significantly higher than those with normal ABI values (47.3 ± 0.4 vs. 25.5 ± 0.2 ng/mL, p < 0.001). Moreover, eGFR inversely correlated with serum CyPA level (p < 0.05) in participants with CKD, but not in participants with normal renal function. In conclusion, with a prevalence of PAOD as high as 14.4% in an elderly community, CyPA might be the link between PAOD and advanced impaired renal function.