The Effects of Periostin in a Rat Model of Isoproterenol: Mediated Cardiotoxicity

Proteomic analysis of epicardial adipose tissue from heart disease patients with concomitant heart failure with preserved ejection fraction

BACKGROUND

Although epicardial adipose tissue (EAT) is known to be a major contributor to the pathogenesis of heart failure with preserved ejection fraction (HFpEF), the underlying mechanisms remain incompletely understood. This study aimed to compare the proteomic profiles of EAT from HFpEF patients and patients without HF (non-HF) and to explore candidate molecules characteristic of EAT in HFpEF.

METHODS

EAT samples were collected from patients who underwent cardiac surgery. Proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and protein-protein interaction network analysis were conducted. The gene expression of one significant differentially expressed protein was examined by quantitative reverse transcription polymerase chain reaction.

RESULTS

A total of 2416 proteins were detected by LC-MS/MS experiments, and expression levels were quantified for 2349 proteins. Among them, 96 proteins (including 71 upregulated proteins and 25 downregulated proteins) were significantly differentially expressed between the HFpEF (n = 5) and non-HF groups (n = 5). GO enrichment and KEGG pathway analyses revealed that these differentially expressed proteins were predominantly involved in HFpEF-related processes, including lipid metabolic disorder, inflammation, and mitochondrial dysfunction.

CONCLUSIONS

The results of this comprehensive analysis of the EAT proteome in HFpEF patients offer new insights into the pathogenesis of HFpEF and potential molecular targets in EAT.

Effects of exercise training on behavior and brain function after high dose isoproterenol-induced cardiac damage

Acute sympathetic stress can result in cardiac fibrosis, but may also lead to mental dysfunction. Exercise training after isoproterenol (ISO)-induced acute sympathetic stress was investigated regarding cardiac damage, neuroinflammation, brain function and behavior. Male Wistar rats (12 months) received ISO or saline. One week later, treadmill running or control handling (sedentary) started. After 4 weeks, cognitive- and exploratory behavior were evaluated, and heart and brain tissues were analyzed regarding cardiac damage, hippocampal neuroinflammation and neuronal function. ISO did not affect cognitive performance nor hippocampal function. However, ISO reduced anxiety, coinciding with locally reduced microglia (processes) size in the hippocampus. Exercise in ISO rats reversed anxiety, did not affect microglia morphology, but increased brain function. Thus, exercise after ISO did not affect cardiac damage, cognition or hippocampal neuroinflammation, but normalized anxiety. Increased localized BDNF expression may indicate improved brain function.

Primary Unilateral Small Cell Neuroendocrine Carcinoma of the Kidney in a Dog

Primary small cell carcinomas are rare in domestic animals. A mass measuring 15 × 20 × 9 cm was detected in the left abdominal cavity of a 7.5-year-old female golden retriever. The cut surface of the excised mass showed a tumour replacing the left kidney. Microscopically, the mass was composed of polymorphic, small basophilic cells with a high nuclear to cytoplasmic ratio and round, oval or short slender fusiform nuclei with condensed or finely granular chromatin, absent or inconspicuous nucleoli, and scant, faintly eosinophilic cytoplasm with poorly defined cytoplasmic borders. Immunohistochemically, most of the neoplastic cells were immunoreactive for thyroid transcription factor 1 and CD56, moderately positive for vimentin and weakly or sparsely labelled for chromogranin A, synaptophysin, Wilms' tumour 1 protein, neuron-specific enolase, pan-cytokeratin (CK) AE1/AE3 and epithelial membrane antigen. The tumour cells were negative for glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1, CK7, CK20, CD3, CD45 and CD99. These findings indicated a neuroendocrine origin of the tumour. To the best of author's knowledge, this is the first report of a small cell neuroendocrine carcinoma originating as a primary tumour in the kidney of a dog.

Anti-fibrotic Actions of Roselle Extract in Rat Model of Myocardial Infarction

Heart failure-associated morbidity and mortality is largely attributable to extensive and unregulated cardiac remodelling. Roselle (Hibiscus sabdariffa) calyces are enriched with natural polyphenols known for antioxidant and anti-hypertensive effects, yet its effects on early cardiac remodelling in post myocardial infarction (MI) setting are still unclear. Thus, the aim of this study was to investigate the actions of roselle extract on cardiac remodelling in rat model of MI. Male Wistar rats (200-300 g) were randomly allotted into three groups: Control, MI, and MI + Roselle. MI was induced with isoprenaline (ISO) (85 mg/kg, s.c) for two consecutive days followed by roselle treatment (100 mg/kg, orally) for 7 days. Isoprenaline administration showed changes in heart weight to body weight (HW/BW) ratio. MI was especially evident by the elevated cardiac injury marker, troponin-T, and histological observation. Upregulation of plasma levels and cardiac gene expression levels of inflammatory cytokines such as interleukin (IL)-6 and IL-10 was seen in MI rats. A relatively high percentage of fibrosis was observed in rat heart tissues with over-expression of collagen (Col)-1 and Col-3 genes following isoprenaline-induced MI. On top of that, cardiomyocyte areas were larger in heart tissues of MI rats with upregulation of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) gene expression, indicating cardiac hypertrophy. Interestingly, roselle supplementation attenuated elevation of plasma troponin-T, IL-6, IL10, and gene expression level of IL-10. Furthermore, reduction of cardiac fibrosis and hypertrophy were observed. In conclusion, roselle treatment was able to limit early cardiac remodelling in MI rat model by alleviating inflammation, fibrosis, and hypertrophy; hence, the potential application of roselle in early adjunctive treatment to prevent heart failure.

Olmesartan attenuates pressure-overload- or post-infarction-induced cardiac remodeling in mice

Either angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor 1 blocker (ARB) attenuates cardiac remodeling. However, the overall molecular modulation of the reversing remodeling process in response to the ACEI or ARB treatment is not yet well determined. In this study, we examined whether gene expressions are modulated by ACEI (temocapril), ARB (olmesartan) or both in a murine model with transverse aortic constriction (TAC) and confirm whether periostin is a target gene of olmesartan in mice with myocardial infarction (MI). We detected 109 genes that were significantly up-regulated in TAC mice and a majority of these were down-regulated in response to temocapril, olmesartan or their combination which significantly attenuated cardiac remodeling at one or four weeks. Real-time RT-PCR demonstrated that olmesartan, temocapril or their combination down-regulated the expression of periostin. In MI mice treated with olmesartan for 4 weeks, the left ventricular end-diastolic and systolic dimensions measured with echocardiography were lower, whereas maximum rate of rise and fall rate of LV pressure (±dp/dt max) were greater, and Azan-staining cardiac fibrotic area was smaller. Furthermore, periostin was upregulated in response to MI, whereas olmesartan blocked this upregulation. Post-MI fibrosis was smaller in periostin knockout adult mice than in wildtype mice, while glycogen synthase kinase 3β was increased and cyclin D1 was decreased in periostin knockout mice. These findings indicate that periostin is a target gene of ARB and olmesartan reverses cardiac remodeling at least partially through the downregulation of periostin.