Introduction: Microalbuminuria is a risk factor for cardiovascular morbidity and mortality in hypertensive patients. However, the relationship between low-grade albuminuria, a higher level of albuminuria below microalbuminuria threshold, and hypertension-related organ damage is unclear. Left ventricular (LV) hypertrophy (LVH) is well recognized to be a subclinical organ damage of hypertension, and LV diastolic dysfunction is also reported to be an early functional cardiac change of hypertension that predicts heart failure. The present study aimed to investigate the association of low-grade albuminuria with LVH and LV diastolic dysfunction in hypertensive patients. Methods: This cross-sectional observational clinical study was retrospectively performed in 870 hypertensive patients admitted to our hospital. Urinary albumin to creatinine ratio (UACR) was calculated to assess the levels of albuminuria: macroalbuminuria (≥300 mg/g), microalbuminuria (≥30 mg/g, but <300 mg/g), and normal albuminuria (<30 mg/g). Low-grade albuminuria was defined as sex-specific highest tertile within normal albuminuria (8.1–29.6 mg/g in males and 11.8–28.9 mg/g in females). LVH and LV diastolic dysfunction were identified as recommended by American Society of Echocardiography. Results: Of the 870 patients, 765 (87.9%) had normal albuminuria, 77 (8.9%) had microalbuminuria, and 28 (3.2%) had macroalbuminuria. Percentage of LVH and LV diastolic dysfunction was increased with ascending UACR. UACR was independently associated with LVH and LV diastolic dysfunction, even in patients with normal albuminuria. Multivariable logistic regression showed that the patients with the highest tertile within normal albuminuria had nearly 80% increase in LVH and nearly 60% increase in LV diastolic dysfunction (adjusted OR for LVH 1.788, 95% CI 1.181–2.708, p = 0.006; adjusted OR for LV diastolic dysfunction 1.567, 95% CI 1.036–2.397, p = 0.034). After further stratification analyses in patients with normal albuminuria, it was shown that this independent association persisted in female patients, those who were younger than 70 years old, and those with duration of hypertension <15 years. Conclusion: Low-grade albuminuria was associated with LVH and LV diastolic dysfunction in hypertensive patients, especially in patients younger than 70 years old, and those with duration of hypertension <15 years.

Pulmonary arterial hypertension (PAH) is a serious disease characterized by elevated pulmonary artery pressure, inflammatory cell infiltration and pulmonary vascular remodeling. However, little is known about the pathogenic mechanisms underlying the disease onset and progression. RNA sequencing (RNA-seq) was used to identify the transcriptional profiling in control and rats injected with monocrotaline (MCT) for 1, 2, 3 and 4 weeks. A total of 23200 transcripts and 280, 1342, 908 and 3155 differentially expressed genes (DEGs) were identified at the end of week 1, 2, 3 and 4, of which Svop was the common top 10 DEGs over the course of PAH progression. Functional enrichment analysis of DEGs showed inflammatory/immune response occurred in the early stage of PAH development. KEGG pathway enrichment analysis of DEGs showed that cytokine-cytokine receptor interaction and neuroactive ligand-receptor interaction were in the initiation and progression of PAH. Further analysis revealed impaired expression of cholinergic receptors, adrenergic receptors including alpha1, beta1 and beta2 receptor, and dysregulated expression of γ-aminobutyric acid receptors. In summary, the dysregulated inflammation/immunity and neuroactive ligand receptor signaling pathways may be involved in the onset and progression of PAH.

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Pulmonary arterial hypertension (PAH) in humans manifests as a chronic process. However, PAH induced by high-dose monocrotaline (MCT) in animals occurs as a subacute process. To establish a chronic PAH model, rats were randomly divided into three groups, control (ctrl), single injection (SI), and twice injection (TI) groups. Rats in the SI group received a single intraperitoneal injection of 40 mg/kg MCT on day 0. Rats in the TI group received twice injections of 20 mg/kg MCT on days 0 and 7. Survival percentage, characteristic changes of pulmonary arterial variables, and right ventricular features were evaluated. Thirty-five days after the first MCT injection, survival percentage in TI group was higher than that in the SI group. The mean pulmonary arterial pressure (mPAP), right ventricular hypertrophy index (RVHI), pulmonary vascular remodeling, serum tumor necrosis factor α (TNFα), and interleukin-6 (IL-6) were higher either in SI or in TI 28 and 35 days after the first MCT injection. The rats in the SI and TI groups exhibited higher right ventricle end diastolic diameter (RVEDD) and lower adjusted pulmonary artery acceleration time (PAAT/HR), tricuspid annular plane systolic excursion (TAPSE), cardiac output (CO) and right ventricle fractional shortening (RVFS) when compared with controls. However, mPAP, RVHI, TAPSE, PAAT/HR, CO, TNFα, and IL-6 were lower and RVEDD were higher in the TI group than in the SI group. Pulmonary macrophage infiltration and right ventricle (RV) fibrosis were lower in TI than SI groups. The cardiomyocyte cross-sectional area and the beta myosin heavy chain (MYH7) mRNA level of RV were lower in TI than SI, whereas alpha myosin heavy chain (MYH6) was increased. These results show that two intraperitoneal injections of 20 mg/kg MCT with seven days interval could induce a model similar to chronic PAH with increased survival percentage in rats. Impact statement We demonstrated previously that a single intraperitoneal injection of 40 mg/kg MCT produced a subacute, not chronic, PAH model in rats, and the short survival periods of these rats did not represent adequately the chronic PAH seen in humans. To overcome this limitation, in this study, the single dose of 40 mg/kg MCT was divided into twice injections of 20 mg/kg with an interval of seven days. This modified administration of MCT produced an animal model much more similar to chronic PAH with prolonged survival and characteristic changes of structures and function in pulmonary arteries and right ventricles.

Sinoatrial node fibrosis is involved in the pathogenesis of sinus sick syndrome (SSS). Transient receptor potential (TRP) subfamily M member 7 (TRPM7) is implicated in cardiac fibrosis. However, the mechanisms underlying the regulation of sinoatrial node (SAN) fibrosis in SSS by TRPM7 remain unknown. The aim of this study was to investigate the role of angiotensin II (Ang II)/TRPM7/Smad pathway in the SAN fibrosis in rats with SSS. The rat SSS model was established with sodium hydroxide pinpoint pressing permeation. Forty-eight rats were randomly divided into six groups: normal control (ctrl), sham operation (sham), postoperative 1-, 2-, 3-, and 4-week SSS, respectively. The tissue explant culture method was used to culture cardiac fibroblasts (CFs) from rat SAN tissues. TRPM7 siRNA or encoding plasmids were used to knock down or overexpress TRPM7. Collagen (Col) distribution in SAN and atria was assessed using PASM–Masson staining. Ang II, Col I, and Col III levels in serum and tissues or in CFs were determined by ELISA. TRPM7, smad2 and p-smad2 levels were evaluated by real-time PCR, and/or western blot and immunohistochemistry. SAN and atria in rats of the SSS groups had more fibers and higher levels of Ang II, Col I and III than the sham rats. Similar findings were obtained for TRPM7 and pSmad2 expression. In vitro, Ang II promoted CFs collagen synthesis in a dose-dependent manner, and potentiated TRPM7 and p-Smad2 expression. TRPM7 depletion inhibited Ang II-induced p-Smad2 expression and collagen synthesis in CFs, whereas increased TRPM7 expression did the opposite. SAN fibrosis is regulated by the Ang II/TRPM7/Smad pathway in SSS, indicating that TRPM7 is a potential target for SAN fibrosis therapy in SSS.

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We investigated the effect of adipose-derived stem cells (ADSCs) transplantation effects on structural remodeling and pulmonary artery pressure in monocrotaline (MCT)-induced pulmonary hypertensive rats. In the first experiment, 32 male Sprague-Dawley (SD) rats were randomly divided into four groups (n = 8/group): 3 ADSCs treated groups and normal control (Ctrl). ADSCs were administered through the left jugular vein at 10(5), 10(6) and 10(7) cells, respectively, and a cell density of 10(6)cells/ml was shown to be optimal. The GFP-tagged ADSCs were identified in the lungs and differentiated into endothelial-like cells. In the second experiment, 96 male SD rats were randomly divided into three groups (n = 32/group): Ctrl, MCT-induced pulmonary arterial hypertension (PAH), and PAH treated with ADSCs (ADSCs). Two weeks post-MCT administration, the ADSCs group received 1 × 10(6) ADSCs via the external jugular vein. Compared to PAH rats, mean pulmonary arterial pressure was decreased in rats at 1, 2, and 3 weeks after ADSCs-treatment (18.63 ± 2.15 mmHg versus 24.53 ± 2.90 mmHg; 23.07 ± 2.84 mmHg versus 33.18 ± 2.30 mmHg; 22.98 ± 2.34 mmHg versus 36.38 ± 3.28 mmHg, p < 0.05). Meanwhile, the right heart hypertrophy index (36.2 1 ± 4.27% versus 41.01 ± 1.29%; 39.47 ± 4.02% versus 48.75 ± 2 .13%; 41.02 ± 0.9% versus 50.52 ± 1.49%, p < 0.05, respectively), ratio of wall/lumen thickness, as well as the wall/lumen area were significantly reduced in PAH rats at these time points following ADSCs-treatment, as compared with untreated PAH rats. In summary, ADSCs may colonize the pulmonary arteries, attenuate pulmonary arterial hypertension and ameliorate pulmonary arterial remodeling.

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