Icariin improves cardiac function and remodeling via the TGF-ß1/Smad signaling pathway in rats following myocardial infarction.

BACKGROUND: Postinfarction cardiac remodeling presents a compensatory mechanism aimed at mitigating congestive heart failure. It is distinguished by progressive dilatation and hypertrophy of the ventricular chambers, fibrotic alterations, and prolonged apoptosis of cardiomyocytes. The primary objective of this study was to assess the effects of icariin on myocardial fibrosis and ventricular remodeling in rats subjected to myocardial infarction (MI). METHODS: Male Sprague‒Dawley (SD) rats were subjected to randomization and subsequently divided into distinct groups: the control group, the sham group (undergoing sham operation), the MI group (experiencing ligation of the left anterior descending artery), and the icariin group. Within the icariin group, rats were further categorized into three different dose groups based on the administered icariin dosage: the MI30 group (30 mg/kg/day), the MI60 group (60 mg/kg/day), and the MI120 group (120 mg/kg/day). Cardiac function evaluation was carried out using echocardiography. Histological examinations, including hematoxylin and eosin (HE) staining, Masson staining, and immunohistochemistry studies, were conducted 90 days after the occurrence of MI. Additionally, Western blotting was employed to assess TGF-ß1, p-Smad2, and p-Smad3 levels. RESULTS: The administration of icariin revealed a noteworthy enhancement in cardiac function among rats afflicted with left anterior descending coronary artery (LAD) ligation. In comparison to the icariin groups, the MI group exhibited reduced EF and FS, along with elevated LVEDD and LVESD. Furthermore, the cardiac fibrosis levels in the MI group rats exhibited a considerable increase compared to those in the icariin group. Notably, the levels of Collagen I, Collagen III, MMP2, and MMP9 were significantly higher in the MI group than in the icariin group, with evident distinctions. Moreover, the expression levels of TGF-ß, IL-13, p-Smad2, and p-Smad3 were notably upregulated in the MI group compared to the icariin group. CONCLUSIONS: In an experimental rat model of MI, the administration of icariin resulted in the amelioration of both cardiac function and remodeling processes, operating through the intricate TGF-ß1/Smad signaling pathway.

Astragalus (Astragalus mongholicus) Improves Ventricular Remodeling via ESR1 Downregulation RhoA/ROCK Pathway.

Astragalus (Astragalus mongholicus) alleviates myocardial remodeling caused by hypertension. However, the detailed molecular mechanism is unclear. This study aims to investigate the effect of Astragalus on ventricular remodeling in ovariectomized spontaneous hypertensive rats (OVX-SHR).Female SHR/NCrl rats were subjected to bilateral ovariectomy to establish the OVX-SHR model and treated with Astragalus extract by gavage. The hemodynamics and cardiac function parameters were measured. HE and Masson staining were used to detect the pathological structure of myocardial remodeling and observe the hyperplasia of myocardial collagen fibers. The immunohistochemistry tested the level of α-SMA. The expression levels of inflammatory cytokines, IκB, p65, Cleaved-Caspase3, RhoA, and ROCK1/2 were detected using Western blot. The method of qRT-PCR measured the expression of matrix metalloproteinase (MMP-2 and MMP-9).Hemodynamic and cardiac function parameters were significantly improved after a high dose of Astragalus extract and Valsartan treatment. The myocardial integrity of the model group was significantly reduced, arranged loosely, and disordered, while the expression of α-SMA was increased. However, Astragalus extract and Valsartan treatments significantly reduced the pathological damage and α-SMA. The levels of TNF-α, IL-1ß, IL-6, TGF-ß, MMP-2, and MMP-9 in the model group were increased but decreased after Astragalus extract treatment. Adding an ESR1 inhibitor attenuated the improvement effect of Astragalus extract on myocardial remodeling and restored the expression of RhoA and ROCK1/2.Astragalus extract attenuates the cardiac damage in OVX-SHR by downregulating the RhoA/ROCK pathway through ESR1.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomal microRNA-29b-3p Promotes Angiogenesis and Ventricular Remodeling in Rats with Myocardial Infarction by Targeting ADAMTS16.

An increasing amount of evidence has suggested that microRNA (miR) plays a role in myocardial infarction (MI). Our study aimed to discuss the impact of exosomal miR-29b-3p in MI by regulating A Disintegrin and Metalloproteinase with Thrombospondin Motifs 16 (ADAMTS16). Exosomes were extracted from bone marrow mesenchymal stem cells (BMSCs). In a rat model of MI, myocardial angiogenesis and ventricular remodeling-related factors, as well as myocardial fibrosis, collagen volume fraction (CVF), capillary density, level of vascular endothelial growth factor (VEGF), and apoptosis of cardiomyocytes, were tested. ADAMTS16 and miR-29b-3p levels in the myocardial tissue of MI rats were tested. miR-29b-3p expression was decreased and ADAMTS16 expression was increased in the myocardial tissue of MI rats. ADAMTS16 was a target gene of miR-29b-3p. Upregulated miR-29b-3p delivered by BMSC-derived exosomes improved myocardial angiogenesis and ventricular remodeling, reduced myocardial fibrosis and CVF, increased capillary density and VEGF expression, and suppressed apoptosis of cardiomyocytes in MI rats. ADAMTS16 overexpression accelerated MI in rats, and ADAMTS16 upregulation reversed the protective effects of miR-29b-3p upregulation on MI rats. Our study provides evidence that upregulated miR-29b-3p delivered by BMSC-secreted exosomes can improve myocardial angiogenesis and ventricular remodeling in rats with MI by targeting ADAMTS16.

Amperometric hydrazine sensor based on the use of a gold nanoparticle-modified nanocomposite consisting of porous polydopamine, multiwalled carbon nanotubes and reduced graphene oxide.

A porous hybrid material was prepared from polydopamine-modified multiwalled carbon nanotubes and reduced graphene oxide. It was employed as a supporting material for an electrochemical hydrazine sensor. Gold nanoparticles with a size of about 13 nm were placed on the material which then was characterized by transmission electron microscopy, field emission-scanning electron microscopy, Raman spectra, FTIR and nitrogen absorption/desorption plots. The material is highly porous and has a specific surface of 290 m2 g-1, which is larger than that of P-MWCNT/rGO alone (149 m2 g-1), and an increased pore volume. It was placed on a glassy carbon electrode (GCE), and cyclic voltammetry, chronoamperometry and amperometric i-t curves were used to characterize the catalytic activity of the sensor. The kinetic parameters of the modified GCE were calculated which proved that it has a high catalytic efficiency in promoting the electron transfer kinetics of hydrazine. The amperometric signal (obtained at a typical working potential of 0.35 V vs. SCE) has two linear ranges, one from 1 µM - 3 mM and one from 3 to 55 mM, with sensitivities of 524 and 98 A mM-1 cm-2, respectively. The detection limit is 0.31 µM. Graphical abstractThe porous nanocomposite was synthesized by etching silver nanoparticles and a enhanced non-enzymatic electrochemical sensor of hydrazine was successfully designed. The electrochemical performances of the modified electrode were also examined.

High-index {hk0} facets platinum concave nanocubes loaded on multiwall carbon nanotubes and graphene oxide nanocomposite for highly sensitive simultaneous detection of dopamine and uric acid.

Carbon materials and the metal nanocrystals enclosed by high-index facets have aroused considerable attention due to their large specific surface area, excellent electrical properties and catalysis activity, and easy accessibility for target molecules. In this study, the Pt concave nanocube (CNC) with high-index {410} and {510} facets was successfully prepared via a simple hydrothermal method. The multiwalled carbon nanotubes (MWCNT) and graphene oxide (GO) were chosen as the supporting materials to further improve the dispersion of Pt CNC and the electrical conductivity of nanocomposite. The nanocomposite was used to modify electrode for sensitive simultaneous detection dopamine and uric acid. The cyclic voltammetry and differential pulse voltammetry were applied to confirm the catalytic activity of proposed sensor. By using the as-synthesized nanomaterial as nonenzymatic sensing material, dopamine and uric acid can be detected with high sensitivity and selectivity. The linear range towards dopamine sensing is from 0.8 to 300 µM, and the limit of detection is 0.27 µM. For uric acid sensing, the sensor exhibited over two wide linear ranges (from 1 µM to 0.3 mM and from 0.3 mM to 1 mM) with a detection limit of 0.35 µM. The sensor also possessed a long-term stability, good reproducibility and a promising application for electrochemical detection of both dopamine and uric acid in real samples.

Graphene oxide nanosheet-supported Pt concave nanocubes with high-index facets for high-performance H2O2 sensing.

As is known, the catalytic activity of metal nanocrystals is strongly affected by their size and shape, and the shape has a greater impact. Among them, metal nanocrystals enclosed by high-index facets have attracted significant attention due to their excellent properties. In this study, platinum concave nanocubes (Pt CNC) with different sizes and angles distributed on polyvinyl pyrrolidone-functional graphene oxide (GO) were synthesized by a one-pot hydrothermal process. The platinum concave nanocubes mainly enclosed by {410}, {510}, and {610} were prepared and used as modified glassy carbon electrodes; cyclic voltammetry and chronoamperometry were applied to investigate the difference between the catalytic activities of platinum concave nanocubes with different facets. The electrodes induced efficient electrocatalysis of hydrogen peroxide (H2O2), and the electrode modified with Pt CNC/rGO-220 showed the highest reduction current. H2O2 was detected with a detection limit of 0.7 µM over two wide linear ranges (from 3 µM to 1 mM and from 1 mM to 0.1 M) and with high sensitivities (757.4 µA mM-1 cm-2 and 315.4 µA mM-1 cm-2), respectively. The modified glassy carbon electrodes also exhibited good stability and selectivity.

Direct growth of ordered PdCu and Co doped PdCu nanoparticles on graphene oxide based on a one-step hydrothermal method for ultrasensitive sensing of H2O2 in living cells.

Ordered PdCu and Co doped PdCu nanoparticles have been synthesized on graphene oxide (GO). The obtained Co-PdCu/GO composites were used to fabricate a H2O2 electrochemical sensor which exhibits an ultralow LOD (limit of detection) of 1.2 nM and an extra broad linear range of 5 nM-5.774 mM, and has been used to detect H2O2 in living cells successfully.

Effects of Baicalin on Blood Pressure and Left Ventricular Remodeling in Rats with Renovascular Hypertension.

BACKGROUND This study aimed to explore the effect of baicalin, which is a kind of bioactive flavonoid, on blood pressure and left ventricular remodeling in rats with renovascular hypertension. MATERIAL AND METHODS A total of 40 male Wistar rats were randomly assigned into sham-operation (n=10) and renal hypertension model groups (2-kidney-1 clip; 2K-1C, n=30). The rats in the renal hypertension model group were randomly subdivided into 2K-1C (n=13) and 2K-1C/Baicalin groups (n=14). The cardiac function indexes were determined after 4 weeks. The morphological changes in the myocardial tissue were observed using hematoxylin and eosin and Masson staining. The myocardial apoptosis was detected using the terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling method, and the expression of C/EBP homologous protein and caspase-3 was monitored by Western blot. The expression of GRP78 and GRP94 in myocardial cells of rats was detected by qPCR and Western blot technology. RESULTS No significant change in blood pressure was observed in the 2K-1C/Baicalin group compared with the 2K-1C group, but the indexes of left ventricular remodeling significantly improved. Pathological myocardial fibrosis and expression of fibrosis-related factors significantly decreased in the 2K-1C/Baicalin group compared with the 2K-1C group. The expression of glucose-regulated protein (GRP)78, GRP94, CHOP, and caspase-3, and apoptosis of cardiomyocytes also decreased in the 2K-1C/Baicalin group. CONCLUSIONS Baicalin has no significant antihypertensive effect, but reduced pathological changes in the myocardium, alleviated endoplasmic reticulum stress, and reduced myocardial apoptosis, reverting left ventricular remodeling in rats with renovascular hypertension.

Conditionally replicative adenovirus-based mda-7/IL-24 expression enhances sensitivity of colon cancer cells to 5-fluorouracil and doxorubicin.

BACKGROUND: Multiple drug resistance (MDR) greatly limits the efficacy of chemotherapy for colon cancer. An adenovirus armed with Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24; abbreviated to 'IL-24' here) was shown to reverse the MDR of colon cancer cells to oxaliplatin and doxorubicin. However, the relatively low expression level of IL-24 mediated by a replication-deficient adenoviral vector hindered its clinical application. METHODS: To enhance IL-24-dependentreversion of the MDR phenotype, we utilized a conditionally replicative adenoviral vector, AdBB-IL24, to express IL-24 at a high level for more efficient MDR reversion. RESULTS: An enzyme-linked immunosorbent assay (ELISA) suggested conditionally replicative adenoviral vector-mediated IL-24 expression was elevated in comparison with that of a replication-deficient adenoviral vector, Ad-IL24. AdBB-IL24 was shown to reverse MDR in colon cancer cells more potently than Ad-IL24. The AdBB-IL24-induced MDR reversion was linked to reduced P-glycoprotein (Pgp) and breast cancer resistance protein 1 (BCRP1) expression. Consistently, 5-fluorouracil and doxorubicin induced more apoptosis in AdBB-IL24-infected colon cancer cells compared with that in the Ad-IL24-infected cells. A cell viability assay showed that AdBB-IL24 could enhance the growth-inhibitory effect of 5-fluorouracil and doxorubicin on colon cancer cells more effectively than Ad-IL24 in vitro. In a mouse model, we also found that the combination of 5-fluorouracil and doxorubicin with AdBB-IL24 completely inhibited the growth of colon cancer cells. CONCLUSION: We here provide evidence supporting conditionally replicative adenoviral vector-based gene therapy as a powerful strategy to enhance mda7/IL-24-dependent MDR reversion of colon cancer cells.

[Erythropoietin inhibits angiotensin II induced cardiomyocyte hypertrophy in vitro via activating PI3K/Akt-eNOS pathway].

OBJECTIVE: To explore the effect of erythropoietin (EPO) on angiotensin II (AngII) induced neonatal rat cardiomyocyte hypertrophy and the association with PI3K/Akt-eNOS signaling pathway. METHODS: Cardiomyocytes were isolated from new-born Sprague-Dawley rats and stimulated by AngII in vitro. The cell surface area and mRNA expression of atrial natriuretic factor (ANF) of cardiomyocytes were determined in the presence and absence of various concentrations of EPO, phosphatidylinositol 3'-kinase (PI3K) inhibitor LY294002 and nitric oxide synthase (NOS) inhibitor L-NAME. Intracellular signal molecules, such as Akt, phosphorylated Akt, eNOS and phosphorylated eNOS protein expressions were detected by western blot. Nitric oxide (NO) level in the supernatant of cultured cardiomyocytes was assayed by NO assay kit. RESULTS: EPO (20 U/ml) significantly inhibited AngII induced cardiomyocyte hypertrophy as shown by decreased cell surface area and ANF mRNA expression (all P < 0.05). EPO also activated Akt and enhanced the expression of eNOS and its phosphorylation (all P < 0.05), increased the NO production (P < 0.01). These effects could be partially abolished by cotreatment with LY294002 or L-NAME (all P < 0.05). CONCLUSION: EPO attenuates AngII induced cardiomyocytes hypertrophy via activating PI3K-Akt-eNOS pathway and promoting NO production.

Erythropoietin attenuates hypertrophy of neonatal rat cardiac myocytes induced by angiotensin-II in vitro.

OBJECTIVE: Erythropoietin (EPO) is a haematopoietic hormone that has been confirmed as a novel cardioprotective agent. In this study, we test the hypothesis that EPO inhibits angiotensin-II (Ang-II)-induced hypertrophy in cultured neonatal rat cardiomyocytes. MATERIAL AND METHODS: Cultured neonatal rat cardiomyocytes were used to evaluate the effects of EPO on Ang-II-induced hypertrophy in vitro. The surface area and mRNA expression of atrial natriuretic (ANF) myocytes were employed to detect cardiac hypertrophy. A phosphatidylinositol 3'-kinase (PI3K) inhibitor LY294002 and an endothelial nitric oxide synthase (eNOS) inhibitor L-NAME were also employed to detect the underlying mechanism of EPO. Intracellular signal molecules, such as Akt (PKB), phosphorylated Akt, eNOS and transforming growth factor-beta1 (TGF-beta1) protein expression were determined by Western blot. Nitric oxide (NO) levels in the supernatant of cultured cardiomyocytes were assayed using an NO assay kit. RESULTS: The results indicate that EPO significantly attenuates Ang-II-induced hypertrophy shown as inhibition of increases in cell surface area and ANF mRNA levels. NO production was also increased proportionally in the EPO-treated group. EPO enhanced Akt activation and eNOS protein expression, whereas LY294002 or L-NAME partially abolished the anti-hypertrophic effect of EPO, accompanied by a decrease in Akt activation, eNOS protein expression and/or a reduction of NO production. EPO also down-regulated the protein expression of TGF-beta1. CONCLUSION: We conclude that EPO attenuates cardiac hypertrophy via activation of the PI3K-Akt-eNOS-NO pathway and the down-regulation of TGF-beta1.

[Erythropoietin suppresses the expressions of TGF-beta1 and collagen in rat cardiac fibroblasts induced by angiotensin II].

OBJECTIVE: Recent studies have shown cardiac protection effects of erythropoietin (EPO). The present experiment was designed to investigate the effects of EPO on TGF-beta1, nitric oxide synthase (NOS), collagen contents induced by angiotensin II (Ang II) in rat cardiac fibroblasts (CFs) and explore the roles of PI3-K/Akt signaling pathway on related effects. METHODS: Neonatal rat CFs was isolated by collagenase and trypsinase digestion methods. PBS, EPO, Ang II in the absence or presence of LY294002, an inhibitor of PI3-K, or L-NAME, an inhibitor of NOS, were added to CFs and cultured for 24 hours. The concentration of collagen I and collagen III in culture medium were quantitated by ELISA. The levels of nitric oxide (NO) and the activities of NOS as well as NOS isoforms were measured by chemical enzymic method. Western blot was applied to detecting the protein expressions of Akt, p-Akt, eNOS, iNOS, and TGF-beta1. RESULTS: The concentrations of collagen I and collagen III in CFs culture medium were significantly increased while the level of NO was significantly decreased by Ang II and these changes were significantly suppressed by EPO in a dose dependent manner. The effects of EPO on eNOS and NO could be blocked by LY294002. L-NAME could block EPO's effect on NO but not on the eNOS expression. The suppression effects on expressions of TGF-beta1 and collagen by Ang II in CFs were blocked by both LY294002 and L-NAME. CONCLUSION: EPO suppresses the upregulated expressions of TGF-beta1 and increased production of collagen induced by Ang II through activating the PI3-K/Akt signaling pathway in neonatal rat CFs.