The effect of macrophages and their exosomes in ischemic heart disease.

Ischemic heart disease (IHD) is a leading cause of disability and death worldwide, with immune regulation playing a crucial role in its pathogenesis. Various immune cells are involved, and as one of the key immune cells residing in the heart, macrophages play an indispensable role in the inflammatory and reparative processes during cardiac ischemia. Exosomes, extracellular vesicles containing lipids, nucleic acids, proteins, and other bioactive molecules, have emerged as important mediators in the regulatory functions of macrophages and hold promise as a novel therapeutic target for IHD. This review summarizes the regulatory mechanisms of different subsets of macrophages and their secreted exosomes during cardiac ischemia over the past five years. It also discusses the current status of clinical research utilizing macrophages and their exosomes, as well as strategies to enhance their therapeutic efficacy through biotechnology. The aim is to provide valuable insights for the treatment of IHD.

The molecular mechanisms of peptidyl-prolyl cis/trans isomerase Pin1 and its relevance to kidney disease.

Pin1 is a member of the peptidyl-prolyl cis/trans isomerase subfamily and is widely expressed in various cell types and tissues. Alterations in Pin1 expression levels play pivotal roles in both physiological processes and multiple pathological conditions, especially in the onset and progression of kidney diseases. Herein, we present an overview of the role of Pin1 in the regulation of fibrosis, oxidative stress, and autophagy. It plays a significant role in various kidney diseases including Renal I/R injury, chronic kidney disease with secondary hyperparathyroidism, diabetic nephropathy, renal fibrosis, and renal cell carcinoma. The representative therapeutic agent Juglone has emerged as a potential treatment for inhibiting Pin1 activity and mitigating kidney disease. Understanding the role of Pin1 in kidney diseases is expected to provide new insights into innovative therapeutic interventions and strategies. Consequently, this review delves into the molecular mechanisms of Pin1 and its relevance in kidney disease, paving the way for novel therapeutic approaches.

Messenger Nanozyme for Reprogramming the Microenvironment of Rheumatoid Arthritis.

Dysregulation of superoxide anion (O2-) and hydrogen peroxide (H2O2) metabolism in the microenvironment of rheumatoid arthritis (RA) drives the feedback loops of TNF-α and IL-1ß thereby inducing an inflammatory storm between immune cells and joint tissue cells. Here, we combine nanoscale manganese dioxide (MnO2) with microvesicles derived from macrophage (MMV). The former possesses superoxide dismutase (SOD) and catalase (CAT)-like activities that can modulate this imbalance, and we amplify the enzyme-like activities by using the amorphous hollow mesoporous structure and surface modification. The latter is a natural endogenous component with the parent cell-like inflammatory homing ability and a unique function of transmitting information to surrounding and distant cells (″messenger function″), which helps amorphous hollow MnO2 (H-MnO2) nanozymes to cloak in the blood and reach the site of inflammation, where they can not only accumulate in activated macrophages but also pretend to be ″messengers″ that are utilized by fibroblast-like synoviocytes (FLS) and chondrocytes. In addition, we also load dexamethasone sodium phosphate (DSP) for helping the nanozymes work. Messenger nanozyme (MMV-MnO2@DSP) inherits the natural properties of MMV and mimics the enzymatic activity of SOD and CAT. It accumulates in activated macrophages to restore the metabolism of O2- and H2O2 while promoting repolarization and inhibits the feedback loops of TNF-α and IL-1ß among macrophages, fibroblast-like synoviocytes, and chondrocytes, leading to anti-rheumatoid arthritis effects in vitro and in vivo.

An examination of the protective effects and molecular mechanisms of curcumin, a polyphenol curcuminoid in diabetic nephropathy.

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease and is an enormous burden on both patients and society. There is an urgent need for effective alternative therapeutic strategies for the treatment of DN, as medical treatment is currently limited. The anti-inflammatory, antioxidative, anti-apoptotic, and anti-fibrosis properties of curcumin, a polyphenol curcuminoid, have been demonstrated in research on diabetic nephropathy. The clinical and preclinical trials and mechanisms by which curcumin affects DN have been discussed in this review. A deeper understanding of the pharmacological effects of curcumin on diabetic nephropathy may provide new therapies to improve the development and occurrence of diabetic nephropathy.

P21­activated kinase 1 mediates angiotensin II­induced differentiation of human atrial fibroblasts via the JNK/c­Jun pathway.

Cardiac fibrosis is a common pathophysiological condition involved in numerous types of cardiovascular disease. The renin­angiotensin system, particularly angiotensin II (AngII), serves an important role in cardiac fibrosis and remodeling. Furthermore, p21­activated kinase 1 (PAK1) is a highly conserved serine/threonine protein kinase, which is abundantly expressed in all regions of the heart. However, the role of PAK1 in AngII­mediated activation of cardiac fibroblasts remains unknown. Therefore, the present study aimed to investigate the role of PAK1 in cardiac fibroblasts and its underlying mechanisms. Human cardiac fibroblasts (HCFs) were cultured and treated with PAK1 inhibitor IPA­3 or transduced with PAK1 short hairpin (sh)RNA by lentiviral particles to silence PAK1 expression levels. Subsequently, the cell proliferation and migration abilities of the HCFs were determined. Western blot analysis was used to detect the phosphorylation status of Janus kinase (JNK) and c­Jun. A Cell Counting Kit­8 assay showed that PAK1 inhibition following treatment of HCFs with 5 µM IPA­3 or PAK1­shRNA, significantly attenuated AngII­induced proliferation of fibroblasts. In addition, wound healing and Transwell migration assays demonstrated that inhibition of PAK1 significantly inhibited AngII­induced cell migration. Finally, decreased PAK1 expression levels downregulated AngII­mediated upregulation of α­smooth muscle actin (α­SMA), collagen I, phosphorylated (p)­JNK and p­c­Jun, a downstream molecule of JNK signaling. These findings indicate that PAK1 contributes to AngII­induced proliferation, migration and transdifferentiation of HCFs via the JNK/c­Jun pathway.

Principles of Optogenetic Methods and Their Application to Cardiac Experimental Systems.

Optogenetic techniques permit studies of excitable tissue through genetically expressed light-gated microbial channels or pumps permitting transmembrane ion movement. Light activation of these proteins modulates cellular excitability with millisecond precision. This review summarizes optogenetic approaches, using examples from neurobiological applications, and then explores their application in cardiac electrophysiology. We review the available opsins, including depolarizing and hyperpolarizing variants, as well as modulators of G-protein coupled intracellular signaling. We discuss the biophysical properties that determine the ability of microbial opsins to evoke reliable, precise stimulation or silencing of electrophysiological activity. We also review spectrally shifted variants offering possibilities for enhanced depth of tissue penetration, combinatorial stimulation for targeting different cell subpopulations, or all-optical read-in and read-out studies. Expression of the chosen optogenetic tool in the cardiac cell of interest then requires, at the single-cell level, introduction of opsin-encoding genes by viral transduction, or coupling "spark cells" to primary cardiomyocytes or a stem-cell derived counterpart. At the system-level, this requires construction of transgenic mice expressing ChR2 in their cardiomyocytes, or in vivo injection (myocardial or systemic) of adenoviral expression systems. Light delivery, by laser or LED, with widespread or multipoint illumination, although relatively straightforward in vitro may be technically challenged by cardiac motion and light-scattering in biological tissue. Physiological read outs from cardiac optogenetic stimulation include single cell patch clamp recordings, multi-unit microarray recordings from cell monolayers or slices, and electrical recordings from isolated Langendorff perfused hearts. Optical readouts of specific cellular events, including ion transients, voltage changes or activity in biochemical signaling cascades, using small detecting molecules or genetically encoded sensors now offer powerful opportunities for all-optical control and monitoring of cellular activity. Use of optogenetics has expanded in cardiac physiology, mainly using optically controlled depolarizing ion channels to control heart rate and for optogenetic defibrillation. ChR2-expressing cardiomyocytes show normal baseline and active excitable membrane and Ca2+ signaling properties and are sensitive even to ~1 ms light pulses. They have been employed in studies of the intrinsic cardiac adrenergic system and of cardiac arrhythmic properties.

Resveratrol alleviates hypoxia/reoxygenation injury­induced mitochondrial oxidative stress in cardiomyocytes.

Resveratrol (RES) is a naturally occurring antioxidant compound found in red wine. Although it has been demonstrated to have a cardioprotective effect, the mechanism underlying this effect remains to be fully elucidated. The aim of the present study was to determine whether RES exerts a protective effect against mitochondrial oxidative stress and apoptosis in neonatal rat cardiomyocytes (NRCMs) induced by hypoxia/reoxygenation (H/R) injury. Primary cultured NRCMs were used as a model system and were divided into four experimental groups: Control, H/R, H/R + DMSO (H/R with 0.2% DMSO) and H/R + RES (H/R with 100 µM RES) groups. Mitochondrial oxidative stress was determined by measuring the alteration in the mitochondrial membrane potential (ΔΨm) of NRCMs, the release of lactate dehydrogenase (LDH) and the ratio of B­cell lymphoma 2 (Bcl­2)/Bcl­2­associated X protein (Bax) from NRCMs. Cell apoptosis was assessed by measuring cell apoptotic rates and the activity of caspase 3. In the H/R+RES group, RES significantly alleviated structural impairment, including disordered α­actin and F­actin, in the NRCMs induced by H/R injury. RES attenuated H/R injury­induced mitochondria oxidative stress. RES also attenuated H/R injury­induced cell apoptosis; it decreased the NRCM apoptotic rate from 84.25±7.41% (H/R) to 46.39±5.43% (H/R+RES) (P<0.05, n=4), rescued the decrease in the Bcl2/Bax ratio induced by H/R from 0.53±0.08­fold (H/R) to 0.86±0.06­fold (H/R+RES) (P<0.05, n=5) and alleviated the increased activity of caspase 3 induced by H/R from 1.32±0.06­fold to 1.02±0.04­fold (P<0.05, n=5). Furthermore, RES significantly attenuated the increment of LDH release induced by H/R injury in NRCMs from 1.41±0.03­fold (H/R) to 1.02±0.06­fold (H/R+RES) (P<0.01, n=4) and alleviated the depolarization of ΔΨm induced by H/R, shifting the ratio of JC­1 monomer from 62.39±1.82% (H/R) to 35.31±8.63% (H/R+RES) (P<0.05, n=4). RES alleviated the decrease in sirtuin 1 induced by H/R injury from 0.61±0.06­fold (H/R) to 1.01±0.05­fold (H/R+RES) (P<0.05, n=5). In conclusion, the present study is the first, to the best of our knowledge, to demonstrate that RES provides cardioprotection against H/R injury through decreasing mitochondria­mediated oxidative stress injury and structural impairment in NRCMs. These results provide scientific evidence for the clinical application of RES in the treatment of cardiac conditions.

Dexmedetomidine attenuates H2O2-induced neonatal rat cardiomyocytes apoptosis through mitochondria- and ER-medicated oxidative stress pathways.

Dexmedetomidine (DEX), an α2 adrenoceptor agonist, has sedative and analgesic properties and myocardial protective effects. However, the mechanism underlying the protective effects of DEX on the myocardium remain unclear. The present study aimed to determine whether DEX serves an important role on cardioprotection through the endoplasmic reticulum (ER)­ and mitochondria­mediated apoptosis signaling pathways. Neonatal rat cardiomyocytes (NRCMs) were cultured and divided four groups: i) Normal culture medium with 10% fetal bovine serum (control group); ii) H2O2 at 500 µM (H2O2 group); iii) DEX at 5 µM (DEX group); and iv) H2O2 plus DEX (H2O2 + DEX group). The levels of apoptosis and oxidative stress of NRCMs were investigated by ELISA, western blotting, flow cytometry and cell immunofluorescence. DEX significantly suppressed H2O2­induced apoptosis, and increased activity of caspases 3, 8 and 9 of NRCMs. DEX inhibited mitochondria­mediated oxidative stress and apoptosis, as evidenced by decreased levels of reactive oxygen species and lactic dehydrogenase, alleviated mitochondrial membrane potential depolarization, and increased Bcl­2­associated X protein/B­cell lymphoma 2 ratio. In addition, DEX decreased the activity of caspase 12, and the expression levels of glucose­regulated protein 78 kDa and serine/threonine­protein kinase/endoribonuclease IRE1, three major signaling molecules involved in the ER stress­mediated apoptosis pathway. Preventive treatment with DEX alleviates cardiomyocyte against H2O2­induced oxidative stress injury through attenuating the mitochondria­ and ER­mediated apoptosis pathways.

Multi-walled carbon nanotubes act as a chemokine and recruit macrophages by activating the PLC/IP3/CRAC channel signaling pathway.

The impact of nanomaterials on immune cells is gaining attention but is not well documented. Here, we report a novel stimulating effect of carboxylated multi-walled carbon nanotubes (c-MWCNTs) on the migration of macrophages and uncover the underlying mechanisms, especially the upstream signaling, using a series of techniques including transwell migration assay, patch clamp, ELISA and confocal microscopy. c-MWCNTs dramatically stimulated the migration of RAW264.7 macrophages when endocytosed, and this effect was abolished by inhibiting phospholipase C (PLC) with U-73122, antagonizing the IP3 receptor with 2-APB, and blocking calcium release-activated calcium (CRAC) channels with SK&F96365. c-MWCNTs directly activated PLC and increased the IP3 level and [Ca2+]i level in RAW264.7 cells, promoted the translocation of the ER-resident stromal interaction molecule 1 (STIM1) towards the membranous calcium release-activated calcium channel modulator 1 (Orai1), and increased CRAC current densities in both RAW264.7 cells and HEK293 cells stably expressing the CRAC channel subunits Orai1 and STIM1. c-MWCNTs also induced dramatic spatial polarization of KCa3.1 channels in the RAW264.7 cells. We conclude that c-MWCNT is an activator of PLC and strongly recruits macrophages via the PLC/IP3/CRAC channel signaling cascade. These novel findings may provide a fundamental basis for the impact of MWCNTs on the immune system.

Propofol attenuates H2O2-induced oxidative stress and apoptosis via the mitochondria- and ER-medicated pathways in neonatal rat cardiomyocytes.

Previous studies have shown that propofol, an intravenous anesthetic commonly used in clinical practice, protects the myocardium from injury. Mitochondria- and endoplasmic reticulum (ER)-mediated oxidative stress and apoptosis are two important signaling pathways involved in myocardial injury and protection. The present study aimed to test the hypothesis that propofol could exert a cardio-protective effect via the above two pathways. Cultured neonatal rat cardiomyocytes were treated with culture medium (control group), H2O2 at 500 µM (H2O2 group), propofol at 50 µM (propofol group), and H2O2 plus propofol (H2O2 + propofol group), respectively. The oxidative stress, mitochondrial membrane potential (ΔΨm) and apoptosis of the cardiomyocytes were evaluated by a series of assays including ELISA, flow cytometry, immunofluorescence microscopy and Western blotting. Propofol significantly suppressed the H2O2-induced elevations in the activities of caspases 3, 8, 9 and 12, the ratio of Bax/Bcl-2, and cell apoptosis. Propofol also inhibited the H2O2-induced reactive oxygen species (ROS) generation, lactic dehydrogenase (LDH) release and mitochondrial transmembrane potential (ΔΨm) depolarization, and restored the H2O2-induced reductions of glutathione (GSH) and superoxide dismutase (SOD). In addition, propofol decreased the expressions of glucose-regulated protein 78 kDa (Grp78) and inositol-requiring enzyme 1α (IRE1α), two important signaling molecules in the ER-mediated apoptosis pathway. Propofol protects cardiomyocytes from H2O2-induced injury by inhibiting the mitochondria- and ER-mediated apoptosis signaling pathways.

Activation of AMPA receptor promotes TNF-α release via the ROS-cSrc-NFκB signaling cascade in RAW264.7 macrophages.

The relationship between glutamate signaling and inflammation has not been well defined. This study aimed to investigate the role of AMPA receptor (AMPAR) in the expression and release of tumor necrosis factor-alpha (TNF-α) from macrophages and the underlying mechanisms. A series of approaches, including confocal microscopy, immunofluorescency, flow cytometry, ELISA and Western blotting, were used to estimate the expression of AMPAR and downstream signaling molecules, TNF-α release and reactive oxygen species (ROS) generation in the macrophage-like RAW264.7 cells. The results demonstrated that AMPAR was expressed in RAW264.7 cells. AMPA significantly enhanced TNF-α release from RAW264.7 cells, and this effect was abolished by CNQX (AMPAR antagonist). AMPA also induced elevation of ROS production, phosphorylation of c-Src and activation of nuclear factor (NF)-κB in RAW264.7 cells. Blocking c-Src by PP2, scavenging ROS by glutathione (GSH) or inhibiting NF-κB activation by pyrrolidine dithiocarbamate (PDTC) decreased TNF-α production from RAW264.7 cells. We concluded that AMPA promotes TNF-α release in RAW264.7 macrophages likely through the following signaling cascade: AMPAR activation â†’ ROS generation â†’ c-Src phosphorylation â†’ NF-κB activation â†’ TNF-α elevation. The study suggests that AMPAR may participate in macrophage activation and inflammation.

[ß-estradiol activates BK(Ca) in mesenteric artery smooth muscle cells of post-menopause women].

The aim of the present study was to study the effect of ß-estradiol (ß-E(2)) on the large-conductance Ca(2+)-activated potassium (BK(Ca)) channel in mesenteric artery smooth muscle cells (SMCs). The mesenteric arteries were obtained from post-menopause female patients with abdominal surgery, and the SMCs were isolated from the arteries using an enzymatic disassociation. According to the sources, the SMCs were divided into non-hypertension (NH) and essential hypertension (EH) groups. Single channel patch clamp technique was used to investigate the effect of ß-E(2) and ICI 182780 (a specific blocker of estrogen receptor) on BK(Ca) in the SMCs. The results showed the opening of BK(Ca) in the SMCs was voltage and calcium dependent, and could be blocked by IbTX. ß-E(2) (100 µmol/L) significantly increased open probability (Po) of BK(Ca) in both NH and EH groups. After ß-E(2) treatment, NH group showed higher Po of BK(Ca) compared with EH group. ICI 182780 could inhibit the activating effect of ß-E(2) on BK(Ca) in no matter NH or EH groups. These results suggest ß-E(2) activates BK(Ca) in mesenteric artery SMCs from post-menopause women via estrogen receptor, but hypertension may decline the activating effect of ß-E(2) on BK(Ca).

[Atrial myocytes KChIP2 mRNA expression in rheumatic heart disease patients with atrial fibrillation].

OBJECTIVE: To detect the KChIP2 mRNA level in rheumatic heart disease patients with or without atrial fibrillation (AF) by real-time PCR. METHODS: Right atrial appendage samples from rheumatic heart disease patients with (n = 17) or without AF (n = 13) were obtained during cardiac surgery. Total RNA was extracted from the atrial tissues, and the KChIP2 and Kv4.3 mRNA were detected by SYBR Green I real-time PCR with the GAPDH as the house keeping gene. RESULT: The ratio of KChIP2/GAPDH (0.1468 +/- 0.0452 vs. 0.2200 +/- 0.0388, P<0.01) and the ratio of Kv4.3/GAPDH (0.3946 +/- 0.1826 vs. 0.5257 +/- 0.1427, P<0.05) were significantly lower in AF patients compared to non-AF patients. CONCLUSION: Down-regulated atrial KChIP2 and Kv4.3 mRNA expressions in rheumatic heart disease patients with chronic AF might be one of the molecular bases responsible for the down-regulation of the I(to) current density of AF.