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American Journal of Physiology. Heart... Jul 2024Perivascular adipose tissue (PVAT) regulates vascular tone by releasing anticontractile factors. These anticontractile factors are driven by processes downstream of...
Perivascular adipose tissue (PVAT) regulates vascular tone by releasing anticontractile factors. These anticontractile factors are driven by processes downstream of adipocyte stimulation by norepinephrine; however, whether norepinephrine originates from neural innervation or other sources is unknown. The goal of this study was to test the hypothesis that neurons innervating PVAT provide the adrenergic drive to stimulate adipocytes in aortic and mesenteric perivascular adipose tissue (aPVAT and mPVAT), and white adipose tissue (WAT). Healthy male and female mice (8-13 wk) were used in all experiments. Expression of genes associated with synaptic transmission were quantified by qPCR and adipocyte activity in response to neurotransmitters and neuron depolarization was assessed in mice. Immunostaining, tissue clearing, and transgenic reporter lines were used to assess anatomical relationships between nerves and adipocytes. Although synaptic transmission component genes are expressed in adipose tissues (aPVAT, mPVAT, and WAT), strong nerve stimulation with electrical field stimulation does not significantly trigger calcium responses in adipocytes. However, norepinephrine consistently elicits strong calcium responses in adipocytes from all adipose tissues studied. Bethanechol induces minimal adipocyte responses. Imaging neural innervation using various techniques reveals that nerve fibers primarily run alongside blood vessels and rarely branch into the adipose tissue. Although nerve fibers are associated with blood vessels in adipose tissue, they demonstrate limited anatomical and functional interactions with adjacent adipocytes, challenging the concept of classical innervation. These findings dispute the significant involvement of neural input in regulating PVAT adipocyte function and emphasize alternative mechanisms governing adrenergic-driven anticontractile functions of PVAT. This study challenges prevailing views on neural innervation in perivascular adipose tissue (PVAT) and its role in adrenergic-driven anticontractile effects on vasculature. Contrary to existing paradigms, limited anatomical and functional connections were found between PVAT nerve fibers and adipocytes, underscoring the importance of exploring alternative mechanistic pathways. Understanding the mechanisms involved in PVAT's anticontractile effects is critical for developing potential therapeutic interventions against dysregulated vascular tone, hypertension, and cardiovascular disease.
Topics: Animals; Male; Female; Adipocytes; Norepinephrine; Mice; Adipose Tissue; Mice, Inbred C57BL; Synaptic Transmission; Adipose Tissue, White; Mice, Transgenic; Calcium Signaling
PubMed: 38787382
DOI: 10.1152/ajpheart.00041.2024 -
Cells May 2024Heart failure is the common concluding pathway for a majority of cardiovascular diseases and is associated with cardiac dysfunction. Since heart failure is invariably... (Review)
Review
Heart failure is the common concluding pathway for a majority of cardiovascular diseases and is associated with cardiac dysfunction. Since heart failure is invariably preceded by adaptive or maladaptive cardiac hypertrophy, several biochemical mechanisms have been proposed to explain the development of cardiac hypertrophy and progression to heart failure. One of these includes the activation of different neuroendocrine systems for elevating the circulating levels of different vasoactive hormones such as catecholamines, angiotensin II, vasopressin, serotonin and endothelins. All these hormones are released in the circulation and stimulate different signal transduction systems by acting on their respective receptors on the cell membrane to promote protein synthesis in cardiomyocytes and induce cardiac hypertrophy. The elevated levels of these vasoactive hormones induce hemodynamic overload, increase ventricular wall tension, increase protein synthesis and the occurrence of cardiac remodeling. In addition, there occurs an increase in proinflammatory cytokines and collagen synthesis for the induction of myocardial fibrosis and the transition of adaptive to maladaptive hypertrophy. The prolonged exposure of the hypertrophied heart to these vasoactive hormones has been reported to result in the oxidation of catecholamines and serotonin via monoamine oxidase as well as the activation of NADPH oxidase via angiotensin II and endothelins to promote oxidative stress. The development of oxidative stress produces subcellular defects, Ca-handling abnormalities, mitochondrial Ca-overload and cardiac dysfunction by activating different proteases and depressing cardiac gene expression, in addition to destabilizing the extracellular matrix upon activating some metalloproteinases. These observations support the view that elevated levels of various vasoactive hormones, by producing hemodynamic overload and activating their respective receptor-mediated signal transduction mechanisms, induce cardiac hypertrophy. Furthermore, the occurrence of oxidative stress due to the prolonged exposure of the hypertrophied heart to these hormones plays a critical role in the progression of heart failure.
Topics: Heart Failure; Humans; Cardiomegaly; Signal Transduction; Animals; Angiotensin II; Oxidative Stress
PubMed: 38786079
DOI: 10.3390/cells13100856 -
Biomolecules May 2024The active vitamin D metabolites, 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D), are produced by successive hydroxylation steps and play key roles in...
The active vitamin D metabolites, 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D), are produced by successive hydroxylation steps and play key roles in several cellular processes. However, alternative metabolic pathways exist, and among them, the 4-hydroxylation of 25D is a major one. This study aims to investigate the structure-activity relationships of 4-hydroxy derivatives of 1,25D. Structural analysis indicates that 1,4α,25(OH)D and 1,4β,25(OH)D maintain the anchoring hydrogen bonds of 1,25D and form additional interactions, stabilizing the active conformation of VDR. In addition, 1,4α,25D and 1,4β,25D are as potent as 1,25D in regulating the expression of VDR target genes in rat intestinal epithelial cells and in the mouse kidney. Moreover, these two 4-hydroxy derivatives promote hypercalcemia in mice at a dose similar to that of the parent compound.
Topics: Animals; Mice; Structure-Activity Relationship; Receptors, Calcitriol; Rats; Calcitriol; Male; Vitamin D; Hypercalcemia; Kidney
PubMed: 38785958
DOI: 10.3390/biom14050551 -
Renal Failure Dec 2024Renal fibrosis contributes to chronic renal failure and a decline in the quality of life. Bushen Huoxue (BSHX) formula is a Traditional Chinese Medicine used to treat...
BACKGROUND
Renal fibrosis contributes to chronic renal failure and a decline in the quality of life. Bushen Huoxue (BSHX) formula is a Traditional Chinese Medicine used to treat chronic renal failure. However, its mechanisms of action remain unclear.
METHODS AND RESULTS
In this study, a rat model of renal fibrosis was constructed by 5/6 nephrectomy , and histopathological changes were analyzed using hematoxylin-eosin and Masson's trichrome staining. Angiotensin II (Ang II) was used to establish an renal fibrosis cell model . Pyroptosis was measured using flow cytometry. Related markers of fibrosis and NOD-like receptor protein 3 (NLRP3) inflammasome activation were measured using western blotting and enzyme-linked immunosorbent assay. Treatment with BSHX (0.25, 0.5, and 1 g/kg) significantly inhibited renal fibrosis and damage in 5/6 nephrectomized rats and simultaneously reduced oxidative stress and NLRP3 inflammasome activation. Similarly, BSHX treatment reduced the levels of hydroxyproline, transforming growth factor-β, matrix metalloproteinase 2, and matrix metalloproteinase 9 and inactivated the Smad2/3 signaling pathway in Ang II-treated HK-2 cells. Our data also showed that treatment with BSHX reduced NLRP3 inflammasome activation and pyroptosis in Ang II-treated HK-2 cells. Moreover, fibrosis and pyroptosis in HK-2 cells induced by NLRP3 overexpression were reduced by treatment with BSHX.
CONCLUSIONS
BSHX significantly reduced renal fibrosis and pyroptosis, and its mechanism was mainly associated with the inhibition of reactive oxygen species (ROS)/NLRP3-mediated inflammasome activation.
Topics: Animals; NLR Family, Pyrin Domain-Containing 3 Protein; Pyroptosis; Rats; Drugs, Chinese Herbal; Fibrosis; Inflammasomes; Reactive Oxygen Species; Male; Renal Insufficiency, Chronic; Disease Models, Animal; Rats, Sprague-Dawley; Oxidative Stress; Humans; Kidney; Signal Transduction; Cell Line; Angiotensin II; Nephrectomy
PubMed: 38785272
DOI: 10.1080/0886022X.2024.2354444 -
Journal of Cellular and Molecular... May 2024Heart failure is a leading cause of death in the elderly. Traditional Chinese medicine, a verified alternative therapeutic regimen, has been used to treat heart failure,...
Heart failure is a leading cause of death in the elderly. Traditional Chinese medicine, a verified alternative therapeutic regimen, has been used to treat heart failure, which is less expensive and has fewer adverse effects. In this study, a total of 15 active ingredients of Astragalus membranaceus (Huangqi, HQ) were obtained; among them, Isorhamnetin, Quercetin, Calycosin, Formononetin, and Kaempferol were found to be linked to heart failure. Ang II significantly enlarged the cell size of cardiomyocytes, which could be partially reduced by Quercetin, Isorhamnetin, Calycosin, Kaempferol, or Formononetin. Ang II significantly up-regulated ANP, BNP, β-MHC, and CTGF expressions, whereas Quercetin, Isorhamnetin, Calycosin, Kaempferol or Formononetin treatment partially downregulated ANP, BNP, β-MHC and CTGF expressions. Five active ingredients of HQ attenuated inflammation in Ang II-induced cardiomyocytes by inhibiting the levels of TNF-α, IL-1β, IL-18 and IL-6. Molecular docking shows Isorhamnetin, Quercetin, Calycosin, Formononetin and Kaempferol can bind with its target protein ESR1 in a good bond by intermolecular force. Quercetin, Calycosin, Kaempferol or Formononetin treatment promoted the expression levels of ESR1 and phosphorylated ESR1 in Ang II-stimulated cardiomyocytes; however, Isorhamnetin treatment had no effect on ESR1 and phosphorylated ESR1 expression levels. In conclusion, our results comprehensively illustrated the bioactives, potential targets, and molecular mechanism of HQ against heart failure. Isorhamnetin, Quercetin, Calycosin, Formononetin and Kaempferol might be the primary active ingredients of HQ, dominating its cardioprotective effects against heart failure through regulating ESR1 expression, which provided a basis for the clinical application of HQ to regulate cardiac hypertrophy and heart failure.
Topics: Astragalus propinquus; Heart Failure; Molecular Docking Simulation; Myocytes, Cardiac; Animals; Drugs, Chinese Herbal; Network Pharmacology; Quercetin; Angiotensin II; Kaempferols; Rats; Humans; Isoflavones
PubMed: 38780500
DOI: 10.1111/jcmm.18331 -
Scientific Reports May 2024We studied the inhibitory actions of docosahexaenoic acid (DHA) on the contractions induced by carbachol (CCh), angiotensin II (Ang II), and bradykinin (BK) in guinea...
We studied the inhibitory actions of docosahexaenoic acid (DHA) on the contractions induced by carbachol (CCh), angiotensin II (Ang II), and bradykinin (BK) in guinea pig (GP) gastric fundus smooth muscle (GFSM), particularly focusing on the possible inhibition of store-operated Ca channels (SOCCs). DHA significantly suppressed the contractions induced by CCh, Ang II, and BK; the inhibition of BK-induced contractions was the strongest. Although all contractions were greatly dependent on external Ca, more than 80% of BK-induced contractions remained even in the presence of verapamil, a voltage-dependent Ca channel inhibitor. BK-induced contractions in the presence of verapamil were not suppressed by LOE-908 (a receptor-operated Ca channel (ROCC) inhibitor) but were suppressed by SKF-96365 (an SOCC and ROCC inhibitor). BK-induced contractions in the presence of verapamil plus LOE-908 were strongly inhibited by DHA. Furthermore, DHA inhibited GFSM contractions induced by cyclopiazonic acid (CPA) in the presence of verapamil plus LOE-908 and inhibited the intracellular Ca increase due to Ca addition in CPA-treated 293T cells. These findings indicate that Ca influx through SOCCs plays a crucial role in BK-induced contraction in GP GFSM and that this inhibition by DHA is a new mechanism by which this fatty acid inhibits GFSM contractions.
Topics: Animals; Guinea Pigs; Docosahexaenoic Acids; Bradykinin; Muscle, Smooth; Carbachol; Muscle Contraction; Angiotensin II; Gastric Fundus; Verapamil; Calcium; Male; Humans; Calcium Channels; HEK293 Cells; Calcium Channel Blockers; Imidazoles
PubMed: 38778154
DOI: 10.1038/s41598-024-62578-y -
Clinical Nutrition ESPEN Jun 2024Shock is a common critical illness characterized by microcirculatory disorders and insufficient tissue perfusion. Patients with shock and hemodynamic instability... (Review)
Review
Shock is a common critical illness characterized by microcirculatory disorders and insufficient tissue perfusion. Patients with shock and hemodynamic instability generally require vasopressors to maintain the target mean arterial pressure. Enteral nutrition (EN) is an important therapeutic intervention in critically ill patients and has unique benefits for intestinal recovery. However, the initiation of early EN in patients with shock receiving vasopressors remains controversial. Current guidelines make conservative and vague recommendations regarding early EN support in patients with shock. Increasing studies demonstrates that early EN delivery is safe and feasible in patients with shock receiving vasopressors; however, this evidence is based on observational studies. Changes in gastrointestinal blood flow vary by vasopressor and inotrope and are complex. The risk of gastrointestinal complications, especially the life-threatening complications of non-occlusive mesenteric ischemia and non-occlusive bowel necrosis, cannot be ignored in patients with shock during early EN support. It remains a therapeutic challenge in critical care nutrition therapy to determine the initiation time of EN in patients with shock receiving vasopressors and the safe threshold region for initiating EN with vasopressors. Therefore, the current review aimed to summarize the evidence on the optimal and safe timing of early EN initiation in patients with shock receiving vasopressors to improve clinical practice.
Topics: Humans; Vasoconstrictor Agents; Enteral Nutrition; Shock; Critical Illness; Critical Care; Time Factors
PubMed: 38777444
DOI: 10.1016/j.clnesp.2024.03.007 -
Aging May 2024Atrial fibrillation (AF) is often associated with atrial fibrosis and oxidative stress. Neferine, a bisbenzylisoquinoline alkaloid, has been reported to exert an...
BACKGROUND
Atrial fibrillation (AF) is often associated with atrial fibrosis and oxidative stress. Neferine, a bisbenzylisoquinoline alkaloid, has been reported to exert an antiarrhythmic effect. However, its impact on Angiotensin II (Ang II) infusion-induced AF and the underlying mechanism remains unclear. This study aimed to investigate whether neferine alleviates Ang II-induced AF and explore the underlying mechanisms.
METHODS
Mice subjected to Ang II infusion to induce AF were concurrently treated with neferine or saline. AF incidence, myocardial cell size, fibrosis, and oxidative stress were then examined.
RESULTS
Neferine treatment inhibited Ang II-induced AF, atrial size augmentation, and atrial fibrosis. Additionally, we observed that Ang II increased reactive oxygen species (ROS) generation, induced mitochondrial membrane potential depolarization, and reduced glutathione (GSH) and superoxide dismutase (SOD) levels, which were reversed to some extent by neferine. Mechanistically, neferine activated the Nrf2/HO-1 signaling pathway and inhibited TGF-β/p-Smad2/3 in Ang II-infused atria. Zinc Protoporphyrin (ZnPP), an HO-1 inhibitor, reduced the anti-oxidative effect of neferine to some extent and subsequently abolished the beneficial effect of neferine on Ang II-induced AF.
CONCLUSIONS
These findings provide hitherto undocumented evidence that the protective role of neferine in Ang II-induced AF is dependent on HO-1.
Topics: Animals; Angiotensin II; Atrial Fibrillation; Fibrosis; NF-E2-Related Factor 2; Mice; Benzylisoquinolines; Signal Transduction; Smad3 Protein; Male; Transforming Growth Factor beta; Oxidative Stress; Smad2 Protein; Up-Regulation; Mice, Inbred C57BL; Heart Atria; Heme Oxygenase (Decyclizing); Membrane Proteins; Heme Oxygenase-1
PubMed: 38775722
DOI: 10.18632/aging.205829 -
Brazilian Journal of Medical and... 2024Arthritis has important cardiovascular repercussions. Phenylephrine-induced vasoconstriction is impaired in rat aortas in the early phase of the adjuvant-induced...
Arthritis has important cardiovascular repercussions. Phenylephrine-induced vasoconstriction is impaired in rat aortas in the early phase of the adjuvant-induced arthritis (AIA), around the 15th day post-induction. Therefore, the present study aimed to verify the effects of AIA on hyporesponsiveness to phenylephrine in rat aortas. AIA was induced by intradermal injection of Mycobacterium tuberculosis (3.8 mg/dL) in the right hind paw of male Wistar rats (n=27). Functional experiments in isolated aortas were carried out 15 days after AIA induction. Morphometric and stereological analyses of the aortas were also performed 36 days after the induction of AIA. AIA did not promote structural modifications in the aortas at any of the time points studied. AIA reduced phenylephrine-induced contraction in endothelium-intact aortas, but not in endothelium-denuded aortas. However, AIA did not change KCl-induced contraction in either endothelium-intact or denuded aortas. L-NAME (non-selective NOS inhibitor), 1400W (selective iNOS inhibitor), and ODQ (guanylyl cyclase inhibitor) reversed AIA-induced hyporesponsiveness to phenylephrine in intact aortas. 7-NI (selective nNOS inhibitor) increased the contraction induced by phenylephrine in aortas from AIA rats. In summary, the hyporesponsiveness to phenylephrine induced by AIA was endothelium-dependent and mediated by iNOS-derived NO through activation of the NO-guanylyl cyclase pathway.
Topics: Animals; Male; Phenylephrine; Rats, Wistar; Arthritis, Experimental; Nitric Oxide; Vasoconstriction; Endothelium, Vascular; Vasoconstrictor Agents; Rats; Aorta
PubMed: 38775546
DOI: 10.1590/1414-431X2024e13304 -
Pharmaceutical Biology Dec 2024The mechanisms of Traditional Chinese Medicine (TCM) Guizhi-Gancao Decoction (GGD) remain unknown.
Network pharmacology integrated with experimental validation to elucidate the mechanisms of action of the Guizhi-Gancao Decoction in the treatment of phenylephrine-induced cardiac hypertrophy.
CONTEXT
The mechanisms of Traditional Chinese Medicine (TCM) Guizhi-Gancao Decoction (GGD) remain unknown.
OBJECTIVE
This study explores the mechanisms of GGD against cardiac hypertrophy.
MATERIALS AND METHODS
Network pharmacology analysis was carried out to identify the potential targets of GGD. experiments, C57BL/6J mice were divided into Con, phenylephrine (PE, 10 mg/kg/d), 2-chloroadenosine (CADO, the stable analogue of adenosine, 2 mg/kg/d), GGD (5.4 g/kg/d) and GGD (5.4 g/kg/d) + CGS15943 (a nonselective adenosine receptor antagonist, 4 mg/kg/d). experiments, primary neonatal rat cardiomyocytes (NRCM) were divided into Con, PE (100 µM), CADO (5 µM), GGD (10 g/mL) and GGD (10 g/mL) + CGS15943 (5 µM). Ultrasound, H&E and Masson staining, hypertrophic genes expression and cell surface area were conducted to verify the GGD efficacy. Adenosine receptors (ADORs) expression were tested real-time polymerase chain reaction (PCR), western blotting and immunofluorescence analysis.
RESULTS
Network pharmacology identified ADORs among those of the core targets of GGD. experiments demonstrated that GGD attenuated PE-induced increased surface area (with an EC of 5.484 × 10 g/mL). data shown that GGD attenuated PE-induced ventricular wall thickening. and data indicated that GGD alleviated PE-induced hypertrophic gene expression (e.g., ANP, BNP and MYH7/MYH6), A1AR over-expression and A2aAR down-expression. Moreover, CADO exerts effects similar to GGD, whereas CGS15943 eliminated most effects of GGD.
DISCUSSION AND CONCLUSIONS
Our findings suggest the mechanism by which GGD inhibits cardiac hypertrophy, highlighting regulation of ADORs as a potential therapeutic strategy for HF.
Topics: Animals; Drugs, Chinese Herbal; Phenylephrine; Cardiomegaly; Mice, Inbred C57BL; Mice; Male; Rats; Myocytes, Cardiac; Network Pharmacology; Rats, Sprague-Dawley; Cells, Cultured; Disease Models, Animal; Medicine, Chinese Traditional
PubMed: 38773737
DOI: 10.1080/13880209.2024.2354335