RND3 attenuates oxidative stress and vascular remodeling in spontaneously hypertensive rat via inhibiting ROCK1 signaling

Asprosin contributes to vascular remodeling in hypertensive rats via superoxide signaling

OBJECTIVE

Proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to vascular remodeling. Asprosin, a newly discovered protein hormone, is involved in metabolic diseases. Little is known about the roles of asprosin in cardiovascular diseases. This study focused on the role and mechanism of asprosin on VSMC proliferation and migration, and vascular remodeling in a rat model of hypertension.

METHODS AND RESULTS

VSMCs were obtained from the aortic media of 8-week-old male Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Asprosin was upregulated in the VSMCs of SHR. For in vitro studies, asprosin promoted VSMC proliferation and migration of WKY and SHR, and increased Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activity, NOX1/2/4 protein expressions and superoxide production. Knockdown of asprosin inhibited the proliferation, migration, NOX activity, NOX1/2 expressions and superoxide production in the VSMCs of SHR. The roles of asprosin in promoting VSMC proliferation and migration were not affected by hydrogen peroxide scavenger, but attenuated by superoxide scavenger, selective NOX1 or NOX2 inhibitor. Toll-like receptor 4 (TLR4) was upregulated in SHR, TLR4 knockdown inhibited asprosin overexpression-induced proliferation, migration and oxidative stress in VSMCs of WKY and SHR. Asprosin was upregulated in arteries of SHR, and knockdown of asprosin in vivo not only attenuated oxidative stress and vascular remodeling in aorta and mesentery artery, but also caused a subsequent persistent antihypertensive effect in SHR.

CONCLUSIONS

Asprosin promotes VSMC proliferation and migration via NOX-mediated superoxide production. Inhibition of endogenous asprosin expression attenuates VSMC proliferation and migration, and vascular remodeling of SHR.

Fasudil attenuates oxidative stress-induced partial epithelial-mesenchymal transition of tubular epithelial cells in hyperuricemic nephropathy via activating Nrf2

Anti-partial epithelial-mesenchymal transition (pEMT) treatment of renal tubular epithelial cells (TECs) represents a promising therapeutic approach. Hyperuricemia nephropathy (HN) arises as a consequence of hyperuricemia (HUA)-induced tubulointerstitial fibrosis (TIF). Studies have suggested that the Ras homolog member A (RhoA)/Rho-associated kinase (ROCK) pathway is a crucial signaling transduction system in renal fibrosis. Fasudil, a RhoA/ROCK inhibitor, has exhibited the potential to prevent fibrosis progress. However, its impact on the pEMT of TECs in HN remains unclear. Here, an HN rat model and an uric acid (UA)-stimulated human kidney 2 (HK2) cell model were established and treated with Fasudil to explore its effects. Furthermore, the underlying mechanism of action involved in the attenuation of pEMT in TECs by Fasudil during HN was probed by using multiple molecular approaches. The HN rat model exhibited significant renal dysfunction and histopathological damage, whereas in vitro and in vivo experiments further confirmed the pEMT status accompanied by RhoA/ROCK pathway activation and oxidative stress in tubular cells exposed to UA. Notably, Fasudil ameliorated these pathological changes, and this was consistent with the trend of ROCK silencing in vitro. Mechanistically, we identified the Neh2 domain of nuclear factor erythroid 2-related factor 2 (Nrf2) as a target of Fasudil for the first time. Fasudil targets Nrf2 activation and antagonizes oxidative stress to attenuate the pEMT of TECs in HN. Our findings suggest that Fasudil attenuates oxidative stress-induced pEMT of TECs in HN by targeting Nrf2 activation. Thus, Fasudil is a potential therapeutic agent for the treatment of HN.

Mechanistic role of RND3-regulated IL33/ST2 signaling on cardiomyocyte senescence

Hyperinflammatory responses are pivotal in the cardiomyocyte senescence pathophysiology, with IL33 serving as a crucial pro-inflammatory mediator. Our previous findings highlighted RND3's suppressive effect on IL33 expression. This study aims to explore the role of RND3 in IL33/ST2 signaling activation and in cardiomyocyte senescence. Intramyocardial injection of exogenous IL33 reduces the ejection fraction and fractional shortening of rats, inducing the appearance of senescence-associated secretory phenotype (SASP) in myocardial tissues. Recombinant IL33 treatment of AC16 cardiomyocytes significantly upregulated expression of SASP factors like IL1α, IL6, and MCP1, and increased the p-p65/p65 ratio and proportions of SA-β-gal and γH2AX-positive cells. NF-κB inhibitor pyrrolidinedithiocarbamate ammonium (PDTC) and ST2 antibody astegolimab treatments mitigated above effects. RND3 gene knockout H9C2 cardiomyocytes using CRISPR/Cas9 technology upregulated IL33, ST2L, IL1α, IL6, and MCP1 levels, decreased sST2 levels, and increased SA-β-gal and γH2AX-positive cells. A highly possibility of binding between RND3 and IL33 proteins was showed by molecular docking and co-immunoprecipitation, and loss of RND3 attenuated ubiquitination mediated degradation of IL33; what's more, a panel of ubiquitination regulatory genes closely related to RND3 were screened using qPCR array. In contrast, RND3 overexpression in rats by injection of AAV9-CMV-RND3 particles inhibited IL33, ST2L, IL1α, IL6, and MCP1 expression in cardiac tissues, decreased serum IL33 levels, and increased sST2 levels. These results suggest that RND3 expression in cardiomyocytes modulates cell senescence by inhibiting the IL33/ST2/NF-κB signaling pathway, underscoring its potential as a therapeutic target in cardiovascular senescence.

GLP-1 in the Hypothalamic Paraventricular Nucleus Promotes Sympathetic Activation and Hypertension

Glucagon-like peptide-1 (GLP-1) and its analogs are widely used for diabetes treatment. The paraventricular nucleus (PVN) is crucial for regulating cardiovascular activity. This study aims to determine the roles of GLP-1 and its receptors (GLP-1R) in the PVN in regulating sympathetic outflow and blood pressure. Experiments were carried out in male normotensive rats and spontaneously hypertensive rats (SHR). Renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) were recorded. GLP-1 and GLP-1R expressions were present in the PVN. PVN microinjection of GLP-1R agonist recombinant human GLP-1 (rhGLP-1) or EX-4 increased RSNA and MAP, which were prevented by GLP-1R antagonist exendin 9-39 (EX9-39) or GLP-1R antagonist 1, superoxide scavenger tempol, antioxidant N-acetylcysteine, NADPH oxidase (NOX) inhibitor apocynin, adenylyl cyclase (AC) inhibitor SQ22536 or protein kinase A (PKA) inhibitor H89. PVN microinjection of rhGLP-1 increased superoxide production, NADPH oxidase activity, cAMP level, AC, and PKA activity, which were prevented by SQ22536 or H89. GLP-1 and GLP-1R were upregulated in the PVN of SHR. PVN microinjection of GLP-1 agonist increased RSNA and MAP in both WKY and SHR, but GLP-1 antagonists caused greater effects in reducing RSNA and MAP in SHR than in WKY. The increased superoxide production and NADPH oxidase activity in the PVN of SHR were augmented by GLP-1R agonists but attenuated by GLP-1R antagonists. These results indicate that activation of GLP-1R in the PVN increased sympathetic outflow and blood pressure via cAMP-PKA-mediated NADPH oxidase activation and subsequent superoxide production. GLP-1 and GLP-1R upregulation in the PVN partially contributes to sympathetic overactivity and hypertension.

Thioredoxin (Trx): A redox target and modulator of cellular senescence and aging-related diseases

Thioredoxin (Trx) is a compact redox-regulatory protein that modulates cellular redox state by reducing oxidized proteins. Trx exhibits dual functionality as an antioxidant and a cofactor for diverse enzymes and transcription factors, thereby exerting influence over their activity and function. Trx has emerged as a pivotal biomarker for various diseases, particularly those associated with oxidative stress, inflammation, and aging. Recent clinical investigations have underscored the significance of Trx in disease diagnosis, treatment, and mechanistic elucidation. Despite its paramount importance, the intricate interplay between Trx and cellular senescence-a condition characterized by irreversible growth arrest induced by multiple aging stimuli-remains inadequately understood. In this review, our objective is to present a comprehensive and up-to-date overview of the structure and function of Trx, its involvement in redox signaling pathways and cellular senescence, its association with aging and age-related diseases, as well as its potential as a therapeutic target. Our review aims to elucidate the novel and extensive role of Trx in senescence while highlighting its implications for aging and age-related diseases.

Gene co-expression patterns in Atlantic salmon adipose tissue provide a molecular link among seasonal changes, energy balance and age at maturity

Sexual maturation in many fishes requires a major physiological change that involves a rapid transition between energy storage and usage. In Atlantic salmon, this transition for the initiation of maturation is tightly controlled by seasonality and requires a high-energy status. Lipid metabolism is at the heart of this transition since lipids are the main energy storing molecules. The balance between lipogenesis (lipid accumulation) and lipolysis (lipid use) determines energy status transitions. A genomic region containing a transcription co-factor of the Hippo pathway, vgll3, is the main determinant of maturation timing in Atlantic salmon. Interestingly, vgll3 acts as an inhibitor of adipogenesis in mice and its genotypes are potentially associated with seasonal heterochrony in lipid storage and usage in juvenile Atlantic salmon. Here, we explored changes in expression of more than 300 genes directly involved in the processes of adipogenesis, lipogenesis and lipolysis, as well as the Hippo pathway in the adipose tissue of immature and mature Atlantic salmon with distinct vgll3 genotypes. We found molecular evidence consistent with a scenario in which immature males with different vgll3 genotypes exhibit contrasting seasonal dynamics in their lipid profiles. We also identified components of the Hippo signalling pathway as potential major drivers of vgll3 genotype-specific differences in adipose tissue gene expression. This study demonstrates the importance of adipose gene expression patterns for directly linking environmental changes with energy balance and age at maturity through genetic factors bridging lipid metabolism, seasonality and sexual maturation.

RND3 Potentiates Proinflammatory Activation through NOTCH Signaling in Activated Macrophages

Macrophage activation is a complex process with multiple control elements that ensures an adequate response to the aggressor pathogens and, on the other hand, avoids an excess of inflammatory activity that could cause tissue damage. In this study, we have identified RND3, a small GTP-binding protein, as a new element in the complex signaling process that leads to macrophage activation. We show that RND3 expression is transiently induced in macrophages activated through Toll receptors and potentiated by IFN-γ. We also demonstrate that RND3 increases NOTCH signaling in macrophages by favoring NOTCH1 expression and its nuclear activity; however, Rnd3 expression seems to be inhibited by NOTCH signaling, setting up a negative regulatory feedback loop. Moreover, increased RND3 protein levels seem to potentiate NFκB and STAT1 transcriptional activity resulting in increased expression of proinflammatory genes, such as Tnf-α, Irf-1, or Cxcl-10. Altogether, our results indicate that RND3 seems to be a new regulatory element which could control the activation of macrophages, able to fine tune the inflammatory response through NOTCH.

MiR-21-3p in extracellular vesicles from vascular fibroblasts of spontaneously hypertensive rat promotes proliferation and migration of vascular smooth muscle cells

Enhanced proliferation and migration of vascular smooth muscle cells (VSMCs) contributes to vascular remodeling in hypertension. Adventitial fibroblasts (AFs)-derived extracellular vesicles (EVs) modulate vascular remodeling in spontaneously hypertensive rat (SHR). This study shows the important roles of EVs-mediated miR-21-3p transfer in VSMC proliferation and migration and underlying mechanisms in SHR. AFs and VSMCs were obtained from aorta of Wistar-Kyoto rat (WKY) and SHR. EVs were separated from AFs culture with ultracentrifugation method. MiR-21-3p content in the EVs of SHR was increased compared with those of WKY. MiR-21-3p mimic promoted VSMC proliferation and migration of WKY and SHR, while miR-21-3p inhibitor attenuated proliferation and migration only in the VSMCs of SHR. EVs of SHR stimulated VSMC proliferation and migration, which were attenuated by miR-21-3p inhibitor. Sorbin and SH3 domain containing 2 (SORBS2) mRNA and protein levels were reduced in the VSMCs of SHR. MiR-21-3p mimic inhibited, while miR-21-3p inhibitor promoted SORBS2 expressions in the VSMCs of both WKY and SHR. EVs of SHR reduced SORBS2 expression, which was prevented by miR-21-3p inhibitor. EVs of WKY had no significant effect on SORBS2 expressions. SORBS2 overexpression attenuated the roles of miR-21-3p mimic and EVs of SHR in promoting VSMC proliferation and migration of SHR. Overexpression of miR-21-3p in vivo promotes vascular remodeling and hypertension. These results indicate that miR-21-3p in the EVs of SHR promotes VSMC proliferation and migration via negatively regulating SORBS2 expression.

Rnd3 suppresses endothelial cell pyroptosis in atherosclerosis through regulation of ubiquitination of TRAF6

BACKGROUND

As the main pathological basis for various cardiovascular and cerebrovascular diseases, atherosclerosis has become one of the leading causes of death and disability worldwide. Emerging evidence has suggested that Rho GTPase Rnd3 plays an indisputable role in cardiovascular diseases, although its function in atherosclerosis remains unclear. Here, we found a significant correlation between Rnd3 and pyroptosis of aortic endothelial cells (ECs).

METHODS

ApoeKO mice were utilized as a model for atherosclerosis. Endothelium-specific transgenic mice were employed to disrupt the expression level of Rnd3 in vivo. Mechanistic investigation of the impact of Rnd3 on endothelial cell pyroptosis was carried out using liquid chromatography tandem mass spectrometry (LC-MS/MS), co-immunoprecipitation (Co-IP) assays, and molecular docking.

RESULTS

Evidence from gain-of-function and loss-of-function studies denoted a protective role for Rnd3 against ECs pyroptosis. Downregulation of Rnd3 sensitized ECs to pyroptosis under oxidized low density lipoprotein (oxLDL) challenge and exacerbated atherosclerosis, while overexpression of Rnd3 effectively prevented these effects. LC-MS/MS, Co-IP assay, and molecular docking revealed that Rnd3 negatively regulated pyroptosis signaling by direct interaction with the ring finger domain of tumor necrosis factor receptor-associated factor 6 (TRAF6). This leads to the suppression of K63-linked TRAF6 ubiquitination and the promotion of K48-linked TRAF6 ubiquitination, inhibiting the activation of NF-κB and promoting the degradation of TRAF6. Moreover, TRAF6 knockdown countered Rnd3 knockout-evoked exacerbation of EC pyroptosis in vivo and vitro.

CONCLUSIONS

These findings establish a critical functional connection between Rnd3 and the TRAF6/NF-κB/NLRP3 signaling pathway in ECs, indicating the essential role of Rnd3 in preventing pyroptosis of ECs.

Vascular smooth muscle cells specific deletion of angiopoietin-like protein 8 prevents angiotensin II-promoted hypertension and cardiovascular hypertrophy

AIMS

Angiopoietin-like protein 8 (ANGPTL8) plays important roles in lipid metabolism, glucose metabolism, inflammation, and cell proliferation and migration. Clinical studies have indicated that circulating ANGPTL8 concentrations are increased in patients with hypertension and positively associated with blood pressure. ANGPTL8 deficiency ameliorates blood pressure in mice treated with chronic intermittent hypoxia. Currently, little is known regarding the pathophysiological role of the vascular smooth muscle cell (VSMC)-derived ANGPTL8 in hypertension and hypertensive cardiovascular remodelling.

METHODS AND RESULTS

Circulating ANGPTL8 concentrations, as determined by enzyme-linked immunosorbent assay, were significantly higher in hypertensive patients than in controls (524.51 ± 26.97 vs. 962.92 ± 15.91 pg/mL; P < 0.001). In hypertensive mice [angiotensin II (AngII) treatment for 14 days] and spontaneously hypertensive rats, ANGPTL8 expression was increased and predominantly located in VSMCs. In AngII-treated mice, systolic and diastolic blood pressure in Tagln-Cre-ANGPTL8fl/fl mice were approximately 15-25 mmHg lower than that in ANGPTL8fl/fl mice. AngII-induced vascular remodelling, vascular constriction, and increased expression of cell markers of proliferation (PCNA and Ki67) and migration (MMP-2 and MMP-9) were strikingly attenuated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. Furthermore, the AngII-induced increase in the heart size, heart weight, heart/body weight ratio, cardiomyocyte cross-sectional area, and collagen deposition was ameliorated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. In rat artery smooth muscle cells, ANGPTL8-short hairpin RNA decreased intracellular calcium levels and prevented AngII-induced proliferation and migration through the PI3K-Akt pathway, as shown using LY294002 (inhibitor of PI3K) and Akt inhibitor VIII.

CONCLUSION

This study suggests that ANGPTL8 in VSMCs plays an important role in AngII-induced hypertension and associated cardiovascular remodelling. ANGPTL8 may be a novel therapeutic target against pathological hypertension and hypertensive cardiovascular hypertrophy.

Identification of fibroblast-related genes based on single-cell and machine learning to predict the prognosis and endocrine metabolism of pancreatic cancer

Background

Single-cell sequencing technology has become an indispensable tool in tumor mechanism and heterogeneity studies. Pancreatic adenocarcinoma (PAAD) lacks early specific symptoms, and comprehensive bioinformatics analysis for PAAD contributes to the developmental mechanisms.

Methods

We performed dimensionality reduction analysis on the single-cell sequencing data GSE165399 of PAAD to obtain the specific cell clusters. We then obtained cell cluster-associated gene modules by weighted co-expression network analysis and identified tumorigenesis-associated cell clusters and gene modules in PAAD by trajectory analysis. Tumor-associated genes of PAAD were intersected with cell cluster marker genes and within the signature module to obtain genes associated with PAAD occurrence to construct a prognostic risk assessment tool by the COX model. The performance of the model was assessed by the Kaplan-Meier (K-M) curve and the receiver operating characteristic (ROC) curve. The score of endocrine pathways was assessed by ssGSEA analysis.

Results

The PAAD single-cell dataset GSE165399 was filtered and downscaled, and finally, 17 cell subgroups were filtered and 17 cell clusters were labeled. WGCNA analysis revealed that the brown module was most associated with tumorigenesis. Among them, the brown module was significantly associated with C11 and C14 cell clusters. C11 and C14 cell clusters belonged to fibroblast and circulating fetal cells, respectively, and trajectory analysis showed low heterogeneity for fibroblast and extremely high heterogeneity for circulating fetal cells. Next, through differential analysis, we found that genes within the C11 cluster were highly associated with tumorigenesis. Finally, we constructed the RiskScore system, and K-M curves and ROC curves revealed that RiskScore possessed objective clinical prognostic potential and demonstrated consistent robustness in multiple datasets. The low-risk group presented a higher endocrine metabolism and lower immune infiltrate state.

Conclusion

We identified prognostic models consisting of APOL1, BHLHE40, CLMP, GNG12, LOX, LY6E, MYL12B, RND3, SOX4, and RiskScore showed promising clinical value. RiskScore possibly carries a credible clinical prognostic potential for PAAD.

Probiotics: functional food ingredients with the potential to reduce hypertension

Hypertension is an increasingly pressing public health concern across the globe. It can be triggered by a variety of factors such as age and diet, as well as the stress of modern life. The traditional treatment of hypertension includes calcium ion blockers, angiotensin II receptor inhibitors and β-receptor blockers, but these drugs have at least some side effects. Recent studies have revealed that intestinal flora plays a vital role in maintaining and promoting human health. This is due to the type and amount of probiotics present in the flora. Probiotics can reduce hypertension symptoms through four mechanisms: regulating vascular oxidative stress, producing short-chain fatty acids, restoring endothelial cell function, and reducing inflammation. It has been reported that certain functional foods, using probiotics as their raw material, can modify the composition of intestinal flora, thus regulating hypertension symptoms. Consequently, utilizing the probiotic function of probiotics in conjunction with the properties of functional foods to treat hypertension is a novel, side-effect-free treatment method. This study seeks to summarize the various factors that contribute to hypertension, the mechanism of probiotics in mitigating hypertension, and the fermented functional foods with probiotic strains, in order to provide a basis for the development of functional foods which utilize probiotics as their raw material and may have the potential to reduce hypertension.

Oscillatory shear stress promotes vein graft intimal hyperplasia via NADPH oxidase-related pathways

Background

Uncontrolled intimal hyperplasia (IH) after autologous saphenous vein grafting triggers a high restenosis rate; however, its association with the activation of NADPH oxidase (NOX)-related pathways is unclear. Here, we investigated the effects and mechanism of oscillatory shear stress (OSS) on grafted vein IH.

Methods

Thirty male New Zealand rabbits were randomly divided into control, high-OSS (HOSS), and low-OSS (LOSS) groups, and the vein grafts were harvested after 4 weeks. Hematoxylin and eosin staining and Masson staining assays were used to observe morphological and structural changes. Immunohistochemical staining was used to detect α-SMA, PCNA, MMP-2, and MMP-9 expression. Immunofluorescence staining was used to observe reactive oxygen species (ROS) production in the tissues. Western blotting was used to determine the expression levels of pathway-related proteins (NOX1, NOX2, AKT, p-AKT, and BIRC5), PCNA, BCL-2, BAX, and caspase-3/cleaved caspase-3 in tissues.

Results

Blood flow velocity was lower in the LOSS group than in the HOSS group, while vessel diameter did not change significantly. Shear rate was elevated in both HOSS and LOSS groups but was higher in the HOSS group. Additionally, vessel diameter increased with time in the HOSS and LOSS groups, whereas flow velocity did not. Intimal hyperplasia was significantly lower in the LOSS group than in the HOSS group. IH was dominated by smooth muscle fibers in the grafted veins and collagen fibers in the media. OSS restriction significantly reduced the α-SMA, PCNA, MMP-2, and MMP-9 levels. Moreover, ROS production and the expression of NOX1, NOX2, p-AKT, BIRC5, PCNA, BCL-2, BAX, and cleaved caspase-3 were phase-reduced in LOSS compared to the levels in the HOSS group. Total AKT was not differentially expressed among the three groups.

Conclusion

OSS promotes the proliferation, migration, and survival of subendothelial vascular smooth muscle cells in grafted veins, which may be related to the regulation of downstream p-AKT/BIRC5 levels through the increased production of ROS by NOX. Drugs inhibiting this pathway might be used to prolong vein graft survival time.

Dexmedetomidine Attenuates Lipopolysaccharide-Induced Sympathetic Activation and Sepsis via Suppressing Superoxide Signaling in Paraventricular Nucleus

Sympathetic overactivity contributes to the pathogenesis of sepsis. The selective α2-adrenergic receptor agonist dexmedetomidine (DEX) is widely used for perioperative sedation and analgesia. We aimed to determine the central roles and mechanisms of DEX in attenuating sympathetic activity and inflammation in sepsis. Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide (LPS) in rats. Effects of DEX were investigated 24 h after injection of LPS. Bilateral microinjection of DEX in the paraventricular nucleus (PVN) attenuated LPS-induced sympathetic overactivity, which was attenuated by the superoxide dismutase inhibitor DETC, cAMP analog db-cAMP or GABA_A receptor antagonist gabazine. Superoxide scavenger tempol, NADPH oxidase inhibitor apocynin, adenylate cyclase inhibitor SQ22536 or PKA inhibitor Rp-cAMP caused similar effects to DEX in attenuating LPS-induced sympathetic activation. DEX inhibited LPS-induced superoxide and cAMP production, as well as NADPH oxidase, adenylate cyclase and PKA activation. The roles of DEX in reducing superoxide production and NADPH oxidase activation were attenuated by db-cAMP or gabazine. Intravenous infusion of DEX inhibited LPS-induced sympathetic overactivity, NOX activation, superoxide production, TNF-α and IL-1β upregulation in the PVN and plasma, as well as lung and renal injury, which were attenuated by the PVN microinjection of yohimbine and DETC. We conclude that activation of α2-adrenergic receptors with DEX in the PVN attenuated LPS-induced sympathetic overactivity by reducing NADPH oxidase-dependent superoxide production via both inhibiting adenylate cyclase-cAMP-PKA signaling and activating GABA_A receptors. The inhibition of NADPH oxidase-dependent superoxide production in the PVN partially contributes to the roles of intravenous infusion of DEX in attenuating LPS-induced sympathetic activation, oxidative stress and inflammation.

Comparative transcriptomics of high-altitude Vulpes and their low-altitude relatives

The harsh environment of Qinghai-Tibet Plateau (QTP) imposes strong selective stresses (e.g., hypoxia, high UV-radiation, and extreme temperature) to the native species, which have driven striking phenotypic and genetic adaptations. Although the mechanisms of high-altitude adaptation have been explored for many plateau species, how the phylogenetic background contributes to genetic adaption to high-altitude of Vulpes is largely unknown. In this study, we sequenced transcriptomic data across multiple tissues of two high-altitude Vulpes (Vulpes vulpes montana and Vulpes ferrilata) and their low-altitude relatives (Vulpes corsac and Vulpes lagopus) to search the genetic and gene expression changes caused by high-altitude environment. The results indicated that the positive selection genes (PSGs) identified by both high-altitude Vulpes are related to angiogenesis, suggesting that angiogenesis may be the result of convergent evolution of Vulpes in the face of hypoxic selection pressure. In addition, more PSGs were detected in V. ferrilata than in V. v. montana, which may be related to the longer adaptation time of V. ferrilata to plateau environment and thus more genetic changes. Besides, more PSGs associated with high-altitude adaptation were identified in V. ferrilata compared with V. v. montana, indicating that the longer the adaptation time to the high-altitude environment, the more genetic alterations of the species. Furthermore, the result of expression profiles revealed a tissue-specific pattern between Vulpes. We also observed that differential expressed genes in the high-altitude group exhibited species-specific expression patterns, revealed a convergent expression pattern of Vulpes in high-altitude environment. In general, our research provides a valuable transcriptomic resource for further studies, and expands our understanding of high-altitude adaptation within a phylogenetic context.

Rnd3 Expression is Necessary to Maintain Mitochondrial Homeostasis but Dispensable for Autophagy

Autophagy is a highly conserved process that mediates the targeting and degradation of intracellular components to lysosomes, contributing to the maintenance of cellular homeostasis and to obtaining energy, which ensures viability under stress conditions. Therefore, autophagy defects are common to different neurodegenerative disorders. Rnd3 belongs to the family of Rho GTPases, involved in the regulation of actin cytoskeleton dynamics and important in the modulation of cellular processes such as migration and proliferation. Murine models have shown that Rnd3 is relevant for the correct development and function of the Central Nervous System and lack of its expression produces several motor alterations and neural development impairment. However, little is known about the molecular events through which Rnd3 produces these phenotypes. Interestingly we have observed that Rnd3 deficiency correlates with the appearance of autophagy impairment profiles and irregular mitochondria. In this work, we have explored the impact of Rnd3 loss of expression in mitochondrial function and autophagy, using a Rnd3 KO CRISPR cell model. Rnd3 deficient cells show no alterations in autophagy and mitochondria turnover is not impaired. However, Rnd3 KO cells have an altered mitochondria oxidative metabolism, resembling the effect caused by oxidative stress. In fact, lack of Rnd3 expression makes these cells strictly dependent on glycolysis to obtain energy. Altogether, our results demonstrate that Rnd3 is relevant to maintain mitochondria function, suggesting a possible relationship with neurodegenerative diseases.

Adrenomedullin Improves Cardiac Remodeling and Function in Obese Rats with Hypertension

This study aimed to determine whether adrenomedullin (ADM, 7.2 μg/kg/day, ip), an important endogenous active peptide, has a protective role in cardiac remodeling and function in obesity-related hypertension (OH) rats. A high-fat diet (HFD) was used to induce OH for 20 weeks. H9c2 cells incubated with palmitate (PA, 200 μM) to mimic high free fatty acid in obesity were used as an in vitro model. In OH rats, ADM not only decreased body weight (BW) and blood pressure (BP) but also improved systemic inflammation and oxidative stress. Moreover, ADM still had a greater inhibitory effect on local inflammation and oxidative stress in the hearts of OH rats, and the same anti-inflammatory and antioxidant effects were also confirmed in PA-treated H9c2 cells. The ADM receptor antagonist or Akt inhibitor effectively attenuated the inhibitory effects of ADM on inflammation and oxidative stress in PA-stimulated H9c2 cells. Furthermore, ADM application effectively normalized heart function, and hematoxylin-eosin and Masson staining and collagen volume fraction results showed that ADM improved cardiac remodeling in hearts of OH rats. ADM attenuated cardiac inflammation and oxidative stress via the receptor-Akt pathway, which involves the improvement of cardiac remodeling and function in OH rats.

Impact of Selective Renal Afferent Denervation on Oxidative Stress and Vascular Remodeling in Spontaneously Hypertensive Rats

Oxidative stress and sustained sympathetic over-activity contribute to the pathogenesis of hypertension. Catheter-based renal denervation has been used as a strategy for treatment of resistant hypertension, which interrupts both afferent and efferent renal fibers. However, it is unknown whether selective renal afferent denervation (RAD) may play beneficial roles in attenuating oxidative stress and sympathetic activity in hypertension. This study investigated the impact of selective RAD on hypertension and vascular remodeling. Nine-week-old normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were subjected to selective renal afferent denervation (RAD) with 33 mM of capsaicin for 15 min. Treatment with the vehicle of capsaicin was used as a control. The selective denervation was confirmed by the reduced calcitonin gene-related peptide expression and the undamaged renal sympathetic nerve activity response to the stimulation of adipose white tissue. Selective RAD reduced plasma norepinephrine levels, improved heart rate variability (HRV) and attenuated hypertension in SHR.It reduced NADPH oxidase (NOX) expression and activity, and superoxide production in the hypothalamic paraventricular nucleus (PVN), aorta and mesenteric artery of SHR. Moreover, the selective RAD attenuated the vascular remodeling of the aorta and mesenteric artery of SHR. These results indicate that selective removal of renal afferents attenuates sympathetic activity, oxidative stress, vascular remodeling and hypertension in SHR. The attenuated superoxide signaling in the PVN is involved in the attenuation of sympathetic activity in SHR, and the reduced sympathetic activity at least partially contributes to the attenuation of vascular oxidative stress and remodeling in the arteries of hypertensive rats.