Wire myography to test vasomotor functions of blood vessels ex‐vivo are well‐established for the systemic circulation, however, there is no consensus on protocols for pulmonary arteries. We created a ...standardized wire myography protocol for healthy rat PAs and validated this in a pulmonary hypertension (PH) model. Vessels stretched to higher initial tensions (5.0, 7.5 and 10.0 mN) exhibited a uniform response to phenylephrine, a larger dynamic range, and lower EC50 values. The endothelium‐mediated relaxation showed that moderate tensions (7.5 and 10.0 mN) produced robust responses with higher maximum relaxation and lower EC50 values. For endothelium independent responses, the higher initial tension groups had lower and more consistent EC50 values than the lower initial tension groups. Pulmonary arteries from rats with PH were more responsive to vasoactive drugs when subjected to a higher initial tension. Notably, vessels in the PH group subjected to 15.0 mN exhibited high dynamic ranges in contractile and relaxation responses without tearing. Lastly, we observed attenuated cholinergic responses in these vessels—consistent with endothelial dysfunction in PH. Therefore, a moderate initial tension of 7.5–10.0 mN is optimal for healthy rat pulmonary arteries and a higher initial tension of 15.0 mN is optimal for pulmonary arteries from animals with PH.
Hypoxia in the neonatal period is associated with early manifestations of adverse cardiovascular health in adulthood including higher risk of hypertension and atherosclerosis. We hypothesize that ...this occurs due to activation of lysyl oxidases (LOXs) and the remodeling of the large conduit vessels, leading to early arterial stiffening. Newborn C57Bl/6 mice were exposed to hypoxia (FiO2 = 11.5%) from postnatal day 1 (P1) to postnatal day 11 (P11), followed by resumption of normoxia. Controls were maintained in normoxia. Using in vivo (pulse wave velocity; PWV) and ex vivo (tensile testing) arterial stiffness indexes, we determined that mice exposed to neonatal hypoxia had significantly higher arterial stiffness compared with normoxia controls by young adulthood (P60), and it increased further by P120. Echocardiography performed at P60 showed that mice exposed to hypoxia displayed a compensated dilated cardiomyopathy. Western blotting revelated that neonatal hypoxia accelerated age‐related increase in LOXL2 protein expression in the aorta and elevated LOXL2 expression in the PA at P11 with a delayed decay toward normoxic controls. In the heart and lung, gene and protein expression of LOX/LOXL2 were upregulated at P11, with a delayed decay when compared to normoxic controls. Neonatal hypoxia results in a significant increase in arterial stiffness in early adulthood due to aberrant LOX/LOXL2 expression. This suggests an acceleration in the mechanical decline of the cardiovascular system, that contributes to increased risk of hypertension in young adults exposed to neonatal hypoxia that may increase susceptibility to further insults.
Neonatal hypoxia accelerates arterial aging through lysyl oxidase‐like 2 activation in both systemic and pulmonary circulation. Created with BioRender.com.
Olfactory receptors are primarily studied in the nose; but are also expressed and play pivotal roles in non‐olfactory tissues as ecnomotopic receptors. We find that olfactory receptor 558 (Olfr558) ...is expressed in vascular smooth muscle cells in the kidney, including the renal afferent and efferent arterioles. We developed Olfr558 whole‐body knockout (KO) mice to test the hypothesis that Olfr558 plays a role in blood pressure (BP) regulation. Olfr558 wild‐type (WT) vs. KO (males and females) exhibited no genotypic differences in body weight, kidney weight/body weight, heart weight/body weight, glomerular filtration rate, or blood values (electrolytes, glucose, blood urea nitrogen, creatinine, and hemoglobin). However, Olfr558 KO males had lower diastolic blood pressure (DBP) (81.1±1.6 mmHg, n=9, p=0.009) than WT males (89.1±2.2 mmHg, n=7) during the light cycle (telemetry) without a change in mean arterial (MAP) or systolic blood pressure (SBP). In contrast, Olfr558 KO females had increased MAP (KO: 95.0±1.7 mmHg, WT: 89.0±0.9 mmHg, p=0.003), SBP (KO: 108.0±1.7 mmHg, WT: 102.1±1.4 mmHg, p=0.02), and DBP (KO: 81.6±1.6 mmHg, WT: 75.0±0.9 mmHg, p=0.003) during the light cycle (n=8 for WT and KO). A similar trend was observed during the dark cycle. These data suggest that Olfr558 regulates BP in a sex‐specific manner.
To determine the mechanisms underlying the sexually dimorphic effect of Olfr558 on BP regulation, we are examining renin signaling and vascular tone. In males, kidney renin mRNA levels were significantly decreased in Olfr558 KO (0.43±0.04, n=12, p=0.001 vs WT 1±0.14, n=11). Akr1b7 (renin cell marker) mRNA was also reduced in male KO (0.5±0.06, n=12, p=0.002, vs WT 1±0.09, n=10). We then evaluated the % of renin positive to total glomeruli and found that it was reduced in male KO (29.0±0.95, p=0.004, vs WT 43.2±1.88; n=8). We also found that plasma renin activity (PRA) was dramatically decreased in male KO (200.8±20.5, n=11, p=0.001) than WT (401.9±15.2, n=10). These results suggest that Olfr558 regulates BP in males at least in part via renin. In females, there were no differences in renin or Akr1b7 mRNA, nor in the % of renin positive glomeruli, nor PRA. These results suggest that, in females, Olfr558 modulates BP independent of renin. Studies of ex vivo vascular reactivity in males show that aortic rings exhibited less constriction to Phenylephrine (PE) in KO vs WT, which could contribute to the hypotension seen in these mice. In contrast, constriction to KCl and relaxation to Acetylcholine (ACh) and sodium nitroprusside (SNP) showed no genotypic difference. KO mesentery exhibited more relaxation to SNP, but not ACh, and similar constriction to KCl and PE as WT. In females, KO aortic rings exhibited more constriction to KCl, but not PE, and similar relaxation to ACh and SNP as WT. However, mesentery showed no genotypic difference in constriction to KCl and PE, relaxation to ACh and SNP. Thus, our findings suggest that the hypotension seen in Olfr558 KO males is likely contributed to both by decreased renin and by changes in vascular reactivity, whereas the origin of hypertension seen in Olfr558 KO females is still an area of active investigation.
Introduction: Hypertension, a disease with known sexual dimorphism, accelerates aging associated arterial stiffening. In this study, we tested the effect of biological sex and the role of the matrix ...remodeling enzyme lysyl oxidase like 2 (LOXL2) in hypertension induced arterial stiffening. Methods: Hypertension was induced by Angiotensin II (AngII) infusion. Blood pressure and pulse wave velocity (PWV) were measured noninvasively. Wire myography and uniaxial tensile testing were used to test aortic vasoreactivity and mechanical properties. Aortic wall composition was examined by histology and Western blotting. Uniaxial stretch of cultured cells was used to evaluate the effect of biomechanical strain. LOXL2's catalytic function was examined using knockout and inhibition. Results: Ang II infusion induced hypertension in both genotypes and sexes. Hypertensive WT males had higher PWV and passive stiffness. Aortic remodeling with increased wall thickness, intralamellar distance, higher LOXL2, collagen I, and collagen IV content was noted in WT males. Females did not exhibit increased PWV. LOXL2-depletion improved aortic mechanics in both sexes. LOXL2-depletion improved hyper-contractility in males but not females. Hypertensive cyclic strain contributed to LOXL2 upregulation in the cell-derived matrix in VSMCs. LOXL2's catalytic function facilitated VSMC alignment in response to biomechanical strain. Conclusion: In males, arterial stiffening in hypertension is driven by VSMC response and matrix remodeling; females are protected from stiffening independent of LOXL2. VSMCs are the primary source of LOXL2 in the aorta. Hypertension increases LOXL2 processing and collagen I accumulation in the aorta. Overall, LOXL2 depletion offers protection in young hypertensive males and females.
Sex differences in blood pressure are well-established, with premenopausal women having lower blood pressure than men by ~10 millimeters of mercury; however, the underlying mechanisms are not fully ...understood. We report here that sex differences in blood pressure are absent in olfactory receptor 558 knockout (KO) mice.
localizes to renin-positive cells in the kidney and to vascular smooth muscle cells. Female KOs exhibit increased blood pressure and increased pulse wave velocity. In contrast, male KO mice have decreased renin expression and activity, altered vascular reactivity, and decreased diastolic pressure. A rare
(human ortholog) missense variant has a statistically significant sex interaction effect with diastolic blood pressure, increasing diastolic blood pressure in women but decreasing it in men. In summary, our findings demonstrate an evolutionarily conserved role for OLFR558/OR51E1 to mediate sex differences in blood pressure.
Atopic dermatitis (AD) is a chronic inflammatory skin disorder with a complex etiology involving the immune response. Recent studies have demonstrated the role of certain probiotics in the treatment ...and prevention of AD. However, the mechanism by which these probiotics regulate the immune system remains unclear. In this study, we examined the immunomodulatory capacity of Duolac ATP, a mixed formulation of probiotics, both
and
. Results showed that the expression of programmed death-ligand 1(PD-L1) was significantly upregulated on bone marrow-derived dendritic cells (BMDCs) treated with Duolac ATP. Furthermore, the anti-inflammatory cytokines IL-10 and TGF-beta were both upregulated when BMDCs were treated with Duolac ATP. The percentage of proliferated regulatory T cells (Tregs) was enhanced when CD4
T cells were co-cultured with Duolac ATP-treated BMDCs on plates coated with anti-CD3/CD28 antibodies. Intriguingly, IL-10 secretion from CD4
T cells was also observed. The AD symptoms, histologic scores, and serum IgE levels in AD mice were significantly decreased after oral treatment with Duolac ATP. Moreover, the Th1-mediated response in AD-induced mice treated with oral Duolac ATP showed upregulation of IL-2 and IFN-gamma as well as of downstream signaling molecules T-bet, STAT-1, and STAT-4. Conversely, Duolac ATP suppressed Th2 and Th17 responses in AD-like mice, as evidenced by the downregulation of GATA-3, C-maf, IL-4, IL-5, and IL-17. Additionally, Duolac ATP increased the number of Tregs found at Peyer's patches (PP) in treated AD mice. These results suggest that Duolac ATP modulates DCs to initiate both Th1 and Treg responses in AD mice. Thus, Duolac ATP represents a potential preventative agent against AD and could serve as an effective immunomodulator in AD patients.
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•Developed anti-wrinkle peptide (Regentide®-AWP013; RG) loaded solvent-free thermosponge nanoparticles (TNP).•TNP efficiently encapsulated RG in aqueous condition, and improve ...stability and efficacy of RG.•TNP facilitates RG penetration into the skin.•RG@TNP showed significant anti-aging effect on eye wrinkles in clinical trials.•It influenced skin elasticity, brightening, and skin sagging.
With the worldwide increase in life expectancy, the human desire to maintain youth and beauty has intensified, leading to rapid advances in the cosmetic industry. However, recently proposed peptide-based formulations with anti-aging properties exhibit low skin-penetration ability. To overcome this limitation, an anti-wrinkle peptide (Regentide®-AWP013; RG) with time- and dose-dependent cell proliferation, wound-healing activity, and no cytotoxicity was developed in this study. The stability and efficacy of RG were improved using solvent-free thermosponge nanoparticles (TNPs) comprising FDA-approved biocompatible materials, which were developed using a simple nanoprecipitation method. The temperature-responsive TNPs efficiently encapsulated RG in aqueous solutions (without any organic solvents), thus improving the cellular uptake and skin-penetration ability of RG. The loading content of RG in TNPs was optimized by monitoring the changes in the physicochemical properties of the RG-loaded TNPs (RG@TNP). The optimally loaded RG@TNP showed long-term stability under physiological conditions, with better skin-penetration ability than free RG. In clinical trials, the RG@TNP showed excellent anti-aging effects on eye wrinkles; it improved skin elasticity and reduced skin pigmentation and sagging, indicating a massive potential in the cosmetic industry. The results obtained in this study confirm the ability of TNPs to efficiently encapsulate peptides with anti-wrinkle properties that improve their stability and skin-penetration ability.
•We fabricated a novel electrospun fish collagen/PCL composite nanofiber scaffold.•The diameter of the nanofibers decreased as fish collagen content was increased.•The scaffold promoted the cell ...adhesion, spreading, protrusions, and proliferation.•The scaffold stimulated the expression of cell adhesion and thymopoietic molecules.•The scaffold offers a potential platform for a wide range of 3D cell culture models.
One of the most challenging objectives of 3D cell culture is the development of scaffolding materials with outstanding biocompatibility and favorable mechanical strength. In this study, we fabricated a novel nanofibrous scaffold composed of fish collagen (FC) and polycaprolactone (PCL) blends by using the electrospinning method. Nanofibrous scaffolds were characterized using a scanning electron microscope (SEM), and it was revealed that the diameter of nanofibers decreased as FC content was increased in the FC/PCL composite nanofibers. The cytocompatibility of the FC/PCL scaffolds was evaluated by SEM, WST-1 assay, confocal microscopy, western blot, and RT-PCR. It was found that the scaffolds not only facilitated the adhesion, spreading, protrusions, and proliferation of thymic epithelial cells (TECs), but also stimulated the expression of genes and proteins involved in cell adhesion and T-cell development. Thus, these results suggest that the FC/PCL composite nanofibrous scaffolds will be a useful model of 3D cell culture for TECs and may have wide applicability in the future for engineering tissues or organs.
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