Comparative Effects of Basic Fibroblast Growth Factor Delivery or Voluntary Exercise on Muscle Regeneration after Volumetric Muscle Loss

Volumetric muscle loss (VML) is associated with irreversibly impaired muscle function due to traumatic injury. Experimental approaches to treat VML include the delivery of basic fibroblast growth factor (bFGF) or rehabilitative exercise. The objective of this study was to compare the effects of spatially nanopatterned collagen scaffold implants with either bFGF delivery or in conjunction with voluntary exercise. Aligned nanofibrillar collagen scaffold bundles were adsorbed with bFGF, and the bioactivity of bFGF-laden scaffolds was examined by skeletal myoblast or endothelial cell proliferation. The therapeutic efficacy of scaffold implants with either bFGF release or exercise was examined in a murine VML model. Our results show an initial burst release of bFGF from the scaffolds, followed by a slower release over 21 days. The released bFGF induced myoblast and endothelial cell proliferation in vitro. After 3 weeks of implantation in a mouse VML model, twitch force generation was significantly higher in mice treated with bFGF-laden scaffolds compared to bFGF-laden scaffolds with exercise. However, myofiber density was not significantly improved with bFGF scaffolds or voluntary exercise. In contrast, the scaffold implant with exercise induced more re-innervation than all other groups. These results highlight the differential effects of bFGF and exercise on muscle regeneration.

IL-1β promotes hypoxic vascular endothelial cell proliferation through the miR-24-3p/NKAP/NF-kB axis

Purpose: Our previous data indicated that miR‑24-3p is involved in the regulation of vascular endothelial cell proliferation and migration/invasion. However, whether IL-1β affects hypoxic HUVECs by miR-24-3p is still unclear. Therefore, the present study aimed to investigate the role and underlying mechanism of IL-1β in hypoxic HUVECs. Methods: We assessed the mRNA expression levels of miR-24-3p, HIF1A and NKAP by RT-qPCR. ELISA measured the expression level of IL-1β. CCK-8 assays evaluated the effect of miR-24-3p or si-NKAP+miR-24 on cell proliferation (with or without IL-1β). Transwell migration and invasion assays were used to examine the effects of miR-24-3p or si-NKAP+miR-24-3p on cell migration and invasion (with or without IL-1β). Luciferase reporter assays were used to identify the target of miR-24-3p. Results: We demonstrated that in AMI patient blood samples, the expression of miR-24-3p is downregulated, the expression of IL-1β or NKAP is upregulated, and IL-1β or NKAP is negatively correlated with miR-24-3p. Furthermore, IL-1β promotes hypoxic HUVECs proliferation by downregulating miR-24-3p. In addition, IL-1β also significantly promotes the migration and invasion of hypoxic HUVECs; overexpression of miR-24-3p can partially rescue hypoxic HUVECs migration and invasion. Furthermore, we discovered that NF-kappa-B-activating protein (NKAP) is a novel target of miR-24-3p in hypoxic HUVECs. Moreover, both the overexpression of miR-24-3p and the suppression of NKAP can inhibit the NF-kB/pro-IL-1β signaling pathway. However, IL‑1β mediates suppression of miR-24-3p activity, leading to activation of the NKAP/NF‑κB pathway. In conclusion, our results reveal a new function of IL‑1β in suppressing miR-24-3p upregulation of the NKAP/NF-kB pathway.

Autoantibodies Targeting AT1- and ETA-Receptors Link Endothelial Proliferation and Coagulation via Ets-1 Transcription Factor

Scleroderma renal crisis (SRC) is an acute life-threatening manifestation of systemic sclerosis (SSc) caused by obliterative vasculopathy and thrombotic microangiopathy. Evidence suggests a pathogenic role of immunoglobulin G (IgG) targeting G-protein coupled receptors (GPCR). We therefore dissected SRC-associated vascular obliteration and investigated the specific effects of patient-derived IgG directed against angiotensin II type 1 (AT1R) and endothelin-1 type A receptors (ETAR) on downstream signaling events and endothelial cell proliferation. SRC-IgG triggered endothelial cell proliferation via activation of the mitogen-activated protein kinase (MAPK) pathway and subsequent activation of the E26 transformation-specific-1 transcription factor (Ets-1). Either AT1R or ETAR receptor inhibitors/shRNA abrogated endothelial proliferation, confirming receptor activation and Ets-1 signaling involvement. Binding of Ets-1 to the tissue factor (TF) promoter exclusively induced TF. In addition, TF inhibition prevented endothelial cell proliferation. Thus, our data revealed a thus far unknown link between SRC-IgG-induced intracellular signaling, endothelial cell proliferation and active coagulation in the context of obliterative vasculopathy and SRC. Patients’ autoantibodies and their molecular effectors represent new therapeutic targets to address severe vascular complications in SSc.

ASC and SVF Cells Synergistically Induce Neovascularization in Ischemic Hindlimb Following Cotransplantation

Previously, we reported the angio-vasculogenic properties of human stromal vascular fraction (SVF) and adipose tissue-derived mesenchymal stem cells (ASCs). In this study, we investigated whether the combination of ASCs and SVF cells exhibited synergistic angiogenic properties. We conducted quantitative (q)RT-PCR, Matrigel plug, tube formation assays, and in vivo therapeutic assays using an ischemic hind limb mouse model. Immunohistochemical analysis was also conducted. qRT-PCR results revealed that FGF-2 was highly upregulated in ASCs compared with SVF, while PDGF-b and VEGF-A were highly upregulated in SVF. Conditioned medium from mixed cultures of ASCs and SVF (A+S) cells showed higher Matrigel tube formation and endothelial cell proliferation in vitro. A+S cell transplantation into ischemic mouse hind limbs strongly prevented limb loss and augmented blood perfusion compared with SVF cell transplantation. Transplanted A+S cells also showed high capillary density, cell proliferation, angiogenic cytokines, and anti-apoptotic potential in vivo compared with transplanted SVF. Our data indicate that A+S cell transplantation results in synergistic angiogenic therapeutic effects. Accordingly, A+S cell injection could be an alternative therapeutic strategy for treating ischemic diseases.

Dysfunctional Vascular Endothelium as a Driver of Atherosclerosis: Emerging Insights Into Pathogenesis and Treatment

Atherosclerosis, the chronic accumulation of cholesterol-rich plaque within arteries, is associated with a broad spectrum of cardiovascular diseases including myocardial infarction, aortic aneurysm, peripheral vascular disease, and stroke. Atherosclerotic cardiovascular disease remains a leading cause of mortality in high-income countries and recent years have witnessed a notable increase in prevalence within low- and middle-income regions of the world. Considering this prominent and evolving global burden, there is a need to identify the cellular mechanisms that underlie the pathogenesis of atherosclerosis to discover novel therapeutic targets for preventing or mitigating its clinical sequelae. Despite decades of research, we still do not fully understand the complex cell-cell interactions that drive atherosclerosis, but new investigative approaches are rapidly shedding light on these essential mechanisms. The vascular endothelium resides at the interface of systemic circulation and the underlying vessel wall and plays an essential role in governing pathophysiological processes during atherogenesis. In this review, we present emerging evidence that implicates the activated endothelium as a driver of atherosclerosis by directing site-specificity of plaque formation and by promoting plaque development through intracellular processes, which regulate endothelial cell proliferation and turnover, metabolism, permeability, and plasticity. Moreover, we highlight novel mechanisms of intercellular communication by which endothelial cells modulate the activity of key vascular cell populations involved in atherogenesis, and discuss how endothelial cells contribute to resolution biology – a process that is dysregulated in advanced plaques. Finally, we describe important future directions for preclinical atherosclerosis research, including epigenetic and targeted therapies, to limit the progression of atherosclerosis in at-risk or affected patients.

Vascular Response on a Novel Fibrin-Based Coated Flow Diverter

Purpose Due to thromboembolic complications and in-stent-stenosis after flow diverter (FD) treatment, the long-term use of dual antiplatelet treatment (DAPT) is mandatory. The tested nano-coating has been shown to reduce material thrombogenicity and promote endothelial cell proliferation in vitro. We compared the biocompatibility of coated (Derivo Heal) and non-coated (Derivo bare) FDs with DAPT in an animal model. Methods Derivo® bare (n = 10) and Derivo® Heal (n = 10) FD were implanted in the common carotid arteries (CCAs) of New Zealand white rabbits. One additional FD, alternately a Derivo bare (n = 5) or Derivo Heal (n = 5), was implanted in the abdominal aorta (AA) for assessment of the patency of branch arteries. Histopathological examinations were performed after 28 days. Angiography was performed before and after FD implantation and at follow-up. Results Statistical analysis of the included specimens showed complete endothelialization of all FDs with no significant differences in neointima thickness between Derivo® bare and Derivo® Heal (CCA: p = 0.91; AA: p = 0.59). A significantly reduced number of macrophages in the vessel wall of the Derivo Heal was observed for the CCA (p = 0.02), and significantly reduced fibrin and platelet deposition on the surface of the Derivo Heal was observed for the AA. All branch arteries of the stented aorta remained patent. Conclusion In this animal model, the novel fibrin-based coated FD showed a similar blood and tissue compatibility as the non-coated FD.

Prevalence and Outcomes Associated with Hyperuricemia in Hospitalized Patients with COVID-19

<b><i>Introduction:</i></b> Coronavirus 2019 (COVID-19) can increase catabolism and result in hyperuricemia. Uric acid (UA) potentially causes kidney damage by alteration of renal autoregulation, inhibition of endothelial cell proliferation, cell apoptosis, activation of the pro-inflammatory cascade, and crystal deposition. Hyperuricemia in patients with COVID-19 may contribute to acute kidney injury (AKI) and poor outcomes. <b><i>Methods:</i></b> We included 834 patients with COVID-19 who were &#x3e;18 years old and hospitalized for &#x3e;24 h in the Mount Sinai Health System and had at least 1 measurement of serum UA. We examined the association between the first serum UA level and development of acute kidney injury (AKI, defined by KDIGO criteria), major adverse kidney events (MAKE, defined by a composite of all-cause in-hospital mortality or dialysis or 100% increase in serum creatinine from baseline), as well as markers of inflammation and cardiac injury. <b><i>Results:</i></b> Among the 834 patients, the median age was 66 years, 42% were women, and the median first serum UA was 5.9 mg/dL (interquartile range 4.5–8.8). Overall, 60% experienced AKI, 52% experienced MAKE, and 32% died during hospitalization. After adjusting for demographics, comorbidities, and laboratory values, a doubling in serum UA was associated with increased AKI (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.9–4.1), MAKE (OR 2.5, 95% CI 1.7–3.5), and in-hospital mortality (OR 1.7, 95% CI 1.3–2.3). Higher serum UA levels were independently associated with a higher level of procalcitonin (β, 0.6; SE 0.2) and troponin I (β, 1.2; SE 0.2) but were not associated with serum ferritin, C-reactive protein, and interleukin-6. <b><i>Conclusion:</i></b> In patients admitted to the hospital for COVID-19, higher serum UA levels were independently associated with AKI, MAKE, and in-hospital mortality in a dose-dependent manner. In addition, hyperuricemia was associated with higher procalcitonin and troponin I levels.

MicroRNA-146-5p Promotes Pulmonary Artery Endothelial Cell Proliferation under Hypoxic Conditions through Regulating USP3

Objective. MicroRNAs play a pivotal role in the progression of pulmonary hypertension (PAH). Although microRNA-146-5p is specifically expressed in many diseases, but in PAH, its role remains elusive. Patients and Methods. 30 patients with PAH and 20 healthy volunteers in our hospital were enrolled, and their serum samples were extracted for the detection of microRNA-146-5p and ubiquitin specific protease 3 (USP3) expression. In addition, the interaction between microRNA-146-5p and USP3 was examined by luciferase reporting assay. Furthermore, the potential mechanism was explored by cell counting kit-8 (CCK-8), 5-ethynyl-2 ′ -deoxyuridine (EdU), and Western blotting experiments. Results. It was found that microRNA-146-5p was higher in PAH patients than in healthy volunteers. Meanwhile, in hypoxia-induced human pulmonary artery endothelial cell lines (HPAECs), microRNA-146-5p expression was dramatically downregulated while USP3 protein expression was conversely upregulated. Under hypoxic conditions, microRNA-146-5p mimics was able to prompt the growth of HPAECs. In addition, after overexpression of microRNA-146-5p, luciferase reporting assay revealed a reduced luciferase activity of the reporter gene containing the USP3 3 ′ -untranslated region, and a reduction of USP3 protein expression was also confirmed. However, USP3 overexpression partially attenuated the impact of upregulated microRNA-146-5p on the proliferation capacity of HPAECs. Conclusions. MicroRNA-146-5p was able to enhance the proliferation ability of HPAEC cells under hypoxic conditions through targeting USP3, suggesting the microRNA-146-5p/USP3 axis may act as a target for PAH treatment.