Qingda granule ameliorates vascular remodeling and phenotypic transformation of adventitial fibroblasts via suppressing the TGF-β1/Smad2/3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Qingda granule (QDG) exhibits significant therapeutic effects on high blood pressure, vascular dysfunction, and elevated proliferation of vascular smooth muscle cells by inhibiting multiple pathways. However, the effects and underlying mechanisms of QDG treatment on hypertensive vascular remodeling are unclear.

AIM OF THE STUDY

The aim of this study was to determine the role of QDG treatment in hypertensive vascular remodeling in vivo and in vitro.

MATERIALS AND METHODS

An ACQUITY UPLC I-Class system coupled with a Xevo XS quadrupole time of flight mass spectrometer was used to characterize the chemical components of QDG. Twenty-five spontaneously hypertensive rats (SHR) were randomly divided into five groups, including SHR (equal volume of double distilled water, ddH₂O), SHR + QDG-L (0.45 g/kg/day), SHR + QDG-M (0.9 g/kg/day), SHR + QDG-H (1.8 g/kg/day), and SHR + Valsartan (7.2 mg/kg/day) groups. QDG, Valsartan, and ddH₂O were administered intragastrically once a day for 10 weeks. For the control group, ddH₂O was intragastrically administered to five Wistar Kyoto rats (WKY group). Vascular function, pathological changes, and collagen deposition in the abdominal aorta were evaluated using animal ultrasound, hematoxylin and eosin and Masson staining, and immunohistochemistry. Isobaric tags for relative and absolute quantification (iTRAQ) was performed to identify differentially expressed proteins (DEPs) in the abdominal aorta, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. Cell Counting Kit-8 assays, phalloidin staining, transwell assays, and western-blotting were performed to explore the underlying mechanisms in primary isolated adventitial fibroblasts (AFs) stimulated with transforming growth factor-β 1 (TGF-β1) with or without QDG treatment.

RESULTS

Twelve compounds were identified from the total ion chromatogram fingerprint of QDG. In the SHR group, QDG treatment significantly attenuated the increased pulse wave velocity, aortic wall thickening, and abdominal aorta pathological changes and decreased Collagen I, Collagen III, and Fibronectin expression. The iTRAQ analysis identified 306 DEPs between SHR and WKY and 147 DEPs between QDG and SHR. GO and KEGG pathway analyses of the DEPs identified multiple pathways and functional processes involving vascular remodeling, including the TGF-β receptor signaling pathway. QDG treatment significantly attenuated the increased cell migration, actin cytoskeleton remodeling, and Collagen I, Collagen III, and Fibronectin expression in AFs stimulated with TGF-β1. QDG treatment significantly decreased TGF-β1 protein expression in abdominal aortic tissues in the SHR group and p-Smad2 and p-Smad3 protein expression in TGF-β1-stimulated AFs.

CONCLUSIONS

QDG treatment attenuated hypertension-induced vascular remodeling of the abdominal aorta and phenotypic transformation of adventitial fibroblasts, at least partly by suppressing TGF-β1/Smad2/3 signaling.

Periostin contributes to the adventitial remodeling of atherosclerosis by activating adventitial fibroblasts

Background and aims

Adventitial remodeling is an important pathological process of atherosclerosis, but cues implicated in adventitial remodeling are far from fully understood. Periostin (POSTN), a matricellular protein, has been demonstrated to have multiple roles in cardiovascular diseases. The aim of the study was to explore the function of POSTN in adventitial remodeling during atherosclerosis.

Methods

An atherosclerosis model was constructed based on ApoE-/- mice fed a high-fat and high-cholesterol diet. The expression of POSTN in the adventitia of mouse atherosclerotic vascular specimens was detected by immunohistochemical staining. The roles of POSTN in regulating adventitial fibroblast activation were assessed by cell contractility and activation marker α-smooth muscle actin (α-SMA) expression evaluation in adventitial fibroblasts overexpressing POSTN. In addition, we performed quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting to examine the expression of the proinflammatory chemokines transforming growth factor-β1 (TGF-β1) and monocyte chemotactic protein 1 (MCP1), as well as some extracellular matrix (ECM)-related proteins, in POSTN-overexpressing adventitial fibroblasts. Finally, the integrin-related signaling pathway was detected upon POSTN overexpression in adventitial fibroblasts.

Results

POSTN was highly expressed in the adventitia of atherosclerotic aortae in the mouse atherosclerosis model and promoted the activation and contraction of adventitial fibroblasts. Meanwhile, POSTN also induced adventitial fibroblasts to express TGF-β1, monocyte chemotactic protein-1 (MCP1), and ECM-related proteins and activated the phosphorylation of focal adhesion kinase (FAK) and Src.

Conclusions

Our results revealed that POSTN is elevated in adventitia during atherosclerosis and contributes to the adventitial remodeling of atherosclerosis by activating adventitial fibroblasts.

Elabela prevents angiotensin II-induced apoptosis and inflammation in rat aortic adventitial fibroblasts via the activation of FGF21-ACE2 signaling

Apoptosis, inflammation, and fibrosis contribute to vascular remodeling and injury. Elabela (ELA) serves as a crucial regulator to maintain vascular function and has been implicated in the pathogenesis of hypertensive vascular remodeling. This study aims to explore regulatory roles and underlying mechanisms of ELA in rat aortic adventitial fibroblasts (AFs) in response to angiotensin II (ATII). In cultured AFs, exposure to ATII resulted in marked decreases in mRNA and protein levels of ELA, fibroblast growth factor 21 (FGF21), and angiotensin-converting enzyme 2 (ACE2) as well as increases in apoptosis, inflammation, oxidative stress, and cellular migration, which were partially blocked by the exogenous replenishment of ELA and recombinant FGF21, respectively. Moreover, treatment with ELA strikingly reversed ATII-mediated the loss of FGF21 and ACE2 levels in rat aortic AFs. FGF21 knockdown with small interfering RNA (siRNA) significantly counterbalanced protective effects of ELA on ATII-mediated the promotion of cell migration, apoptosis, inflammatory, and oxidative injury in rat aortic AFs. More importantly, pretreatment with recombinant FGF21 strikingly inhibited ATII-mediated the loss of ACE2 and the augmentation of cell apoptosis, oxidative stress, and inflammatory injury in rat aortic AFs, which were partially prevented by the knockdown of ACE2 with siRNA. In summary, ELA exerts its anti-apoptotic, anti-inflammatory, and anti-oxidant effects in rat aortic AFs via activation of the FGF21-ACE2 signaling. ELA may represent a potential candidate to predict vascular damage and targeting the FGF21-ACE2 signaling may be a promising therapeutic intervention for vascular adventitial remodeling and related disorders.

Chronic inflammation within the vascular wall in pulmonary arterial hypertension: more than a spectator

This review seeks to provide an update of preclinical findings and available clinical data on the chronic persistent inflammation and its direct role on the pulmonary arterial hypertension (PAH) progression. We reviewed the different mechanisms by which the inflammatory and immune pathways contribute to the structural and functional changes occurring in the three vascular compartments: the tunica intima, tunica media, and tunica adventitia. We also discussed how these inflammatory mediator changes may serve as a biomarker of the PAH progression and summarize unanswered questions and opportunities for future studies in this area.

MicroRNA-122 aggravates angiotensin II-mediated apoptosis and autophagy imbalance in rat aortic adventitial fibroblasts via the modulation of SIRT6-elabela-ACE2 signaling

Abnormal aortic adventitial fibroblasts (AFs) play essential roles in the development of vascular remodeling and disorders. Previous studies revealed that microRNA-122 (miR-122) levels were elevated in the aortic adventitia of hypertensive rats with vascular injury. Here, we aim to evaluate the biological effects and underlying mechanisms of miR-122 in rat AFs. Exposure to angiotensin II (ATII) in rat AFs resulted in decreased levels of sirtuin 6 (SIRT6), elabela (ELA), and angiotensin-converting enzyme 2 (ACE2). Additionally, stimulation with ATII contributed to a decline in autophagic flux and obvious increases in cellular migration, oxidative stress, and apoptosis, which were exacerbated by the transfection of miR-122-5p mimic but were rescued by miR-122-5p inhibitor, exogenous replenishment of ELA, and recombinant adeno-associated virus expressing SIRT6 (rAAV-SIRT6), respectively. Moreover, stimulation with miR-122-5p mimic led to a marked reduction in the levels of SIRT6 and ELA in rat AFs, which were elevated by stimulation with rAAV-SIRT6. Furthermore, miR-122-5p inhibitor-mediated pro-autophagic, anti-oxidant and anti-apoptotic effects in rat AFs were partially suppressed by 3-methyladenine, SIRT6 small interfering RNA (siRNA) and ELA siRNA, which were linked with the downregulation in the protein levels of LC3-II, beclin-1, and ACE2 and the upregulation of p62 expression and bax/bcl-2 ratio. Our findings indicated that miR-122-5p inhibition prevented ATII-mediated loss of autophagy, and the promotion of apoptosis and oxidative stress via activating the SIRT6-ELA-ACE2 signaling. MiR-122-5p may be a novel predictive biomarker of adventitial injury, and targeting the SIRT6-ELA-ACE2 signaling may have the potential therapeutic importance of controlling vascular remodeling and disorders.

Effect of CTRP3 on activation of adventitial fibroblasts induced by TGF-β1 from rat aorta in vitro

CTRP3, discovered as novel adipokines, is a member of the C1q tumor necrosis factor (TNF) related protein (CTRP) super-family. CTRP3 is found to function as adipokines that display diverse biological activities in metabolic and cardiovascular diseases. Recent study demonstrated that CTRP3 was protective against pathological cardiac remodeling in mice. Nevertheless, the effect of CTRP3 on vascular remodeling remains undefined. Our present study aimed to explore the effects of adipokine CTRP3 on the activation of adventitial fibroblasts (AFs) induced by TGF-β1. Immunofluorescent staining, real-time PCR and Western blot were conducted to evaluate the expression of α-smooth muscle-actin (α-SMA) and collagen I. The expression of CTGF was evaluated by enzymelinked immunosorbent assay (ELISA), while the proliferation and migration of adventitial fibroblasts were detected by using cell counting kit-8 (CCK-8) assay and Transwell technique, respectively. Functional analysis showed that CTRP3 inhibited TGF-β1 inducing AFs phenotypic conversion, collagen synthesis, proliferation and migration. The secretion of CTGF was also inhibited by CTRP3. Our findings suggest that CTRP3 may be beneficial to the prevention of cardiovascular diseases and provide a promising therapeutic strategy to attenuate vascular remodeling.