TGF-β1 in Vascular Wall Pathology: Unraveling Chronic Venous Insufficiency Pathophysiology

Chondroitin polymerizing factor (CHPF) promotes the progression of colorectal cancer through ASB2-mediated ubiquitylation of SMAD9

Chondroitin polymerizing factor (CHPF) has been reported to play a pivotal role in the progression of multiple cancers, however, the relationship between CHPF and colorectal cancer (CRC) progression has not been fully understood. The current study revealed that CHPF expression was upregulated in patients with CRC and correlated with an unfavorable prognosis. Also, CHPF knockdown effectively suppressed the viability and mobility of CRC cells and the growth of xenograft tumors. Additionally, SMAD9 was identified as a downstream target of CHPF. SMAD9 knockdown successfully abrogated the promotion of CHPF overexpression in CRC progression, indicating that CHPF regulated the development of CRC through SMAD9. Mechanistically, SMAD9 is ubiquitinated by ASB2, and the regulatory effect of CHPF on SMAD9 activity was exerted via its mediation of ASB2. Collectively, CHPF functioned as a promising prognostic biomarker and tumor-promoter of CRC by regulating the ASB2-mediated ubiquitination of SMAD9.

Key Regulators of Angiogenesis and Inflammation Are Dysregulated in Patients with Varicose Veins

Varicose veins (VVs) are the most common manifestation of chronic venous disease (CVD) and appear as abnormally enlarged and tortuous superficial veins. VVs result from functional abnormalities in the venous circulation of the lower extremities, such as venous hypertension, venous valve incompetence, and venous reflux. Previous studies indicate that enhanced angiogenesis and inflammation contribute to the progression and onset of VVs; however, dysregulations in signaling pathways associated with these processes in VVs patients are poorly understood. Therefore, in our study, we aimed to identify key regulators of angiogenesis and inflammation that are dysregulated in patients with VVs. Expression levels of 18 genes were analyzed in peripheral blood mononuclear cells (PBMC) using real-time PCR, as well as plasma levels of 6 proteins were investigated using ELISA. Higher levels of CCL5, PDGFA, VEGFC, TGF-alpha, TGF-beta 1, and VEGF-A, as well as lower levels of VEGFB and VEGF-C, were found to be statistically significant in the VV group compared to the control subjects without VVs. None of the analyzed factors was associated with the venous localization of the varicosities. The presented study identified dysregulations in key angiogenesis- and inflammation-related factors in PBMC and plasma from VVs patients, providing new insight into molecular mechanisms that could contribute to the development of VVs and point out promising candidates for circulatory biomarkers of this disease.

Role of platelet factor 4 in arteriovenous fistula maturation failure: What do we know so far?

The rate of arteriovenous fistula (AVF) maturation failure remains unacceptably high despite continuous efforts on technique improvement and careful pre-surgery planning. In fact, half of all newly created AVFs are unable to be used for hemodialysis (HD) without a salvage procedure. While vascular stenosis in the venous limb of the access is the culprit, the underlying factors leading to vascular narrowing and AVF maturation failure are yet to be determined. We have recently demonstrated that AVF non-maturation is associated with post-operative medial fibrosis and fibrotic stenosis, and post-operative intimal hyperplasia (IH) exacerbates the situation. Multiple pathological processes and signaling pathways are underlying the stenotic remodeling of the AVF. Our group has recently indicated that a pro-inflammatory cytokine platelet factor 4 (PF4/CXCL4) is upregulated in veins that fail to mature after AVF creation. Platelet factor 4 is a fibrosis marker and can be detected in vascular stenosis tissue, suggesting that it may contribute to AVF maturation failure through stimulation of fibrosis and development of fibrotic stenosis. Here, we present an overview of the how PF4-mediated fibrosis determines AVF maturation failure.

Protocatechuic aldehyde increases pericyte coverage and mitigates pericyte damage to enhance the atherosclerotic plaque stability

Pericyte dysfunction and loss contribute substantially to the destabilization and rupture of atherosclerotic plaques. Protocatechuic aldehyde (PCAD), a natural polyphenol, exerts anti-atherosclerotic effects. However, the effects and mechanisms of this polyphenol on pericyte recruitment, coverage, and pericyte function remain unknown. We here treated apolipoprotein E-deficient mice having high-fat diet-induced atherosclerosis with PCAD. PCAD achieved therapeutic effects similar to rosuvastatin in lowering lipid levels and thus preventing atherosclerosis progression. With PCAD administration, plaque phenotype exhibited higher stability with markedly reduced lesion vulnerability, which is characterized by reduced lipid content and macrophage accumulation, and a consequent increase in collagen deposition. PCAD therapy increased pericyte coverage in the plaques, reduced VEGF-A production, and inhibited intraplaque neovascularization. PCAD promoted pericyte proliferation, adhesion, and migration to mitigate ox-LDL-induced pericyte dysfunction, which thus maintained the capillary network structure and stability. Furthermore, TGFBR1 silencing partially reversed the protective effect exerted by PCAD on human microvascular pericytes. PCAD increased pericyte coverage and impeded ox-LDL-induced damages through TGF-β1/TGFBR1/Smad2/3 signaling. All these novel findings indicated that PCAD increases pericyte coverage and alleviates pericyte damage to improve the stability of atherosclerotic plaques, which is accomplished by regulating TGF-β1/TGFBR1/Smad2/3 signaling in pericytes.

Melatonin and TGF-β-Mediated Release of Extracellular Vesicles

The immune system, unlike other systems, must be flexible and able to "adapt" to fully cope with lurking dangers. The transition from intracorporeal balance to homeostasis disruption is associated with activation of inflammatory signaling pathways, which causes modulation of the immunology response. Chemotactic cytokines, signaling molecules, and extracellular vesicles act as critical mediators of inflammation and participate in intercellular communication, conditioning the immune system's proper response. Among the well-known cytokines allowing for the development and proper functioning of the immune system by mediating cell survival and cell-death-inducing signaling, the tumor necrosis factor α (TNF-α) and transforming growth factor β (TGF-β) are noteworthy. The high bloodstream concentration of those pleiotropic cytokines can be characterized by anti- and pro-inflammatory activity, considering the powerful anti-inflammatory and anti-oxidative stress capabilities of TGF-β known from the literature. Together with the chemokines, the immune system response is also influenced by biologically active chemicals, such as melatonin. The enhanced cellular communication shows the relationship between the TGF-β signaling pathway and the extracellular vesicles (EVs) secreted under the influence of melatonin. This review outlines the findings on melatonin activity on TGF-β-dependent inflammatory response regulation in cell-to-cell communication leading to secretion of the different EV populations.

TGF-β1-containing exosomes from cardiac microvascular endothelial cells mediate cardiac fibroblast activation under high glucose conditions

Cardiac fibroblast (CF)-mediated extracellular matrix (ECM) remodeling is the key pathological basis for the occurrence and development of diabetic cardiomyopathy (DCM); its specific regulatory mechanisms have been widely studied but remain unclear. Exosomes are a type of stable signal transmission medium, and exosome-mediated cell-cell interactions play an important role in DCM. Endothelial cells form an important barrier between circulation and cardiomyocytes, in addition to being an important endocrine organ of the heart and an initial target for hyperglycemia, a key aspect in the development of DCM. We previously showed that exosomes derived from cardiac microvascular endothelial cells (CMECs) under high glucose conditions can be taken up by cardiomyocytes and regulate autophagy, apoptosis, and glucose metabolism. Consequently, in the present study, we focused on how exosomes mediate the interaction between CMECs and CFs. Surprisingly, exosomes derived from CMECs under high glucose were rich in TGF-β1 mRNA, which significantly promoted the activation of CFs. Additionally, exosomes derived from CMECs under high glucose conditions aggravated perivascular and interstitial fibrosis in mice treated with streptozotocin. Herein, we demonstrated for the first time the capacity of exosomes, released by CMECs under high glucose, to mediate fibroblast activation through TGF-β1 mRNA, which may be potentially beneficial in the development of exosome-targeted therapies to control DCM.

Myricetin suppresses the proliferation and migration of vascular smooth muscle cells and inhibits neointimal hyperplasia via suppressing TGFBR1 signaling pathways

BACKGROUND

Neointimal formation, mediated by the proliferation and migration of vascular smooth muscle cells (VSMCs), is a common pathological basis for atherosclerosis and restenosis. Myricetin, a natural flavonoid, reportedly exerts anti-atherosclerotic effects. However, the effect and mechanism of myricetin on VSMCs proliferation and migration and neointimal hyperplasia (NIH) remain unknown.

PURPOSE

We investigated myricetin's effect on NIH, as well as the potential involvement of transforming growth factor-beta receptor 1 (TGFBR1) signaling in mediating myricetin's anti-atherosclerotic and anti-restenotic actions.

METHODS

Myricetin's effects on the proliferation and migration of HASMCs and A7R5 cells were determined by CCK-8, EdU assays, wound healing, Transwell assays, and western blotting (WB).Molecular docking, molecular dynamics (MD) simulation, surface plasmon resonance (SPR) and TGFBR1 kinase activity assays were employed to investigate the interaction between myricetin and TGFBR1. An adenovirus vector encoding TGFBR1 was used to verify the effects of myricetin. In vivo, the left common carotid artery (LCCA) ligation mouse model was adopted to determine the impacts of myricetin on neointimal formation and TGFBR1 activation.

RESULTS

Myricetin dose-dependently inhibited the migration and proliferation in VSMCs, suppressed the expression of CDK4, cyclin D3, MMP2, and MMP9. Molecular docking revealed that myricetin binds to key regions for TGFBR1 antagonist binding, and the binding energy was -9.61 kcal/mol. MD simulation indicated stable binding between TGFBR1 and myricetin. Additionally, SPR revealed an equilibrium dissociation constant of 4.35 × 10^-5 M between myricetin and TGFBR1. According to the TGFBR1 kinase activity assay, myricetin directly inhibited TGFBR1 kinase activity (IC₅₀ = 8.551 μM). Furthermore, myricetin suppressed the phosphorylation level of TGFBR1, Smad2, and Smad3 in a dose-dependent pattern, which was partially inhibited by TGFBR1 overexpression. Consistently, TGFBR1 overexpression partially rescued the suppressive roles of myricetin on VSMCs migration and proliferation. Moreover, myricetin dramatically inhibited NIH and reduced TGFBR1, Smad2, and Smad3 phosphorylation in the LCCA.

CONCLUSION

This is the first study to demonstrate that myricetin suppresses NIH and VSMC proliferation and migration via inhibiting TGFBR1 signaling. Myricetin can be developed as a potential therapeutic candidate for treating atherosclerosis and vascular restenosis.

hiPSC Modeling of Lineage-Specific Smooth Muscle Cell Defects Caused by TGFBR1A230T Variant, and its Therapeutic Implications for Loeys-Dietz Syndrome

Background: Loeys-Dietz Syndrome (LDS) is an inherited disorder predisposing individuals to thoracic aortic aneurysm and dissection (TAAD). Currently, there are no medical treatments except surgical resection. Although the genetic basis of LDS is well-understood, molecular mechanisms underlying the disease remain elusive impeding the development of a therapeutic strategy. In addition, aortic smooth muscle cells (SMC) have heterogenous embryonic origins depending on their spatial location, and lineage-specific effects of pathogenic variants on SMC function, likely causing regionally constrained LDS manifestations, have been unexplored. Methods: We identified an LDS family with a dominant pathogenic variant in TGFBR1 gene (TGFBR1^A230T) causing aortic root aneurysm and dissection. To accurately model the molecular defects caused by this mutation, we used human-induced pluripotent stem cells (hiPSC) from subject with normal aorta to generate hiPSC carrying TGFBR1^A230T, and corrected the mutation in patient-derived hiPSC using CRISPR-Cas9 gene editing. Following their lineage-specific SMC differentiation through cardiovascular progenitor cell (CPC) and neural crest stem cell (NCSC) lineages, we employed conventional molecular techniques and single-cell RNA-sequencing (scRNA-seq) to characterize the molecular defects. The resulting data led to subsequent molecular and functional rescue experiments employing Activin A and rapamycin. Results: Our results indicate the TGFBR1^A230T mutation impairs contractile transcript and protein levels, and function in CPC-SMC, but not in NCSC-SMC. ScRNA-seq results implicate defective differentiation even in TGFBR1^A230T/+ CPC-SMC including disruption of SMC contraction, and extracellular matrix formation. Comparison of patient-derived and mutation-corrected cells supported the contractile phenotype observed in the mutant CPC-SMC. TGFBR1^A230T selectively disrupted SMAD3 and AKT activation in CPC-SMC, and led to increased cell proliferation. Consistently, scRNA-seq revealed molecular similarities between a loss-of-function SMAD3 mutation (SMAD3^c.652delA/+) and TGFBR1^A230T/+. Lastly, combination treatment with Activin A and rapamycin during or after SMC differentiation significantly improved the mutant CPC-SMC contractile gene expression, and function; and rescued the mechanical properties of mutant CPC-SMC tissue constructs. Conclusions: This study reveals that a pathogenic TGFBR1 variant causes lineage-specific SMC defects informing the etiology of LDS-associated aortic root aneurysm. As a potential pharmacological strategy, our results highlight a combination treatment with Activin A and rapamycin that can rescue the SMC defects caused by the variant.

Understanding Chronic Venous Disease: A Critical Overview of Its Pathophysiology and Medical Management

Chronic venous disease (CVD) is a multifactorial condition affecting an important percentage of the global population. It ranges from mild clinical signs, such as telangiectasias or reticular veins, to severe manifestations, such as venous ulcerations. However, varicose veins (VVs) are the most common manifestation of CVD. The explicit mechanisms of the disease are not well-understood. It seems that genetics and a plethora of environmental agents play an important role in the development and progression of CVD. The exposure to these factors leads to altered hemodynamics of the venous system, described as ambulatory venous hypertension, therefore promoting microcirculatory changes, inflammatory responses, hypoxia, venous wall remodeling, and epigenetic variations, even with important systemic implications. Thus, a proper clinical management of patients with CVD is essential to prevent potential harms of the disease, which also entails a significant loss of the quality of life in these individuals. Hence, the aim of the present review is to collect the current knowledge of CVD, including its epidemiology, etiology, and risk factors, but emphasizing the pathophysiology and medical care of these patients, including clinical manifestations, diagnosis, and treatments. Furthermore, future directions will also be covered in this work in order to provide potential fields to explore in the context of CVD.

MicroRNA-665 Regulates Cell Proliferation and Apoptosis of Vascular Smooth Muscle Cells by Targeting TGFBR1

Coronary artery disease (CAD) is one of the heavy health burdens worldwide. Aberrant proliferation of vascular smooth muscle cells (VSMCs) contributes to the occurrence and development of CAD. This study aimed at exploring differentially expressed microRNAs (miRNAs) and their regulatory mechanisms in the development of CAD.The miRNA expression profile of GSE28858 was obtained from the Gene Expression Omnibus database. Differentially expressed miRNAs (DEmiRNAs) between CAD and healthy control samples were analyzed using limma package in R. Target genes of DEmiRNAs were predicted, and a miRNA-target gene network was constructed. The relationship between miR-665 and transforming growth factor beta receptor 1 (TGFBR1) was selected for further analysis. The interaction between miR-665 and TGFBR1 was confirmed by dual luciferase reporter assay. Effects of miR-665 on cell viability and apoptosis of VSMCs were evaluated by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Besides, western blot assays for BCL2L11 and caspase 3 were also conducted.A total of 38 upregulated miRNAs and 28 downregulated miRNAs were identified. The expression level of miR-665 was significantly downregulated in patients with CAD. TGFBR1 was proved to be a target gene of miR-665. Besides, ectopic expression of miR-665 obviously inhibited VSMC growth and promoted VSMC apoptosis. TGFBR1 overexpression in VSMCs transfected with miR-665 mimic could restore the effect of miR-665 on the proliferation and apoptosis of VSMCs.MiR-665 might participate in the proliferation and apoptosis of VSMCs by targeting TGFBR1.

Chronic Metformin Therapy is Associated with a Lower Risk of Hemorrhoid in Patients with Type 2 Diabetes Mellitus

Background: Metformin has anti-inflammatory property and reduces the risk of varicose vein in our previous study.

Aim: To investigate the risk of hemorrhoid, another common disease involving the hemorrhoidal venous plexus, in ever vs. never users of metformin in patients with type 2 diabetes mellitus.

Methods: This is a population-based retrospective cohort study. Patients with new-onset type 2 diabetes mellitus during 1999–2005 were enrolled from Taiwan’s National Health Insurance. All patients who were alive on January 1, 2006 were followed up until December 31, 2011. Analyses were conducted in both an unmatched cohort of 152,347 ever users and 19,523 never users and in 19,498 propensity score (PS)-matched pairs of ever and never users. Traditional Cox regression and Cox regression incorporated with the inverse probability of treatment weighting (IPTW) using the PS were used to estimate hazard ratios.

Results: New-onset hemorrhoid was diagnosed in 8,211 ever users and 2025 never users in the unmatched cohort and in 1,089 ever users and 2022 never users in the matched cohort. The hazard ratio for ever vs. never users derived from the traditional Cox regression was 0.464 (95% confidence interval: 0.440–0.488) in the unmatched cohort; and was 0.488 (0.453–0.525) in the matched cohort. In the IPTW models, the hazard ratio was 0.464 (0.442–0.487) in the unmatched cohort and was 0.492 (0.457–0.530) in the matched cohort. A dose-response pattern was observed while comparing the tertiles of cumulative duration, cumulative dose and defined daily dose of metformin therapy to never users in all analyses. A risk reduction of approximately 40–50% was consistently observed in various sensitivity analyses.

Conclusion: Chronic therapy with metformin in patients with type 2 diabetes mellitus is associated with a lower risk of hemorrhoid.

The Inhibition of Prolyl Oligopeptidase as New Target to Counteract Chronic Venous Insufficiency: Findings in a Mouse Model

(1) Background: Chronic venous insufficiency (CVI) is a common disorder related to functional and morphological abnormalities of the venous system. Inflammatory processes and angiogenesis alterations greatly concur to the onset of varicose vein. KYP-2047 is a selective inhibitor of prolyl oligopeptidase (POP), a serine protease involved in the release of pro-angiogenic molecules. The aim of the present study is to evaluate the capacity of KYP-2047 to influence the angiogenic and inflammatory mechanisms involved in the pathophysiology of CVI. (2) Methods: An in vivo model of CVI-induced by saphene vein ligation (SVL) and a tissue block culture study were performed. Mice were subjected to SVL followed by KYP-2047 treatment (intraperitoneal, 10 mg/kg) for 7 days. Histological analysis, Masson's trichrome, Van Gieson staining, and mast cells evaluation were performed. Release of cytokines, nitric oxide synthase production, TGF-beta, VEGF, α-smooth muscle actin, PREP, Endoglin, and IL-8 quantification were investigated. (3) Results: KYP-2047 treatment ameliorated the histological abnormalities of the venous wall, reduced the collagen increase and modulated elastin content, lowered cytokines levels and prevented mast degranulation. Moreover, a decreased expression of TGF-beta, eNOS, VEGF, α-smooth muscle actin, IL-8, and PREP was observed in in vivo study; also a reduction in VEGF and Endoglin expression was confirmed in tissue block culture study. (4) Conclusions: For the first time, this research, highlighting the importance of POP as new target for vascular disorders, revealed the therapeutic potential of KYP-2047 as a helpful treatment for the management of CVI.

Noninvasive measurement of venous wall deformation induced by changes in transmural pressure shows altered viscoelasticity in patients with chronic venous disease

OBJECTIVE

The noninvasive measurement of venous wall deformation induced by changes in transmural pressure could allow for the assessment of viscoelasticity and differentiating normal from diseased veins.

METHODS

In 57 patients with limbs in the C1s (telangiectasia or reticular veins and symptoms), C3 (edema), or C5 (healed venous ulcer) CEAP (clinical, etiologic, anatomic, pathophysiologic) category of chronic venous disease and 54 matched healthy controls, we measured the changes in the cross-sectional area of the small saphenous vein and a deep calf vein in the supine and standing positions and under compression with an ultrasound probe using ultrasonography.

RESULTS

The small saphenous vein, but not the deep calf vein, cross-sectional area was smaller in the limbs of the controls than in the limbs with C3 or C5 disease but was not different from that in C1s limbs. When changing from the supine to the standing position, a greater force was required to collapse the leg veins. Their cross-sectional area increased in most subjects but decreased in 31.5% of them as for the small saphenous veins and 40.5% for the deep calf vein. The small saphenous vein area vs compression force function followed a hysteresis loop, demonstrating viscoelastic features. Its area, which represents the viscosity component, was greater (P < .001) in the pooled C3 and C5 limbs (median, 2.40 N⋅mm²; lower quartile [Q1] to upper quartile [Q3], 1.65-3.88 N⋅mm²) than in the controls (median, 1.24 N⋅mm²; Q1-Q3, 0.64-2.14 N⋅mm²) and C1s limbs (median, 1.15 N⋅mm²; Q1-Q3, 0.71-2.97 N⋅mm²). The area increased (P < .0001) in the standing position in all groups.

CONCLUSIONS

Postural changes in the cross-sectional area of the leg veins were highly diverse among patients with chronic venous disease and among healthy subjects and appear unsuitable for pathophysiologic characterization. In contrast, small saphenous vein viscoelasticity increased consistently in the standing position and the viscosity was greater in limbs with C3 and C5 CEAP disease than in controls.

Retracted: Transforming Growth Factor Beta-1 Promotes Smooth Muscle Cell Proliferation and Migration in an Arteriovenous Fistulae: The Role of Wall Shear Stress

Retraction: Lan Jia, Fang Wei, Lihua Wang, Haiyan Chen, Haibo Yu, Zhe Wang and Aili Jiang "Transforming Growth Factor Beta-1 Promotes Smooth Muscle Cell Proliferation and Migration in an Arteriovenous Fistulae: The Role of Wall Shear Stress" Therapeutic Apheresis and Dialysis (https://onlinelibrary.wiley.com/doi/10.1111/1744-9987.12781). The above article, published online on 06 December 2018 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, Tadao Akizawa, and John Wiley and Sons Australia Ltd. The retraction has been agreed due to major overlap with a previously published article.

Clinical Genetics of Prolidase Deficiency: An Updated Review

Prolidase is a ubiquitous enzyme that plays a major role in the metabolism of proline-rich proteins. Prolidase deficiency is a rare autosomal recessive inborn metabolic and multisystemic disease, characterized by a protean association of symptoms, namely intellectual disability, recurrent infections, splenomegaly, skin lesions, auto-immune disorders and cytopenia. To our knowledge, no published review has assembled the different clinical data and research studies over prolidase deficiency. The aim of this study is to summarize the actual state of the art from the descriptions of all the patients with a molecular diagnosis of prolidase deficiency reported to date regarding the clinical, biological, histopathological features, therapeutic options and functional studies.

In Vitro Lineage-Specific Differentiation of Vascular Smooth Muscle Cells in Response to SMAD3 Deficiency: Implications for SMAD3-Related Thoracic Aortic Aneurysm

OBJECTIVE

SMAD3 pathogenic variants are associated with the development of thoracic aortic aneurysms. We sought to determine the role of SMAD3 in lineage-specific vascular smooth muscle cells (VSMCs) differentiation and function. Approach and Results: SMAD3 c.652delA, a frameshift mutation and nonsense-mediated decay, was introduced in human-induced pluripotent stem cells using CRISPR-Cas9. The wild-type and SMAD3^-/- (c.652delA) human-induced pluripotent stem cells were differentiated into cardiovascular progenitor cells or neural crest stem cells and then to lineage-specific VSMCs. Differentiation, contractility, extracellular matrix synthesis, and TGF-β (transforming growth factor-β) signaling of the differentiated VSMCs were analyzed. The homozygous frameshift mutation resulted in SMAD3 deficiency and was confirmed in human-induced pluripotent stem cells by Sanger sequencing and immunoblot analysis. In cardiovascular progenitor cell-VSMCs, SMAD3 deletion significantly disrupted canonical TGF-β signaling and decreased gene expression of VSMC markers, including SM α-actin, myosin heavy chain 11, calponin-1, SM22α, and key controlling factors, SRF and myocardin, but increased collagen expression. The loss of SMAD3 significantly decreased VSMC contractility. In neural crest stem cells-VSMCs, SMAD3 deficiency did not significantly affect the VSMC differentiation but decreased ELN (elastin) expression and increased phosphorylated SMAD2. Expression of mir-29 was increased in SMAD3^-/- VSMCs, and inhibition of mir-29 partially rescued ELN expression.

CONCLUSIONS

SMAD3-dependent TGF-β signaling was essential for the differentiation of cardiovascular progenitor cell-VSMCs but not for the differentiation of neural crest stem cell-VSMCs. The lineage-specific TGF-β responses in human VSMCs may potentially contribute to the development of aortic root aneurysms in patients with SMAD3 mutations.

Physiological changes during prolonged standing and walking considering age, gender and standing work experience

Occupational standing is associated with musculoskeletal and venous disorders. The aim was to investigate whether lower leg oedema and muscle fatigue development differ between standing and walking and whether age, gender and standing work habituation are factors to consider. Sixty participants (15 young females, 15 young males, 15 older males, and 15 young males habituated to standing work) were included and required to stand/walk for 4.5 hours in three periods with two seated breaks. Waterplethysmography/bioelectrical impedance, muscle twitch force and surface electromyography were used to assess lower leg swelling (LLS) and muscle fatigue as well as gastrocnemius muscle activity, respectively. While standing led to LLS and muscle fatigue, walking did not. Low-level medial gastrocnemius activity was not continuous during standing. No significant influence of age, gender and standing habituation was observed. Walking can be an effective prevention measure to counteract the detrimental effects of quasi-static standing.Practitioner summary: Prolonged standing leads to lower leg oedema and muscle fatigue while walking does not. The primary cause of fatigue may be in other muscles than the medial gastrocnemius. Walking may be an effective prevention measure for health risks of occupational standing when included intermittently.Abbreviation: BI: bioelectrical impedance; LLS: lower leg swelling; SEMG: surface electromyography; MTF: muscle twitch force; WP: waterplethysmography; Bsl: Baseline; L: Lunch; E: Evening; MTM: method times measurement; EA: electrical activity; IQR: interquartile range; p: percentile; M: mean; SE: standard error; Adj: adjusted.

Metformin reduces risk of varicose veins in patients with type 2 diabetes

AIM

This population-based retrospective cohort study compared the incidence of varicose veins in an unmatched cohort and a cohort of 1:1 propensity score (PS)-matched pairs of ever and never users of metformin in type 2 diabetes patients.

METHODS

Patients with new-onset type 2 diabetes during 1999 to 2005 were enrolled from Taiwan's National Health Insurance and followed until December 31, 2011. Analyses were conducted in an unmatched cohort of 123 710 ever users and 15 095 never users and in 15 088 PS-matched pairs of ever users and never users. Hazard ratios were estimated by Cox proportional hazards model incorporated with the inverse probability of treatment weighting using the PS.

RESULTS

New-onset varicose veins were diagnosed in 126 never users and 633 ever users in the unmatched cohort and in 126 never users and 80 ever users in the matched cohort. The respective incidences were 191.36 and 110.04 per 100 000 person-years in the unmatched cohort and 191.41 and 115.81 per 100 000 person-years in the matched cohort. The hazard ratio for ever versus never users in the unmatched cohort was 0.57 (95% confidence interval, 0.47-0.69) and was 0.60 (0.45-0.80) for the matched cohort. In the unmatched cohort, the hazard ratios for the first, second, and third tertiles of cumulative duration were 1.03 (0.83-1.28), 0.55 (0.44-0.69), and 0.29 (0.23-0.37), respectively. The respective hazard ratios in the matched cohort were 0.97 (0.65-1.43), 0.79 (0.55-1.15), and 0.24 (0.13-0.42).

CONCLUSION

Metformin use is associated with a lower risk of varicose veins in patients with type 2 diabetes.

Unravelling the Role of MAPKs (ERK1/2) in Venous Reflux in Patients with Chronic Venous Disorder

Chronic venous disorder (CVeD), is a disorder in which there is a modification in the conditions of blood return to the heart. The disorder may arise from incompetent valves and the resultant venous reflux (chronic venous insufficiency, CVI). The economic burden of CVeD on health systems is high, and research efforts have sought to elucidate the mechanisms involved as possible therapeutic targets. The mitogen-activated protein kinase (MAPK) enzymes mediate a wide array of physiopathological processes in human tissues. In this family of proteins, extracellular signal-regulated kinase (ERK)1/2 plays a direct role in the cell homeostasis that determines the viability of mammalian tissues. This study sought to examine whether ERK1/2 plays a role in venous reflux. This was a prospective study performed on 56 participants including 11 healthy controls. Of the CVeD patients, 23 had venous reflux with CVI (CVI-R) and 22 had no reflux (NR). Distribution by age was: controls <50 years (n = 4) and ≥50 years (n = 7); NR <50 years (n = 9) and ≥50 years (n = 13); CVI-R <50 years (n = 11) and ≥50 years (n = 12). Great saphenous vein specimens were subjected to gene (real-time polymerase chain reaction, RT-qPCR) and protein (immunohistochemistry, IHC) expression techniques to identify ERK1/2. Data was compared between groups using the Mann Whitney U test. Patients with CVI showed significant gene activation of ERK1/2 protein, and, in those with venous reflux, the expression of this gene was significantly greater. The CVI-R group <50 years showed significantly greater ERK1/2 gene expression than their age-matched controls. Expression patterns were consistent with IHC findings. Our studies suggest that ERK1/2 expression is involved in venous vascular disease.

MiR-27 alleviates myocardial cell damage induced by hypoxia/reoxygenation via targeting TGFBR1 and inhibiting NF-κB pathway

MiR-27 prevents atherosclerosis by inhibiting inflammatory responses induced by lipoprotein lipase. Overexpression of miR-27b attenuates angiotensin-induced atrial fibrosis. Nevertheless, studies have rarely investigated on the effect of miR-27 in cardiomyocyte injury. H9c2 cells were transfected with miR-27 mimic/inhibitor. Then the cell proliferation was tested by MTT assay and the cell apoptosis was detected by flow cytometry. The luciferase activity assay was utilized to analyze the relationship between miR-27 and TGFBR1. Quantificational real-time polymerase chain reaction and western blot were utilized to detect the cardiomyocyte differentiation marker and nuclear factor kappa B (NF-κB) pathway. Our outcomes demonstrated that miR-27 expression was downregulated cardiomyocyte injury subjected to hypoxia/reoxygenation (H/R). Additionally, overexpression of miR-27 could significantly alleviate cardiomyocyte injury by regulating cell activity and apoptosis. The luciferase activity assay confirmed that transforming growth factor ß receptor 1 (TGFBR1) is a direct hallmark of miR-27. Besides, overexpression of miR-27 promoted the expression of TGFBR1 in H/R model. After transfection with miR-27 mimic/inhibitor, the expression of NF-κB pathway-related proteins was decreased/increased. Taken together, our data manifested that miR-27 repressed cardiomyocyte injury induced by H/R via mediating TGFBR1 and inhibiting NF-κB signaling pathway. Furthermore, miR-27/ TGFBR1 might be utilized as hopeful biomarkers for myocardial ischemia diagnosis and treatment.

TINAGL1 promotes hepatocellular carcinogenesis through the activation of TGF-β signaling-medicated VEGF expression

Background and purpose

Tubulointerstitial nephritis antigen-like 1 (TINAGL1) is an extracellular matrix protein that plays an important role in cell adhesion and therefore modulates cell proliferation, migration, and differentiation. In addition, it is frequently upregulated in highly metastatic tumors. The aim of our study was to determine the role of TINAGL1 in the progression and metastasis of hepatocellular carcinoma (HCC).

Materials and methods

TINAGL1 mRNA levels were analyzed in HCC and adjacent non-tumorous samples by reverse transcription polymerase chain reaction (RT-PCR). Human HCC cell lines were transfected with lentiviral plasmids expressing either si-TINAGL1 or TINAGL1 and subjected to CCK-8, colony forming, transwell migration, Annexin V/propidium iodide, and 5-ethynyl-2′-deoxyuridine uptake assays. Suitably transfected HCC cells were injected into athymic nude mice to establish xenograft tumors that were imaged and measured on a weekly basis. Mediators of the TGF-β signaling pathway were analyzed by Western blot.

Results

TINAGL1 was upregulated in human HCC tissues and associated with poor prognosis. TINAGL1 knockdown suppressed HCC cell growth, proliferation, and migration and induced apoptosis in HCC cells, whereas TINAGL1 overexpression had opposite effects. In addition, inhibition of TINAGL1 retarded xenograft tumor growth in a nude mouse model. Mechanistically, TINAGL1 activated the TGF-β signaling pathway and increased VEGF secretion.

Conclusion

TINAGL1 promotes hepatocellular carcinogenesis and metastasis via the TGF-β/Smad3/VEGF axis and is a potential new biomarker of HCC.

Luteolin Inhibits Vascular Smooth Muscle Cell Proliferation and Migration by Inhibiting TGFBR1 Signaling

Vascular smooth muscle cell (VSMC) proliferation and migration play a critical role in the development of arterial remodeling during various vascular diseases including atherosclerosis, hypertension, and related diseases. Luteolin is a food-derived flavonoid that exerts protective effects on cardiovascular diseases. Here, we investigated whether transforming growth factor-β receptor 1 (TGFBR1) signaling underlies the inhibitory effects of luteolin on VSMC proliferation and migration. We found that luteolin reduced the proliferation and migration of VSMCs, specifically A7r5 and HASMC cells, in a dose-dependent manner, based on MTS and EdU, and Transwell and wound healing assays, respectively. We also demonstrated that it inhibited the expression of proliferation-related proteins including PCNA and Cyclin D1, as well as the migration-related proteins MMP2 and MMP9, in a dose-dependent manner by western blotting. In addition, luteolin dose-dependently inhibited the phosphorylation of TGFBR1, Smad2, and Smad3. Notably, adenovirus-mediated overexpression of TGFBR1 enhanced TGFBR1, Smad2, and Smad3 activation in VSMCs and partially blocked the inhibitory effect of luteolin on TGFBR1, Smad2, and Smad3. Moreover, overexpression of TGFBR1 rescued the inhibitory effects of luteolin on the proliferation and migration of VSMCs. Additionally, molecular docking showed that this compound could dock onto an agonist binding site of TGFBR1, and that the binding energy between luteolin and TGFBR1 was -10.194 kcal/mol. Simulations of molecular dynamics showed that TGFBR1-luteolin binding was stable. Collectively, these data demonstrated that luteolin might inhibit VSMC proliferation and migration by suppressing TGFBR1 signaling.

Chronic Venous Disorders: The Dangerous, the Good, and the Diverse

Chronic venous disorders are common vascular pathology of great medical and socioeconomic impact, characterized by a wide spectrum of clinical manifestations occurring with symptoms and/or signs that vary in type and severity. The predominant pathophysiological mechanisms of chronic venous disease start from the development of venous hypertension from shear stress and reflux, leading to endothelial dysfunction and venous wall dilatation. The altered hemodynamic transduces physical signals into harmful bio-molecular pathways, creating a vicious cycle among shear stress, proteolytic remodeling, and inflammatory processes. This intricate network is further exacerbated by the degradation of protective endothelial glycocalyx. In this special issue, at least three main aspects of these interactions are highlighted: the dangerous, the good, and the diverse, which may help to focus attention on the biomolecular mechanisms and the possible targeted therapy of chronic venous disorders (CVeD).

Formononetin protects against balloon injury‑induced neointima formation in rats by regulating proliferation and migration of vascular smooth muscle cells via the TGF‑β1/Smad3 signaling pathway

The present study investigated the effects of formononetin (FMN) against balloon injury‑induced neointima formation in vivo and platelet‑derived growth factor (PDGF)‑BB‑induced proliferation and migration of vascular smooth muscle cells (VSMCs) in vitro, and explored the underlying mechanisms. A rat model of carotid artery injury was established, in order to examine the effects of FMN on balloon injury‑induced neointima formation. Histological observation of the carotid artery tissues was conducted by hematoxylin and eosin staining. VSMC proliferation during neointima formation was observed by proliferating cell nuclear antigen staining. Subsequently, rat aortic VSMCs were isolated, and the effects of FMN on PDGF‑BB‑induced VSMC proliferation and migration were determined using Cell Counting Kit‑8 and Transwell/wound healing assays, respectively. Immunohistochemical and immunocytochemical staining was applied to measure the expression of transforming growth factor (TGF)‑β in carotid artery tissues and VSMCs, respectively. SMAD family member 3 (Smad3)/phosphorylated (p)‑Smad3 expression was examined by western blotting. FMN treatment significantly inhibited the abnormal proliferation of smooth muscle cells in neointima, and alterations to the vascular structure were attenuated. In addition, pretreatment with FMN effectively inhibited the proliferation of PDGF‑BB‑stimulated VSMCs (P<0.05). FMN also reduced the number of cells that migrated to the lower surface of the Transwell chamber and decreased wound‑healing percentage (P<0.05). The expression levels of TGF‑β were decreased by FMN treatment in vivo and in vitro, and Smad3/p‑Smad3 expression was also markedly inhibited. In conclusion, FMN significantly protected against balloon injury‑induced neointima formation in the carotid artery of a rat model; this effect may be associated with the regulation of VSMC proliferation and migration through altered TGF‑β1/Smad3 signaling.

Variability of MMP/TIMP and TGF-β1 Receptors throughout the Clinical Progression of Chronic Venous Disease

Chronic venous disease (CVeD) is a prevalent condition with a significant socioeconomic burden, yet the pathophysiology is only just beginning to be understood. Previous studies concerning the dysregulation of matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of metalloproteinases (TIMPs)) within the varicose vein wall are inconsistent and disregard clinical progression. Moreover, it is highly plausible that MMP and TIMP expression/activity is affected by transforming growth factor (TGF)-β1 and its signaling receptors (TGFβRs) expression/activity in the vein wall. A case–control study was undertaken to analyze genetic and immunohistochemical differences between healthy (n = 13) and CVeD (early stages: n = 19; advanced stages: n = 12) great saphenous vein samples. Samples were grouped based on anatomic harvest site and subjected to quantitative polymerase chain reaction for MMP1, MMP2, MMP8, MMP9, MMP12, MMP13, TIMP1, TIMP2, TIMP3, TIMP4, TGFβR1, TGFβR2, and TGFβR3 gene expression analysis, and then to immunohistochemistry for immunolocalization of MMP2, TIMP2, and TGFβR2. Decreased gene expression of MMP12, TIMP2, TIMP3, TIMP4, and TGFβR2 was found in varicose veins when compared to controls. Regarding CVeD clinical progression, two facts arose: results across anatomical regions were uneven; decreased gene expression of MMP9 and TGFβR3 and increased gene expression of MMP2 and TIMP3 were found in advanced clinical stages. Most immunohistochemistry results for tunica intima were coherent with qPCR results. In conclusion, decreased expression of TGFβRs might suggest a reduction in TGF-β1 participation in the MMP/TIMP imbalance throughout CVeD progression. Further studies about molecular events in the varicose vein wall are required and should take into consideration the venous anatomical region and CVeD clinical progression.