Reduced Collagen Synthesis Research Articles

Impact of systemic diseases on oral health and facial surgery outcomes

Systemic diseases have a profound influence on oral health and maxillofacial surgical outcomes, presenting challenges that require comprehensive management. Diabetes mellitus is a prominent example, with its impact on periodontal health and healing processes being well-established. Elevated blood glucose levels in diabetic patients impair immune response, reduce collagen synthesis, and delay wound healing, increasing the risk of periodontitis and postoperative complications following surgical interventions such as dental implants. Similarly, cardiovascular diseases exacerbate the inflammatory response linked to periodontal disease, potentially worsening both oral health and systemic conditions, thus complicating the recovery process after maxillofacial surgery. These patients often face heightened risks of infections and slower healing, partly due to the frequent use of anticoagulant medications, which can interfere with surgical procedures. Immunocompromised individuals, such as those with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) or undergoing chemotherapy, also experience significant oral health challenges, including higher susceptibility to oral infections and delayed tissue repair. Reduced immune function and mucosal integrity make it difficult for these patients to recover effectively after maxillofacial surgery, increasing the risk of complications such as infection and wound dehiscence. Moreover, osteoporosis, a systemic condition characterized by reduced bone density, affects the success of dental implants and bone grafting procedures. The decreased bone quality in osteoporotic patients compromises the ability to achieve stable osseointegration, leading to higher implant failure rates and additional surgical challenges. Addressing these complex interactions between systemic health and oral conditions requires an interdisciplinary approach, integrating medical and dental care to enhance treatment outcomes. Proper management of systemic diseases, along with individualized dental and surgical protocols, is essential to improving the prognosis for patients with concurrent systemic and oral health issues.

Association of ethanolamine desaturase TMEM189-plasmalogen axis with the stability of atherosclerotic plaque and cardiovascular events after acute coronary syndrome

Abstract Background Patients with acute coronary syndrome (ACS) are still at high risk of recurring major adverse cardiovascular events (MACE). Disorders of lipid metabolism play an important role in the pathogenesis and progression of ACS. However, whether there are lipid components that can play an early warning role on the recurrence of MACE in patients with ACS and its potential mechanism is not yet known. Purpose To explore the changes of lipid profile before recurrent MACE in ACS patients, screen lipid molecules related to recurrent MACE, and explore their effects on pathological changes of atherosclerotic plaque. Methods We selected 44 Chinese ACS patients from the ‘Peking and Rotterdam on Mission to Reduce Coronary Artery Disease’ (PRoMISS) study. Among them, patients with recurrent MACE within 1 year after first onset of ACS were defined as MACE group, and the control group was recruited through 1:1 matching. The lipid profile of patients was analyzed by liquid chromatography-mass spectrometry. The effects of the screened potential lipid biomarkers and their synthesis enzymes were evaluated by real-time PCR, Western blot, IHC staining and ELISA. The enzyme knockout mice and ApoE knockout mice were hybridized and bred to obtain double gene knockout mice to determine whether the enzyme deficiency affects atherosclerotic plaque. Results Lipomic analysis showed that in the MACE group, plasmalogens and their 12 subtypes continued to decrease three months before the MACE recurrence. The most critical ethanolamine desaturase in the synthesis pathway of plasmalogen, transmembrane protein 189 (TMEM189) was also significantly lower in the MACE group than in the control group, and the level of TMEM189 was positively correlated with plasmalogen. Analysis of single-cell RNA sequencing results in human carotid artery plaques shows that TMEM189 is enriched in endothelial cells and smooth muscle cells (VSMC). In VSMC, treatment with oxLDL reduced TMEM189 expression. Overexpression of TMEM189 significantly improved oxLDL induced reduction in collagen synthesis, expression of alpha-smooth muscle actin (alpha-SMA) and smooth muscle protein 22 (SM22). Overexpression of TMEM189 in VSMC, significantly reduced the content of plasmalogens in the cells. After 12 weeks of feeding with high-fat and high-cholesterol diet, it was found that the content of smooth muscle cells and vulnerability index in the aortic plaque in TMEM189 -/-ApoE -/- mice were significantly decreased than in ApoE -/- mice. Conclusions Before the recurrence of MACE in ACS patients, the synthesis pathway of plasmalogen was gradually damaged, and the reduction of plasmalogen was a potential marker for predicting the recurrence of MACE in ACS patients. The deficiency of TMEM189 - plasmalogen axis aggravates atherosclerosis, it can regulate the phenotype transformation of smooth muscle cells, inhibit their collagen synthesis, and thus affect plaque stability.

Ghrelin alleviated TiO2 NPs-induced inhibition of endochondral osteogenesis and promoted longitudinal growth of long bones in juvenile rats via Wnt/β-catenin signaling pathway

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in children's daily necessities and foods, and their health hazards to children have attracted particular attention. Childhood is a critical time for accelerated bone growth and development. Current studies revealed that TiO2 NPs exposure causes bone damage in juvenile rats; however, the underlying mechanism is unknown. Ghrelin is a polypeptide hormone that is considered to be a candidate factor for regulating bone growth and development. In this research, 3-week-old juvenile male rats were administered 0, 100 or 200 mg/kg TiO2 NPs and 50 μg/kg ghrelin for 4 weeks to explore the underlying mechanism of TiO2 NPs-induced bone damage, and the protective effect of ghrelin. Our results revealed that TiO2 NPs resulted in decreased synthesis of bone growth-related hormones, disturbed bone metabolism, and destruction of bone structure. Further mechanism studies showed that TiO2 NPs inhibited Wnt/β-catenin pathway, reduced collagen synthesis, inhibited chondrocyte proliferation and differentiation, promoted chondrocyte apoptosis, and inhibited endochondral osteogenesis, ultimately leading to long bone longitudinal growth retardation and osteoporosis. Ghrelin alleviated the negative effects of TiO2 NPs-induced bone growth in juvenile rats by upregulating the Wnt/β-catenin signaling pathway. This study provided a reference for the clinical treatment of growth retardation and idiopathic short stature in juvenile children caused by environmental pollutants.

Vasoactive and Antifibrotic Properties of Cannabinoids and Applications to Vasospastic/Vaso-Occlusive Disorders

Background Management of vasospastic and vaso-occlusive disorders is a complex challenge, with current treatments showing varied success. Cannabinoids have demonstrated both vasodilatory and antifibrotic properties, which present potential mechanisms for therapeutic relief. No existing review examines these effects in peripheral circulation in relation to vasospastic and vaso-occlusive disorders. This study aims to investigate vasodilatory and antifibrotic properties of cannabinoids in peripheral vasculature for application in vasospastic and vaso-occlusive disorders affecting the hand. Methods A systematic search was conducted by 2 independent reviewers across PubMed, Cochrane, Ovid MEDLINE, and CINAHL to identify studies in accordance with the determined inclusion/exclusion criteria. Information regarding study design, medication, dosage, and hemodynamic or antifibrotic effects were extracted. Descriptive statistics were used to summarize study findings as appropriate. Results A total of 584 articles were identified, and 32 were selected for inclusion. Studies were grouped by effect type: hemodynamic (n = 17, 53%) and antifibrotic (n = 15, 47%). Vasodilatory effects including reduced perfusion pressure, increased functional capillary density, inhibition of vessel contraction, and increased blood flow were reported in 82% of studies. Antifibrotic effects including reduced dermal thickening, reduced collagen synthesis, and reduced fibroblast migration were reported in 100% of studies. Conclusion Overall, cannabinoids were found to have vasodilatory and antifibrotic effects on peripheral circulation via both endothelium-dependent and independent mechanisms. Our review suggests the applicability of cannabis-based medicines for vasospastic and vaso-occlusive disorders affecting the hand (eg, Raynaud disease, Buerger disease). Future research should aim to assess the effectiveness of cannabis-based medicines for these conditions.

Discovery of small molecule guanylyl cyclase B receptor positive allosteric modulators.

Myocardial fibrosis is a pathological hallmark of cardiovascular disease (CVD), and excessive fibrosis can lead to new-onset heart failure and increased mortality. Currently, pharmacological therapies for myocardial fibrosis are limited, highlighting the need for novel therapeutic approaches. The particulate guanylyl cyclase B (GC-B) receptor possesses beneficial antifibrotic actions through the binding of its natural ligand C-type natriuretic peptide (CNP) and the generation of the intracellular second messenger, cyclic guanosine 3',5'-monophosphate (cGMP). These actions include the suppression of fibroblast proliferation and reduction in collagen synthesis. With its abundant expression on fibroblasts, the GC-B receptor has emerged as a key molecular target for innovative CVD therapeutics. However, small molecules that can bind and potentiate the GC-B/cGMP pathway have yet to be discovered. From a cell-based high-throughput screening initiative of the NIH Molecular Libraries Small Molecule Repository and hit-to-lead evolution based on a series of structure-activity relationships, we report the successful discovery of MCUF-42, a GC-B-targeted small molecule that acts as a positive allosteric modulator (PAM). Studies herein support MCUF-42's ability to enhance the binding affinity between GC-B and CNP. Moreover, MCUF-42 potentiated cGMP levels induced by CNP in human cardiac fibroblasts (HCFs) and notably also enhanced the inhibitory effect of CNP on HCF proliferation. Together, our findings highlight that MCUF-42 is a small molecule that can modulate the GC-B/cGMP signaling pathway, potentially enhancing the antifibrotic actions of CNP. Thus, these data underscore the continued development of GC-B small molecule PAMs as a novel therapeutic strategy for targeting cardiac fibrosis and CVD.

Catechin Hydrate Improves Hypertrophic Scar in Rabbit Ear Model via Reduction of Collagen Synthesis.

Hypertrophic scar (HS) is a cutaneous condition results from abnormal wound healing following deep tissue injury. To date, there is no optimal treatment for this skin disorder. Catechins possess anti-inflammatory, antioxidant and anti-fibrotic properties. In this study we investigated the effects of catechin hydrate (CH) in rabbit ear model of HS. A rabbit ear model of hypertrophic scar was set up. Ten New Zealand white rabbit were divided into 5 equal groups: non-treatment group, vehicle control, treated with intralesional injection of dimethyl sulfoxide (DMSO), and test groups, received intralesional injection of CH/DMSO solution at concentration of 0.25, 1.25 and, 2.5 mg/ml, respectively. The treatments were initiated ‏‎35 days after wounding once a ‏week for ‏‎4 ‎weeks‎.‎ ‏ The scar elevation index (SEI) and the epidermal thickness index (ETI) were measured using Hematoxylin and Eosin (H & E) ‏staining and the amount of collagen deposition were determined after Masson‎' ‎trichrome staining‎. ‎In addition‎, the enzyme-linked immunosorbent assay (ELISA) ‎‏method was used to determine the levels of ‎ type І ‏and ІІІ collagen and matrix metalloproteinase ‏‎1 (MMP1) in scar tissues. CH improved abnormal scarring at concentrations of 1.25 and 2.5 mg/ml and significantly (P<0.001) reduced the SEI and ETI. The levels of collagen type І and type ІІІ, and total collagen deposition were significantly (P<0.05) decreased in scar tissues of CH treated groups and no significant effect on MMP1 levels. Our findings demonstrated that CH has the potential for the treatment of HSs.

Palmitic acid in type 2 diabetes mellitus promotes atherosclerotic plaque vulnerability via macrophage Dll4 signaling

Patients with Type 2 Diabetes Mellitus are increasingly susceptible to atherosclerotic plaque vulnerability, leading to severe cardiovascular events. In this study, we demonstrate that elevated serum levels of palmitic acid, a type of saturated fatty acid, are significantly linked to this enhanced vulnerability in patients with Type 2 Diabetes Mellitus. Through a combination of human cohort studies and animal models, our research identifies a key mechanistic pathway: palmitic acid induces macrophage Delta-like ligand 4 signaling, which in turn triggers senescence in vascular smooth muscle cells. This process is critical for plaque instability due to reduced collagen synthesis and deposition. Importantly, our findings reveal that macrophage-specific knockout of Delta-like ligand 4 in atherosclerotic mice leads to reduced plaque burden and improved stability, highlighting the potential of targeting this pathway. These insights offer a promising direction for developing therapeutic strategies to mitigate cardiovascular risks in patients with Type 2 Diabetes Mellitus.

Regulation of matrix reloading by tumor endothelial marker 1 protects against abdominal aortic aneurysm.

Tumor endothelial marker 1 (TEM1), an activated mesenchymal cell marker, is implicated in tissue remodeling and repair. Herein, we investigated the role and therapeutic implications of TEM1 in abdominal aortic aneurysm (AAA), a potentially life-threatening aortic disease characterized by vascular inflammation and matrix turnover. Characterization of human AAA revealed increased TEM1 expression derived mainly from medial vascular smooth muscle cells (VSMCs) and adventitial fibroblasts. Bioinformatics analysis demonstrated the association between TEM1-expressing VSMCs and fibroblasts and collagen gene expression. Consistently, collagen content and TEM1 expressed by VSMCs and fibroblasts were increased during CaCl2-induced AAA formation in mice. TEM1 silencing in VSMCs and fibroblasts inhibited transforming growth factor-β1-induced phenotypic change, SMAD2 phosphorylation, and COL1A1 gene expression. Also, Tem1 deficiency reduced collagen synthesis and exacerbated CaCl2-induced AAA formation in mice without disturbing elastin destruction and inflammatory responses. In contrast, rTEM1 promoted phenotypic change and COL1A1 gene expression through SMAD2 phosphorylation in VSMCs and fibroblasts. Treatment with rTEM1 enhanced collagen synthesis, attenuated elastin fragmentation, and inhibited CaCl2-induced and angiotensin II-infused AAA formation. In summary, TEM1 in resident stromal cells regulates collagen synthesis to counteract aortic wall failure during AAA formation. Matrix integrity restored by rTEM1 treatment may hold therapeutic potential against AAA.

Omentin-1 induces mechanically activated fibroblasts lipogenic differentiation through pkm2/yap/pparγ pathway to promote lung fibrosis resolution.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease characterized by extensive extracellular matrix (ECM) deposition by activated myofibroblasts, which are specialized hyper-contractile cells that promote ECM remodeling and matrix stiffening. New insights on therapeutic strategies aimed at reversing fibrosis by targeting myofibroblast fate are showing promise in promoting fibrosis resolution. Previously, we showed that a novel adipocytokine, omentin-1, attenuated bleomycin (BLM)-induced lung fibrosis by reducing the number of myofibroblasts. Apoptosis, deactivation, and reprogramming of myofibroblasts are important processes in the resolution of fibrosis. Here we report that omentin-1 reverses established lung fibrosis by promoting mechanically activated myofibroblasts dedifferentiation into lipofibroblasts. Omentin-1 promotes myofibroblasts lipogenic differentiation by inhibiting dimerization and nuclear translocation of glycolytic enzymes pyruvate kinase isoform M2 (PKM2) and activation of the downstream Yes-associated protein (YAP) by increasing the cofactor fructose-1,6-bisphosphate (F1, 6BP, FBP). Moreover, omentin-1 activates proliferator-activated receptor gamma (PPARγ) signaling, the master regulator of lipogenesis, and promotes the upregulation of the lipogenic differentiation-related protein perilipin 2 (PLIN2) by suppressing the PKM2-YAP pathway. Ultimately, omentin-1 facilitates myofibroblasts transformation into the lipofibroblast phenotype, with reduced collagen synthesis and enhanced degradation properties, which are crucial mechanisms to clear the ECM deposition in fibrotic tissue, leading to fibrosis resolution. Our results indicate that omentin-1 targets mechanical signal accelerates fibrosis resolution and reverses established lung fibrosis by promoting myofibroblasts lipogenic differentiation, which is closely associated with ECM clearance in fibrotic tissue. These findings suggest that targeting mechanical force to promote myofibroblast lipogenic differentiation is a promising therapeutic strategy against persistent lung fibrosis.

P05 Osteoporosis in thalassemia; a case with multifactorial aetiology

Abstract Introduction Thalassemia patients are prone to osteoporosis due to multifactorial reasons, including anaemia, bone marrow expansion, iron overload and hypogonadism. Case description A 41-year-old British Asian male with beta thalassemia major was referred to rheumatology in 2018 for osteoporosis. In 2008, aged 27 years, whilst playing football, he developed a distal radial fracture and ulnar styloid process fracture and a DEXA scan had revealed low bone mineral density (BMD) for age. Subsequently, he was started on Ibandronic acid by his haematologist for a total of 10 years. After he was referred to rheumatology in 2018, bisphosphonates were discontinued as he had 5% improvement in BMD, a decade of bisphosphonates and no further fractures. Further assessment revealed multiple contributory factors for his osteoporosis. • Consistency low vitamin D – 9.6 nmol/L in 2009, average value of 20 • He was diagnosed with hypogonadism, poor compliance with IM testosterone injections • He had diabetes which was not optimally controlled • Evidence of iron overload with average serum ferritin of 2000 ug/L with deferasirox While these factors were optimised, it was decided to adopt a watch and wait policy with regards to specific osteoporosis treatment. Review in 2023 revealed serum testosterone level of 20.1 nmol/L (6.9-23.2) with better compliance with testosterone injections. Fructosamine levels were 310 (normal range 200-285) but it has reduced from a peak of 370. Serum ferritin levels have reduced to 776 down from a high of 5600. Normal vitamin D levels were maintained. The DEXA scan in 2023 revealed a spine T score of −2.4 which showed 10.2% increase in bone mineral density. DEXA scan in 2020 revealed T score of −3.1 in spine and −1.9 in hips. The P1NP level was 56 (19-69) which has reduced from 100 in 2021. Improvements in BMD and bone turnover markers were achieved through optimising contributory factors without any specific osteoporosis treatment. He will be monitored with periodic BMD and bone turnover markers. Discussion Anaemia and subsequent bone marrow expansion is a recognised cause for osteoporosis in thalassemia patients. While regular blood transfusions inhibit bone marrow expansion, ineffective erythropoiesis is not fully supressed. This patient received 3 units of blood every 4 weeks. Bone marrow expansion occurs mostly in trabecular bone resulting in low BMD is areas which generally have increased amount of trabecular bone such as the spine. Our patient had a lower BMD in the spine compared to the femoral neck. Iron overload directly disrupts bone formation and can result in endocrinopathies which contributes to osteoporosis. Hypogonadism is another well-recognised cause and is primarily results from iron deposition in pituitary and at times in the gonads. Hormonal replacement therapy reduces bone loss. Studies have shown that hypogonadic patients have more severe osteoporosis and predominant involvement of the femoral neck. Iron overload can cause diabetes mellitus and impaired growth hormone/ insulin growth factor-1 (IGF-1) axis which can contribute to osteoporosis. Our patient did have diabetes but had normal IGF-1 levels when checked previously. Deferoxamine which is one of iron chelating agents have been shown to reduce collagen synthesis and increases osteoblast apoptosis which might contribute to the development of osteoporosis. Vitamin D levels are well known to be low in patients with thalassemia compared to the general population. While there are no RCT’s to show that bisphosphonates reduce fracture risk, surrogate markers such as increased BMD and reduction in bone turnover markers are known to occur. Therefore, current guidance (Standards for the Clinical Care of Children and Adults with Thalassaemia in the UK) recommends bisphosphonates to be considered in patients with a low BMD for age (Z-score &amp;lt; −2.0, T-score &amp;lt; −2.5 if post-menopausal or over 50), if there are fragility fractures or falling BMD despite adequate vitamin D levels, and hormone supplementation. Key learning points Learning point Important to assess for osteoporosis in thalassaemic patients. There are multiple factors contributing to the development of osteoporosis which needs to be addressed together with endocrinologist and haematologist. Bisphosphonates are recommended though further RCT evidence is required to support this

Targeting Wnt-ß-Catenin-FOSL Signaling Ameliorates Right Ventricular Remodeling.

The ability of the right ventricle (RV) to adapt to an increased pressure afterload determines survival in patients with pulmonary arterial hypertension. At present, there are no specific treatments available to prevent RV failure, except for heart/lung transplantation. The wingless/int-1 (Wnt) signaling pathway plays an important role in the development of the RV and may also be implicated in adult cardiac remodeling. Molecular, biochemical, and pharmacological approaches were used both in vitro and in vivo to investigate the role of Wnt signaling in RV remodeling. Wnt/β-catenin signaling molecules are upregulated in RV of patients with pulmonary arterial hypertension and animal models of RV overload (pulmonary artery banding-induced and monocrotaline rat models). Activation of Wnt/β-catenin signaling leads to RV remodeling via transcriptional activation of FOSL1 and FOSL2 (FOS proto-oncogene [FOS] like 1/2, AP-1 [activator protein 1] transcription factor subunit). Immunohistochemical analysis of pulmonary artery banding -exposed BAT-Gal (β-catenin-activated transgene driving expression of nuclear β-galactosidase) reporter mice RVs exhibited an increase in β-catenin expression compared with their respective controls. Genetic inhibition of β-catenin, FOSL1/2, or WNT3A stimulation of RV fibroblasts significantly reduced collagen synthesis and other remodeling genes. Importantly, pharmacological inhibition of Wnt signaling using inhibitor of PORCN (porcupine O-acyltransferase), LGKK-974 attenuated fibrosis and cardiac hypertrophy leading to improvement in RV function in both, pulmonary artery banding - and monocrotaline-induced RV overload. Wnt- β-Catenin-FOSL signaling is centrally involved in the hypertrophic RV response to increased afterload, offering novel targets for therapeutic interference with RV failure in pulmonary hypertension.

MicroRNA-202-5p-dependent inhibition of Bcl-2 contributes to macrophage apoptosis and atherosclerotic plaque formation

BackgroundThe identification of microRNA (miRNA)-related molecular mechanisms has advanced the development of new therapeutics for atherosclerosis (AS). The roles of miR-202-5p- in the pathogenic mechanisms of AS have not been explored. MethodsMacrophages were transfected with a series of miR-202-5p mimic/inhibitor, and then assessed for changes in viability, apoptosis, and secretion of inflammatory cytokines. The regulatory mechanism of miR-202-5p was explored through dual-luciferase reporter gene assay. A mouse model of AS was developed in ApoE-/- mice fed with high-fat diet to examine the in vivo effects of miR-202-5p on atherosclerotic plaque formation, collagen synthesis, and fiber cap thickness. ResultsElevated miR-202-5p was found in atherosclerotic plaque tissues of the mice. miR-202-5p was able to induce macrophage apoptosis and release of pro-inflammatory factors. Besides, miR-202-5p limited Bcl-2 expression and elevated the levels of Bax, cleaved caspase-3, and cleaved caspase-9. Bcl-2 was concluded as a target gene of miR-202-5p. The pro-apoptotic effect of miR-202-5p on macrophages was achieved via limiting Bcl-2. In the mouse AS model, restoration of miR-202-5p stimulated atherosclerotic plaque formation, but reduced collagen synthesis and fiber cap thickness. ConclusionThese data collectively suggest a pro-apoptotic action of miR-202-5p in macrophages that contributes to atherosclerotic plaque formation.

17α-estradiol, a lifespan-extending compound, attenuates liver fibrosis by modulating collagen turnover rates in male mice.

Estrogen signaling is protective against chronic liver diseases, although men and a subset of women are contraindicated for chronic treatment with 17β-estradiol (17β-E2) or combination hormone replacement therapies. We sought to determine if 17α-estradiol (17α-E2), a naturally occurring diastereomer of 17β-E2, could attenuate liver fibrosis. We evaluated the effects of 17α-E2 treatment on collagen synthesis and degradation rates using tracer-based labeling approaches in male mice subjected to carbon tetrachloride (CCl4)-induced liver fibrosis. We also assessed the effects of 17α-E2 on markers of hepatic stellate cell (HSC) activation, collagen cross-linking, collagen degradation, and liver macrophage content and polarity. We found that 17α-E2 significantly reduced collagen synthesis rates and increased collagen degradation rates, which was mirrored by declines in transforming growth factor β1 (TGF-β1) and lysyl oxidase-like 2 (LOXL2) protein content in liver. These improvements were associated with increased matrix metalloproteinase 2 (MMP2) activity and suppressed stearoyl-coenzyme A desaturase 1 (SCD1) protein levels, the latter of which has been linked to the resolution of liver fibrosis. We also found that 17α-E2 increased liver fetuin-A protein, a strong inhibitor of TGF-β1 signaling, and reduced proinflammatory macrophage activation and cytokines expression in the liver. We conclude that 17α-E2 reduces fibrotic burden by suppressing HSC activation and enhancing collagen degradation mechanisms. Future studies will be needed to determine if 17α-E2 acts directly in hepatocytes, HSCs, and/or immune cells to elicit these benefits.

Deletion of the extracellular matrix glycoprotein ADAMTSL3 increases pro-fibrotic signalling and exacerbates heart failure in mice

Abstract Background/Introduction Cardiac fibrosis is a central pathophysiological process accompanying most cardiac diseases including heart failure, and is a predictor of poor outcomes. The fibrotic process is mediated by activated cardiac fibroblasts (CFBs), so-called myofibroblasts, which produce excessive amounts of type I collagen and other ECM molecules. The ADAMTSL family of glycoproteins is upregulated in the cardiac extracellular matrix (ECM) during heart failure, but their function in the heart is unknown. Some ADAMTSL proteins are suggested to regulate the TGFβ, a major driver of myofibroblast activation and cardiac fibrosis. Purpose The purpose of this study was to examine the role of ADAMTSL3 in TGFβ-regulation and heart failure. Methods ADAMTSL3 expression was analysed in failing hearts of patients and mice. To study the functional role of ADAMTSL3 in the failing heart, an Adamtsl3 knock-out (L3-KO) mouse was generated, and WT and L3-KO littermates were subjected to experimental heart failure by aortic banding (AB), or sham surgery, for a total of six weeks. The mice were followed with echocardiography and MRI, and the left ventricles (LVs) were harvested one and six weeks after AB or sham surgery, with molecular analyses performed. To elucidate molecular functions of ADAMTSL3 in vitro, we overexpressed ADAMTSL3 in CFBs producing an extensive ECM. Results We determined that ADAMTSL3 was produced by CFBs and upregulated in failing hearts of patients and mice. The L3-KO mice had a normal cardiac phenotype at baseline, but upon increased LV afterload developed a dilated cardiomyopathy phenotype with increased LV dilation and reduced systolic function from one week post-AB. Furthermore, high mortality was observed in the L3-KO mice post-AB, with 60% vs. 96% survival of WTs over six weeks. At one week post-AB RNA sequencing of LVs revealed 233 differentially expressed genes in L3-KO vs. WT, with Col1a1 and Postn among the most upregulated, suggesting increased fibrosis and TGFβ signalling. Increased canonical TGFβ signalling was confirmed by increased SMAD2/3 phosphorylation and increased Lox expression in L3-KOs six weeks post-AB. In vitro, ADAMTSL3 overexpression in cultured CFBs resulted in reduced collagen synthesis and reduced expression of COL1A1, LOX, CTGF and POSTN, indicating anti-fibrotic properties. Furthermore, ADAMTSL3 inhibited the expression of ACTA2 and SPP1, reduced α-SMA protein by 25%, and reduced proliferation and CFB contraction, suggesting attenuated TGFβ signalling and inhibited myofibroblast differentiation. Conclusions ADAMTSL3 was upregulated in human and mouse heart failure, and served an anti-fibrotic and cardio-protective role in failing mouse hearts. Mechanistically, ADAMTSL3 was produced by CFBs and inhibited myofibroblast differentiation and collagen synthesis through TGFβ in cultured CFBs. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Research Council of Norway

Histopathological effects of nimodipine and pentoxifylline on the vessel wall in end-to-end anastomoses in rat carotid arteries

When reperfusion following ischemia occurs, oxygen returns to the ischemic tissue, increasing free oxygen radicals and inducing paradox secondary damage. Before infarction, revascularization may influence the morbidity rate. Successful revascularization is not always achieved due to stenosis incidence, proliferation of smooth muscle cells, and intimal hyperplasia. This study compares the effects of nimodipine that prevents vasospasm and pentoxifylline, which stimulates growth factors and reduces collagen synthesis on intimal hyperplasia. Eighteen randomly selected Sprague-Dawley rats were divided into three groups: Group 1, the control group; Group 2, intraperitoneally administered nimodipine; Group 3, orally administered pentoxifylline. Their right-sided carotid arteries were used for anastomosis and the left-sided ones for the control. After a 7-day treatment, both the right and left carotid arteries were removed. In the biopsy, the lumen’s area and diameter, thickness of tunica media thickness, thrombus, edema, intimal hyperplasia, vessel wall injury, and inflammation were analyzed. Pentoxifylline was effective in preventing intimal hyperplasia and tunica intima was similar to that in untreated carotid arteries. However, nimodipine inhibited intimal hyperplasia, but it was not as effective as pentoxifylline. The effects of pentoxifylline after anastomosis should be further assessed in vasoprotective treatment taking into account its efficacy against intimal hyperplasia.

A novel, simple and reliable method for the determination of hydronidone and its metabolites M3 and M4 in human plasma and urine by HPLC-MS/MS and its application to a pharmacokinetic study in health Chinese subjects

In this study, a novel, simple and reliable high-performance liquid chromatography with tandem mass spetrometry method (HPLC-MS/MS) was developed for the determination of hydronidone and its metabolites M3 and M4 in human plasma and urine so as to study the clinical pharmacokinetics of hydronidone. By effectively inhibiting the proliferation of hepatic stellate cells (HSC), hydronidone can reduce collagen synthesis and curbs the process of liver fibrosis, and is currently in the stage of clinical research for anti-liver fibrosis. Hydronidone and its metabolites M3, M4 were extracted from human plasma by protein precipitation, and the urine samples were directly diluted with acetonitrile and analyzed by HPLC-MS/MS. The quantification ranges in plasma were 1.00–1000 ng/mL, 2.00–2000 ng/mL and 4.00–4000 ng/mL, respectively and in urine were 10.0–2000 ng/L, 100–25000 ng/L and 300–75000 ng/L, respectively. Coefficients of variation of less than 15% between intraday and interday accuracy and precision values were observed for hydronidone, M3 and M4. The S/N (signal-to-noise ratio) of the analyte in each Low limit of quantification sample in the analytical batch was greater than 5, indicating good sensitivity. The recovery rates were above 50% for all analytes. The parameters such as linearity, selectivity, lower precision, accuracy, recovery, stability and matrix effects were validated by the methodology and met the requirements specified by the FDA and the European Medicines Agency. The method has been successfully applied to the pharmacokinetics of hydronidone and its metabolites M3 and M4 in healthy Chinese volunteers.

The Traditional Chinese Medicine Formula FTZ Protects against Cardiac Fibrosis by Suppressing the TGFβ1-Smad2/3 Pathway.

Background Fu fang Zhen Zhu Tiao Zhi (FTZ) is a patented preparation of Chinese herbal medicine that has been used as a natural medicine to treat several chronic diseases including cardiovascular disease. However, its effects on cardiac fibrosis remain unclear. Therefore, this study was designed to investigate the effects and potential mechanisms of FTZ in treating cardiac fibrosis. Methods FTZ was administered to mice by oral gavage daily at a dosage of 1.2 g/kg or 2.4 g/kg of body weight for 7 weeks after a transverse aorta constriction (TAC) surgery. Doppler echocardiography, hematoxylin and eosin staining, and Masson's trichrome staining were used to assess the effect of FTZ on the cardiac structure and function of mice that had undergone TAC. EdU and wound-healing assays were performed to measure the proliferative and migratory abilities of cardiac fibroblasts. Western blotting and qRT-PCR were used to determine the expression of TGFβ1, Col1A2, Col3, and α-SMA proteins and mRNA levels. Results FTZ treatment reduced collagen synthesis, attenuated cardiac fibrosis, and improved cardiac function in mice subjected to TAC. Moreover, FTZ treatment prevented the proliferation and migration of cardiac fibroblasts and reduced Ang-II-induced collagen synthesis. Furthermore, FTZ downregulated the expression of TGFβ1, p-smad2, and p-smad3 and inhibited the TGFβ1-Smad2/3 pathway in the setting of cardiac fibrosis. Conclusion FTZ alleviated the proliferation and migration of cardiac fibroblasts and suppressed collagen synthesis via the TGFβ1-Smad2/3 pathway during the progression of cardiac fibrosis. These findings indicated the therapeutic potential of FTZ in treating cardiac fibrosis.

Repression of the Antioxidant Pyrroloquinoline Quinone in Skin Aging Induced by Bmi-1 Deficiency.

It is uncertain whether Bmi-1 deficiency could lead to skin aging by redox imbalance and DNA damage. In this study, we first confirmed that Bmi-1 had a relatively high expression level in the skin and Bmi-1 expression levels gradually decreased with age. Then, we studied the role of Bmi-1 in the skin using a Bmi-1−/− mouse model. Bmi-1−/− mice were supplemented with or without pyrroloquinoline quinone (PQQ) for 5 weeks, and their skin phenotypes were compared with Bmi1−/− and wild-type littermates. Our results showed that Bmi-1−/− mice displayed decreased vertical thickness of skin, sparse hair follicles, and thinner and more irregular collagen bundles. Mechanistically, increased oxidative stress with reducing antioxidant capacity and induced DNA damage occurred in Bmi-1−/− mice. Subsequently, this would lead to reduced cell proliferation, increased cell senescence and matrix metalloproteinases (MMPs), and the degradation of fibroblast function and further reduce collagen synthesis. All pathological alterations in the skin of Bmi-1−/− mice were alleviated by PQQ supplementation. These results demonstrated that Bmi-1 might play a key role in protection from skin aging by maintaining redox balance and inhibiting DNA damage response and will be a novel and potential target for preventing skin aging.

ROLE OF ZINC IN PERIODONTAL HEALTH AND DISEASE

Trace mineral zinc is present in our saliva and helps us ght bacteria as well as plaque that is responsible for dental caries and gum disease. Zinc in dentifrices has the potential for hampering the acid production by Streptococcus mutans by up to 50% whereas when used along with uoride, it proved to be bactericidal. Zinc can combat against Fusobacterium nucleatum and Prevotella intermedia, which are causative pathogens of gingivitis. Role of zinc in periodontitis is mainly related to its inuence on oral mucosa, bone metabolism and host response. Zinc deciency affects the functioning of immune cells and also increases the secretion of cytokines causing increased production of free radicals. Zinc deciency results in signicant reduction in collagen synthesis and reduced alkaline phosphatase activity. There is an inverse relationship between serum zinc levels and marginal alveolar bone loss. Therefore, its optimum levels are a prerequisite to maintain periodontal health.

Reversion of glucocorticoid-induced senescence and collagen synthesis decrease by LY294002 is mediated through p38 in skin

Glucocorticoids (GCs) are the most common treatment for inflammatory skin disorders; however, they show several adverse side effects, including atrophy and collagen decrease following chronic treatment. In particular, transcription factors and p38 signaling for collagen synthesis have been shown to be suppressed by the active glucocorticoid receptor (GR). LY294002 (LY), a phosphoinositide 3-kinase (PI3K) inhibitor, has been reported to protect keratinocytes in epidermis against GC-induced hypoplasia; however, its protective effect in dermis remains unclear. Furthermore, clobetasol propionate (CP) is the most used commercial synthetic GC, yet studies on how CP causes side effects in dermal fibroblasts are limited. In this study, dermal atrophy was modeled using CP in human dermal fibroblasts (HDFs) and C57BL/6 mice. CP treatment significantly upregulated FK506 binding protein 5 (FKBP51), an atrophy marker (2.4 ± 0.25 and 3.3 ± 0.3 fold in in vitro and in vivo, respectively), phosphorylated GR (1.96 ± 0.08 and 2.29 ± 0.25 fold in in vitro and in vivo, respectively), decreased fibroblast proliferation (82.71 ± 1.95% in in vitro), reduced collagen synthesis (0.36 ± 0.05 and 0.3 ± 0.1 fold in in vitro and in vivo, respectively), and induced aging, all of which were reversed by LY treatment (from 1.43 ± 0.08 to 2.8 ± 0.12 fold) without showing growth inhibition and exerting the anti-inflammation of CP. Interestingly, the protective effect of LY was dose-dependently reversed by treatment with a p38 inhibitor and reached 2.9 ± 0.15 fold at dose 20 µM. Taken together, our results demonstrate that LY reduced CP-induced upregulation of the atrophy marker FKBP51, GR phosphorylation, and GR nuclear translocation via the activation of p38, whilst maintaining the anti-inflammatory effect of glucocorticoids.