ER-anchored CRTH2 antagonizes collagen biosynthesis and organ fibrosis via binding LARP6.

Excessive deposition of extracellular matrix, mainly collagen protein, is the hallmark of organ fibrosis. The molecular mechanisms regulating fibrotic protein biosynthesis are unclear. Here, we find that chemoattractant receptor homologous molecule expressed on TH2 cells (CRTH2), a plasma membrane receptor for prostaglandin D2, is trafficked to the endoplasmic reticulum (ER) membrane in fibroblasts in a caveolin-1-dependent manner. ER-anchored CRTH2 binds the collagen mRNA recognition motif of La ribonucleoprotein domain family member 6 (LARP6) and promotes the degradation of collagen mRNA in these cells. In line, CRTH2 deficiency increases collagen biosynthesis in fibroblasts and exacerbates injury-induced organ fibrosis in mice, which can be rescued by LARP6 depletion. Administration of CRTH2 N-terminal peptide reduces collagen production by binding to LARP6. Similar to CRTH2, bumetanide binds the LARP6 mRNA recognition motif, suppresses collagen biosynthesis, and alleviates bleomycin-triggered pulmonary fibrosis in vivo. These findings reveal a novel anti-fibrotic function of CRTH2 in the ER membrane via the interaction with LARP6, which may represent a therapeutic target for fibrotic diseases.

Substance P promotes transforming growth factor-ß-induced collagen synthesis in human corneal fibroblasts.

Corneal fibroblasts maintain homeostasis of the corneal stroma by mediating the synthesis and degradation of extracellular collagen, and these actions are promoted by transforming growth factor-ß (TGF-ß) and interleukin-1ß (IL-1ß), respectively. The cornea is densely innervated with sensory nerve fibers that are not only responsible for sensation but also required for physiological processes such as tear secretion and wound healing. Loss or dysfunction of corneal nerves thus impairs corneal epithelial wound healing and can lead to neurotrophic keratopathy. The sensory neurotransmitter substance P (SP) promotes corneal epithelial wound healing by enhancing the stimulatory effects of growth factors and fibronectin. We have now investigated the role of SP in collagen metabolism mediated by human corneal fibroblasts in culture. Although SP alone had no effect on collagen synthesis or degradation by these cells, it promoted the stimulatory effect of TGF-ß on collagen type I synthesis without affecting that of IL-1ß on the expression of matrix metalloproteinase-1. This effect of SP on TGF-ß-induced collagen synthesis was accompanied by activation of p38 mitogen-activated protein kinase (MAPK) signaling and was attenuated by pharmacological inhibition of p38 or of the neurokinin-1 receptor. Our results thus implicate SP as a modulator of TGF-ß-induced collagen type I synthesis by human corneal fibroblasts, and they suggest that loss of this function may contribute to the development of neurotrophic keratopathy.NEW & NOTEWORTHY This study investigates the role of substance P (SP) in collagen metabolism mediated by human corneal fibroblasts in culture. We found that, although SP alone had no effect on collagen synthesis or degradation by corneal fibroblasts, it promoted the stimulatory effect of transforming growth factor-ß on collagen type I synthesis without affecting that of interleukin-1ß on the expression of matrix metalloproteinase-1.

In vitro collagen biomarkers in mechanically stimulated human tendon cells: a systematic review.

OBJECTIVE: The aim of this study was to comprehensively examine and summarize the available in vitro evidence regarding the relationship between mechanical stimulation and biomarkers of collagen synthesis in human-derived tendon cells. METHODS: Systematic review with narrative analyses and risk of bias assessment guided by the Health Assessment and Translation tool. The electronic databases MEDLINE (Ovid), EMBASE (Ovid), CENTRAL (Ovid) and COMPENDEX (Engineering Village) were systematically searched from inception to 3 August 2023. Inclusion criteria encompassed English language, original experimental, or quasi-experimental in vitro publications that subjected human tendon cells to mechanical stimulation, with collagen synthesis (total collagen, type I, III, V, XI, XII, and XIV) and related biomarkers (matrix metalloproteinases, transforming growth factor ß, scleraxis, basic fibroblast growth factor) as outcomes. RESULTS: Twenty-one publications were included. A pervasive definite high risk of bias was evident in all included studies. Owing to incomplete outcome reporting and heterogeneity in mechanical stimulation protocols, planned meta-analyses were unfeasible. Reviewed data suggested that human tendon cells respond to mechanical stimulation with increased synthesis of collagen (e.g., COL1A1, procollagen, total soluble collagen, etc.), scleraxis and several matrix metalloproteinases. Results also indicate that mechanical stimulation dose magnitude may influence synthesis in several biomarkers. CONCLUSIONS: A limited number of studies, unfortunately characterized by a definite high risk of bias, suggest that in vitro mechanical stimulation primarily increases type I collagen synthesis by human tendon cells. Findings from this systematic review provide researchers and clinicians with biological evidence concerning the possible beneficial influence of exercise and loading on cellular-level tendon adaptation.

Emodin ameliorates myocardial fibrosis in mice by inactivating the ROS/PI3K/Akt/mTOR axis.

BACKGROUND: Emodin is a traditional medicine that has been shown to exert anti-inflammatory and anti-oxidative effects. Previous research has indicated that emodin can alleviate myocardial remodeling and inhibit myocardial hypertrophy and fibrosis. However, the mechanism by which emodin affects myocardial fibrosis (MF) has not yet been elucidated. METHODS: Fibroblasts were treated with ANGII, and a mouse model of MF was established by ligation of the left anterior descending coronary artery. Cell proliferation was examined by a Cell Counting Kit-8 (CCK8) assay. Dihydroethidium (DHE) was used to measure reactive oxygen species (ROS) levels, and Masson and Sirius red staining were used to examine changes in collagen fiber levels. PI3K was over-expressed by lentiviral transfection to verify the effect of emodin on the PI3K/AKT/mTOR signaling axis. Changes in cardiac function in each group were examined by echocardiography. RESULTS: Emodin significantly inhibited fibroblast proliferation, decreased intracellular ROS levels, significantly upregulated collagen II expression, downregulated α-SMA expression, and inhibited PI3K/AKT/mTOR pathway activation in vitro. Moreover, the in vivo results were consistent with the in vitro. Emodin significantly decreased ROS levels in heart tissue and reduced collagen fibrillogenesis. Emodin could regulate the activity of PI3K to increase the expression of collagen II and downregulate α-SMA expression in part through the PI3K/AKT/mTOR pathway, and emodin significantly improved cardiac structure and function in mice. CONCLUSIONS: This study revealed that emodin targeted the PI3K/AKT/mTOR pathway to inhibit the development of myocardial fibrosis and may be an antifibrotic agent for the treatment of cardiac fibrosis.

No correlation to collagen synthesis disorders in patients with Perthes' disease: a nationwide Swedish register study of 3488 patients.

BACKGROUND: Mutations of the COL2A1 gene have been identified in patients with Perthes' disease. Several studies have hypothesised a connection between Perthes' disease and collagen synthesis disorders, especially COL2A1-related disorders, but no large studies on the subject have been made. The aim of this study was thus to discover if there is a connection between patients presenting with Perthes' disease, and collagen synthesis disorders. A secondary aim was to see if the children with both disorders had less optimal birth characteristics than the rest. METHODS: Swedish national registers were used to collect data on children diagnosed with Perthes' disease or a collagen synthesis disorder. These registers include all births in Sweden, and data from both outpatient and in-hospital visits. A wide range of data is included besides diagnoses. All children with follow-up data to the age of 15 years were included. Pearson's chi-square was used for analysis. Statistical significance was further analysed with Fisher's Exact Test. RESULTS: In total, 3488 children with either diagnosis were included. 1620 children had only Perthes disease, while 1808 children had only a collagen synthesis disorder. Five children were found to have both the diagnosis Perthes' disease and a collagen synthesis disorder. One child was large for their gestational age and none of the children had a low birthweight. Two of the children were moderately preterm. CONCLUSIONS: The distinct lack of overlap in such a large body of material raises doubt about a connection between the presentation of Perthes' disease and collagen synthesis disorders, either COL2A1-related or not. We could not find an overrepresentation of less optimal birth characteristics either.

Piezo1 Activation Drives Enhanced Collagen Synthesis in Aged Animal Skin Induced by Poly L-Lactic Acid Fillers.

Poly L-lactic acid (PLLA) fillers stimulate collagen synthesis by activating various immune cells and fibroblasts. Piezo1, an ion channel, responds to mechanical stimuli, including changes in extracellular matrix stiffness, by mediating Ca2+ influx. Given that elevated intracellular Ca2+ levels trigger signaling pathways associated with fibroblast proliferation, Piezo1 is a pivotal regulator of collagen synthesis and tissue fibrosis. The aim of the present study was to investigate the impact of PLLA on dermal collagen synthesis by activating Piezo1 in both an H2O2-induced cellular senescence model in vitro and aged animal skin in vivo. PLLA elevated intracellular Ca2+ levels in senescent fibroblasts, which was attenuated by the Piezo1 inhibitor GsMTx4. Furthermore, PLLA treatment increased the expression of phosphorylated ERK1/2 to total ERK1/2 (pERK1/2/ERK1/2) and phosphorylated AKT to total AKT (pAKT/AKT), indicating enhanced pathway activation. This was accompanied by upregulation of cell cycle-regulating proteins (CDK4 and cyclin D1), promoting the proliferation of senescent fibroblasts. Additionally, PLLA promoted the expression of phosphorylated mTOR/S6K1/4EBP1, TGF-ß, and Collagen I/III in senescent fibroblasts, with GsMTx4 treatment mitigating these effects. In aged skin, PLLA treatment similarly upregulated the expression of pERK1/2/ERK1/2, pAKT/AKT, CDK4, cyclin D1, mTOR/S6K1/4EBP1, TGF-ß, and Collagen I/III. In summary, our findings suggest Piezo1's involvement in PLLA-induced collagen synthesis, mediated by heightened activation of cell proliferation signaling pathways such as pERK1/2/ERK1/2, pAKT/AKT, and phosphorylated mTOR/S6K1/4EBP1, underscoring the therapeutic potential of PLLA in tissue regeneration.

Novel Insights into Phaseolus vulgaris L. Sprouts: Phytochemical Analysis and Anti-Aging Properties.

Skin aging is an inevitable and intricate process instigated, among others, by oxidative stress. The search for natural sources that inhibit this mechanism is a promising approach to preventing skin aging. The purpose of our study was to evaluate the composition of phenolic compounds in the micellar extract of Phaseolus vulgaris sprouts. The results of a liquid chromatography-mass spectrometry (LC-MS) analysis revealed the presence of thirty-two constituents, including phenolic acids, flavanols, flavan-3-ols, flavanones, isoflavones, and other compounds. Subsequently, the extract was assessed for its antioxidant, anti-inflammatory, anti-collagenase, anti-elastase, anti-tyrosinase, and cytotoxic properties, as well as for the evaluation of collagen synthesis. It was demonstrated that micellar extract from common bean sprouts has strong anti-aging properties. The performed WST-8 (a water-soluble tetrazolium salt) assay revealed that selected concentrations of extract significantly increased proliferation of human dermal fibroblasts compared to the control cells in a dose-dependent manner. A similar tendency was observed with respect to collagen synthesis. Our results suggest that micellar extract from Phaseolus vulgaris sprouts can be considered a promising anti-aging compound for applications in cosmetic formulations.

Control of the extracellular matrix by hypoxic lymphatic endothelial cells: Impact on the progression of lymphedema?

BACKGROUND: Initial lymphatic vessels do not have a continuous basement membrane. Therefore, the ability of lymphatic endothelial cells (LECs) to produce extracellular matrix (ECM) has received little attention. Untreated lymphedema is a chronic disease that progresses to massive fibrosclerosis in advanced stages. Expansion of the intercellular space and fibrosclerosis cause hypoxia, which also affects the LECs. RESULTS: We studied the expression of genes in human LECs in vitro by RNA sequencing, analyzed the effects of hypoxia (1% O2 ) vs. normoxia (21% O2 ), and focused on ECM genes. LECs express fibrillin-1 and many typical components of a basement membrane such as type IV, VIII, and XVIII collagen, laminin ß1, ß2, and α4, perlecan, and fibronectin. Under hypoxia, we found significant upregulation of expression of genes controlling hydroxylation of procollagen (PLOD2, P4HA1), and also cross-linking, bundling, and stabilization of collagen fibrils and fibers. Also striking was the highly significant downregulation of elastin expression, whereas fibulin-5, which controls the assembly of tropoelastin monomers, was upregulated under hypoxia. In the dermis from genital lymphedema, we observed significant PLOD2 expression in initial lymphatics. CONCLUSIONS: Overall, hypoxia results in the picture of a dysregulated ECM production of LECs, which might be partly responsible for the progression of fibrosclerosis in lymphedema.

Preliminary Evaluation of Wound Healing Potential of Leonurus japonicus Houtt. Extracts.

Leonurus japonicus Houtt. is a medicinal plant popular in Brazil as "rubim", used in local folk medicine for several applications as an anti-inflammatory, antioxidant, analgesic, and antimicrobial phytomedicine. The traditional use for wound healing is related; however, few studies have evaluated the wound healing activity. Thus, this study aimed to analyse the popular indication of the hydroalcoholic and aqueous extracts of L. japonicus aerial parts in a rat wound healing model. The initial chemical characterization was performed using flavonoid quantification and complemented with mass spectroscopy/chemometrics analysis. The wound's lesion contraction and tissue regeneration (histological study stained with hematoxylin-eosin and picrosirius) were determined. Hydroalcoholic and aqueous extracts presented high flavonoid content, and mass spectrometry analysis of the extracts demonstrated the presence of compounds with a mass between 100-650, reinforcing the presence of polyphenolic constituents. The extracts of L. japonicus improve various wound healing phases, like inflammatory modulation, wound contraction, and collagen synthesis, resulting in faster healing in rats. These effects could be related to the extracts' polyphenolic compounds.

Comparison of posterior root remnant cells and horn cells of the medial meniscus.

PURPOSE/AIM OF THE STUDY: Previous studies have noted distinctions between medial meniscus posterior root and horn cells. However, the characteristics of root remnant cells have not been explored in detail. The purpose of this study was to evaluate the gene expression levels, proliferation, and resistance to mechanical stress of remnant and horn cells. MATERIALS AND METHODS: Medial meniscus tissue samples were obtained from patients who underwent total or uni-compartmental knee arthroplasty. Cellular morphology, sry-type HMG box 9, type II collagen, and chondromodulin-I gene expression levels were analyzed. Collagen synthesis was assessed by immunofluorescence staining. Proliferation analysis after 4 h-cyclic tensile strain was performed. RESULTS: Horn cells displayed triangular morphology, whereas root remnant cells appeared fibroblast-like. sry-type HMG box 9 mRNA expression levels were similar in both cells, but type II collagen and chondromodulin-I mRNA expressions were observed only in horn cells. The ratio of type II collagen-positive cells in horn cells was about 10-fold higher than that in root remnant cells, whereas the ratio of sry-type HMG box 9-positive cells was similar. A significant increase in proliferation was observed in root remnant cells compared to that in horn cells. Further, under cyclic tensile strain, the survival rate was higher in root remnant cells than in horn cells. CONCLUSIONS: Medial meniscus root remnant cells showed higher proliferation and resistant properties to cyclic tensile strain than horn cells and showed no chondromodulin-I expression. Preserving the medial meniscus posterior root remnant during pullout repair surgery might maintain mechanical stress-resistant tissue and support healing.

The effects of oestrogen on vaginal wound healing: A systematic review and meta-analysis.

AIMS: To determine the effects of oestrogen or oestrogen deprivation on vaginal wound healing. Impaired wound healing following prolapse surgery may increase the risk of recurrent prolapse in the future. Vaginal oestrogen therapy may improve wound healing, hereby possibly improving surgical outcomes. METHODS: A systematic search of OVID MEDLINE, OVID Embase, and Web of Science was conducted up to January 28, 2020. We included original studies comparing wound healing-related outcomes of oestrogen exposed subjects (female animals and women) to hypo-oestrogenic subjects after vaginal surgery. Data on wound healing-related outcome measures were extracted. For each individual comparison, the standardised mean difference (Hedges' g; SMD) and 95% confidence interval (CI) were calculated. RESULTS: Of the 1474 studies reviewed, 14 studies were included for review, and 11 provided data for meta-analysis. Oestrogen improves neovascularisation (SMD: 1.13, 95% CI: 0.67-1.60), microscopic wound closure (SMD: 0.98, 95% CI: 0.66-1.29), collagen synthesis (SMD: 1.08, 95% CI: 0.42-1.74), and tissue strength (SMD: 1.26, 95% CI: 0.53-1.99) in animals. Oestrogen increases granulation (SMD: 1.67, 95% CI: 0.54-2.79) and accelerates macroscopic wound closure (SMD: 1.82, 95% CI: 1.22-2.42) in women and animals. Oestrogen decreases the inflammatory response (SMD: -0.58, 95% CI: -1.14 to -0.02) in women and animals and reduces levels of transforming growth factor (TGF)-ß1 (SMD: -1.68, 95% CI: -2.52 to -0.83) in animals. All results were statistically significant. CONCLUSIONS: Oestrogen therapy has a positive effect on vaginal wound healing. Future studies should determine whether oestrogen therapy has the potential to improve surgical outcomes.

Plant leads for mitigation of oral submucous fibrosis: Current scenario and future prospect.

The aim of this review is to enumerate medicinal plants and their bioactive compounds that may become potential leads in the mitigation of oral submucous fibrosis (OSMF) in the forthcoming future. It is focused on pathophysiology, risk factors, current treatment regimen, potential plant leads, and future therapies for OSMF. Data were extracted from a vast literature survey by using SciFinder, Web of Science, Google Scholar, and PubMed search engines with relevant keywords. Upon literature survey, we found that the phytochemical 'arecoline' present in the areca nut is the main causative agent of OSMF condition. Currently, OSMF is treated by immunomodulatory and anti-inflammatory agents such as corticosteroids, enzymes (hyaluronidase, chymotrypsin, and collagenase), anti-inflammatory mediators (isoxsuprine and pentoxifylline), dietary supplements (vitamins, antioxidants, and micronutrients), and anti-fibrotic cytokines like interferon-gamma that provides short-term symptomatic relief to OSMF patients. However, some plant leads have been proven effective in alleviating symptoms and mitigating OSMF, which ultimately improves the quality of OSMF patients' life. We concluded that plant drugs like lycopene, curcumin, Aloe vera, colchicine, and Glycyrrhiza glabra are effective against OSMF in various in vitro and/or clinical studies and are being used by modern and traditional practitioners.

CircAMD1 regulates proliferation and collagen synthesis via sponging miR-27a-3p in P63-mutant human dermal fibroblasts.

Transcription factor p63 has critical functions in epidermal, hindgut/anorectal, and limb development. Human mutations in P63 correlate with congenital syndromes affecting the skin, anorectal, and limbs. Nevertheless, less are detected regarding networks and functions controlled by P63 mutations in dermal fibroblasts, which are closely related to skin physiology. To screen for new targets, we employed microarray technology to investigate the R226Q P63 mutation with regards to the resulting circular RNA (circRNA) profiles from P63 point mutations in human dermal fibroblasts (HDFs). In this study, we show that P63-mutant HDFs display reduced proliferation, collagen synthesis, and myofibroblast differentiation; circAMD1 was also downregulated in P63-mutant HDFs compared with wild-type HDFs. Furthermore, overexpressing circAMD1 rescued the functional and phenotypic alterations of p63-mutant HDFs. We as well determined that miR-27a-3p was circAMD1 target involved in effects of circAMD1 in P63-mutant HDFs. Collectively, our data show that circAMD1 functions as a miR-27a-3p sponge that inhibits the functional and phenotypical alteration of P63-mutant HDFs and may be a critical marker in pathogenesis regarding P63-associated traits.

Discovery of Natural Small Molecules Promoting Collagen Secretion by High-Throughput Screening in Caenorhabditis elegans.

Advancing approaches for drug screening are in great demand to explore natural small molecules that may play important roles in collagen biogenesis, secretion, and assembly, which may find novel lead compounds for treating collagen-related diseases or preventing skin aging. In this study, we generated a single copy insertion transgenic Pcol-19- COL-12::GFP Caenorhabditis elegans (C. elegans) strain to label epidermis collagen XII (COL-12), a cuticle structure component, and established an efficient high-content screening techniques to discover bioactive natural products in this worm strain through quantification of fluorescence imaging. We performed a preliminary screening of 614 compounds from the laboratory's library of natural small molecule compounds on the COL-12 labeling worm model, which was tested once at a single concentration of 100 µM to screen for compounds that promoted COL-12 protein amount. Besides col-12, the transcriptional levels of worm-associated collagen coding genes col-19 and sqt-3 were also examined, and none of the compounds affected their transcriptional levels. Meanwhile, the protein levels of COL-12 were significantly upregulated after treating with Danshensu, Lawsone, and Sanguinarine. The effects of these drugs on COL-12 overexpressing worms occur mainly after collagen transcription. Through various validation methods, Danshensu, Lawsone, and Sanguinarine were more effective in promoting the synthesis or secretion of COL-12.

Distinctive roles of fibrillar collagen I and collagen III in mediating fibroblast-matrix interaction: A nanoscopic study.

One major goal in tissue engineering is to create functional materials, mimicking scaffolds in native tissues, to modulate cell function for tissue repair. Collagen is the most abundant structural protein in human body. Though collagen I (COLI) and collagen III (COLIII) are the predominant collagen types in connective tissues and they form stable hybrid fibrils at varied ratios, cell responses to the hybrid matrices are underinvestigated. In this work, we aim to explicate the distinctive roles of COLI and COLIII in fibroblast activation. Unidirectionally aligned COLI, COLIII and COLI-COLIII hybrid nanofibrils were generated via epitaxial growth of collagen on mica. AFM analyses revealed that, with the increase of COLI/COLIII ratio, the fibril width and stiffness increased and the binding affinity of cells to the matrix decreased. A hybrid matrix was found to activate fibroblasts the most effectively, characterized by extensive cell polarization with rigid stress fiber bundles and high α-SMA expression, and by the highest-level of collagen synthesis. It is ascribed to the fine balance between biochemical and biophysical cues achieved on the hybrid matrix. Thus, matrices of aligned COLI-COLIII hybrid fibrils and their derived multifunctional composites can be good candidates of implantation scaffolds for tissue regeneration.

Effects of dietary methionine on growth performance, muscle nutritive deposition, muscle fibre growth and type I collagen synthesis of on-growing grass carp (Ctenopharyngodon idella).

In the current research, a 60-d experiment was conducted with the purpose of exploring the impacts of methionine (Met) on growth performance, muscle nutritive deposition, muscle fibre growth and type I collagen synthesis as well as the related signalling pathway. Six diets (iso-nitrogenous) differing in Met concentrations (2·54, 4·85, 7·43, 10·12, 12·40 and 15·11 g/kg diets) were fed to 540 grass carp (178·47 (SD 0·36) g). Results showed (P < 0·05) that compared with Met deficiency, optimal level of dietary Met (1) increased feed intake, feed efficiency, specific growth rate and percentage weight gain (PWG); (2) increased fish muscle protein, lipid and free amino acid contents and improved fish muscle fatty acid profile as well as increased protein content in part associated with the target of rapamycin complex 1 (TORC1)/S6K1 signalling pathway; (3) increased the frequency distribution of muscle fibre with >50 µm of diameter; (4) increased type I collagen synthesis partly related to the transforming growth factor-ß1/Smads and CK2/TORC1 signalling pathways. In conclusion, dietary Met improved muscle growth, which might be due to the regulation of muscle nutritive deposition, muscle fibre growth and type I collagen synthesis-related signal molecules. Finally, according to PWG and muscle collagen content, the Met requirements for on-growing grass carp (178-626 g) were estimated to be 9·56 g/kg diet (33·26 g/kg protein of diet) and 9·28 g/kg diet (32·29 g/kg of dietary protein), respectively.

Magnolol, a natural aldehyde dehydrogenase-2 agonist, inhibits the proliferation and collagen synthesis of cardiac fibroblasts.

Inhibiting myocardial fibrosis can help prevent cardiovascular diseases, including heart failure. Magnolol (Mag), a natural component of Magnoliae officinalis, has been reported to inhibit fibrosis. However, the mechanism of Mag activity and its effects on myocardial fibrosis remain unclear. Here, we investigated the involvement of ALDH2, an endogenous protective agent against myocardial fibrosis, in the Mag-mediated inhibition of cardiac fibroblast proliferation and collagen synthesis. We found that Mag significantly inhibited cardiac fibroblast proliferation and collagen synthesis, based on the results of MTT, EdU and western blot assays. Moreover, molecular docking, molecular dynamics simulation and surface plasmon resonance (SPR) assays showed that Mag could bind directly and stably to ALDH2. Further analysis of the mechanism of these effects indicated that treatment with Mag dose-dependently enhanced ALDH2 activity without altering protein expression. Mag could enhance the activity of recombinant human ALDH2 proteins with a half-maximal effective concentration of 5.79 × 10-5 M. In addition, ALDH2 activation via Alda-1 inhibited cardiac fibroblast proliferation and collagen synthesis, while ALDH2 inhibition via daidzin partially blocked the suppressive effects of Mag. In summary, Mag may act as a natural ALDH2 agonist and inhibit cardiac fibroblast proliferation and collagen synthesis.

The effect of Q-switched 1064-nm Nd: YAG laser on skin barrier and collagen synthesis via miR-663a to regulate TGFß1/smad3/p38MAPK pathway.

BACKGROUND: Our previous research found that Q-switched 1064-nm Nd: YAG laser (1064-QSNYL) induces skin collagen synthesis by activating TGFß1/Smad3/p38MAPKs pathway. Moreover, a lot of studies shown that MicroRNAs (miRNAs) contribute to regulate collagen synthesis and skin barrier. Therefore, we intend to explore the mechanism of 1064-QSNYL on collagen synthesis and skin barrier through miRNAs. METHODS: We predicted the upstream miRNAs of TGFß1 by bioinformatics databases, and verified them through dual-luciferase reporter genes and Western blotting. The expression of collagen, skin barrier-related protein K10 and filaggrin, TIMP-1, and MMP-2 were detected by RT-qPCR and Western blotting, respectively. Moreover, we detected moisture content, elasticity value, TEWL value, SOD vitality, and hydroxyproline content to evaluate skin barrier of mice. H&E staining to observe the change of dermis thickness and inflammation and infiltration of mice skin. RESULTS: The results shown that TGFß1 was target gene of miR-663a. Moreover, we found that 1064-QSNYL activated TGFß1/smad3/p38MAPK pathway by down-regulating the expression of miR-663a in HaCaT, HDF cells, and mice, thereby promoting expression of Collagen I, Collagen IV, TIMP-1, K10, and filaggrin and inhibiting MMP-2. Furthermore, 1064-QSNYL contributed to moisture content, elasticity, SOD vitality, and hydroxyproline content via miR-663a to activate TGFß1/smad3/p38MAPK pathway. CONCLUSIONS: In summary, this study found for the first time that 1064-QSNYL contributed to collagen synthesis and skin repair via miR-663a to regulate TGFß1/smad3/p38MAPK pathway, thereby achieving skin rejuvenation.

Intense Pulsed Light as a Treatment for Senile Purpura: A Pilot Study.

BACKGROUND AND OBJECTIVES: Senile purpura is a common condition characterized by recurrent ecchymoses in the elderly on the extensor surfaces of the forearms, hands, and legs. Our objective is to assess the efficacy and safety of a protocol using intense pulsed light (BBL; Sciton Inc., Palo Alto, CA) to improve the appearance of senile purpura on subjects' extensor forearms. STUDY DESIGN/MATERIALS AND METHODS: Five subjects over 65 years of age, with ecchymotic lesions measuring over 1 cm on each forearm and five younger subjects under 35 years of age, without any ecchymotic lesions, were included in the study. The subjects were treated on one randomized forearm with a new intense pulsed light protocol for four weekly sessions. Photographs and subject questionnaires were taken weekly before each treatment as well as 1 month after all treatments. Skin biopsies were taken 1 day after the last of four weekly treatments. Histological analysis, including hematoxylin and eosin, elastic van Gieson, and Masson's Trichrome staining, were carried out to assess both the epidermal thickness and dermal connective tissue structure. The protocol consists of multiple passes using an intense pulsed light (BBL; Sciton Inc.) device in which the wavelength, filter, and fluence are adjusted for each step. Step 1 uses infrared light (800-1,400 nm), high intensity, a smooth adapter, and a constant motion technique. Step 2 employs a 590-nm filter with two different fluences and step 3 utilizes a 560-nm filter. The fluence of steps 2-3 is increased by 1 J each treatment if no side effects are noted. RESULTS: Using a new intense pulsed light protocol in subjects with senile purpura, both the number and square area of ecchymoses on the treated arm were significantly reduced (P = 0.02 and P = 0.04, respectively, paired t test) as compared with the untreated arm at 1 month after four weekly treatments. Despite this pilot study including challenging cases of subjects on both inhaled and injected corticosteroids and blood thinners, all subjects with senile purpura had at least a 50% reduction in the total square area of their ecchymoses on their treated arm. There were no significant or long-lasting side effects, and all subjects reported satisfaction with the treatment with a desire to continue treatments on their control arm. Blinded evaluators were able to select 100% of the time in the subjects with senile purpura, which was the treated arm as compared with the control arm when reviewing photographs from 1 month after the last treatment. In addition, several subjects were noted to have a significant improvement in the appearance of hemosiderin deposition and photodamage. Histologically, intense pulsed light treatments significantly increased epidermal thickness in elderly subjects by 21.14% (P = 0.0153, two-tailed, paired t test), to levels comparable with young subjects. Such restoration is consistent with the other histological observations by blinded evaluators of more abundant and organized collagen fibers in the dermis and reduced aggregates of disorganized elastin fibers. CONCLUSION: This new intense pulsed light protocol is safe and effective in improving the clinical appearance of senile purpura as well as preventing future lesions by improving the structure of the skin by increasing epidermal thickness and improving collagen and elastic fiber morphology. The treatment was well-tolerated, adverse effects were minimal, and there was high patient satisfaction. Lasers Surg. Med. 2020. © 2020 Wiley Periodicals LLC.

Effects of aging on the histology and biochemistry of rat tendon healing.

INTRODUCTION: Tendon diseases and injuries are a serious problem for the aged population, often leading to pain, disability and a significant decline in quality of life. The purpose of this study was to determine the influence of aging on biochemistry and histology during tendon healing and to provide a new strategy for improving tendon healing. METHOD: A total of 24 Sprague-Dawley rats were equally divided into a young and an aged group. A rat patellar tendon defect model was used in this study. Tendon samples were collected at weeks 2 and 4, and hematoxylin-eosin, alcian blue and immunofluorescence staining were performed for histological analysis. Meanwhile, reverse transcription-polymerase chain reaction (RT-PCR) and western blot were performed to evaluate the biochemical changes. RESULTS: The histological scores in aged rats were significantly lower than those in young rats. At the protein level, collagen synthesis-related markers Col-3, Matrix metalloproteinase-1 and Metallopeptidase Inhibitor 1(TIMP-1) were decreased at week 4 in aged rats compared with those of young rats. Though there was a decrease in the expression of the chondrogenic marker aggrecan at the protein level in aged tendon, the Micro-CT results from weeks 4 samples showed no significant difference(p>0.05) on the ectopic ossification between groups. Moreover, we found more adipocytes accumulated in the aged tendon defect with the Oil Red O staining and at the gene and protein levels the markers related to adipogenic differentiation. CONCLUSIONS: Our findings indicate that tendon healing is impaired in aged rats and is characterized by a significantly lower histological score, decreased collagen synthesis and more adipocyte accumulation in patellar tendon after repair.