Synthesis Of Extracellular Matrix Components Research Articles

Human Chondrocytes, Metabolism of Articular Cartilage, and Strategies for Application to Tissue Engineering

Hyaline cartilage, which is characterized by the absence of vascularization and innervation, has minimal self-repair potential in case of damage and defect formation in the chondral layer. Chondrocytes are specialized cells that ensure the synthesis of extracellular matrix components, namely type II collagen and aggregen. On their surface, they express integrins CD44, α1β1, α3β1, α5β1, α10β1, αVβ1, αVβ3, and αVβ5, which are also collagen-binding components of the extracellular matrix. This article aims to contribute to solving the problem of the possible repair of chondral defects through unique methods of tissue engineering, as well as the process of pathological events in articular cartilage. In vitro cell culture models used for hyaline cartilage repair could bring about advanced possibilities. Currently, there are several variants of the combination of natural and synthetic polymers and chondrocytes. In a three-dimensional environment, chondrocytes retain their production capacity. In the case of mesenchymal stromal cells, their favorable ability is to differentiate into a chondrogenic lineage in a three-dimensional culture.

Bioinspired scaffolds based on aligned polyurethane nanofibers mimic tendon and ligament fascicles.

Topographical factors of scaffolds play an important role in regulating cell functions. Although the effects of alignment topography and three-dimensional (3D) configuration of nanofibers as well as surface stiffness on cell behavior have been investigated, there are relatively few reports that attempt to understand the relationship between synergistic effects of these parameters and cell responses. Herein, the influence of biophysical and biomechanical cues of electrospun polyurethane (PU) scaffolds on mesenchymal stem cells (MSCs) activities was evaluated. To this aim, multiscale bundles were developed by rolling up the aligned electrospun mats mimicking the fascicles of tendons/ligaments and other similar tissues. Compared to mats, the 3D bundles not only maintained the desirable topographical features (i.e., fiber diameter, fiber orientation, and pore size), but also boosted tensile strength (∼40MPa), tensile strain (∼260%), and surface stiffness (∼1.75MPa). Alignment topography of nanofibers noticeably dictated cell elongation and a uniaxial orientation, resulting in tenogenic commitment of MSCs. MSCs seeded on the bundles expressed higher levels of tenogenic markers compared to mats. Moreover, the biomimetic bundle scaffolds improved synthesis of extracellular matrix components compared to mats. These results suggest that biophysical and biomechanical cues modulate cell-scaffold interactions, providing new insights into hierarchical scaffold design for further studies.

Adaption of Pseudomonas ogarae F113 to the Rhizosphere Environment-The AmrZ-FleQ Hub.

Motility and biofilm formation are two crucial traits in the process of rhizosphere colonization by pseudomonads. The regulation of both traits requires a complex signaling network that is coordinated by the AmrZ-FleQ hub. In this review, we describe the role of this hub in the adaption to the rhizosphere. The study of the direct regulon of AmrZ and the phenotypic analyses of an amrZ mutant in Pseudomonas ogarae F113 has shown that this protein plays a crucial role in the regulation of several cellular functions, including motility, biofilm formation, iron homeostasis, and bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, controlling the synthesis of extracellular matrix components. On the other hand, FleQ is the master regulator of flagellar synthesis in P. ogarae F113 and other pseudomonads, but its implication in the regulation of multiple traits related with environmental adaption has been shown. Genomic scale studies (ChIP-Seq and RNA-Seq) have shown that in P. ogarae F113, AmrZ and FleQ are general transcription factors that regulate multiple traits. It has also been shown that there is a common regulon shared by the two transcription factors. Moreover, these studies have shown that AmrZ and FleQ form a regulatory hub that inversely regulate traits such as motility, extracellular matrix component production, and iron homeostasis. The messenger molecule c-di-GMP plays an essential role in this hub since its production is regulated by AmrZ and it is sensed by FleQ and required for its regulatory role. This regulatory hub is functional both in culture and in the rhizosphere, indicating that the AmrZ-FleQ hub is a main player of P. ogarae F113 adaption to the rhizosphere environment.

The Human Myofibroblast Marker Xylosyltransferase-I: A New Indicator for Macrophage Polarization.

Chronic inflammation and excessive synthesis of extracellular matrix components, such as proteoglycans (PG), by fibroblast- or macrophage-derived myofibroblasts are the hallmarks of fibrotic diseases, including systemic sclerosis (SSc). Human xylosyltransferase-I (XT-I), which is encoded by the gene XYLT1, is the key enzyme that is involved in PG biosynthesis. Increased cellular XYLT1 expression and serum XT-I activity were measured in SSc. Nothing is known so far about the regulation of XT-I in immune cells, and their contribution to the increase in measurable serum XT-I activity. We utilized an in vitro model, with primary human CD14+CD16+ monocyte-derived macrophages (MΦ), in order to investigate the role of macrophage polarization on XT-I regulation. The MΦ generated were polarized towards two macrophage phenotypes that were associated with SSc, which were classified as classical pro-inflammatory (M1-like), and alternative pro-fibrotic (M2-like) MΦ. The fully characterized M1- and M2-like MΦ cultures showed differential XT-I gene and protein expressions. The fibrotic M2-like MΦ cultures exhibited higher XT-I secretion, as well as increased expression of myofibroblast marker α-smooth muscle actin, indicating the onset of macrophage-to-myofibroblast transition (MMT). Thus, we identified XT-I as a novel macrophage polarization marker for in vitro generated M1- and M2-like MΦ subtypes, and broadened the view of XT-I as a myofibroblast marker in the process of MMT.

Pathogenetic features of experimental osteoarthrosis induced by dexamethasone and talc

The aim of the study was to investigate the pathogenesis of experimental osteoarthrosis induced by dexamethasone and talc by examining the structure and defining the morphometric and metabolic features of knee joint skeletal connective tissues in rats.Materials and methods. We performed a morphometric evaluation of articular cartilages (their thickness, extracellular matrix arrangement, spatial arrangement of the main components, distribution density, and main cellular indices of chondrocytes), as well as changes in subchondral bones (the presence of trabeculae in the basal layer of the articular cartilage and individual osteophytes) in 30 rats with a model of primary osteoarthrosis induced by sequential administration of 0.5 ml dexamethasone (2 mg) and 1 ml 10% sterile talc suspension mixed with normal saline into the joint cavity. We studied the histologic specimens of the knee joints stained with hematoxylin – eosin, Alcian blue (рН 1.0 and 2.5), as well as with Van Gieson’s, Masson’s, and Mallory’s trichome stains. The metabolic features of the articular cartilage and bone tissues were investigated by determining the hyaluronan, osteocalcin, and type I collagen levels in the serum of the rats.Results. In the rats with dexamethasone- and talc-induced osteoarthrosis, the thickness of cartilages in their weight-bearing areas decreased by 50%, the spatial arrangement of chondrocytes was impaired, and the nuclear – cytoplasmatic ratio (р < 0.01) decreased to 0.3. Besides, a rise in the serum levels of hyaluronan (p < 0.001) to 110.2 ng / ml, type I collagen fragments (p < 0.001) to 217.9 ng / ml, and osteocalcin (p < 0.001) to 231.1 ng / ml was detected.Conclusion. The main pathogenetic features of experimental osteoarthrosis induced by dexamethasone and talc include impaired distribution density, morphological characteristics, and functional activity of chondrocytes, which results in inhibited synthesis of extracellular matrix components in the articular cartilage and activated destruction of proteoglycans containing unsulphated glycosaminoglycans. The subchondral bone remodeling in experimental osteoarthrosis induced by dexamethasone and talc is characterized by intensification of synthetic activity of osteoblasts.

Regulation of extracellular matrix components by AmrZ is mediated by c-di-GMP in Pseudomonas ogarae F113

The AmrZ/FleQ hub has been identified as a central node in the regulation of environmental adaption in the plant growth-promoting rhizobacterium and model for rhizosphere colonization Pseudomonas ogarae F113. AmrZ is involved in the regulation of motility, biofilm formation, and bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, among others, in this bacterium. The mutants in amrZ have a pleiotropic phenotype with distinguishable colony morphology, reduced biofilm formation, increased motility, and are severely impaired in competitive rhizosphere colonization. Here, RNA-Seq and qRT-PCR gene expression analyses revealed that AmrZ regulates many genes related to the production of extracellular matrix (ECM) components at the transcriptional level. Furthermore, overproduction of c-di-GMP in an amrZ mutant, by ectopic production of the Caulobacter crescentus constitutive diguanylate cyclase PleD*, resulted in increased expression of many genes implicated in the synthesis of ECM components. The overproduction of c-di-GMP in the amrZ mutant also suppressed the biofilm formation and motility phenotypes, but not the defect in competitive rhizosphere colonization. These results indicate that although biofilm formation and motility are mainly regulated indirectly by AmrZ, through the modulation of c-di-GMP levels, the implication of AmrZ in rhizosphere competitive colonization occurs in a c-di-GMP-independent manner.

Role of MicroRNAs in Signaling Pathways Associated with the Pathogenesis of Idiopathic Pulmonary Fibrosis: A Focus on Epithelial-Mesenchymal Transition.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disease with high mortality and unclear etiology. Previous evidence supports that the origin of this disease is associated with epigenetic alterations, age, and environmental factors. IPF initiates with chronic epithelial lung injuries, followed by basal membrane destruction, which promotes the activation of myofibroblasts and excessive synthesis of extracellular matrix (ECM) proteins, as well as epithelial-mesenchymal transition (EMT). Due to miRNAs’ role as regulators of apoptosis, proliferation, differentiation, and cell-cell interaction processes, some studies have involved miRNAs in the biogenesis and progression of IPF. In this context, the analysis and discussion of the probable association of miRNAs with the signaling pathways involved in the development of IPF would improve our knowledge of the associated molecular mechanisms, thereby facilitating its evaluation as a therapeutic target for this severe lung disease. In this work, the most recent publications evaluating the role of miRNAs as regulators or activators of signal pathways associated with the pathogenesis of IPF were analyzed. The search in Pubmed was made using the following terms: “miRNAs and idiopathic pulmonary fibrosis (IPF)”; “miRNAs and IPF and signaling pathways (SP)”; and “miRNAs and IPF and SP and IPF pathogenesis”. Additionally, we focus mainly on those works where the signaling pathways involved with EMT, fibroblast differentiation, and synthesis of ECM components were assessed. Finally, the importance and significance of miRNAs as potential therapeutic or diagnostic tools for the treatment of IPF are discussed.

Serum level of laminin in rats fed with a high-fat diet with sulodexide administration

Background. Increased consumption of animal fat with food contributes to the accumulation of lipids both in the blood and in individual cell structures. Excess fat initiates oxidative stress reactions, which may result in a violation of the structural and functional integrity of cells, in particular, hepatocytes and endotheliocytes. Cytolysis may release specific liver enzymes and activate synthesis of extracellular matrix components, one of the markers of which is a non-collagen glycoprotein laminin.The drug sulodexide, having a pronounced angioprotective, hypolipidemic, and fibrinolytic effects, contributes to restoration of a number of metabolic disorders.Aim. To study the content of lipid metabolism parameters, major enzymes of hepatic cytolysis, and laminin in the blood of rats fed with a high-fat diet against the background of sulodexide administration.Materials and methods. For the study, outbred rats were selected, which were divided into three groups – two experimental groups and one control group. The rats of the first and second experimental groups were fed with a diet with a high content of animal fat (44% of the daily calorie content) for 35 days. In addition, the rats of the second experimental group were daily subcutaneously injected with sulodexide at a dose of 8.5 LRU / kg in terms of the animal’s body weight for 35 days. Starting from day 36 of the experiment, the rats of the control group, as well as the rats of the two experimental groups were fed with a standard diet of the vivarium. The animals were decapitated and blood was taken on day 21, 35, and 60 of the experiment. In the blood serum, the levels of the main lipid metabolism parameters, specific liver enzymes, and laminin were determined.Results. An increase in the body weight of animals and the level of the studied lipid metabolism parameters in the blood serum was revealed. It is likely that the structural integrity of hepatocytes was affected with the release of liver enzymes into the bloodstream and an increase in their content in the blood of rats. In addition, synthesis of extracellular matrix components was activated with an increase in the serum level of laminin, which performs important structural and regulatory functions.Conclusion. The use of sulodexide had a favorable effect on the studied metabolic disorders caused by a high-fat diet. It resulted in the normalization of the synthesis of laminin, one of the major non-collagen proteins of the extracellular matrix.

Human dermal fibroblast response to hyaluronic acid-based injectable dermal fillers: an in vitro study.

Hyaluronic acid (HA)-based injectable dermal fillers (IDFs) used in aesthetic procedures may increase fibroblast activity and ultimately improve subcutaneous tissue quality. To further our understanding of fibroblast response to different commercial HA-based IDFs. Normal human dermal fibroblasts (NHDFs) were cultured with four different commercially available HA-based IDFs to assess their effects on the synthesis of extracellular matrix components and regulators (type I collagen, type III collagen, elastin, and transforming growth factor (TGF)-β1) as well as pro-inflammatory and oxidative DNA damage markers (interleukin (IL)-1β and 8-hydroxy-2'-deoxyguanosine (8-OHdG)). The six biomarkers were measured in supernatants from NHDF cultures after 24 h, 48 h, and 72 h of exposure to HA-based IDFs. All tested IDFs elicited a higher release of type I collagen in NHDF culture supernatants, although Juvederm Voluma was found to induce the most pronounced increase. Agex Fill Ultra induced the highest production of type III collagen and elastin. Levels of TGF-β1 and type I collagen in cell culture supernatants were positively correlated to each other (r = 0.57, p < 0.05). Conversely, 8-OHdG concentrations were inversely associated with both type III collagen (r = -0.41, p < 0.05) and elastin (r = -0.46, p < 0.05). Commercially available HA-based IDFs may elicit different in vitro fibroblast responses - a finding with potential implications in the prediction of their effects in aesthetic procedures. Our results also confirm that in vitro experiments may be viable tools for testing the effects of HA-based IDFs without resorting to animal studies.

Extracellular vesicles as novel approaches for the treatment of osteoarthritis: a narrative review on potential mechanisms.

Osteoarthritis (OA) is a progressive degeneration of articular cartilage with involvement of synovial membrane, and subchondral bone. Current treatment approaches have focused on controlling the OA symptoms, pain, and inflammation. Recently, cell-based therapies, including the application of stem cells such as mesenchymal stem cells (MSCs), have been introduced for restoration of the articular cartilage. Despite promising outcomes, there are some limitations in the application of MSCs for OA treatment. It has been demonstrated that the regenerative potential of stem cells is related to the production of paracrine factors. Extracellular vehicles (EVs), the main component of cell secretome, are membrane-bounded structures that deliver biologically active agents. The delivery of molecules (e.g., nucleic acids, proteins, and lipids) leads to cell-to-cell communication and the alteration of cell functions. In this review, general characteristics of EVs, as well as their potential mechanisms in the prevention and treatment of OA were considered. Based on in vitro and in vivo studies, EVs have shown to contribute to cartilage regeneration via suppression of degenerative factors and regulation of chondrocyte function in the synthesis of extracellular matrix components. Also, they inhibit the progression of OA or protect the cartilage from degradation via their impact on inflammatory cytokines. The different signaling pathways of EVs against the pathologic features of OA were summarized in this review. According to the results obtained from several investigations, more investigations should be design to prove the safety and effectiveness of EVs in the treatment and prevention of OA progression.

Notch1 signaling enhances collagen expression and fibrosis in mouse uterus

AbstractFibrosis is a pathological process characterized by abnormal activation of fibroblasts with increased synthesis of extracellular matrix components, including collagens. It may lead to loss of proper tissue architecture and organ function in clinical diseases such as systemic sclerosis and liver fibrosis. Excess accumulation of collagens is considered the primary indicator of fibrosis. Notch signaling has been reported to be involved in the fibrosis of many different organs, including the liver. Our previous study showed that the uterine‐specific over‐activation of canonical Notch1 signaling in the mouse uterus (Pgrcre/+ Rosa26N1ICD/+, OEx) results in complete infertility as a consequence of multiple developmental and physiological defects, together with increased collagen accumulation evidenced by Masson's staining. In this study, we further detected expressions of all 44 collagen genes in these Notch1 gain‐of‐function transgenic mice and found that 18 collagens have been largely affected. In another aspect, using an intrauterine adhesion model (IUA), we mimicked fibrosis in the mouse uterine. The results suggested that Notch receptors were upregulated only 3 days after induction, and most of the fibril‐forming collagen began to upregulate 6 days after the surgery. Furthermore, when induced IUA in the N1ICD‐OEx mice, the expression of collagens and fibrosis levels were significantly enhanced. At last, as a Notch signaling inhibitor, the γ‐secretase inhibitor N‐[N‐(3,5‐difl uorophenacetyl)‐L‐alanyl]‐S‐phenylglycine t‐butyl ester (DAPT) pretreatment could alleviate the expression of collagens and the symptoms of fibrosis. These results demonstrate that Notch signaling may play a role in upregulating collagens expression in endometrial fibrosis and might be a potential target of fibrosis therapy in the endometrium.

Beneficial impact of cathelicidin on hypersensitivity pneumonitis treatment-In vivo studies.

Cathelicidin (CRAMP) is a defence peptide with a wide range of biological responses including antimicrobial, immunomodulatory and wound healing. Due to its original properties the usefulness of CRAMP in the treatment of pulmonary fibrosis was assessed in a murine model of hypersensitivity pneumonitis (HP). The studies were conducted on mouse strain C57BL/6J exposed to a saline extract of Pantoea agglomerans cells (HP inducer). Cathelicidin was administered in the form of an aerosol during and after HP development. Changes in the composition of immune cell populations (NK cells, macrophages, lymphocytes: Tc, Th, Treg, B), were monitored in lung tissue by flow cytometry. Extracellular matrix deposition (collagens, hydroxyproline), the concentration of cytokines involved in inflammatory and the fibrosis process (IFNγ, TNFα, TGFβ1, IL1β, IL4, IL5, IL10, IL12α, IL13) were examined in lung homogenates by the ELISA method. Alterations in lung tissue morphology were examined in mouse lung sections stained with haematoxylin and eosin as well as Masson trichrome dyes. The performed studies revealed that cathelicidin did not cause any negative changes in lung morphology/structure, immune cell composition or cytokines production. At the same time, CRAMP attenuated the immune reaction induced by mice chronic exposure to P. agglomerans and inhibited hydroxyproline and collagen deposition in the lung tissue of mice treated with bacteria extract. The beneficial effect of CRAMP on HP treatment was associated with restoring the balance in quantity of immune cells, cytokines production and synthesis of extracellular matrix components. The presented study suggests the usefulness of cathelicidin in preventing lung fibrosis; however, cathelicidin was not able to reverse pathological changes completely.

Detection of horizontal gene transfer in the genome of the choanoflagellate Salpingoeca rosetta

Horizontal gene transfer (HGT), the movement of heritable materials between distantly related organisms, is crucial in eukaryotic evolution. However, the scale of HGT in choanoflagellates, the closest unicellular relatives of metazoans, and its possible roles in the evolution of animal multicellularity remains unexplored. We identified at least 175 candidate HGTs in the genome of the colonial choanoflagellate Salpingoeca rosetta using sequence-based tests. The majority of these were orthologous to genes in bacterial and microalgal lineages, yet displayed genomic features consistent with the rest of the S. rosetta genome—evidence of ancient acquisition events. Putative functions include enzymes involved in amino acid and carbohydrate metabolism, cell signaling, and the synthesis of extracellular matrix components. Functions of candidate HGTs may have contributed to the ability of choanoflagellates to assimilate novel metabolites, thereby supporting adaptation, survival in diverse ecological niches, and response to external cues that are possibly critical in the evolution of multicellularity in choanoflagellates.

Bioactive response of PMMA coating obtained by electrospinning on ISO5832-9 and Ti6Al4V biomaterials

Abstract Degenerative diseases, such as osteoarthritis, osteoporosis and accidents can cause hip problems and injuries leading to a necessary hip prosthetic replacement. Acetabular and femoral prosthesis parts, consisting of special alloys of steel and titanium, are fixed to the bones using orthopedic cement based on poly(methyl methacrylate) (PMMA). With aim of improving implant material properties in terms of compatibility with the human body, were evaluated the bioactive responses of ISO 5832-9 steel and Ti6Al4V alloy coated with electrospun PMMA nanofibers. The electrospinning technique is widely used due to the possibility of easily producing fibers within nano or micrometric scale using a low cost, simple experimental apparatus that allows large-scale production. In this work the metallic substrates were submitted to surface pretreatments with sanding alone or in combination with acid etching. After deposition by electrospinning, the surfaces were characterized morphologically, chemically, and for roughness. PMMA fibers were obtained, with nanometric diameter, forming a uniform and homogeneous layer over both metal sample surfaces without appreciable differences in adhesion. The sanded surface, being a one-step process, was chosen for the next step. Fibroblasts were grown on the sample surfaces, for seven days, to determine biocompatibility. Electrospinning Induced Surface Activation (EISA) was used to incorporate hydroxyl radicals into the PMMA chain to produce hydroxylated PMMA, that was later redissolved and electrospun into nanofibers. Both samples (PMMA and PMMA-OH nanofibers) resulted in good cell adhesion properties. However, a denser cell monolayer was observed on the hydroxyl-terminated sample, indicating better cell-material interaction. Hydroxyl (OH) functionalized molecules can regulate cell behavior acting as a linker capable of reacting with proteins, thus accelerating cell growth, migration, differentiation, synthesis of extracellular matrix components, and tissue morphogenesis. By a simple two-step methodology it was possible to obtain electrospun hydroxyl functionalized bioactive PMMA nanofibers deposited on metallic implant samples with an increased cell response.

Biotribological Tests of Osteochondral Grafts after Treatment with Pro-Inflammatory Cytokines.

ObjectiveDuring osteoarthritis progression, cartilage degrades in a manner that influences its biomechanical and biotribological properties, while chondrocytes reduce the synthesis of extracellular matrix components and become apoptotic. This study investigates the effects of inflammation on cartilage under biomechanical stress using biotribological tests.MethodsBovine osteochondral grafts from five animals were punched out from the medial condyle and treated with or without pro-inflammatory cytokines (interleukin-1β [IL-1β], tumor necrosis factor-α [TNF-α], IL-6) for 2 weeks. After incubation, biotribological tests were performed for 2 hours (alternating 10 minutes test and pause respectively at 39°C, 180 N, 1 Hz, and 2 mm stroke). Before and after testing, the cartilage surface was imaged with a 3-dimensional microscope. During testing, the coefficient of friction (COF) was measured, while gene expression analysis and investigation of metabolic activity of chondrocytes were carried out after testing. Histological sections of the tissue and wear debris from the test fluid were also analyzed.ResultsAfter biotribological tests, surface cracks were found in both treated and untreated osteochondral grafts. In treated grafts, the COF increased, and the proteoglycan content in the cartilage tissue decreased, leading to structural changes. Chondrocytes from treated grafts showed increased expression of genes encoding for degradative enzymes, while cartilage-specific gene expression and metabolic activity exhibited no significant differences between treated and untreated groups. No measurable difference in the wear debris in the test fluid was found.ConclusionsTreatment of osteochondral grafts with cytokines results in a significantly increased COF, while also leading to significant changes in cartilage proteoglycan content and cartilage matrix compression during biotribological tests.

Terapia por fotobiomodulação: mecanismo de ação e importância clínica no tratamento da osteoartrite de joelho

A osteoartrite do joelho (OAJ) é uma das doenças articulares degenerativa progressiva mais comuns em todo o mundo e também uma das principais causas de incapacidade e danos à qualidade de vida. A terapia de fotobiomodulação (PBMT, do inglês Photobiomodulation Therapy) através de laser de baixa intensidade (LLLT, do inglês Low Level Laser Therapy) tem mostrado ser um tratamento promissora e com bons resultados para diversas doenças crônicas, incluindo as alterações que acometem o sistema articular. Dentro deste contexto, o objetivo deste estudo é proporcionar, por meio de uma revisão narrativa, uma compreensão das evidências atuais disponíveis sobre o mecanismo de ação e importância clínica da PBMT a laser no tratamento da OAJ. As buscas foram realizadas nas bases de dados bibliográficas do PubMed/MEDLINE, Biblioteca virtual da saúde (BVS), Web of Science e SciELO. Com base nos estudos revisados ​​por pares, os dados laboratoriais em modelos animais experimentais e estudos clínicos mostram que a PBM é capaz de reduzir a morte de condrócitos, estimular a síntese de componentes da matriz extracelular (MEC), atenuar a liberação de mediadores inflamatórios e proteolíticos presente em doenças articulares crônicas, prevenindo assim a degradação do tecido articular e periarticulares. Consequentemente, clinicamente, pode ser observado melhora da dor, funcionalidade e qualidade de vida do indivíduo acometido com OAJ e tratados com a PBMT a laser. Assim, podemos concluir que a PBMT a laser pode constituir um excelente coadjuvante no tratamento da OAJ, uma vez que é um método não invasivo e também apresenta custos relativamente baixos.

Honokiol protects against epidural fibrosis byinhibiting fibroblast proliferation and extracellular matrix overproduction in rats post‑laminectomy.

Epidural fibrosis (EF)-induced failed back surgery syndrome (FBSS) in patients post-laminectomy remains a medical challenge. Although the scarring mechanisms remain unclear, the majority of aetiological studies have reported fibroblast dysfunction. Honokiol, the major bioactive constituent of the magnolia tree, exerts a variety of pharmacological effects, including anti-proliferative and anti-fibrotic effects, on various cell types. The present study investigated whether honokiol attenuates EF progression. In vitro, it was found that honokiol inhibited excessive fibroblast proliferation induced by transforming growth factor-β1 (TGF-β1) and the synthesis of extracellular matrix (ECM) components, including fibro-nectin and type I collagen, in a dose-dependent manner. These effects were attributed to the ability of honokiol to suppress the activity of connective tissue growth factor (CTGF), which is indispensable for the progression of fibrosis. Mechanistically, honokiol attenuated the TGF-β1-induced activation of the Smad2/3 and mitogen-activated protein kinase (MAPK) signalling pathways in fibroblasts. In vivo, honokiol reduced the proliferation of fibroblasts and the synthesis of ECM components, thus ameliorating EF in a rat model post-laminectomy. Taken together, these preclinical findings suggest that honokiol deserves further consideration as a candidate therapeutic agent for EF.

Milk exosomes and miRNA cross the placenta and promote embryo survival in mice.

Exosomes facilitate cell-to-cell communication by transferring regulatory molecules such as miRNA from donor to recipient cells, for example, miR-21-5p and miR-30d promote placentation. Exosomes and their miRNA cargos are not exclusively obtained from endogenous synthesis but may also be absorbed from dietary sources, such as milk. This study assessed the effects of milk exosomes and miRNA cargos on embryo development and fertility in C57BL/6 mice. Fluorophore-labeled milk exosomes, miR-21-5p and miR-30d accumulated in murine placenta and embryos following oral gavage. Seventeen mRNAs, miR-21-5p and miR-30d were differentially expressed in placentas of pregnant mice fed a milk exosome and RNA-depleted (ERD) diet or a milk exosome and RNA-sufficient (ERS) diet. Eight of these mRNAs encode proteins implicated in the synthesis of extracellular matrix components, cell adhesion and migration. Changes in mRNA expression were associated with corresponding changes in protein expression, for example, collagen type I. The size of litters born to dams fed ERD was 25-50% smaller than those born to ERS controls. This study implicates dietary exosomes and miRNA in placenta development and embryo survival.

Osmolarity controls the differentiation of adipose-derived stem cells into nucleus pulposus cells via histone demethylase KDM4B.

Adipose-derived stem cells (ADSCs) are an ideal source of cells for intervertebral disc (IVD) regeneration, but the effect of an increased osmotic microenvironment on ADSC differentiation remains unclear. Here, we aimed to elucidate whether hyperosmolarity facilitates ADSC nucleus pulposus (NP)-like differentiation and whether histone demethylase KDM4B is involved in this process. ADSCs were cultured under standard and increased osmolarity conditions for 1-3weeks, followed by analysis for proliferation and viability. Differentiation was then quantified by gene and protein analysis. Finally, KDM4B knockdown ADSCs were generated using lentiviral vectors. The results showed that increasing the osmolarity of the differentiation medium to 400mOsm significantly increased NP-like gene expression and the synthesis of extracellular matrix (ECM) components during ADSC differentiation; however, further increasing the osmolarity to 500mOsm suppressed the NP-like differentiation of ADSCs. KDM4B, as well as the IVD formation regulators forkhead box (Fox)a1/2 and sonic hedgehog (Shh), were found to be significantly upregulated at 400mOsm. KDM4B knockdown reduced Foxa1/2, Shh, and NP-associated markers' expression, as well as the synthesis of ECM components. The reduction in NP-like differentiation caused by KDM4B knockdown was partially rescued by Purmorphamine, a specific agonist of Shh. Moreover, we found that KDM4B can directly bind to the promoter region of Foxa1/2 and decrease the content of H3K9me3/2. In conclusion, our results indicate that a potential optimal osmolarity window might exist for successful ADSC differentiation. KDM4B plays an essential role in regulating the osmolarity-induced NP-like differentiation of ADSCs by interacting with Foxa1/2-Shh signaling.

Application of blood plasma enriched with platelet derived growth factors in experimental perforation of the tympanic membrane

Acute traumatic perforation of the tympanic membrane occupies a significant place in the structure of the pathology of the middle ear, since «persistent» perforation of the tympanic membrane is the main cause of chronic inflammation in the middle ear, leading to hearing loss and reducing the quality of life of patients. «Persistent» perforation of the tympanic membrane, according to various authors, is formed in 84-392 cases per 10,000 population, so restoring the integrity of the damaged tympanic membrane is one of the main tasks of reconstructive otosurgery. Most authors are of the opinion that it is advisable to close the traumatic eardrum defect early. To date, many ways to close it have been developed. In modern otorhinolaryngology there is extensive experience in using various methods of myringoplasty using various materials for traumatic perforation of the tympanic membrane. However, such a wide variety of plastic techniques and the variety of materials used for this indicates an unresolved problem of closing the perforation of the tympanic membrane. To date, many works have been published that confirm the effectiveness of the use of blood plasma enriched with platelet growth factors in plastic surgery, cosmetology, traumatology, and dentistry. The result of exposure to blood plasma enriched with growth factors is the expression of proteins that regulate chemotaxis, adhesion, cell proliferation, angiogenesis, cell differentiation and the synthesis of extracellular matrix components. Blood plasma enriched with growth factors is autologous (biocompatible), safe from the point of view of the transfer of infectious pathogens. Thus, it can be assumed that the use of plasma enriched with growth factors during surgery during closure of acute perforation of the tympanic membrane will lead to accelerated tissue regeneration and, consequently, a reduction in the length of the postoperative period, and improved treatment outcomes. The use of this method is possible even in a day hospital.