Matrix Proteins Research Articles

Unveiling the Pathophysiology of Osteoarthritis in Joint Anatomy

Background: Osteoarthritis (OA) is a prevalent and debilitating joint disorder characterized by the degeneration of articular cartilage and underlying bone. Understanding the pathophysiology of OA is essential for developing targeted therapies and improving patient outcomes. Objective: To explore the underlying pathophysiological mechanisms of osteoarthritis within the context of joint anatomy, focusing on cartilage degradation, synovial inflammation, and subchondral bone changes. Methods: This prospective study was conducted at private hospitals in Karachi from June 2022 to December 2022. Eighty patients aged 45 to 70 years, diagnosed with OA, were included. Detailed clinical evaluations were performed, including pain assessment using the Visual Analog Scale (VAS) and functional status assessment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Radiographic analysis was conducted using the Kellgren-Lawrence grading scale. Biochemical analysis of serum and synovial fluid was performed to measure levels of collagen type II cleavage products (C2C), cartilage oligomeric matrix protein (COMP), and inflammatory cytokines such as interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). Synovial fluid and tissue samples were collected during arthroscopy or joint replacement surgery for molecular pathway analysis. Data were analyzed using SPSS version 25, with correlations and regression analyses performed to identify predictors of disease progression. Results: OA was associated with significant pain and functional impairment, with a mean pain score of 7.2 ± 1.3 on the VAS and WOMAC scores averaging 55 ± 10 for physical function and 30 ± 5 for stiffness. Radiographic analysis showed 25% of patients classified as grade II, 50% as grade III, and 25% as grade IV. Biochemical markers indicated elevated levels of C2C (serum: 150 ± 20 ng/mL; synovial fluid: 200 ± 25 ng/mL) and COMP (serum: 10 ± 2 µg/mL; synovial fluid: 15 ± 3 µg/mL). Inflammatory cytokines were also elevated (IL-1β: 50 ± 5 pg/mL; TNF-α: 75 ± 10 pg/mL; IL-6: 100 ± 12 pg/mL). A strong positive correlation (r = 0.85, p < 0.01) was observed between VAS pain scores and synovial IL-1β levels. Conclusion: The pathophysiology of osteoarthritis involves a complex interplay of biomechanical, biochemical, and cellular factors. The findings from this study enhance the understanding of OA mechanisms and provide a foundation for developing more effective therapeutic strategies aimed at halting or reversing the progression of OA.

Characterisation of colorectal cancer by hierarchical clustering analyses for five stroma-related markers.

Evidence for the tumour-supporting capacities of the tumour stroma has accumulated rapidly in colorectal cancer (CRC). Tumour stroma is composed of heterogeneous cells and components including cancer-associated fibroblasts (CAFs), small vessels, immune cells, and extracellular matrix proteins. The present study examined the characteristics of CAFs and collagen, major components of cancer stroma, by immunohistochemistry and Sirius red staining. The expression status of five independent CAF-related or stromal markers, decorin (DCN), fibroblast activation protein (FAP), podoplanin (PDPN), alpha-smooth muscle actin (ACTA2), and collagen, and their association with clinicopathological features and clinical outcomes were analysed. Patients with DCN-high tumours had a significantly worse 5-year survival rate (57.3% versus 79.0%; p = 0.044). Furthermore, hierarchical clustering analyses for these five markers identified three groups that showed specific characteristics: a solid group (cancer cell-rich, DCNLowPDPNLow); a PDPN-dominant group (DCNMidPDPNHigh); and a DCN-dominant group (DCNHighPDPNLow), with a significant association with patient survival (p = 0.0085). Cox proportional hazards model identified the PDPN-dominant group (hazard ratio = 0.50, 95% CI = 0.26-0.96, p = 0.037) as a potential favourable factor compared with the DCN-dominant group. Of note, DCN-dominant tumours showed the most advanced pT stage and contained the lowest number of CD8+ and FOXP3+ immune cells. This study has revealed that immunohistochemistry and special staining of five stromal factors with hierarchical clustering analyses could be used for the prognostication of patients with CRC. Cancer stroma-targeting therapies may be candidate treatments for patients with CRC.

T cells use focal adhesions to pull themselves through confined environments.

Immune cells are highly dynamic and able to migrate through environments with diverse biochemical and mechanical compositions. Their migration has classically been defined as amoeboid under the assumption that it is integrin independent. Here, we show that activated primary Th1 T cells require both confinement and extracellular matrix proteins to migrate efficiently. This migration is mediated through small and dynamic focal adhesions that are composed of the same proteins associated with canonical mesenchymal cell focal adhesions, such as integrins, talin, and vinculin. These focal adhesions, furthermore, localize to sites of contractile traction stresses, enabling T cells to pull themselves through confined spaces. Finally, we show that Th1 T cells preferentially follow tracks of other T cells, suggesting that these adhesions modify the extracellular matrix to provide additional environmental guidance cues. These results demonstrate not only that the boundaries between amoeboid and mesenchymal migration modes are ambiguous, but that integrin-mediated focal adhesions play a key role in T cell motility.

Exploring textural, solubility and rheological characteristics of high‐moisture extruded meat analogues: effects of wheat gluten and rice protein incorporation in pea protein isolate and feed moisture levels

SummaryThis research explores the development of high‐moisture meat analogues (HMMA) by blending wheat gluten (WG) and rice protein (RP) with pea protein isolate (PPI) in a twin‐screw extruder under high‐moisture extrusion conditions. The study investigates the effects of incorporating RP and WG with PPI on textural, rheological and colour properties, as well as the underlying protein–protein interactions through protein solubility. From the compositional analysis of these secondary ingredients, there was no significant difference between them. However, results from the extrusion indicated that WG‐PPI showed good fibration and higher instrumental anisotropy than RP‐PPI blend extrudates. RP‐PPI blends exhibit inferior textural and rheological properties, attributed to RP's limited crosslinking ability within the protein matrix. This has resulted in a poor structure and lower textural values at higher incorporation of RP (50%) in the pea protein matrix. This was due to the insoluble protein fraction of the RP resulting in a non‐melting in the extrusion barrel. These findings underscore the importance of understanding protein interactions in developing optimised HMMA formulations, paving the way for further exploration into developing modified RP with improved physiochemical properties which can be integrated into meat analogues.

Inhibition of tartrate-resistant acid phosphatase 5 can prevent cardiac fibrosis after myocardial infarction

BackgroundMyocardial infarction (MI) leads to enhanced activity of cardiac fibroblasts (CFs) and abnormal deposition of extracellular matrix proteins, resulting in cardiac fibrosis. Tartrate-resistant acid phosphatase 5 (ACP5) has been shown to promote cell proliferation and phenotypic transition. However, it remains unclear whether ACP5 is involved in the development of cardiac fibrosis after MI. The present study aimed to investigate the role of ACP5 in post-MI fibrosis and its potential underlying mechanisms.MethodsClinical blood samples were collected to detect ACP5 concentration. Myocardial fibrosis was induced by ligation of the left anterior descending coronary artery. The ACP5 inhibitor, AubipyOMe, was administered by intraperitoneal injection. Cardiac function and morphological changes were observed on Day 28 after injury. Cardiac CFs from neonatal mice were extracted to elucidate the underlying mechanism in vitro. The expression of ACP5 was silenced by small interfering RNA (siRNA) and overexpressed by adeno-associated viruses to evaluate its effect on CF activation.ResultsThe expression of ACP5 was increased in patients with MI, mice with MI, and mice with Ang II-induced fibrosis in vitro. AubipyOMe inhibited cardiac fibrosis and improved cardiac function in mice after MI. ACP5 inhibition reduced cell proliferation, migration, and phenotypic changes in CFs in vitro, while adenovirus-mediated ACP5 overexpression had the opposite effect. Mechanistically, the classical profibrotic pathway of glycogen synthase kinase-3β (GSK3β)/β-catenin was changed with ACP5 modulation, which indicated that ACP5 had a positive regulatory effect. Furthermore, the inhibitory effect of ACP5 deficiency on the GSK3β/β-catenin pathway was counteracted by an ERK activator, which indicated that ACP5 regulated GSK3β activity through ERK-mediated phosphorylation, thereby affecting β-catenin degradation.ConclusionACP5 may influence the proliferation, migration, and phenotypic transition of CFs, leading to the development of myocardial fibrosis after MI through modulating the ERK/GSK3β/β-catenin signaling pathway.

Time-Dependent Effect of Eggshell Membrane on Monosodium-Iodoacetate-Induced Osteoarthritis: Early-Stage Inflammation Control and Late-Stage Cartilage Protection.

Osteoarthritis (OA) is a chronic degenerative joint disease that causes chronic pain, swelling, stiffness, disability, and significantly reduces the quality of life. Typically, OA is treated using painkillers and non-steroidal anti-inflammatory drugs (NSAIDs). While current pharmacologic treatments are common, their potential side effects have prompted exploration into functional dietary supplements. Recently, eggshell membrane (ESM) has emerged as a potential functional ingredient for joint and connective tissue disorders due to its clinical efficacy in relieving joint pain and stiffness. Despite promising clinical evidence, the effects of ESM on OA progression and its mechanism of action remain poorly understood. This study evaluated the efficacy of Ovomet®, a powdered natural ESM, against joint pain and disease progression in a monosodium iodoacetate (MIA)-induced rodent model of OA in mice and rats. The results demonstrate that ESM significantly alleviates joint pain and attenuates articular cartilage destruction in both mice and rats that received oral supplementation for 5 days prior to OA induction and for 28 days thereafter. Interestingly, ESM significantly inhibited mRNA expression levels of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), as well as inflammatory mediators, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase in the knee joint cartilage at the early stage of OA, within 7 days after OA induction. However, this effect was not observed in the late stage at 28 days after OA induction. ESM further attenuates the induction of protein expression for cartilage-degrading enzymes like matrix metalloproteinase (MMPs) 3 and 13, and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), in the late-stage. In addition, MIA-induced reduction of the protein expression levels of cartilage components, cartilage oligomeric matrix protein (COMP), aggrecan (ACAN) and collagen type II α-1 chain (COL2α1), and cartilage extracellular matrix (ECM) synthesis promoting transcriptional factor SRY-Box 9 (SOX-9) were increased via ESM treatment in the cartilage tissue. Our findings suggest that Ovomet®, a natural ESM powder, is a promising dietary functional ingredient that can alleviate pain, inflammatory response, and cartilage degradation associated with the progression of OA.

The hepatocyte epidermal growth factor receptor (EGFR) pathway regulates the cellular interactome within the liver fibrotic niche.

Liver fibrosis is the consequence of chronic liver injury in the presence of an inflammatory component. Although the main executors of this activation are known, the mechanisms that lead to the inflammatory process that mediates the production of pro-fibrotic factors are not well characterized. Epidermal growth factor receptor (EGFR) signaling in hepatocytes is essential for the regenerative processes of the liver; however, its potential role in regulating the fibrotic niche is not yet clear. Our group generated a mouse model that expresses an inactive truncated form of the EGFR specifically in hepatocytes (ΔEGFR mice). Here, we have analyzed the response of WT and ΔEGFR mice to chronic treatment with carbon tetrachloride (CCl4), which induces a pro-inflammatory and fibrotic process in the liver. The results indicated that the hallmarks of liver fibrosis were attenuated in CCl4-treated ΔEGFR mice when compared with CCl4-treated WT mice, coinciding with a faster resolution of the fibrotic process and ameliorated damage. The absence of EGFR activity in hepatocytes induced changes in the pattern of immune cells in the liver, with a notable increase in the population of M2 macrophages, more related to fibrosis resolution, as well as in the population of lymphocytes related to eradication of the damage. Transcriptome analysis of hepatocytes, and secretome studies of extracellular media from in vitro experiments, allowed us to elucidate the specific molecular mechanisms regulated by EGFR that mediate hepatocyte production of both pro-fibrotic and pro-inflammatory mediators; these have consequences for the deposition of extracellular matrix proteins, as well as for the immune microenvironment. Overall, our study uncovered novel mechanistic insights regarding EGFR kinase-dependent actions in hepatocytes that reveal its key role in chronic liver damage. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Tao-Hong-Si-Wu-Tang improves thioacetamide-induced liver fibrosis by reversing ACSL4-mediated lipid accumulation and promoting mitophagy

Ethnopharmacological relevanceLiver fibrosis is a generic fibrous scarring event resulting from accumulation of extracellular matrix (ECM) proteins, easily progressing to end-stage liver diseases. Tao-Hong-Si-Wu-Tang (THSWT) is a traditional Chinese medicine formula applied in clinics to treat gynecological and chronic liver diseases. However, the role of THSWT on thioacetamide (TAA)-induced hepatic fibrosis and the specific mechanisms remains unclear. Aim of the studyTo investigate the improving effects of THSWT on TAA-insulted hepatic fibrosis and the underlying mechanisms. Materials and methodsUHPLC-MS/MS was performed to explore the chemical characterization of THSWT. Mice were orally administered with THSWT once daily for 6 weeks along with TAA challenge. Liver function was reflected through serum biomarkers and histopathological staining. RNA sequencing, non-targeted metabolomics and molecular biology experiments were applied to investigate the underlying mechanisms. ResultsTHSWT profoundly repaired lipid metabolism dysfunction and blocked collagen accumulation both in TAA-stimulated mice and in hepatocytes. Results of RNA sequencing and non-targeted metabolomics revealed that the anti-fibrotic effects of THSWT mostly relied on lipid metabolism repairment by increasing levels of acetyl-CoA, phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine and lysophosphatidylethanolamine, and decreasing relative abundances of acyl-CoA, total cholesterol, diacylglycerol, triacylglycerol and phosphatidylinositol. Mechanically, long-chain acyl-CoA synthetases 4 (ACSL4) was a key profibrotic target both in human and mice by disrupting lipid oxidation and metabolism in hepatic mitochondria. THSWT effectively blocked ACSL4 and promoted mitophagy to reverse above outcomes, which was verified by mitophagy depletion. ConclusionTHSWT may be a promising therapeutic option for treating hepatic fibrosis and its complications by modulating lipid metabolism and promoting mitophagy in livers.

Metformin as adjuvant therapy in obese knee osteoarthritis patients

AimsThis study aimed at investigating the efficacy of metformin as adjuvant therapy for obese knee osteoarthritis (OA) patients, considering its anti-inflammatory and cartilage-protective effects.Patients and methodsIn this randomized, double-blind, placebo-controlled study, 50 obese knee OA patients were assigned randomly to two groups, the metformin group (n = 25) which was treated with metformin 500 mg orally BID plus celecoxib 200 mg orally once daily, and the placebo group (n = 25) which was treated with placebo tablets BID plus celecoxib 200 mg orally once daily for 12 weeks. Cartilage Oligomeric Matrix Protein (COMP), C-terminal cross-linked telopeptide of type I collagen (CTX-1), and Interleukin 1-beta (IL-1β) serum levels were measured, while Western Ontario and McMaster Universities Arthritis Index (WOMAC) score assessed knee pain, stiffness, and physical function at baseline and after 12 weeks.ResultsFollowing a 12-week treatment, the metformin group exhibited significantly reduced levels of COMP, CTX-1, and IL-1β in the serum compared to the placebo group (p = 0.0081, p = 0.0106, and p = 0.0223, respectively). Furthermore, metformin group produced significant improvements in WOMAC total scale (p < 0.0001), specifically in knee pain, stiffness, and physical function compared to placebo group (p < 0.0001, p < 0.0001, and p < 0.0001, respectively).ConclusionMetformin as an adjuvant therapy in obese knee OA patients may have beneficial effects on cartilage degradation and inflammation, as evidenced by the significant decreases in serum COMP, CTX-1, and IL-1β levels. Additionally, metformin may improve clinical outcomes, as shown by the significant improvements in WOMAC scores.Clinicaltrials.gov IDNCT05638893/Registered December 6, 2022 — Retrospectively.

MRGPRX2-mediated mast cell activation by substance P from overloaded human tenocytes induces inflammatory and degenerative responses in tendons

Mast cells are immune cells minimally present in normal tendon tissue. The increased abundance of mast cells in tendinopathy biopsies and at the sites of tendon injury suggests an unexplored role of this cell population in overuse tendon injuries. Mast cells are particularly present in tendon biopsies from patients with more chronic symptom duration and a history of intensive mechanical loading. This study, therefore, examined the cross talk between mast cells and human tendon cells in either static or mechanically active conditions in order to explore the potential mechanistic roles of mast cells in overuse tendon injuries. A coculture of isolated human tenocytes and mast cells (HMC-1) combined with Flexcell Tension System for cyclic stretching of tenocytes was used. Additionally, human tenocytes were exposed to agonists and antagonists of substance P (SP) receptors. Mast cell degranulation was assessed by measuring β-hexosaminidase activity. Transwell and cell adhesion assays were used to evaluate mast cell migration and binding to tendon extracellular matrix components (collagen and fibronectin), respectively. Gene expressions were analyzed using real time qRT-PCR. Our results indicate that mechanical stimulation of human tenocytes leads to release of SP which, in turn, activates mast cells through the Mas-related G-protein-coupled receptor X2 (MRGPRX2). The degranulation and migration of mast cells in response to MRGPRX2 activation subsequently cause human tenocytes to increase their expression of inflammatory factors, matrix proteins and matrix metalloproteinase enzymes. These observations may be important in understanding the mechanisms by which tendons become tendinopathic in response to repetitive mechanical stimulation.

Kinetic and dynamical properties of truncated hemoglobins of the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125.

Due to the low temperature, the Antarctic marine environment is challenging for protein functioning. Cold-adapted organisms have evolved proteins endowed with higher flexibility and lower stability in comparison to their thermophilic homologs, resulting in enhanced reaction rates at low temperatures. The Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 (PhTAC125) genome is one of the few examples of coexistence of multiple hemoglobin genes encoding, among others, two constitutively transcribed 2/2 hemoglobins (2/2Hbs), also named truncated Hbs (TrHbs), belonging to the Group II (or O), annotated as PSHAa0030 and PSHAa2217. In this work, we describe the ligand binding kinetics and their interrelationship with the dynamical properties of globin Ph-2/2HbO-2217 by combining experimental and computational approaches and implementing a new computational method to retrieve information from molecular dynamic trajectories. We show that our approach allows us to identify docking sites within the protein matrix that are potentially able to transiently accommodate ligands and migration pathways connecting them. Consistently with ligand rebinding studies, our modeling suggests that the distal heme pocket is connected to the solvent through a low energy barrier, while inner cavities play only a minor role in modulating rebinding kinetics.

Antibiofilm activity of d-limonene against spoilage Bacillus amyloliquefaciens

This study aimed to determine the efficacy of d-limonene in preventing biofilm formation by Bacillus amyloliquefaciens, a soy food spoilage bacterium. The minimal biofilm inhibitory concentrations (MBICs) of d-limonene against two strains of B. amyloliquefaciens were determined using a twofold dilution method. Furthermore, the ability of d-limonene to eradicate preformed biofilms was evaluated using the TTC reduction method. Subsequent analyses investigated the effects of d-limonene on biofilm morphology, cell motility, cell surface characteristics, and the composition of the biofilm matrix. The MBICs of d-limonene for B. amyloliquefaciens strains DY1a and DY1b were determined to be 24 and 36 μL/mL, respectively. At 2 MBIC, d-limonene eradicated 63.67% of the DY1a biofilms and 52.63% of the DY1b biofilms. Significantly, d-limonene markedly reduced swimming and swarming motility at concentrations ranging from 1/2 to 1 MBIC. In particular, at 1/2 MBIC, d-limonene decreased swimming and swarming abilities by 85.88% and 37.84%, respectively, for strain DY1a and by 75.00% and 95.07%, respectively, for strain DY1b. Furthermore, d-limonene suppressed the biosynthesis of polysaccharides and proteins in the extracellular biofilm matrix and reduced cell surface hydrophobicity, surface charge, and autoaggregation. These findings suggest that d-limonene could be an effective antibiofilm agent for the control of B. amyloliquefaciens in the soybean food industry.

Metabolic syndrome and neuroprotection

Introduction. Over the years, the prevalence of metabolic syndrome has increased dramatically in developing countries as a major by-product of industrialization. Many factors, such as the consumption of hypercaloric diets and sedentary lifestyles, favor the spread of this disorder. Undoubtedly, the massive and still growing incidence of metabolic syndrome makes this epidemic a major public health problem. Metabolic syndrome is also a neurological and psychiatric risk factor. In this paper, an exploratory literature review on the subject will be performed. In this paper, we survey the information as to what is known about the metabolic syndrome beyond its classical association with cardiovascular disease and type 2 diabetes mellitus, since the metabolic syndrome also represents a risk factor for nervous tissue and threatens neuronal function. First, we present some essential concepts of the pathophysiology of metabolic syndrome. Second, we explore some neuroprotective approaches in metabolic syndrome related to cerebral hypoxia. Objectives. To update, review in an exploratory manner, and synthesize the literature concerning the neurological impact of metabolic syndrome, beyond its classical association with cardiovascular disease and type 2 diabetes mellitus. Define and review essential concepts of the pathophysiology of metabolic syndrome. To explore neuropreventive and neuroprotective strategies in metabolic syndrome related to therapeutic cerebral hypoxia. Material and methods. An exploratory survey of scientific literature from January 1989-November 2022 was carried out. Selection/inclusion criteria: scientific publications containing exploratory data and information on metabolic syndrome and neurological comorbidity and possible neurotherapeutic approaches. Pathophysiology. The metabolic pathways characteristically impaired in metabolic syndrome lead to hyperglycemia, insulin resistance, inflammation and hypoxia, all closely related to a generalized prooxidative state. Oxidative stress is well known to cause destruction of cellular structures and tissue architecture. Altered redox homeostasis and oxidative stress alter the macromolecular matrix of nuclear genetic material, lipids and proteins, which in turn disrupts biochemical pathways necessary for normal cellular function. Neuroprotection. Different neuroprotective strategies involving lifestyle changes, medications aimed at mitigating the cardinal symptoms of metabolic syndrome, and treatments aimed at reducing oxidative stress are discussed. It is well known that routine physical exercise, particularly aerobic activity, and a complete and balanced diet are key factors in preventing metabolic syndrome. However, pharmacological control of the metabolic syndrome as a whole and related hypertension, dyslipidemia and endothelial injury contribute to the improvement of neuronal health. Conclusion. The development of metabolic syndrome presents as a risk factor for the development and/or exacerbation of neurological alterations. Therapeutic strategies include multidisciplinary approaches aimed at addressing, in a concerted manner, different pathways involved in its pathophysiology

The extracellular matrix protein EFEMP2 is involved in the response to VHSV infection in the olive flounder Paralichthys olivaceus

The EGF-containing fibulin-like extracellular matrix protein 2 (EFEMP2) is involved in connective tissue development, elastic fiber formation, and tumor growth. In this study, we characterized the cDNA of EFEMP2 (PoEFEMP2), a member of the fibulin family of ECM proteins, in the olive flounder Paralichthys olivaceus. The coding region of PoEFEMP2 encodes a protein that contains six calcium-binding EGF-like (EGF-CA) domains and four complement Clr-like EGF-like (cEGF) domains. PoEFEMP2 shows 67.51–96.77 % similarities to orthologs in a variety of fish species. PoEFEMP2 mRNA was detected in all tissues examined; the highest levels of PoEFEMP2 mRNA expression were observed in the heart, testis, ovary and muscle. The PoEFEMP2 mRNA level increases during early development. In addition, the PoEFEMP2 mRNA level increased at 3 h post-infection (hpi) and decreased from 6 to 48 hpi in flounder Hirame natural embryo (HINAE) cells infected with viral hemorrhagic septicemia virus (VHSV). Disruption of PoEFEMP2 using the clustered regularly interspaced short palindromic repeats/CRISPR-associated-9 (CRISPR/Cas9) system resulted in a significant upregulation of VHSV G mRNA levels and immune-related genes expression in knockout cells. These findings implicate PoEFEMP2 in antiviral responses in P. olivaceus.

Diversification of von Willebrand Factor A and Chitin-Binding Domains in Pif/BMSPs Among Mollusks

Pif is a shell matrix protein (SMP) identified in the nacreous layer of Pinctada fucata (Pfu) comprised two proteins, Pif97 and Pif 80. Pif97 contains a von Willebrand factor A (VWA) and chitin-binding domains, whereas Pif80 can bind calcium carbonate crystals. The VWA domain is conserved in the SMPs of various mollusk species; however, their phylogenetic relationship remains obscure. Furthermore, although the VWA domain participates in protein–protein interactions, its role in shell formation has not been established. Accordingly, in the current study, we investigate the phylogenetic relationship between PfuPif and other VWA domain-containing proteins in major mollusk species. The shell-related proteins containing VWA domains formed a large clade (the Pif/BMSP family) and were classified into eight subfamilies with unique sequential features, expression patterns, and taxa diversity. Furthermore, a pull-down assay using recombinant proteins containing the VWA domain of PfuPif 97 revealed that the VWA domain interacts with five nacreous layer-related SMPs of P. fucata, including Pif 80 and nacrein. Collectively, these results suggest that the VWA domain is important in the formation of organic complexes and participates in shell mineralisation.

Proteomic analysis of endothelial cells and extracellular vesicles in response to indoxyl sulfate: Mechanisms of endothelial dysfunction in chronic kidney disease

AimsCardiovascular pathology is the main cause of death in chronic kidney disease (CKD) patients. CKD is associated with the accumulation of uremic toxins in the bloodstream, and indoxyl sulfate (IS) is one of the most abundant uremic toxins found in the blood of CKD patients. We conducted an in vitro study to assess the mechanisms underlying the IS-induced endothelial dysfunction that could lead to cardiovascular diseases. We also studied their extracellular vesicles (EVs) owing to their capacity to act as messengers that transmit signals through their cargo. Main methodsEVs were characterized by nanoparticle tracking analysis, transmission electron microscopy, flow cytometry, and tetraspanin expression. Cell lysates and isolated EVs were analyzed using liquid chromatography coupled with mass spectrometry, followed by Gene Set Enrichment Analysis to identify the altered pathways. Key findingsProteomic analysis of endothelial cells revealed that IS causes an increase in proteins related to adipogenesis, inflammation, and xenobiotic metabolism and a decrease in proliferation. Extracellular matrix elements, as well as proteins associated with myogenesis, response to UV irradiation, and inflammation, were found to be downregulated in IS-treated EVs. Fatty acid metabolism was also found to be increased along with adipogenesis and inflammation observed in cells. SignificanceThe treatment of endothelial cells with IS increased the expression of proteins related to adipogenesis, inflammation, and xenobiotic metabolism and was less associated with proliferation. Furthermore, EVs from cells treated with IS may mediate endothelial dysfunction, since they present fewer extracellular matrix elements, myogenesis, inflammatory factors, and proteins downregulated in response to UV radiation.

Odontogenic and anti-inflammatory effects of magnesium-doped bioactive glass in vital pulp therapy

This study aimed to investigate the effects of magnesium-doped bioactive glass (Mg-BG) on the mineralization, odontogenesis, and anti-inflammatory abilities of human dental pulp stem cells (hDPSCs). Mg-BG powders with different Mg concentrations were successfully synthesized via the sol-gel method and evaluated using x-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Apatite formation was observed on the surfaces of the materials after soaking in simulated body fluid. hDPSCs were cultured with Mg-BG powder extracts in vitro, and no evident cytotoxicity was observed. Mg-BG induced alkaline phosphatase (ALP) expression and mineralization of hDPSCs and upregulated the expression of odontogenic genes, including those encoding dentin sialophosphoprotein, dentin matrix protein 1, ALP, osteocalcin, and runt-related transcription factor 2. Moreover, Mg-BG substantially suppressed the secretion of inflammatory cytokines (interleukin [IL]-4, IL-6, IL-8, and tumor necrosis factor-alpha). Collectively, the results of this study suggest that Mg-BG has excellent in vitro bioactivity and is a potential material for vital pulp therapy of inflamed pulps.

Assessment of Cartilage Oligomeric Matrix Protein Biomarker for Laboratory Diagnosis of Hepatocellular Carcinoma

Assessment of Cartilage Oligomeric Matrix Protein Biomarker for Laboratory Diagnosis of Hepatocellular Carcinoma

Hydroxyapatite Nanoparticles Promote the Development of Bone Microtissues for Accelerated Bone Regeneration by Activating the FAK/Akt Pathway.

Scaffold-free bone microtissues differentiated from mesenchymal stem cell (MSC) spheroids offer great potential for bottom-up bone tissue engineering as a direct supply of cells and osteogenic signals. Many biomaterials or biomolecules have been incorporated into bone microtissues to enhance their osteogenic abilities, but these materials are far from clinical approval. Here, we aimed to incorporate hydroxyapatite (HAP) nanoparticles, an essential component of bone matrix, into MSC spheroids to instruct their osteogenic differentiation into bone microtissues and further self-organization into bone organoids with a trabecular structure. Furthermore, the biological interaction between HAP nanoparticles and MSCs and the potential molecular mechanisms in the bone development of MSC spheroids were investigated by both in vitro and in vivo studies. As a result, improved cell viability and osteogenic abilities were observed for the MSC spheroids incorporated with HAP nanoparticles at a concentration of 30 μg/mL. HAP nanoparticles could promote the sequential expression of osteogenic markers (Runx2, Osterix, Sclerostin), promote the expression of bone matrix proteins (OPN, OCN, and Collagen I), promote the mineralization of the bone matrix, and thus promote the bone development of MSC spheroids. The differentiated bone microtissues could further self-organize into linear, lamellar, and spatial bone organoids with trabecular structures. More importantly, adding FAK or Akt inhibitors could decrease the level of HAP-induced osteogenic differentiation of bone microtissues. Finally, excellent new bone regeneration was achieved after injecting bone microtissues into cranial bone defect models, which could also be eliminated by the Akt inhibitor. In conclusion, HAP nanoparticles could promote the development of bone microtissues by promoting the osteogenic differentiation of MSCs and the formation and mineralization of the bone matrix via the FAK/Akt pathway. The bone microtissues could act as individual ossification centers and self-organize into macroscale bone organoids, and in this meaning, the bone microtissues could be called microscale bone organoids. Furthermore, the bone microtissues revealed excellent clinical perspectives for injectable cellular therapies for bone defects.

Factor VIII promotes angiogenesis and vessel stability regulating extracellular matrix proteins.

Not available.