Production Of Matrix Metalloproteinases Research Articles

Fenebrutinib, a Bruton’s tyrosine kinase inhibitor, blocks distinct human microglial signaling pathways

BackgroundBruton’s tyrosine kinase (BTK) is an intracellular signaling enzyme that regulates B-lymphocyte and myeloid cell functions. Due to its involvement in both innate and adaptive immune compartments, BTK inhibitors have emerged as a therapeutic option in autoimmune disorders such as multiple sclerosis (MS). Brain-penetrant, small-molecule BTK inhibitors may also address compartmentalized neuroinflammation, which is proposed to underlie MS disease progression. BTK is expressed by microglia, which are the resident innate immune cells of the brain; however, the precise roles of microglial BTK and impact of BTK inhibitors on microglial functions are still being elucidated. Research on the effects of BTK inhibitors has been limited to rodent disease models. This is the first study reporting effects in human microglia.MethodsHere we characterize the pharmacological and functional properties of fenebrutinib, a potent, highly selective, noncovalent, reversible, brain-penetrant BTK inhibitor, in human microglia and complex human brain cell systems, including brain organoids.ResultsWe find that fenebrutinib blocks the deleterious effects of microglial Fc gamma receptor (FcγR) activation, including cytokine and chemokine release, microglial clustering and neurite damage in diverse human brain cell systems. Gene expression analyses identified pathways linked to inflammation, matrix metalloproteinase production and cholesterol metabolism that were modulated by fenebrutinib treatment. In contrast, fenebrutinib had no significant impact on human microglial pathways linked to Toll-like receptor 4 (TLR4) and NACHT, LRR and PYD domains-containing protein 3 (NLRP3) signaling or myelin phagocytosis.ConclusionsOur study enhances the understanding of BTK functions in human microglial signaling that are relevant to MS pathogenesis and suggests that fenebrutinib could attenuate detrimental microglial activity associated with FcγR activation in people with MS.

The Role of Macrophages in the Pathogenesis of Celiac Disease

Aim: to present data on the involvement of macrophages in the pathogenesis of celiac disease and the development of possible treatment methods for this disease aimed at changing the function of macrophages.Key points. Celiac disease is an autoimmune disease with a characteristic serological (antibodies to tissue transglutaminase, endomysium, deamidated gliadin peptides) and histological profile (inflammatory infiltration of the villous epithelium by lymphocytes and their atrophy, crypt hyperplasia) caused by gluten consumption in genetically predisposed individuals. Macrophages, as key cells that provide a link between innate and adaptive immunity, are of significant importance in the pathogenesis of celiac disease. Gliadin peptides stimulate the activation of macrophages according to the proinflammatory phenotype with the production of cytokines, which causes the immune response of T-helpers 1 and T-helpers 17. The result of these processes is the development of an inflammatory reaction and damage to the intestinal mucosa due to the production of matrix metalloproteinases and reactive oxygen species by macrophages. Therapeutic tactics for celiac disease today include a gluten-free diet, which is not so easy to follow. Of interest is the study of the possibility of using polyphenols in celiac disease, which are capable of precipitating gliadins and inhibiting the polarization of macrophages towards a proinflammatory phenotype, while simultaneously stimulating an increase in the population of macrophages of an anti-inflammatory phenotype associated with a decrease in tissue damage.Conclusion. Impaired macrophage function/differentiation results in either inadequate, excessive immune activation or failure to mount effective protective immune responses against pathogens, which may result in the development of gastrointestinal diseases. Studying the involvement of macrophages at different stages of celiac disease progression is important for the development of new treatments for this disease.

Impact of the tumor microenvironment of breast cancer on prognosis and treatment

According to world Health Organization, breast cancer (BC) ranks first among cancer diseases in women in many developed countries of the world and in the Russian Federation. Over the past 20 years, the incidence of breast cancer in the world has increased and continues to increase. This phenomenon dictates the need for a more in-depth molecular biological, genetic and immunological study of the mechanisms of development and progression of this heterogeneous malignant tumor.Recently, there has been increasing interest in the world not on lyin the direct causes of tumor development, but also in factors contributing to its progression, such as the cellular microenvironment of the tumor, the composition of which has a great influence on cancer development, treatment and prognosis. In the cellular microenvironment of the tumor, mononuclear cells are assessed, the proportion of which determines the severity and direction of the immuneresponse. Their importance for choosing the priority type of drug therapy and assessing its effectiveness is shown. The article provide scurrent data on subpopulations of T cells (CD8+, CD4+), B cells (CD20+), and natural killer. Their role in the development and progression of breast cancer is discussed depending on their phenotype. Modern research pays attention to a minor subpopulation of T lymphocytes – TCR-Vδ1+ cells. This subpopulation is represented predominantly in tumor tissue and has an immunosuppressive effect on T-effectors. At the present stage, inflammatory cells – macrophages and neutrophils – are of no less interest. Their role in tumor progression is widely debated. It is known that the differentiation of macrophages into M1 or M2 phenotypes is determined by the tumor microenvironment. The predominance of macrophages with protumor activity promotes tumor progression and cancer metastasis. Additionally, macrophages can stimulate the migration of neutrophils, which, in turn, support the metastasis of breast cancer through the production of matrix metalloproteinases. Matrix metalloproteinase 9 has been reported to promote the formation of vascular endothelial growth factor, which explains the protumor properties of neutrophils. In the context of growing tumor immunotherapy, assessment of tumor microenvironmental factors is promising both in relation to monitoring the effectiveness of breast cancer therapy and in relation to the search for potential therapeutic targets. The review systematizes and summarizes information on this issue to date.

ZnO nanoparticles induce melanoma-like lesions via recruiting dermal dendritic cells in barrier-damaged skin in mice

ZnO nanoparticles (NPs) are used in skin treatments and cosmetics, the toxicity of long-term and continuous exposure to ZnO NPs is unknown. Mice with epidermal barrier dysfunction revealed melanoma-like lesions after continuous exposure to ZnO NPs. However, the effects of metallic NPs on the skin microenvironment and immune system remain poorly understood. Mice with epidermal barrier failure were given continuous exposure to ZnO NPs for 7 weeks. The malignant transformation of melanocytes was induced with ZnO NPs 2.5 μg/ml for 72 h exposure. The supernatant of the culture medium from dendritic cells after being exposed to 10 μg/ml ZnO NPs for 24 h was applied to melanocytes to explore the effect of recruitment of DCs. The expressure of ZnO NPs resulted in a tendency of malignant transformation of melanocytes, the recruitment of DCs induces this process by produce inflammatory factors such as TNF-α. These DC-produced inflammatory factors, which were induced by ZnO NP exposure, increased the production of matrix metalloproteinases in melanocytes and expedited the malignant transformation process. Our findings revealed that the disrupted cutaneous microenvironment by ZnO NPs penetrated directly promoted the malignant transformation of melanocytes, which process also indirectly enhanced by the TNF-αsecreted from the recruited DCs.

Dapagliflozin alleviates right heart failure by promoting collagen degradation by reducing ROS levels

BackgroundRight ventricular (RV) fibrosis is an important pathological change that occurs during the development of right heart failure (RHF) induced by pulmonary hypertension (PH). Dapagliflozin (DAPA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, has been shown to play a major role in left heart failure, but it is unclear whether it has a positive effect on RHF. This study aimed to clarify the effect of DAPA on PH-induced RHF and investigate the underlying mechanisms. MethodsWe conducted experiments on two rat models with PH-induced RHF and cardiac fibroblasts (CFs) exposed to pathological mechanical stretch or transforming growth factor-beta (TGF-β) to investigate the effect of DAPA. ResultsIn vivo, DAPA could improve pulmonary hemodynamics and RV function. It also attenuated right heart hypertrophy and RV fibrosis. In vitro, DAPA reduced collagen expression by increasing the production of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9). Additionally, DAPA was found to reduce reactive oxygen species (ROS) levels in CFs and the right heart in rats. Similar to DAPA, the ROS scavenger N-acetylcysteine (NAC) exerted antifibrotic effects on CFs. Therefore, we further investigated the mechanism by which DAPA promoted collagen degradation by reducing ROS levels. ConclusionsIn summary, we concluded that DAPA ameliorated PH-induced structural and functional changes in the right heart by increasing collagen degradation. Our study provides new ideas for the possibility of using DAPA to treat RHF.

Inhibition of nitric oxide production in RAW 264.7 cells and cytokines IL-1β in osteoarthritis rat models of 70 % ethanol extract of Arcangelisia flava (L.) merr stems

IntroductionOne of the most frequent types of arthritis is osteoarthritis, also referred to as a degenerative joint disease. Interleukin-1β (IL-1β) and nitric oxide (NO) are essential factors in the pain response; IL-1β and NO are responsible for increasing the production of matrix metalloproteinases (MMP) and a disintegrin-like and metalloproteinases with thrombospondin motifs (ADAMS) in chondrocytes. Arcangelisia flava (L.) Merr. Has been traditionally used to treat jaundice, liver disease, diarrhea, fever, and inflammation. MethodsThis study used in vitro and in vivo models to determine the effect of a 70 % ethanol extract of Arcangelisia flava (L.) Merr. stems on the inhibition of NO production in RAW 264.7 cells induced with lipopolysaccharide (LPS) and IL-1β in osteoarthritis rats induced with monosodium iodoacetate (MIA). The NO inhibition test was determined by the NO colorimetric assay using Griess reagent and measured by the ELISA plate reader. The measurement of joint diameter and hyperalgesia in osteoarthritis rats was carried out once a week for 7 weeks, and then the IL-1β levels were measured at weeks 3 and 7. ResultThe viability of cell line this extract was greater than 80 %, and the extract at 25, 50, and 100 μg/mL significantly inhibited NO production (p < 0.0001) in RAW 264.7 cells induced with LPS. Meanwhile, this extract at 10, 30, and 90 mg/200g BW increased latency time, reduced joint swelling, and reduced IL-1β levels in the serum in the osteoarthritis rat model. Conclusion70 % ethanol extract of Arcangelisia flava (L.) Merr. Has the potential to be an anti-osteoarthritis drug.

Skin anti-aging and wound healing effects of a passion fruit seed extract rich in piceatannol

BACKGROUND: UVB radiation triggers skin photoaging by inducing excess cellular oxidants, contributing to senescence, and overproducing matrix metalloproteinase-1 (MMP-1), causing skin wrinkles. Senescence also impedes skin wound closure. Passion fruit seeds (PFS) boast abundant piceatannol (PCT), recognized for its antioxidant and anti-aging properties. OBJECTIVE: To study potential of PFS extract in diminishing photoaging, accelerating wound healing, and enhancing SIRT1 production in human keratinocytes (HaCaT cells). METHODS: The PFS extract was assessed for PCT using HPLC analysis. The antioxidant effects, reduced senescence-associated β-galactosidase (SA-β-gal) activity, and MMP-1 production were measured in HaCaT cells exposed to UVB using a DCFA-DA assay, SA-β-gal activity, and flow cytometry/immunofluorescent including MMP-1 mRNA expression, respectively. The effect of wound healing acceleration was evaluated, including EGFR mRNA expression. Additionally, SIRT1 enhancement was investigated using flow cytometry and immunofluorescent techniques, which also included the assessment of SIRT1 mRNA expression. RESULTS: The PFS extract, which is rich in PCT, effectively diminished cellular oxidants and aging. It decreased UVB-induced cellular oxidants, senescence, and MMP-1 production at both protein and mRNA levels. Moreover, the extract enhanced wound closure by boosting cell migration and increasing EGFR mRNA expression. Additionally, SIRT1 production and expression, associated with cellular rejuvenation, increased in extract-treated cells. CONCLUSIONS: PFS extract exhibits potential for skincare and wound healing applications, offering a natural strategy to combat skin aging effects and support tissue repair.

Effects of rice fermentation and its bioactive components on UVA-induced oxidative stress and senescence in dermal fibroblasts.

Photoaging, caused by ultraviolet (UV) radiation, is characterized by the senescence of skin cells and reduction of collagens. Although rice fermentation is widely used in the cosmetics, its impact on skin photoaging is still not well understood. Herein, we investigated the possible effectiveness of Maifuyin, a fermented rice product, and its components, succinic acid (SA), and choline, for safeguarding UVA-exposed human dermal fibroblasts (HDFs) against photoaging. In this study, the effects of Maifuyin, SA, and choline on UVA-induced cell death and senescence in fibroblasts were evaluated in cell counting kit-8 (CCK-8), expression of β-galactosidase (β-GAL), and matrix metalloproteinases (MMP)-1. To identify oxidative stress, the investigation focused on reactive oxygen species, glutathione, superoxide dismutase, and malondialdehyde. Additionally, a mRNA sequencing technology (RNA-seq) was applied to study the underlying mechanisms of these components on UVA-induced photoaging. Meanwhile, the level of C-X-C motif chemokine ligand 2 (CXCL2) in the cell supernatant was confirmed to assess the autocrine chemokine level. To reassess the involvement of CXCL2, the expression of β-GAL was evaluated in fibroblasts treated with or without CXCL2. The results indicated that 1 mg/mL Maifuyin and SA inhibited UVA-induced senescence in fibroblasts, MMP-1 expression, and oxidative damage. The RNA-seq revealed 1 mg/mL Maifuyin and SA might be recruited chemokine CXCLs to inhibit MMPs production and fibroblast senescence via TNFα, MAPK, and NF-κB pathways. ELISA results showed a significant reduction of autocrine CXCL2 in UVA-irradiated HDFs by pretreating Maifuyin and SA. The β-GAL staining assay revealed that CXCL2 treatment increased β-GAL activity, while the administration of Maifuyin and SA counteracted this effect in HDFs. These results highlighted the potential use of Maifuyin and SA as promising candidates for anti-photoaging applications.

Acetyl-11-keto-β-boswellic acid restrains the progression of synovitis in osteoarthritis via the Nrf2/HO-1 pathway.

Synovial inflammation plays a key role in osteoarthritis (OA) pathogenesis. Fibroblast-like synoviocytes (FLSs) represent a distinct cell subpopulation within the synovium, and their unique phenotypic alterations are considered significant contributors to inflammation and fibrotic responses. The underlying mechanism by which acetyl-11-keto-β-boswellic acid (AKBA) modulates FLS activation remains unclear. This study aims to assess the beneficial effects of AKBA through both in vitro and in vivo investigations. Network pharmacology evaluation is used to identify potential targets of AKBA in OA. We evaluate the effects of AKBA on FLSs activation in vitro and the regulatory role of AKBA on the Nrf2/HO-1 signaling pathway. ML385 (an Nrf2 inhibitor) is used to verify the binding of AKBA to its target in FLSs. We validate the in vivo efficacy of AKBA in alleviating OA using anterior cruciate ligament transection and destabilization of the medial meniscus (ACLT+DMM) in a rat model. Network pharmacological analysis reveals the potential effect of AKBA on OA. AKBA effectively attenuates lipopolysaccharide (LPS)-induced abnormal migration and invasion and the production of inflammatory mediators, matrix metalloproteinases (MMPs), and reactive oxygen species (ROS) in FLSs, contributing to the restoration of the synovial microenvironment. After treatment with ML385, the effect of AKBA on FLSs is reversed. In vivo studies demonstrate that AKBA mitigates synovial inflammation and fibrotic responses induced by ACLT+DMM in rats via activation of the Nrf2/HO-1 axis. AKBA exhibits theoretical potential for alleviating OA progression through the Nrf2/HO-1 pathway and represents a viable therapeutic candidate for this patient population.

Combination of Nicotinamide and Agastache rugosa Extract: A Potent Strategy for Protecting Hs68 Cells from UVB-Induced Photoaging.

This study investigated the protective effects of nicotinamide (NAM) and Agastache rugosa extract (AR) against ultraviolet B (UVB)-induced photoaging in Hs68 cells. The results demonstrated that NAM and AR, alone or in combination, exhibited concentration-dependent protective effects against UVB radiation. The highest synergistic effect was observed at a NAM:AR ratio of 6:4. This combination exhibited a synergistic protective effect against UVB-induced photoaging. The sample concentration required for 80% cell survival was 9.70 μM and 131.16 ppm for NAM and AR, respectively. However, when combined, they exhibited strong synergistic effects with concentrations as low as 0.11 μM and 17.50 ppm. Moreover, 5.26 μM of NAM and 1,082.13 ppm of AR were required to inhibit 30% of reactive oxygen species, but the combination treatment required 0.62 μM and 95.49 ppm, respectively. This combination significantly reduced the production of matrix metalloproteinase and increased collagen production. These findings highlight the potential of combining NAM and AR as functional cosmetic materials to protect against UVB-induced photoaging. The synergistic effects observed in this study provide valuable information for developing novel strategies for cosmetic combinations that target UVB-mediated skin damage.

NF-κB/RelA signaling in secretoglobin progenitors mediates plasticity and MMP-induced barrier disruption in house dust mite-induced allergic asthma.

The mechanisms how aeroallergens induce sensitization are incompletely understood. The house dust mite (HDM) Dermatophagoides pteronyssius (Der p) is a ubiquitous aeroallergen that represents a major cause of allergic rhinitis and asthma. Herein, we tested whether HDM-induced aeroallergen exposure sensitivity is caused by the innate-immune response in small airway epithelial cells. HDM exposure is a rapid activator of NF-κB/RelA in the Secretoglobin (Scgb1a1+) lineage associated with upregulation of NF-κB/RelA-dependent markers of epithelial plasticity. To determine the effect of epithelial NF-κB signaling, NF-κB was depleted in a tamoxifen (TMX)-inducible Scgb1a1-CreERTM mouse within a CL57B/L6 background. Corn oil or TMX-treated/RelA-depleted [RelA knockdown (KD)] mice were repetitively exposed to airway HDM challenges to induce airway hyperresponsiveness (AHR). Strikingly, we observed that HDM induces hallmarks of epithelial plasticity through upregulation of the mesenchymal core factors SNAI1 and ZEB1 and production of metalloproteinase (MMP)9 that are RelA-dependent. Downstream, HDM-induced mucous metaplasia, Th2 polarization, allergen sensitivity, and airway hyperreactivity were all reduced in the RelA-depleted mice. Mechanistically, HDM-induced functional and structural barrier disruption was dependent on RelA signaling and associated with active MMP secretion into the bronchoalveolar lavage fluid. To establish the role of MMP2/9 in barrier disruption, we observe that a small-molecule MMP inhibitor (SB-3CT) blocked HDM-induced barrier disruption and activation of plasticity in naïve wild-type (WT) mice. Loss of functional barrier was associated with MMP disruption of zona occludens (ZO)-1 containing adherens junctions. Overall, this data indicates that host innate signaling in the Scgb1a1+ progenitors is directly linked to epithelial plasticity, MMP9 secretion, and enhanced barrier permeability that allows allergen penetration, sensitization producing allergic asthma (AA) in vivo. We propose that maintenance of epithelial integrity may reduce allergic sensitization and AA.NEW & NOTEWORTHY Allergic asthma from house dust mite (HDM) allergy causes substantial morbidity. This study examines the dynamic changes in small airway epithelial cells in a mouse model of HDM exposure. Our findings indicate that NF-κB/RelA signaling mediates matrix metalloproteinase production, disrupting the epithelial barrier resulting in allergic sensitization. Our findings bring new insight into mechanisms for epithelial cell-state change in the allergen response, creating a potential therapeutic pathway for maintaining barrier function in asthma.

Investigation of multinucleation and apoptosis of macrophages of BCG-infected mice and their production of cathepsins and matrix metalloproteinases

The relevance of the study of the role of macrophages and their multinucleated forms in the pathogenesis of tuberculous granulomatosis is determined by its wide prevalence, the presence of severe socio-economic consequences of its morbidity and necrotic complications, which are based on the high destructive potential of macrophages associated with the role of hydrolases in the degradation of extracellular matrix components. Aim of the study was to investigate the features of the multinucleation, apoptosis and expression of a number of hydrolases in macrophages of BCG-infected mice. Material and methods. The intensity of macrophage multinucleation and apoptosis, the peculiarities of their expression of matrix metalloproteinases (MMP-1, MMP-9), catepsins (CatB, CatD), caspase-3, and p53 protein were studied in peritoneal cells cultures of intact and BCG-infected BALB/c mice. Results. The number of multinucleated macrophages increased according to the terms of the experiment, having a maximum value for 3 months of observation, but after 2 months almost reaching this level. The realization of apoptosis, multinucleation of macrophages had a complex character, determining the composition of their subpopulations. The dynamics of the expression of the studied hydrolases by macrophages indicated their unequal role in tissue necrosis at various stages of granulomogenesis. The high functional ability of multinucleated macrophages to produce hydrolases of certain types is shown. Intense expression of MMP-1 in the early stages of granulomogenesis and its maximum value, as well as CatD expression for 3 months, and strong expression of MMP-9 for 6 months were noted. Conclusions. Stimulation of plastic processes in macrophages under conditions of BCG-granulomatosis determines the formation of multinucleated macrophages with high functional potential and intensive expression of hydrolases by macrophages for 2 and 3 months of granulomogenesis. These are periods of high risk of necrotic complications of tuberculous granulomatosis, which should be taken into account when developing methods for their prevention and therapeutic correction.

Targeting cancer-derived extracellular vesicles by combining CD147 inhibition with tissue factor pathway inhibitor for the management of urothelial cancer cells

BackgroundExtracellular vesicles (EVs), including microvesicles, hold promise for the management of bladder urothelial carcinoma (BLCA), particularly because of their utility in identifying therapeutic targets and their diagnostic potential using easily accessible urine samples. Among the transmembrane glycoproteins highly enriched in cancer-derived EVs, tissue factor (TF) and CD147 have been implicated in promoting tumor progression. In this in vitro study, we explored a novel approach to impede cancer cell migration and metastasis by simultaneously targeting these molecules on urothelial cancer-derived EVs.MethodsCell culture supernatants from invasive and non-invasive bladder cancer cell lines and urine samples from patients with BLCA were collected. Large, microvesicle-like EVs were isolated using sequential centrifugation and characterized by electron microscopy, nanoparticle tracking analysis, and flow cytometry. The impact of urinary or cell supernatant-derived EVs on cellular phenotypes was evaluated using cell-based assays following combined treatment with a specific CD147 inhibitor alone or in combination with a tissue factor pathway inhibitor (TFPI), an endogenous anticoagulant protein that can be released by low-molecular-weight heparins.ResultsWe observed that EVs obtained from the urine samples of patients with muscle-invasive BLCA and from the aggressive bladder cancer cell line J82 exhibited higher TF activity and CD147 expression levels than did their non-invasive counterparts. The shedding of GFP-tagged CD147 into isolated vesicles demonstrated that the vesicles originated from plasma cell membranes. EVs originating from invasive cancer cells were found to trigger migration, secretion of matrix metalloproteinases (MMPs), and invasion. The same induction of MMP activity was replicated using EVs obtained from urine samples of patients with invasive BLCA. EVs derived from cancer cell clones overexpressing TF and CD147 were produced in higher quantities and exhibited a higher invasive potential than those from control cancer cells. TFPI interfered with the effect when used in conjunction with the CD147 inhibitor, further suppressing homotypic EV-induced migration, MMP production, and invasion.ConclusionsOur findings suggest that combining a CD147 inhibitor with low molecular weight heparins to induce TFPI release may be a promising therapeutic approach for urothelial cancer management. This combination can potentially suppress the tumor-promoting actions of cancer-derived microvesicle-like EVs, including collective matrix invasion.Graphical

A Model for Membrane Degradation Using a Gelatin Invadopodia Assay.

One of the most crucial and lethal characteristics of solid tumors is represented by the increased ability of cancer cells to migrate and invade other organs during the so-called metastatic spread. This is allowed thanks to the production of matrix metalloproteinases (MMPs), enzymes capable of degrading a type of collagen abundant in the basal membrane separating the epithelial tissue from the connective one. In this work, we employ a synergistic experimental and mathematical modelling approach to explore the invasion process of tumor cells. A mathematical model composed of reaction-diffusion equations describing the evolution of the tumor cells density on a gelatin substrate, MMPs enzymes concentration and the degradation of the gelatin is proposed. This is completed with a calibration strategy. We perform a sensitivity analysis and explore a parameter estimation technique both on synthetic and experimental data in order to find the optimal parameters that describe the in vitro experiments. A comparison between numerical and experimental solutions ends the work.

Ketosis prevents abdominal aortic aneurysm rupture through C–C chemokine receptor type 2 downregulation and enhanced extracellular matrix balance

Abdominal aortic aneurysms (AAAs) are prevalent with aging, and AAA rupture is associated with increased mortality. There is currently no effective medical therapy to prevent AAA rupture. The monocyte chemoattractant protein (MCP-1)/C–C chemokine receptor type 2 (CCR2) axis critically regulates AAA inflammation, matrix-metalloproteinase (MMP) production, and extracellular matrix (ECM) stability. We therefore hypothesized that a diet intervention that can modulate CCR2 axis may therapeutically impact AAA risk of rupture. Since ketone bodies (KBs) can trigger repair mechanisms in response to inflammation, we evaluated whether systemic ketosis in vivo could reduce CCR2 and AAA progression. Male Sprague–Dawley rats underwent surgical AAA formation using porcine pancreatic elastase and received daily β-aminopropionitrile to promote AAA rupture. Rats with AAAs received either a standard diet, ketogenic diet (KD), or exogenous KBs (EKB). Rats receiving KD and EKB reached a state of ketosis and had significant reduction in AAA expansion and incidence of rupture. Ketosis also led to significantly reduced aortic CCR2 content, improved MMP balance, and reduced ECM degradation. Consistent with these findings, we also observed that Ccr2−/− mice have significantly reduced AAA expansion and rupture. In summary, this study demonstrates that CCR2 is essential for AAA expansion, and that its modulation with ketosis can reduce AAA pathology. This provides an impetus for future clinical studies that will evaluate the impact of ketosis on human AAA disease.

Osmolarity-Induced Altered Intracellular Molecular Crowding Drives Osteoarthritis Pathology.

Osteoarthritis (OA) is a multifactorial degenerative joint disease of which the underlying mechanisms are yet to be fully understood. At the molecular level, multiple factors including altered signaling pathways, epigenetics, metabolic imbalance, extracellular matrix degradation, production of matrix metalloproteinases, and inflammatory cytokines, are known to play a detrimental role in OA. However, these factors do not initiate OA, but are mediators or consequences of the disease, while many other factors causing the etiology of OA are still unknown. Here, it is revealed that microenvironmental osmolarity can induce and reverse osteoarthritis-related behavior of chondrocytes via altered intracellular molecular crowding, which represents a previously unknown mechanism underlying OA pathophysiology. Decreased intracellular crowding is associated with increased sensitivity to proinflammatory triggers and decreased responsiveness to anabolic stimuli. OA-induced lowered intracellular molecular crowding could be renormalized via exposure to higher extracellular osmolarity such as those found in healthy joints, which reverse OA chondrocyte's sensitivity to catabolic stimuli as well as its glycolytic metabolism.

STAT3 ACTIVATION IN THE SYNOVIAL TISSUES FROM THE HIP JOINT IN THE EARLY STAGE OF RAPIDLY DESTRUCTIVE COXOPATHY

The interleukin-6/gp130-associated Janus Kinases/STAT3 axis is known to play an important role in mediating inflammatory signals, resulting in production of matrix metalloproteinase-3 (MMP-3). The hip joints with rapidly destructive coxopathy (RDC) demonstrate rapid chondrolysis, probably by increased production of MMP-3 observed in the early stage of RDC. In the recent study, no apparent activation of STAT3 has been shown in the synovial tissues obtained from the osteoarthritic joint at operation. However, no data are currently available on STAT3 activation in the synovial tissues in the early stage of RDC. This study aimed to elucidate STAT3 activation in the synovial tissues in the early stage of RDC. Synovial tissues within 7 months from the disease onset were obtained from four RDC patients with femoral head destruction and high serum levels of MMP-3. RDC synovial tissues showed the synovial lining hyperplasia with an increase of CD68-positive macrophages and CD3-positive T lymphocytes. STAT3 phosphorylation was found in the synovial tissues by immunohistochemistry using anti-phospho-STAT3 antibody. The majority of phospho-STAT3-positive cells were the synovial lining cells and exhibited negative expression of macrophage or T cell marker. Treatment with tofacitinib, a Janus Kinase inhibitor, resulted in a decrease in phospho-STAT3-positive cells, especially with high intensity, indicating effective suppression of STAT3 activation in RDC synovial tissues. Inhibitory effect of tofacitinib could act through the Janus Kinase/STAT3 axis in the synovial tissues in the early stage of RDC. Therefore, STAT3 may be a potential therapeutic target for prevention of joint structural damage in RDC.Acknowledgements: This study was supported by Katakami Foundation for Clinical Research.

A novel chitosan-PEG hydrogel embedded with in situ silver nanoparticles of Clerodendrum glandulosum Lindl. extract: evaluation of its in vivo diabetic wound healing properties using an image-guided machine learning model.

The pathophysiology of chronic wounds related to diabetes mellitus is a result of a series of complications induced by hyperglycemia. The symptoms include impaired growth factor production, decreased keratinocyte proliferation and migration, reduced angiogenesis and cytokine synthesis, lowered matrix metalloproteinase (MMP) production, neuropathy, reduced nitric oxide synthase production, decreased fibroblast synthesis and migration, and impaired inflammatory cell functions. This multifaceted mechanism of diabetic wounds needs a suitable novel topical formulation that can deliver the active constituent by a controlled means, target the various stages of wound healing, absorb the wound exudates, and prevent secondary infections. To meet the above requirements, the Clerodendrum glandulosum (CG) extract reduced silver nanoparticle (AgNP) impregnated chitosan-polyethylene glycol (PEG) hydrogel was synthesized. The findings of the physicochemical characterization studies suggested that the hydrogel exhibited excellent formulation characteristics and showed controlled release for seven days, making it suitable for chronic wound healing studies. In subsequent studies, these formulations showed good antioxidant and antimicrobial properties, and hemocompatibility, with the least cytotoxic properties. The results of the diabetic wound healing studies showed a faster wound closure rate and improved extracellular matrix formation. These antioxidant, antimicrobial, anti-inflammatory and wound-healing properties suggest that the CG-AgNP loaded chitosan-PEG hydrogel is a promising material for novel topical formulation of diabetic wounds.

Urolithin B reduces cartilage degeneration and alleviates osteoarthritis by inhibiting inflammation.

Osteoarthritis is the most prevalent degenerative joint disease reported worldwide. Conventional treatment strategies mainly focus on medication and involve surgical joint replacement. The use of these therapies is limited by gastrointestinal complications and the lifespan of joint prostheses. Hence, safe and efficacious drugs are urgently needed to impede the osteoarthritis progression. Urolithin B, a metabolite of ellagic acid in the gut, exhibits anti-inflammatory and antioxidant properties; however, its role in osteoarthritis remains unclear. In this study, we demonstrated that urolithin B efficiently inhibits the inflammatory factor-induced production of matrix metalloproteinases (MMP3 and MMP13) in vitro and upregulates the expression of type II collagen and aggrecan. Urolithin B alleviates cartilage erosion and osteophyte formation induced by anterior cruciate ligament transections. Moreover, urolithin B inhibits the activation of the NF-κB pathway by reducing the phosphorylation of Iκb-α and the nuclear translocation of P65. In summary, urolithin B significantly inhibits inflammation and alleviates osteoarthritis. Hence, urolithin B can be considered a potential agent suitable for the effective treatment of osteoarthritis in the future.

The protective effect of Ergolide in osteoarthritis: In vitro and in vivo studies

Osteoarthritis (OA), a prevalent degenerative condition, occurs due to the deterioration of joint tissues and cells. Consequently, safeguarding chondrocytes against damage caused by inflammation is an area of future research emphasis. There is growing evidence that Ergolide (ERG) has multiple biological functions. Nevertheless, it is still uncertain whether it can hinder the advancement of OA. In this study, we investigate the ERG's potential to reduce inflammation and protect cartilage. ERG treatment in vitro effectively inhibited the excessive production of pro-inflammatory substances, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX2), and tumor necrosis factor-α (TNF-α), leading to their complete suppression. Furthermore, ERG suppressed the production of matrix-degrading enzymes (ADAMTS-5) and matrix metalloproteinase 13 (MMP13), consequently impeding the breakdown of extracellular matrix (ECM) and restraining the synthesis of collagenase II and Aggrecan. Through the P38/MAPK pathway, we discovered that ERG hinders the activation of NF-κB in chondrocytes induced by IL-1β. The protective effect of ERG was enhanced by the p38 MAPK inhibitor SB203580. In vivo, ERG further demonstrated protective effects on cartilage in animal models of DMM. In conclusion, the study has discovered that ERG exhibits innovative therapeutic potential in the context of OA.