Increase In Collagen Type Research Articles

Integrin α2β1 deficiency enhances osteogenesis via BMP-2 signaling for accelerated fracture repair

Previous studies have shown that the absence of the collagen-binding integrin α2β1 confers protection against osteoporosis, primarily by enhancing osteoblast-mediated matrix formation, with a particular increase in collagen type I production. This study aimed to elucidate the mechanism underlying this increased matrix production. Our findings demonstrate that osteoblasts lacking integrin α2 secrete a pro-osteogenic factor that activates both TGF-β and BMP signaling pathways. Among these, BMP-2 was identified as the key signaling protein responsible for this effect, as its expression was significantly upregulated during osteoblast differentiation. Moreover, integrin α2 deficiency led to earlier and elevated BMP-2 secretion at the cell surface during osteogenesis, which promoted accelerated osteoblast differentiation. This phenomenon likely contributes to enhanced matrix production in aging animals, providing a protective effect against osteoporosis.To explore the broader implications of this phenotype, we utilized a fracture healing model. In integrin α2-deficient 12 weeks old female mice, elevated serum levels of BMP-2 were detected during the early stages of fracture repair. This upregulation of BMP signaling within the fracture callus accelerated the healing process, resulting in faster formation and mineralization of the cartilaginous callus. Additionally, the elevated BMP-2 levels facilitated earlier differentiation of chondrocytic cells, evidenced by the premature appearance of collagen type II- and type X-positive cells during endochondral ossification. Despite the accelerated healing, the overall biomechanical integrity of the repaired fractures remained uncompromised.Thus, the modulation of integrin α2β1 presents a promising therapeutic target for enhancing fracture repair by regulating BMP-2 signaling in a physiologically relevant manner.

A New Approach with Combined Microneedle and Sublative Fractional Radiofrequency for Photoaging Management: A Clinical, Histometric, and Immunohistochemical Study.

Fractional radiofrequency (FRF) has been reported to be effective in improving wrinkles. A combination of microneedle and sublative fractional radiofrequency (SFRF) may have the potential synergy to improve photoaged skin. To evaluate the efficacy and safety of combined microneedle and SFRF in photoaging management. This prospective study included 12 subjects with moderate photoaging (skin phototype III-IV). The subjects received three consecutive combined microneedle and sublative FRF at 1-month intervals. Punch biopsies were obtained before and after three months of treatment. Routine H&E, Masson-trichrome, Orcein staining, histometric measurements, as well as Collagen type I and Elastin immunohistochemical staining were performed. Significant improvement was noticed regarding skin tightening and texture (p < 0.05), rhytides, and volunteers' satisfaction (p < 0.001). Collagen fibers appeared better organized, with a significant increase in collagen type I (p = 0.001). Meanwhile, normal-appearing elastic fibers were restored, and a significant reduction in abnormal elastin was achieved (p = 0.0005). Combined microneedle and sublative FRF may provide a new therapeutic approach for photoaged skin. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Sera from Rheumatoid Arthritis Patients Induce Oxidative Stress and Pro-Angiogenic and Profibrotic Phenotypes in Human Endothelial Cells.

Background: Rheumatoid arthritis (RA) is a long-term autoimmune condition marked by persistent inflammation of the joints and various systemic complications, including endothelial dysfunction, atherosclerosis, and pulmonary fibrosis. Oxidative stress is a key contributor to the pathogenesis of RA, potentially exacerbating vascular damage and promoting pro-angiogenic and profibrotic processes. Objective: This study aims to investigate the effects of sera from RA patients on human umbilical vein endothelial cells (HUVECs), focusing on the induction of oxidative stress, endothelial cell proliferation, migration, and collagen type I synthesis. Methods: Twenty-eight serum samples were collected from RA patients and healthy donors (HDs). HUVECs were exposed to these sera, and intracellular reactive oxygen species (ROS) levels were fluorescently detected using H2DCF-DA. Cell viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell migration was evaluated through a scratch wound assay, and collagen type I synthesis was measured using a lentiviral vector expressing the green fluorescent protein (GFP) under the control of the human COL1A1 gene promoter. Results: Exposure to RA sera resulted in a significant increase in intracellular ROS levels in HUVECs compared to HD sera, indicating an elevated state of oxidative stress. RA sera also promoted endothelial cell proliferation and migration, suggesting a pro-angiogenic stimulus. Additionally, RA sera significantly increased collagen type I synthesis in HUVECs, implicating a potential role in profibrotic processes associated with RA. Conclusion: The results of this study emphasize the importance of circulating factors in RA sera in promoting oxidative stress, endothelial dysfunction, and pro-angiogenic and profibrotic phenotypes in endothelial cells. These processes may contribute to the vascular and fibrotic complications observed in RA, highlighting the necessity for additional research into focused therapeutic approaches to alleviate these effects.

Effect of Human Platelet-Rich Fibrin Lysate on Collagen Type I, Collagen Type III, and Matrix Metalloproteinase 1 : A Protocol Study on Rat Models with Pelvic Organ Prolapse

Background Pelvic organ prolapse (POP) is a prevalent condition caused by weakened pelvic floor support structures. Extracellular matrix alterations, including changes in collagen type I, collagen type III, and matrix metalloproteinase 1 (MMP-1), contribute to the pathogenesis of this condition. Human platelet-rich fibrin lysate (hPRF-L) is a novel regenerative treatment that has shown beneficial results in treating structural weaknesses related to various pelvic floor diseases, including POP. Methods This study protocol aims to investigate the effects of hPRF-L injection on collagen I, III, and MMP-1 in the vaginal mucosa of a rat POP model. POP will be induced in female Sprague-Dawley rats, which will be randomly assigned to control, sham, and hPRF-L treatment groups. The hPRF-L group will receive weekly injections of hPRF-L (25, 50, or 75 μL) into the vaginal mucosa for 4 weeks. Vaginal tissue samples will be collected, and collagen type I, collagen type III, and MMP-1 expression will be evaluated using quantitative reverse transcription polymerase chain reaction and immunohistochemical analyses. Data analysis will be performed with ANOVA and post-hoc tests. Discussion The findings from this study protocol are expected to provide valuable insights into the mechanisms by which hPRF-L impacts the structural integrity of the pelvic floor. By elucidating these mechanisms, this study aims to inform future POP treatment strategies. The anticipated results are an increase in collagen type I and III expression and a reduction in MMP-1 levels in the hPRF-L treatment group compared to the control and sham groups. These outcomes could support the use of hPRF-L as a regenerative therapy for managing POP, offering a potential alternative to more invasive surgical interventions. Conclusion The expected results will contribute to the development of less invasive treatments for POP, improving patient outcomes and quality of life.

In Vitro Wound-Healing Potential of Phenolic and Polysaccharide Extracts of Aloe vera Gel.

The present study aimed to conduct a comparative investigation of the biological properties of phenolic and polysaccharide extracts obtained using an ultrasound-assisted technique from Aloe vera gel and their effects on each stage of the wound healing process in in vitro experimental models. HPLC analysis showed that the phenolic extract contained aloin, ferulic, and caffeic acid, as well as quercetin dihydrate, as major compounds. Capillary zone electrophoresis indicated the prevalence of mannose and glucose in the polysaccharide extract. Cell culture testing revealed the anti-inflammatory properties of the phenolic extract at a concentration of 0.25 mg/mL through significant inhibition of pro-inflammatory cytokines-up to 28% TNF-α and 11% IL-8 secretion-in inflamed THP-1-derived macrophages, while a pro-inflammatory effect was observed at 0.5 mg/mL. The phenolic extract induced 18% stimulation of L929 fibroblast proliferation at a concentration of 0.5 mg/mL, enhanced the cell migration rate by 20%, and increased collagen type I synthesis by 18%. Moreover, the phenolic extract exhibited superior antioxidant properties by scavenging free DPPH (IC50 of 2.50 mg/mL) and ABTS (16.47 mM TE/g) radicals, and 46% inhibition of intracellular reactive oxygen species (ROS) production was achieved. The polysaccharide extract demonstrated a greater increase in collagen synthesis up to 25%, as well as antibacterial activity against Staphylococcus aureus with a bacteriostatic effect at 25 mg/mL and a bactericidal one at 50 mg/mL. All these findings indicate that the phenolic extract might be more beneficial in formulations intended for the initial phases of wound healing, such as inflammation and proliferation, while the polysaccharide extract could be more suitable for use during the remodeling stage. Moreover, they might be combined with other biomaterials, acting as efficient dressings with anti-inflammatory, antioxidant, and antibacterial properties for rapid recovery of chronic wounds.

Reducing Oxidative Stress Levels and Inhibiting Aging by l-Cysteine-Derived Carbon Dots with Highly Efficient Broad-Spectrum UV Absorption.

Ultraviolet (UV) exposure causes damage to human skin and mucous membranes, resulting in oxidative stress, and can also lead to inflammation of human skin, skin aging, and even diseases such as squamous cell carcinoma and melanoma of the skin. The main means of protection against UV radiation is physical shielding and the use of sunscreen products. Carbon dots as a novel nanomaterial provide a new option for UV protection. In this article, we introduced sulfhydryl groups to synthesize l-cysteine-derived carbon dots (GLCDs) with UV resistance. GLCDs exhibit high-efficiency and excellent UV absorption, achieving 200-400 nm UV absorption (99% UVC, 97% UVB, and 86% UVA) at a low concentration of 0.5 mg/mL. Meanwhile, GLCDs can reduce apoptosis and UVB-induced oxidative damage, increase collagen type I gene expression, and inhibit skin aging in zebrafish. It also inhibits senescence caused by the senescence inducer 2,2'-azobis(2-methylpropionamidine) dihydrochloride and reduces oxidative damage. The above studies show that GLCDs possess efficient broad-spectrum UV absorption, antiphotoaging, and antiaging capabilities, which will have a broad application prospect in UV protection.

Specific Knockdown of the NDUFS4 Gene Reveals Important Roles of Ferroptosis in UVB-induced Photoaging.

Ultraviolet (UV) irradiation significantly contributes to photoaging. Ferroptosis, an iron-dependent cell death mode recently identified, plays a key role in UVB-induced skin photoaging. This study examines the functions and regulatory mechanisms of ferroptosis in this regard. Characterized by increased intracellular iron and reactive oxygen species (ROS), ferroptosis is associated with mitochondrial function and structure. Through RNA sequencing, we identified NADH: ubiquinone oxidoreductase subunit S4 (NDUFS4), a gene implicated in UVB-mediated photoaging, and explored its role in ferroptosis by NDUFS4 knockdown. In vitro, inhibiting NDUFS4 reduced ferroptosis, decreased ROS and matrix metallopeptidase 1 levels, and increased collagen type I alpha 1 chain, glutathione peroxidase 4 (GPX4), ferritin heavy chain 1, and solute carrier family 7 member 11 levels, suggesting a reinforced ferroptosis protective mechanism. Additionally, NDUFS4 regulates ferroptosis via the mitogen-activated protein kinase (MAPK) pathway, with its knockdown reducing p38 and ERK phosphorylation and elevating GPX4 levels, enhancing ferroptosis resistance. Animal experiments supported these findings, demonstrating that Ferrostatin-1, a ferroptosis inhibitor, significantly mitigated UVB-induced skin photoaging and related protein expression. This study uncovers NDUFS4's novel role in regulating ferroptosis and provides new insights into ferroptosis-mediated UVB-induced skin photoaging.

Elderberry (Sambucus nigra) and hawthorn (Crataegus oxyacantha) extract additives in carboxymethyl chitosan scaffolds for osteochondral tissue engineering applications

Elderberry (<i>Sambucus nigra</i>) and hawthorn (<i>Crataegus oxyacantha</i>) extract additives in carboxymethyl chitosan scaffolds for osteochondral tissue engineering applications

Androgenic steroids induce pathologic scarring in a preclinical porcine model via dysfunctional extracellular matrix deposition.

Hypertrophic scarring is a major source of morbidity. Sex hormones are not classically considered modulators of scarring. However, based on increased frequency of hypertrophic scarring in patients on testosterone, we hypothesized that androgenic steroids induce abnormal scarring and developed a preclinical porcine model to explore these effects. Mini-swine underwent castration, received no testosterone (noT) or biweekly testosterone therapy (+T), and underwent excisional wounding. To create a delayed wound healing model, a subset of wounds were re-excised at 2 weeks. Scars from postoperative day 42 (POD42) and delayed wounds (POD28) were harvested 6 weeks after initial wounding for analysis via histology, bulk RNA-seq, and mechanical testing. Histologic analysis of scars from +T animals showed increased mean fibrosis area (16 mm2noT, 28 mm2+T; p = .007) and thickness (0.246 mm2noT, 0.406 mm2+T; p < .001) compared to noT. XX+T and XY+T scars had greater tensile burst strength (p = .024 and p = .013, respectively) compared to noT swine. Color deconvolution analysis revealed greater deposition of type I and type III collagen as well as increased collagen type I:III ratio in +T scars. Dermatopathologist histology scoring showed that +T exposure was associated with worse overall scarring (p < .05). Gene ontology analysis found that testosterone exposure was associated with upregulation of cellular metabolism and immune response gene sets, while testosterone upregulated pathways related to keratinization and laminin formation on pathway analysis. In conclusion, we developed a preclinical porcine model to study the effects of the sex hormone testosterone on scarring. Testosterone induces increased scar tissue deposition and appears to increase physical strength of scars via supraphysiologic deposition of collagen and other ECM factors. The increased burst strength seen in both XX and XY animals suggests that hormone administration has a strong influence on scar mechanical properties independent of chromosomal sex. Anti-androgen topical therapies may be a promising future area of research.

Gums as Macromolecular Crowding Agents in Human Skin Fibroblast Cultures.

Even though tissue-engineered medicines are under intense academic, clinical, and commercial investigation, only a handful of products have been commercialised, primarily due to the costs associated with their prolonged manufacturing. While macromolecular crowding has been shown to enhance and accelerate extracellular matrix deposition in eukaryotic cell culture, possibly offering a solution in this procrastinating tissue-engineered medicine development, there is still no widely accepted macromolecular crowding agent. With these in mind, we herein assessed the potential of gum Arabic, gum gellan, gum karaya, and gum xanthan as macromolecular crowding agents in WS1 skin fibroblast cultures (no macromolecular crowding and carrageenan were used as a control). Dynamic light scattering analysis revealed that all macromolecules had negative charge and were polydispersed. None of the macromolecules affected basic cellular function. At day 7 (the longest time point assessed), gel electrophoresis analysis revealed that all macromolecules significantly increased collagen type I deposition in comparison to the non-macromolecular crowding group. Also at day 7, immunofluorescence analysis revealed that carrageenan; the 50 µg/mL, 75 µg/mL, and 100 µg/mL gum gellan; and the 500 µg/mL and 1000 µg/mL gum xanthan significantly increased both collagen type I and collagen type III deposition and only carrageenan significantly increased collagen type V deposition, all in comparison to the non-macromolecular crowding group at the respective time point. This preliminary study demonstrates the potential of gums as macromolecular crowding agents, but more detailed biological studies are needed to fully exploit their potential in the development of tissue-engineered medicines.

Effects of VX765 on osteoarthritis and chondrocyte inflammation in rats

To investigate the effects and underlying mechanisms of VX765 on osteoarthritis (OA) and chondrocytes inflammation in rats. Chondrocytes were isolated from the knee joints of 4-week-old Sprague Dawley (SD) rats. The third-generation cells were subjected to cell counting kit 8 (CCK-8) analysis to assess the impact of various concentrations (0, 1, 5, 10, 20, 50, 100 μmol/L) of VX765 on rat chondrocyte activity. An in vitro lipopolysaccharide (LPS) induced cell inflammation model was employed, dividing cells into control group, LPS group, VX765 concentration 1 group and VX765 concentration 2 group without obvious cytotoxicity. Western blot, real-time fluorescence quantitative PCR, and ELISA were conducted to measure the expression levels of inflammatory factors-transforming growth factor β 1 (TGF-β 1), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Additionally, Western blot and immunofluorescence staining were employed to assess the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1). Thirty-two SD rats were randomly assigned to sham surgery group (group A), OA group (group B), OA+VX765 (50 mg/kg) group (group C), and OA+VX765 (100 mg/kg) group (group D), with 8 rats in each group. Group A underwent a sham operation with a medial incision, while groups B to D underwent additional transverse incisions to the medial collateral ligament and anterior cruciate ligament, with removal of the medial meniscus. One week post-surgery, groups C and D were orally administered 50 mg/kg and 100 mg/kg VX765, respectively, while groups A and B received an equivalent volume of saline. Histopathological examination using HE and safranin-fast green staining was performed, and Mankin scoring was utilized for evaluation. Immunohistochemical staining technique was employed to analyze the expressions of matrix metalloproteinase 13 (MMP-13) and collagen type Ⅱ. The CCK-8 assay indicated a significant decrease in cell viability at VX765 concentrations exceeding 10 μmol/L ( P<0.05), so 4 μmol/L and 8 μmol/L VX765 without obvious cytotoxicity were selected for subsequent experiments. Following LPS induction, the expressions of TGF-β 1, IL-6, and TNF-α in cells significantly increased when compared with the control group ( P<0.05). However, intervention with 4 μmol/L and 8 μmol/L VX765 led to a significant decrease in expression compared to the LPS group ( P<0.05). Western blot and immunofluorescence staining demonstrated a significant upregulation of Nrf2 pathway-related molecules Nrf2 and HO-1 protein expressions by VX765 ( P<0.05), indicating Nrf2 pathway activation. Histopathological examination of rat knee joint tissues and immunohistochemical staining revealed that, compared to group B, treatment with VX765 in groups C and D improved joint structural damage in rat OA, alleviated inflammatory reactions, downregulated MMP-13 expression, and increased collagen type Ⅱ expression. VX765 can improve rat OA and reduce chondrocyte inflammation, possibly through the activation of the Nrf2 pathway.

Atrial fibrillation in human patients is associated with increased collagen type V and TGFbeta1

Background and aimAtrial fibrosis is an important factor in initiating and maintaining atrial fibrillation (AF). Collagen V belongs to fibrillar collagens. There are, however no data on collagen V in AF. The aim of this work was to study the quantity of collagen V and its relationship with the number of fibroblasts and TGF- b 1 expression in patients in sinus rhythm (SR) and in patients with atrial fibrillation (AF). MethodsWe used quantitative immuhistochemistry to study collagen V in right and left atrial biopsies obtained from 35 patients in SR, 35 patients with paroxysmal AF (pAF) and 27 patients with chronic, long-standing persistent AF (cAF). In addition, we have quantified the number of vimentin-positive fibroblasts and expression levels of TGF-β1. ResultsCompared to patients in SR, collagen V was increased 1.8- and 3.1-fold in patients with pAF and cAF, respectively. In comparison with SR patients, the number of vimentin-positive cells increased significantly 1.46- and 1.8-fold in pAF and cAF patients, respectively.Compared to SR patients, expression levels of TGF-ß1, expressed as fluorescence units per tissue area, was significantly increased by 77 % and 300 % in patients with pAF and cAF, respectively. Similar to intensity measurements, the number of TGFß1-positive cells per 1 mm2 atrial tissue increased significantly from 35.5 ± 5.5 cells in SR patients to 61.9 ± 12.4 cells in pAF and 131.5 ± 23.5 cells in cAF. In both types of measurements, there was a statistically significant difference between pAF and cAF groups. ConclusionsThis is the first study to show that AF is associated with increased expression levels of collagen V and TGF-ß1indicating its role in the pathogenesis of atrial fibrosis. In addition, increases in collagen V correlate with increased number of fibroblasts and TGF-β1 and are more pronounced in cAF patients than those in pAF patients.

LncRNA SNHG8 upregulates MUC5B to induce idiopathic pulmonary fibrosis progression by targeting miR-4701-5p

Long noncoding RNAs (lncRNAs) play a critical role in idiopathic pulmonary fibrosis (IPF); however, the underlying molecular mechanisms are unclear. Our study demonstrated that lncRNA small nucleolar RNA host gene 8 (SNHG8) was increased in bleomycin (BLM)-induced A549 cells. LncRNA SNHG8 overexpression further elevated fibrosis-related factors monocyte chemotactic protein 1 (MCP1), CC motif chemokine ligand 18 (CCL18), and α-smooth muscle actin (α-SMA), as well as increased collagen type I alpha-1 chain (COL1A1) and collagen type III alpha-1 chain (COL3A1). Meanwhile, lncRNA SNHG8 knockdown exhibited an opposite role in reducing BLM-induced pulmonary fibrosis. With regard to the mechanism, SNHG8 was then revealed to act as a competing endogenous RNA (ceRNA) for microRNA (miR)-4701-5p in regulating Mucin 5B (MUC5B) expression. Furthermore, the interactions between SNHG8 and miR-4701-5p, between miR-4701-5p and MUC5B, and between SNHG8 and MUC5B on the influence of fibrosis-related indicators were confirmed, respectively. In addition, SNHG8 overexpression enhanced the levels of transforming growth factor (TGF)-β1 and phosphorylation Smad2/3 (p-Smad2/3), which was suppressed by SNHG8 knockdown in BLM-induced A549 cells. Moreover, miR-4701-5p inhibitor-induced elevation of TGF-β1 and p-Smad2/3 was significantly suppressed by SNHG8 knockdown. In conclusion, SNHG8 knockdown attenuated pulmonary fibrosis progression by regulating miR-4701-5p/MUC5B axis, which might be associated with the modulation of TGF-β1/Smad2/3 signaling. These findings reveal that lncRNA SNHG8 may become a potential target for the treatment of IPF.

Impact of interstitial flow on cartilage matrix synthesis and NF-kB transcription factor mRNA expression in a novel perfusion bioreactor.

This work is focused on designing an easy-to-use novel perfusion system for articular cartilage (AC) tissue engineering and using it to elucidate the mechanism by which interstitial shear upregulates matrix synthesis by articular chondrocytes (AChs). Porous chitosan-agarose (CHAG) scaffolds were synthesized and compared to bulk agarose (AG) scaffolds. Both scaffolds were seeded with osteoarthritic human AChs and cultured in a novel perfusion system with a medium flow velocity of 0.33 mm/s corresponding to 0.4 mPa surfice shear and 40 mPa CHAG interstitial shear. While there were no statistical differences in cell viability for perfusion versus static cultures for either scaffold type, CHAG scaffolds exhibited a 3.3-fold higher (p < 0.005) cell viability compared to AG scaffold cultures. Effects of combined superficial and interstitial perfusion for CHAG showed 150- and 45-fold (p < 0.0001) increases in total collagen (COL) and 13- and 2.2-fold (p < 0.001) increases in glycosaminoglycans (GAGs) over AG non-perfusion and perfusion cultures, respectively, and a 1.5-fold and 3.6-fold (p < 0.005) increase over non-perfusion CHAG cultures. Contrasting CHAG perfusion and static cultures, chondrogenic gene comparisons showed a 3.5-fold increase in collagen type II/type I (COL2A1/COL1A1) mRNA ratio (p < 0.05), and a 1.3-fold increase in aggrecan mRNA. Observed effects are linked to NF-κB signal transduction pathway inhibition as confirmed by a 3.2-fold (p < 0.05) reduction of NF-κB mRNA expression upon exposure to perfusion. Our results demonstrate that pores play a critical role in improving cell viability and that interstitial flow caused by medium perfusion through the porous scaffolds enhances the expression of chondrogenic genes and extracellular matrix through downregulating NF-κB1.

Molecular Phenotyping and Mechanisms of Myocardial Fibrosis in Advanced Chronic Kidney Disease.

Myocardial fibrosis is a major life-limiting problem in chronic kidney disease (CKD). Despite this, the molecular phenotype and metabolism of collagen fibrillogenesis in fibrotic hearts of patients with advanced CKD have been largely unstudied. We analyzed explanted human left ventricular (LV) heart tissues in a 3-arm cross-sectional cohort study of deceased donor patients on hemodialysis (HD, n=18), hypertension with preserved renal function (HTN, n=8), and healthy controls (CON, n=17), ex vivo. RNA-seq and protein analysis was performed on human donor hearts and cardiac fibroblasts treated with mineral stressors (high phosphate and high calcium). Further mechanistic studies were performed using primary cardiac fibroblasts, in vitro treated with mineral stressors, pro-inflammatory and pro-fibrotic cytokines. Of the 43 donor participants, there was no difference in age (P>0.2), sex (P>0.8), or body mass index (P>0.1) between the groups. Hearts from the HD group had extensive fibrosis (P<0.01). All LV tissues expressed only the trimeric form of collagen type I. HD hearts expressed increased collagen type I (P<0.03), elevated collagen type I:III ratio (P<0.05), and decreased MMP1 (P<0.05) and MMP2 (P<0.05). RNA-seq revealed no significant differential gene expression of extracellular matrix proteins of interest in HD hearts, but there was significant upregulation of LH2, periostin, α-SMA, and TGF-β1 gene expression in mineral stressor-treated cardiac fibroblasts. Both mineral stressors (P<0.009) and cytokines (P<0.03) increased collagen type I:III ratio. Mineral stressors induced trimeric collagen type I, but cytokine treatment induced only dimeric collagen type I in cardiac fibroblasts. Mineral stressors downregulated fibronectin (P<0.03) and MMP2 zymogen (P<0.01) but did not significantly affect expression of periostin, MMP1, or cross-linking enzymes. TGF-β upregulated fibronectin (P<0.01) and periostin (P<0.02) only. Myocardial fibrosis in advanced CKD hearts is characterized by increased trimeric collagen type I and dysregulated collagen metabolism, and is differentially regulated by components of uremia.

Empagliflozin decreases ageing-associated arterial stiffening and vascular fibrosis under normoglycemic conditions

Arterial stiffness is a hallmark of vascular ageing and results in increased blood flow pulsatility to the periphery, damaging end-organs such as the heart, kidneys and brain. Treating or “reversing” arterial stiffness has therefore become a central target in the field of vascular ageing. SGLT2 inhibitors, initially developed in the context of type 2 diabetes mellitus, have become a cornerstone of heart failure treatment. Additionally, effects on the vasculature have been reported. Here, we demonstrate that treatment with the SGLT2 inhibitor empagliflozin (7 weeks, 15 mg/kg/day) decreased ageing-induced arterial stiffness of the aorta in old mice with normal blood glucose levels. However, no universal mechanism was identified. While empagliflozin reduced the ageing-associated increase in collagen type I in the medial layer of the abdominal infrarenal aorta and decreased medial TGF-β deposition, this was not observed in the thoracic descending aorta. Moreover, empagliflozin was not able to prevent elastin fragmentation. In conclusion, empagliflozin decreased arterial stiffness in aged mice, indicating that SGLT2 inhibition could be a valuable strategy in mitigating vascular ageing. Further research is warranted to unravel the underlying, possibly region-specific, mechanisms.

Low-oxygen tension augments chondrocyte sensitivity to biomimetic thermomechanical cues in cartilage-engineered constructs

Chondrocytes respond to various biophysical cues, including oxygen tension, transient thermal signals, and mechanical stimuli. However, understanding how these factors interact to establish a unique regulatory microenvironment for chondrocyte function remains unclear. Herein, we explore these interactions using a joint-simulating bioreactor that independently controls the culture's oxygen concentration, evolution of temperature, and mechanical loading. Our analysis revealed significant coupling between these signals, resulting in a remarkable ∼14-fold increase in collagen type II (COL2a) and aggrecan (ACAN) mRNA expression. Furthermore, dynamic thermomechanical stimulation enhanced glycosaminoglycan and COL2a protein synthesis, with the magnitude of the biosynthetic changes being oxygen dependent. Additionally, our mechanistic study highlighted the crucial role of SRY-box transcription factor 9 (SOX9) as a major regulator of chondrogenic response, specifically expressed in response to combined biophysical signals. These findings illuminate the integration of various mechanobiological cues by chondrocytes and provide valuable insights for improving the extracellular matrix content in cartilage-engineered constructs.

Adverse effects of copper, manganese and mercury, alone and in mixtures on the aorta and heart of Spraque-Dawley rats.

Cardiovascular diseases (CVD) are a common global cause of death and are therefore a major health concern. Inhaled or ingested environmental heavy metals contribute to the development of CVD. The aim of this study was to address the limited information available on the effect of relevant dosages of metals in mixtures. Three metals with reported effects on the cardiovascular system (CVS) were identified, and these metals were copper (Cu), manganese (Mn) and mercury (Hg). In Sprague-Dawley rats, the adverse effects of copper (Cu), manganese (Mn) and mercury (Hg), alone and as part of mixtures, on the blood parameters, the aorta and heart were investigated. Forty-eight male Sprague-Dawley rats were randomly divided into eight groups (n = 6): control, Cu, Mn, Hg, Cu + Mn, Cu + Hg, Mn + Hg and Cu, Mn + Hg. The seven experimental groups received the metal mixtures at 100 times the World Health Organisation (WHO) safety limit for drinking water (2mg/L for Cu, 0.4mg/L for Mn and 0.06mg/L for Hg) via oral gavage for 28days. After 28days, compared with the control, red blood cell levels were increased for Cu + Hg. All other measured blood parameters were unchanged. Morphological changes in the tunica media were connective tissue deposition and an abundance of collagen type I in the metal exposed aortic tissues. In the cardiac tissue of metal-exposed rats, changes in the cardiomyocyte and myofibrillar arrangement, with an increase in collagen type I and III was observed. Ultrastructurally, the aortic collagen and elastin band arrangement and the cardiac mitochondrial and myofibrillar arrangement and structures were altered in the experimental groups. These changes indicated that exposure to these metals in rats caused minor changes in the blood parameters, however, the changes in tissue and cellular structure indicated an increased risk for the development of CVD.

Smoking induces increased apoptosis in osteoblasts: changes in bone matrix organic components

Clinical studies demonstrate the impact of smoking on bone tissue fragility and higher incidence of fractures. However, it is not totally understood which physiological mechanisms could be involved in these events. Previously, we showed important changes in bone tissue components in experimental model of cigarette smoke (CS) exposure. CS exposure induces worsening in bone mineralization and a decrease in collagen type I deposition, leading to bone fragility. Considering that the majority of clinical studies described bone structural changes by radiographic images, in this study we performed analyses “in situ” using tissue samples from smokers, former smokers and non-smokers to better understand how the increase in inflammatory mediators induced by smoking exposure could interfere in bone cells activity leading bone structural changes. We observed increased levels of IL-1β, IL-6 and TNF-α in bone tissue homogenates with a concomitant increase in osteoblast apoptosis in smokers and former smokers compared with non-smokers. Histological changes in both smokers and former smokers were characterized by reduction in collagen type I. Only in smokers, it was observed decrease in trabecular area, suggesting increased bone resorption and increase in collagen type V. These results showed that osteoblasts apoptosis in association with increased bone resorption leads bone structural changes in smokers.

The Formulation of the N-Acetylglucosamine as Nanoparticles Increases Its Anti-Inflammatory Activities: An In Vitro Study

Nanomedicine can represent a new strategy to treat several types of diseases such as those with inflammatory aetiology. Through this strategy, it is possible to obtain nanoparticles with controlled shape, size, and eventually surface charge. Moreover, the use of molecules in nanoform may allow more effective delivery into the diseased cells and tissues, reducing toxicity and side effects of the used compounds. The aim of the present manuscript was the evaluation of the effects of N-acetylglucosamine in nanoform (GlcNAc NP) in an in vitro model of osteoarthritis (OA). Human primary chondrocytes were treated with Tumor Necrosis Factor (TNF)-α to simulate a low-grade inflammation and then treated with both GlcNAc and GlcNAc NP, in order to find the lowest concentrations able to counteract the inflammatory state of the cells and ensure a chondroprotective action. The findings showed that GlcNAc NP was able to decrease the pro-inflammatory mediators, IL-6 and IL-8, which are among the main effectors of inflammation; moreover, the nanoparticles downregulated the production of metalloprotease enzymes. GlcNAc NP was effective at a very low concentration compared to GlcNAc in its native form. Furthermore, GlcNAc NP stimulated an increase in collagen type II synthesis. In conclusion, the GlcNAc in nanoform showed better performance than GlcNAc, at concentrations lower than those reached in the joints after oral administration to patients of 1.5 g/die of glucosamine.