Collagen Density Research Articles

Healing of diabetic ulcers using jamaican cherry leaf extract cream (Muntingia calabura l.) based on collagen density in white rats (Rattus norvegicus)

Abstract This research aims to determine the potential of jamaican cherry leaf extract cream (JCLEC) to accelerate the healing process of diabetic ulcers in white rat based on collagen density. The research used 4 month old male white rats (Rattus norvegicus) which were divided into K0 (negative control), KP (silver sulfadiazine), K1 (5% JCLEC), K2 (10% JCLEC), and K3 (15% JCLEC). An incision was made on the back of the rat then given JCLEC. Days 3, 7, and 14 after treatment, the wound tissue was collected after the rat were euthanized. Skin tissue was processed and stained with picrosirious red. The rate of wound healing was observed. Collagen density was presented in scoring. Based on the treatment group and observation time, there was a significant difference in collagen density between the treatment groups compared to the control (P<0.05). Based on the treatment group, the scoring of the collagen density was 1.78±0.6 (K0); 2.56±0.88 (KP); 1.78±0.4 (K1); 2.56±0.88 (K2); and 3.1±0.78 (K3). Based on observation time, the average collagen density scoring was 1.8±0.3 (D-3); 2.6±0.4 (D-7); and 2.8±0.6 (D-14). The conclusion is the 15% JCLEC has the potential to accelerate the healing of diabetic ulcers in white rats by stimulate collagen density.

Collagen density regulates tip-stalk cell rearrangement during angiogenesis via cellular bioenergetics.

Tumor vasculature plays a crucial role in tumor progression, affecting nutrition and oxygen transportation as well as the efficiency of drug delivery. While targeting pro-angiogenic growth factors has been a significant focus for treating tumor angiogenesis, recent studies indicate that metabolism also plays a role in regulating endothelial cell behavior. Like cancer cells, tumor endothelial cells undergo metabolic changes that regulate rearrangement for tip cell position during angiogenesis. Our previous studies have shown that altered mechanical properties of the collagen matrix regulate angiogenesis and can promote a tumor vasculature phenotype. Here, we examine the effect of collagen density on endothelial cell tip-stalk cell rearrangement and cellular energetics during angiogenic sprouting. We find that increased collagen density leads to an elevated energy state and an increased rate of tip-stalk cell switching, which is correlated with the energy state of the cells. Tip cells exhibit higher glucose uptake than stalk cells, and inhibition of glucose uptake revealed that invading sprouts rely on glucose to meet elevated energy requirements for invasion in dense matrices. This work helps to elucidate the complex interplay between the mechanical microenvironment and the endothelial cell metabolic status during angiogenesis, which could have important implications for developing new anti-cancer therapies.

Dental Pulp Vascular Response to Early Stages of Caries

ObjectivesDuring caries progression, dental pulp is increasingly pathologically affected. Since the accurate assessment of pulp is of vital importance in clinical decision-making, this study aimed to evaluate pulpal condition in the early stages of caries via laser Doppler (LD) flowmetry and histologic analysis and determine their agreement. MethodsFourteen patients with severe dental crowding were included. Prior to extractions and orthodontic treatment, dental pulp condition of 52 premolars was evaluated via LD flowmetry. Teeth were assessed for the presence of caries and lesions were graded according to the International Caries Detection and Assessment System (ICDAS). After extractions, teeth were split and histologically stained for endothelial cells with anti–von Willebrand factor and Movat pentachrome for collagen. Volume densities of vessels (Vvasc) and collagen were calculated. ResultsThere was a significant negative correlation between LD flow and Vvasc of the dental pulp with ICDAS grade. Pulpal LD flow and Vvasc in teeth with the initial lesion were increased, decreasing with progressing stages of caries. A significant positive correlation between the the pulpal LD flow and Vvasc, and a negative correlation of LD flow with collagen fibre density were noted. ConclusionsCaries affects the physiology of the dental pulp, initially with increasing vascularity, and decreasing vascularity at later stges of caries progression. Collagen contents increase with grades of ICDAS. LD flow shows good agreement with the histologic constitution of the dental pulp. Use of clinical measurements of pulpal LD flow could provide a good noninvasive indication of pulpal vascular state and its health.

Mitochondrial metabolism blockade nanoadjuvant reversed immune-resistance microenvironment to sensitize albumin-bound paclitaxel-based chemo-immunotherapy

Currently, the efficacy of albumin-bound paclitaxel (PTX@Alb) is still limited due to the impaired PTX@Alb accumulation in tumors partly mediated by the dense collagen distribution. Meanwhile, acquired immune resistance always occurs due to the enhanced programmed cell death-ligand 1 (PD-L1) expression after PTX@Alb treatment, which then leads to immune tolerance. To fill these gaps, we newly revealed that tamoxifen (TAM), a clinically widely used adjuvant therapy for breast cancer with mitochondrial metabolism blockade capacity, could also be used as a novel effective PD-L1 and TGF-β dual-inhibitor via inducing the phosphorylation of adenosine 5ʹ-monophosphate-activated protein kinase (AMPK) protein. Following this, to obtain a more significant effect, TPP-TAM was prepared by conjugating mitochondria-targeted triphenylphosphine (TPP) with TAM, which then further self-assembled with albumin (Alb) to form TPP-TAM@Alb nanoparticles. By doing this, TPP-TAM@Alb nanoparticles effectively decreased the expression of collagen in vitro, which then led to the enhanced accumulation of PTX@Alb in 4T1 tumors. Besides, TPP-TAM@Alb also effectively decreased the expression of PD-L1 and TGF-β in tumors to better sensitize PTX@Alb-mediated chemo-immunotherapy by enhancing T cell infiltration. All in all, we newly put forward a novel mitochondrial metabolism blockade strategy to inhibit PTX@Alb-resistant tumors, further supporting its better clinical application.

Tunnel technique and subepithelial connective tissue graft, with or without cross-linked hyaluronic acid, in the treatment of multiple gingival recessions: 12-month outcomes of a randomized clinical trial.

This study evaluated the influence of the adjunctive application of a cross-linked hyaluronic acid (HA) in the treatment of multiple gingival recessions, using a modified coronally advanced tunnel (MCAT) technique and subepithelial connective tissue graft (SCTG) (MCAT+SCTG±HA). A randomized, split-mouth, double-masked comparison of the effects of MCAT+HA+SCTG (test) versus MCAT+SCTG (control) in the treatment of multiple, contralateral gingival recessions with clinical, esthetic, and histological evaluations was carried out. All samples were stained with hematoxylin and eosin, Masson's trichrome, Verhoeff-Van Gieson, and Alcian blue stain for semiquantitative evaluation. The primary outcome variable was 12-month mean root coverage (MRC). Twenty-four patients with 266 gingival recessions received both control and test treatments (133 recessions per group). 12-month MRC of the MCAT+HA+SCTG group was not significantly different from the MCAT+SCTG group with 84.32%±34.46% and 85.71%±36.43%, respectively (p=0.991). Both treatment modes produced favorable esthetic outcomes (root coverage esthetic score [RES] 9.51±1.01 tests vs. 9.26±1.10 controls, p=0.7292). However, the application of HA improved soft tissue texture (p=0.0091). The remaining end point measures did not differ significantly between groups. Histological evaluation showed a significantly greater number of elastic fibers and a moderate increase in collagen fiber density in biopsy samples taken from the test sides when compared to the control sides (p=0.0419 and p=0.300, respectively). MCAT+SCTG is an effective procedure in the treatment of multiple recession Type 1 (RT1) and RT2 recessions. There were no statistically significant differences in evaluated clinical treatment outcomes in the MCAT+HA+SCTG group compared to the MCAT+SCTG group within a period of 12 months. The application of HA increased collagen and elastic fiber density.

Contactless mechanical stimulation of the skin using shear waves

The skin, the outermost organ of the human body, is vital for sensing and responding to stimuli through mechanotransduction. It is constantly exposed to mechanical stress. Consequently, various mechanical therapies, including compression, massage, and microneedling, have become routine practices for skin healing and regeneration. However, these traditional methods require direct skin contact, restricting their applicability. To address this constraint, we developed shear wave stimulation (SWS), a contactless mechanical stimulation technique. The effectiveness of SWS was compared with that of a commercial compression bioreactor used on reconstructed skin at various stages of maturity. Despite the distinct stimulus conditions applied by the two methods, SWS yielded remarkable outcomes, similar to the effects of the compression bioreactor. It significantly increased the shear modulus of tissue-engineered skin, heightened the density of collagen and elastin fibers, and resulted in an augmentation of fibroblasts in terms of their number and length. Notably, SWS exhibited diverse effects in the low- and high-frequency modes, highlighting the importance of fine-tuning the stimulus intensity. These results unequivocally demonstrated the capability of SWS to enhance the mechanical functions of the skin in vitro, making it a promising option for addressing wound healing and stretch mark recovery.

An Assessment of Administration Route on MSC-sEV Therapeutic Efficacy.

Mesenchymal stem/stromal cell-derived small extracellular vesicles (MSC-sEVs) are promising therapeutic agents. In this study, we investigated how the administration route of MSC-sEVs affects their therapeutic efficacy in a mouse model of bleomycin (BLM)-induced skin scleroderma (SSc). We evaluated the impact of topical (TOP), subcutaneous (SC), and intraperitoneal (IP) administration of MSC-sEVs on dermal fibrosis, collagen density, and thickness. All three routes of administration significantly reduced BLM-induced fibrosis in the skin, as determined by Masson's Trichrome staining. However, only TOP administration reduced BLM-induced dermal collagen density, with no effect on dermal thickness observed for all administration routes. Moreover, SC, but not TOP or IP administration, increased anti-inflammatory profibrotic CD163+ M2 macrophages. These findings indicate that the administration route influences the therapeutic efficacy of MSC-sEVs in alleviating dermal fibrosis, with TOP administration being the most effective, and this efficacy is not mediated by M2 macrophages. Since both TOP and SC administration target the skin, the difference in their efficacy likely stems from variations in MSC-sEV delivery in the skin. Fluorescence-labelled TOP, but not SC MSC-sEVs when applied to skin explant cultures, localized in the stratum corneum. Hence, the superior efficacy of TOP over SC MSC-sEVs could be attributed to this localization. A comparison of the proteomes of stratum corneum and MSC-sEVs revealed the presence of >100 common proteins. Most of these proteins, such as filaggrin, were known to be crucial for maintaining skin barrier function against irritants and toxins, thereby mitigating inflammation-induced fibrosis. Therefore, the superior efficacy of TOP MSC-sEVs over SC and IP MSC-sEVs against SSc is mediated by the delivery of proteins to the stratum corneum to reinforce the skin barrier.

Histological evaluation of decellularization of freeze dried and chemically treated indigenously prepared bovine pericardium membrane.

Decellularization is regarded as a xenogenic antigen-reduction technique because it effectively eliminates all cellular and nuclear components while mitigating any negative impact on the composition, biological functionality, and structural integrity of the remaining extracellular matrix. This study aimed to histologically evaluate native, freeze dried and chemically decellularized bovine pericardium membrane. Also, this study focused on preservation of extracellular matrix after decellularization. Bovine pericardium membrane was decellularized by freeze thaw cycle followed by freeze drying and 1% sodium dodecyl sulphate. Unprocessed pericardium was used as control. The effectiveness of Decellularization was assessed based on the reduction of histologically visible nuclei. Decellularization by freeze thaw cycle followed by freeze drying resulted in 17.84% reduction in nuclei content and decellularization by sodium dodecyl sulphate results in 92% reduction in nuclei content compare to control group. Picrosirius red staining for freeze dried group displayed loosely organised, thin collagen bundles that exhibit reddish-yellow birefringence and sodium dodecyl sulfate group revealed dense collagen bundles that are parallelly organised and compact, exhibiting reddish-yellow birefringence and showed good structural integrity. These results suggested that the sodium do decyl sulfate showed optimal decellularization results with better extracellular matrix preservation. It may be a suitable protocol for producing a suitable scaffold for periodontal tissue regeneration.

Comparative Study of Collagen Density, Fibroblast, and Neovascularization in Tracheal Defect Reconstruction with Primary Repair and External Oblique Muscle Aponeurosis Patch (A Novel Study with New Zealand Rabbit)

Background: The lack of ideal materials and the high incidence of complications make tracheal defect reconstruction challenging. The use of aponeurosis as a surgical patch and flap in reconstruction is not uncommon, but no studies had been conducted to analyse its use in tracheal defect reconstruction, though its effectivity in wound healing was significant in reconstruction of other organs. Objective: This study aims to compare collagen density, fibroblast expression, and neovascularization in tracheal defect reconstruction using primary suture and using external oblique muscle aponeurosis patch. Methods: This randomized control trial is a laboratory experimental study using male New Zealand white rabbits. Randomization was carried out with permuted block randomization into a control group (primary suture) and a treatment group (reconstruction with external oblique muscle aponeurosis patch). Mascroscopic and histopathological assessments were carried out 14 days after surgery. Results: We got homogeneous samples in both groups (9 samples each) in terms of age (p = 0.763), weight before procedure (p = 0.347), and weight after procedure (p = 0.536). Macroscopically, no wound dehiscence, pus, or inflammation at the surgical site in either the control or treatment groups. Histopathological analysis showed that there were no differences in collagen density (p = 1.00), fibroblast expression (p = 0.414), and neovascularization (p = 0.558) between the two groups. Conclusion: It can be concluded that there are no differences in collagen density, fibroblast expression, and neovascularization in New Zealand rabbits with tracheal defect using primary suture and using external oblique muscle aponeurosis patch

DYNAMIC CHANGES IN HISTOLOGICAL AND MORPHOMETRIC INDICATORS OF THE LUNGS IN SEXUALLY IMMATURE RATS DURING SIMULATION OF PARTIAL TRACHEAL STENOSIS

Introduction. The morphological features of the respiratory system in laryngomalacia remain insufficiently understood, particularly regarding structural, cytological, and functional alterations. The aim of this study is to investigate the morphological characteristics of the respiratory compartment in the lungs of sexually immature rats, conduct a morphometric assessment of lung tissue density, analyze the dynamics of erythrocyte mass and collagen accumulation, and identify correlations between these parameters. Materials and Methods: The study involved sexually immature male Wistar rats aged 25-28 days and weighing 40-55 g. Partial tracheal stenosis was induced in experimental animals using a developed method, restricting the tracheal lumen by 20-25%. The stenosis was maintained for 7 and 21 days in different groups. In one group, tracheal stenosis was relieved after 7 days by removing the compressive ligature. Histological, histochemical, and morphometric methods were employed to study changes in lung tissue. Results. Pathological changes in lung tissue during hypoxia were characterized by an increase in the number of different types of cells and erythrocyte mass, especially on the 21st day of the experiment and the removal of ligatures from the trachea in experimental animals. Disturbances in the microcirculation of the lung acini were manifested by a sharp increase in blood filling of the microvessels and expansion of their lumen. In this case, the process of erythrocyte penetration into the lumen of the alveoli was sometimes noted. The results of histochemical detection of collagen indicate that in the lung tissue of experimental animals there is no activation of fibrogenetic processes, which would be accompanied by a simultaneous increase in the specific density of collagen. Indicators characterizing the lung tissue (number of cells, their specific density) made it possible to evaluate the corresponding correlations. At the same time, they were not associated with the level of collagen or erythrocyte density in the studied loci of the respiratory system of experimental sexually immature rats. A significant increase in the specific density of erythrocyte mass in lung tissue did not depend on the duration of the experiment. Removal of the ligature and restoration of the tracheal lumen did not significantly affect the restoration of alveolar acini and the spectrum of identified cells. In addition, an increase in the specific density of lung tissue was observed. Conclusion. The findings of this study contribute to deeper understanding of lung damage in children with laryngomalacia and associated respiratory system ventilation impairment. The observed reactive changes in lung connective tissue and collagen synthesis during hypoxia do not necessarily indicate the development of respiratory system fibrosis. However, longer exposure to hypoxic conditions may increase the risk of fibrosis in children.

Quantifying in vivo collagen reorganization during immunotherapy in murine melanoma with second harmonic generation imaging.

Increased collagen linearization and deposition during tumorigenesis can impede immune cell infiltration and lead to tumor metastasis. Although melanoma is well studied in immunotherapy research, studies that quantify collagen changes during melanoma progression and treatment are lacking. We aim to image in vivo collagen in preclinical melanoma models during immunotherapy and quantify the collagen phenotype in treated and control mice. Second-harmonic generation imaging of collagen was performed in mouse melanoma tumors in vivo over a treatment time course. Animals were treated with a curative radiation and immunotherapy combination. Collagen morphology was quantified over time at an image and single-fiber level using CurveAlign and CT-FIRE software. In immunotherapy-treated mice, collagen was reorganized toward a healthy phenotype, including shorter, wider, curlier collagen fibers, with modestly higher collagen density. Temporally, collagen fiber straightness and length changed late in treatment (days 9 and 12), while width and density changed early (day 6) compared with control mice. Single-fiber collagen features calculated in CT-FIRE were the most sensitive to the changes among treatment groups compared with bulk collagen features. Quantitative second-harmonic generation imaging can provide insight into collagen dynamics in vivo during immunotherapy, with key implications in improving immunotherapy response in melanoma and other cancers.

IDENTIFICATION OF HEALTHY AND TENDINOPATHIC CELL SUBTYPES IN FOOT AND ANKLE TENDONS USING SINGLE-CELL TRANSCRIPTOMICS

Tendinopathy can commonly occur around the foot and ankle resulting in isolated rupture, debilitating pain and degenerative foot deformity. The pathophysiology and key cells involved are not fully understood. This is partly because the dense collagen matrix that surrounds relatively few resident cells limits the ability of previous techniques to identify and target those cells of interest. In this study, we apply novel single cell RNA sequencing (CITE-Seq) techniques to healthy and tendinopathic foot/ankle tendons. For the first time we have identified multiple sub-populations of cells in human tendons. These findings challenge the view that there is a single principal tendon cell type and open new avenues for further study. Healthy tendon samples were obtained from patients undergoing tendon transfer procedures; including tibialis posterior and FHL. Diseased tendon samples were obtained during debridement of intractable Achilles and peroneal tendinopathy, and during fusion of degenerative joints. Single cell RNA sequencing with surface proteomic analysis identified 10 sub-populations of human tendon derived cells. These included groups expressing genes associated with fibro-adipogenic progenitors (FAPs) as well as ITGA7+VCAM1- recently described in mouse muscle but, as yet, not human tendon. In addition we have identified previously unrecognised sub-classes of collagen type 1 associated tendon cells. Each sub-class expresses a different set of extra-cellular matrix genes suggesting they each play a unique role in maintaining the structural integrity of normal tendon. Diseased tendon harboured a greater proportion of macrophages and cytotoxic lymphocytes than healthy tendon. This inflammatory response is potentially driven by resident tendon fibroblasts which show increased expression of pro-inflammatory cytokines. Finally, identification of a previously unknown sub-population of cells found predominantly in tendinopathic tissue offers new insight into the underlying pathophysiology. Further work aims to identify novel proteins targets for possible therapeutic pathways.

FACTORS INFLUENCING POST-CIRCUMCISION WOUND HEALING

Objective: This study aims to determine the effect of the penile gland and smegma smear, the expression of collagen and fibroblasts in the preputium, on post-circumcision wound healing. Material & Methods: A cross-sectional study conducted in Malang with samples obtained by purposive sampling on September 17, 2022. Inclusive criteria were uncircumcised males who agreed to be circumcised and had no contraindications to the procedure. Furthermore, the preputium obtained from the circumcision procedure was stained with Hematoxylin-Eosin (HE) and counted under an optical microscope. Post-circumcision evaluation was carried out seven days after the procedure. The data were analyzed using the regression method; p denotes the probability value or significance level, while the b score denotes the degree of influence. Results: There were total of 31 research samples that had a significant difference in the average age between the samples with post-circumcision complaints (11.25 ± 2.75) and those without complaints (8.5 ± 2.73) (p=0.05). The regression test found that bacterial culture, fibroblasts, and collagen had significant effects of 24%, 25%, and 24%, respectively. Conclusions: Skin elasticity decreases with age, as marked by increased fibroblasts and decreased collagen density. Fibroblast factors, collagen, and bacterial culture are significant in wound healing. Keywords: Circumcision, collagen, fibroblast, wound healing.

Polyphyllin I Mitigated IL-1β-Induced Chondrocytes Damage through Downregulating TWIST1 Expression.

Osteoarthritis (OA) is a chronic joint disease characterized by the degradation of articular cartilage. Polyphyllin I (PPI) has anti-inflammatory effects in many diseases. However, the mechanism of PPI in OA remains unclear. <P> </P> Methods: HC-a cells treated with IL-1β were identified by immunofluorescence staining and microscopic observation. The expression of collagen II and DAPI in HC-a cells was detected by immunofluorescence. The effects of gradient concentration of PPI on IL-1β-induced cell viability, apoptosis, senescence, and inflammatory factor release were detected by MTT, flow cytometry, SA-β-Gal assay and ELISA, respectively. Expressions of apoptosis-related genes, extracellular matrix (ECM)- related genes, and TWIST1 were determined by qRT-PCR and western blot as needed. The above-mentioned experiments were conducted again after TWIST1 overexpression in IL-1β-induced chondrocytes. <P> </P> Results: IL-1β reduced the number of chondrocytes and the density of collagen II. PPI (0.25, 0.5, 1 µmol/L) had no effect on cell viability, but it dose-dependently elevated the inhibition of cell viability regulated by IL-1β. The elevation of cell apoptosis, senescence and expression of IL-6 and TNF-α were suppressed by PPI in a dosedependent manner. Additionally, PPI reduced the expression of cleaved caspase-3, bax, MMP-3, and MMP-13 and promoted the expression of collagen II. TWIST1 expression was diminished by PPI. TWIST1 overexpression reversed the abovementioned effects of PPI on chondrocytes. <P> </P> Conclusion: PPI suppressed apoptosis, senescence, inflammation, and ECM degradation of OA chondrocytes by downregulating the expression of TWIST1.

Paris polyphylla Sm. characterized extract infused ointment accelerates diabetic wound healing in In-vivo model

Ethnopharmacological relevanceThe dried rhizome of Paris polyphylla Sm. is extensively used by traditional healers in India, China, and Vietnam to treat skin inflammation, cut wounds, uterine and traumatic bleeding, and cancer. Aim of the studyThe traditional use of P. polyphylla rhizomes for treating wounds and bleeding has been reported previously. However, the potential of P. polyphylla in the treatment of diabetic wounds has not yet been explored. Our present study focused on the investigation of the wound-healing activity of P. polyphylla infused ointment in streptozotocin (STZ)-induced diabetic rats to validate the traditional claim. Materials and methodsHydroalcoholic extract of the dried rhizomes of P. polyphylla were quantified by validated and optimized HPTLC (High-performance thin layer chromatography) method for Paris saponin VII, Dioscin and Polyphyllin V. The extract was used to prepare P. polyphylla ointments (5 and 10%). P. polyphylla ointment was subjected to physiochemical analysis and skin irritation test. Thirty STZ-induced diabetic adult male Wistar albino rats were divided into five groups (n = 6) and a circular excision wound was created. P. polyphylla ointment, ointment base (OB), and standard (STD) (Povidone Iodine 10%) were administered topically. The wound area of all groups were recorded every six days and compared with that of control. The epithelization period of each group was recorded. On day 18, the histopathological study of skin tissues of all groups was performed using hematoxylin and eosin (H&E) and Mallory's trichrome (MT). ResultsMarker analysis and quantification of phytomolecules in hydroalcoholic extract ofP. Polyphylla were found to be of paris saponin VII (3.28 ± 0.08% w/w), dioscin (1.94 ± 0.12% w/w), and polyphyllin V (1.87 ± 0.84% w/w). A physiochemical study of P. polyphylla ointment showed that the prepared ointment was within an acceptable range and was not irritable to the skin. Daily topical administration of 10% P. polyphylla ointment (PP10) for 18 days completely healed the STZ-induced diabetic wounds. On day 18, the 5% P. polyphylla ointment (PP5) showed 99.1 ± 2.9% wound closure, while that of the standard and control was 78.4 ± 7.3% and 18.5 ± 5.9%, respectively. The epithelialization period of PP10 was 18 days, whereas that of the control was 28 days. Histopathological analysis of the progression of PP10 and PP5 wounds showed a decrease in inflammatory cells, regenerated epithelial layer, keratosis layer, hair follicles, fibroblasts, and collagen. Upon collagen intensity quantification of MT stained sections, an increase in collagen density of PP10 and PP5 treated groups was observed, showing accelerated wound healing potential of P. polyphylla extract in diabetic wounds compared to the standard ointment. ConclusionThis study suggested the potential of P. polyphylla rhizomes derived formulation to treat diabetic wounds, although the plant is traditionally used to treat normal wounds. The results indicate the validation of traditional claim, which has been explored commercially in industrial aspect.

Assessment of the association of myofibroblasts and structural components of the extracellular matrix with histopathological parameters of actinic cheilitis and lower lip squamous cell carcinoma.

To evaluate the presence of myofibroblasts (MFs) in the development of lip carcinogenesis, through the correlation of clinical, histomorphometric and immunohistochemical parameters, in actinic cheilitis (ACs) and lower lip squamous cell carcinomas (LLSCCs). Samples of ACs, LLSCCs, and control group (CG) were prepared by tissue microarray (TMA) for immunohistochemical TGF-β, α-SMA, and Ki-67 and histochemical hematoxylin and eosin, picrosirius red, and verhoeff van gieson reactions. Clinical and microscopic data were associated using the Mann-Whitney, Kruskal-Wallis/Dunn, and Spearman correlation tests (SPSS, p < 0.05). ACs showed higher number of α-SMA+ MFs when compared to CG (p = 0.034), and these cells were associated with the vertical expansion of solar elastosis (SE) itself (p = 0.027). Areas of SE had lower deposits of collagen (p < 0.001), immunostaining for TGF-β (p < 0.001), and higher density of elastic fibers (p < 0.05) when compared to areas without SE. A positive correlation was observed between high-risk epithelial dysplasia (ED) and the proximity of SE to the dysplastic epithelium (p = 0.027). LLSCCs showed a higher number of α-SMA+ MFs about CG (p = 0.034), as well as a reduction in the deposition of total collagen (p = 0.009) in relation to ACs and CG. There was also a negative correlation between the amount of α-SMA+ cells and the accumulation of total collagen (p = 0.041). Collagen and elastic density loss was higher in larger tumors (p = 0.045) with nodal invasion (p = 0.047). Our findings show the possible role of MFs, collagen fibers, and elastosis areas in the lip carcinogenesis process.

Exercise in Chronic Kidney Disease Patients Does Not Significantly Alter Fibrosis in Quadriceps Muscle

Background: Chronic kidney disease (CKD) is commonly associated with decreased physical activity and muscle dysfunction. Muscles in CKD become fibrotic, containing excess extracellular matrix (ECM), particularly collagen. Collagen is cross-linked in the ECM, and increased cross-linking is often associated with fibrosis, stiffness, and reduced ECM remodeling. However, it is not known how exercise in patients with CKD may impact the extent of collagen cross-linking or fibrosis. Additionally, muscle fibrosis may impair muscle adaptations to exercise including, fiber size, fiber type, or vasculature. We predicted that collagen content and cross-linking would decrease, and there would be more Type I fibers and larger fiber size in the patients that were in the exercise group. Methods: Participants were randomized to exercise (n=15) or no exercise (n=5) groups in the Exercise Study Testing Enhanced Energetics of Mitochondria (ESTEEM) clinical trial of non-dialysis patients with CKD. The exercise program consisted of 35 min sessions, 3 times a week for 12 weeks consisting of high-intensity interval training, strength training, and power walking. Vastus lateralis biopsies were obtained before and after the 12 weeks of exercise. A bundle of muscle tissue was powdered and separated into a pepsin soluble and insoluble fraction before applying a hydroxyproline assay for collagen content, with the insoluble fraction representing more cross-linked collagen. For histological analysis 10 μm thick cryosections were stained with Picrosirius Red, or immunofluorescent stains to investigate satellite cells, vasculature, fibro-adipogenic progenitors (FAPs), and muscle fiber types. Picrosirius red sections were imaged under polarized light to look at birefringence as a measure of collagen density. Sections that were stained for fiber type and vasculature were analyzed using semi-automatic muscle analysis using segmentation of histology (SMASH). Results: The overall amount of collagen and collagen cross-linking were not altered in either the exercise or no exercise groups. Picrosirius red stained sections did not reveal a change in ECM area or collagen packing density with exercise. Surprisingly minimum ferret diameter and percentage of type I (slow twitch) fibers decreased in most patients that underwent the exercise program. Type I and type IIa (fast oxidative) fiber size also significantly decreased, while there was no change in type IIx (fast glycolytic) fiber size. Conclusion: This study shows that exercise does not dramatically reduce ECM content or muscle fibrosis in patients with CKD. Surprisingly, the response to exercise was opposite of that anticipated in healthy subject with exercise in CKD producing smaller muscle fibers and a shift away from more oxidative type I fibers. This shows that exercise may have limited capacity to enhance function in CKD muscle, potentially due to irreversible fibrosis. Work supported by mitochondrial bioenergetics in persons with chronic kidney disease (NIH R03DK114502). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Alginate‐Coated Silicone Implants with Antisolvent‐Crystallized Paclitaxel to Prevent Breast Cancer Recurrence and Reduce Fibrosis

AbstractBreast cancer patients undergoing mastectomy receive silicone‐implant‐based breast reconstruction to mitigate the psychological distress of breast loss, typically in conjunction with adjuvant therapy. However, significant problems remain, such as systemic toxicity from chemotherapy and fibrosis that causes capsular contracture. Here, the development of a silicone implant coated with an alginate gel containing antisolvent‐crystallized paclitaxel (acPTX) is reported. By antisolvent crystallization, the compact formulation of acPTX ensures slow release for long‐term breast cancer recurrence prevention. The mixture of acPTX and the biodegradable alginate gel, which reduces fibrosis, is uniformly coated onto the silicone implant using 3D printed implant‐specific molds based on the shape obtained from 3D scanning. In a breast cancer recurrence mouse model, silicone implants coated with acPTX gel show a long‐term preventive effect compared to gel‐coated implants with commercially available PTX. Furthermore, animal studies using C57BL/6 mice show that alginate‐gel‐coated implants significantly reduce capsule thickness, collagen density, and the number of fibrosis‐related cells around the implant compared to silicone implants. The developed acPTX‐gel‐coated implant presents a promising approach for breast reconstruction in mastectomized breast cancer patients. It provides a novel platform for developing implants with long‐term drug release properties.

Collagen and elastic fibers assessment of the human heart valves for age estimation in Thais using image analysis.

The study investigated the relationship between the histological compositions of the tricuspid, pulmonary, mitral, and aortic valves, and age. All 85 fresh human hearts were obtained with an age range between 20 and 90years. The central area of the valves was conducted to analyze the density of collagen and elastic fibers by using an image analysis program. Neural network function in MATLAB was used for classification data and accuracy test of the age predictive model. Overall, a gradual increase in the density of collagen and elastic fibers was demonstrated with age in all valve types. The pulmonary valve cusps had the least density of collagen and elastic contents, whereas the most dense of collagen was found in the mitral leaflets. A similarity was noted for the elastic fibers in the tricuspid, mitral, and aortic valves. The highest correlation between the collagen (r = 0.629) and elastic fibers (r = 0.713) and age was found in the noncoronary cusp of the aortic valve. The established predictive equations using collagen and elastic fibers in the noncoronary cusp provided the standard error of ± 14.0 and 12.5years, respectively. A 60.9% of accuracy was found in all age groups using collagen, while accuracy in elastic fibers showed 70.0% in the classification process using the neural networks. The current study provided additional data regarding age-associated changes of collagen and elastic fibers in the human heart valves in Thais and the benefits and application in age forensic identification.

Combined dasatinib and quercetin treatment contributes to skin rejuvenation through selective elimination of senescent cells in vitro and in vivo.

The skin's protective functions are compromised over time by both endogenous and exogenous aging. Senescence is well-documented in skin phenotypes, such as wrinkling and sagging, a consequence of the senescence-associated secretory phenotype (SASP) that involves the accumulation of senescent fibroblasts, chronic inflammation, and collagen remodeling. Although therapeutic approaches for eliminating senescent cells from the skin are available, their efficacy remains unclear. Accordingly, we aimed to examine the effects of dasatinib in combination with quercetin (D + Q) on senescent human skin fibroblasts and aging human skin. Senescence was induced in human dermal fibroblasts (HDFs) using approaches such as long-term passaging, ionizing radiation, and doxorubicin treatment. The generated senescent cells were treated with D + Q or vehicle. Additionally, a mouse-human chimera model was generated by subcutaneously transplanting whole-skin grafts of aged individuals onto nude mice. Mouse models were administered D + Q or vehicle by oral gavage for 30 days. Subsequently, skin samples were harvested and stained for senescence-associated beta-galactosidase. Senescence-associated markers were assessed by western blotting, reverse transcription-quantitative PCR and histological analyses. Herein, D + Q selectively eliminated senescent HDFs in all cellular models of induced senescence. Additionally, D + Q-treated aged human skin grafts exhibited increased collagen density and suppression of the SASP compared with control grafts. No adverse events were observed during the study period. Collectively, D + Q could ameliorate skin aging through selective elimination of senescent dermal fibroblasts and suppression of the SASP. Our findings suggest that D + Q could be developed as an effective therapeutic approach for combating skin aging.