Corneal stromal structure replicating humanized hydrogel patch for sutureless repair of deep anterior-corneal defect.

A critical shortage of donor corneas exists worldwide. Hydrogel patches with a biological architecture and functions that simulate those of native corneas have garnered considerable attention. This study introduces a stromal structure replicating corneal patch (SRCP) composed of a decellularized cornea-templated nanotubular skeleton, recombinant human collagen, and methacrylated gelatin, exhibiting a similar ultrastructure and transmittance (above 80 %) to natural cornea. The SRCP is superior to the conventional recombinant human collagen patch in terms of biomechanical properties and resistance to enzymatic degradation. Additionally, SRCP promotes corneal epithelial and stromal cell migration while preventing the trans-differentiation of stromal cells into myofibroblasts. When applied to an ocular surface (37 °C), SRCP releases methacrylated gelatin, which robustly binds SRCP to the corneal stroma after activation by 405 nm light. Compared to gelatin-based photocurable hydrogel, the SRCP better supports the restoration of normal corneal curvature and withstands deformation under an elevated intraocular pressure (100 mmHg). In an in vivo deep anterior-corneal defect model, SRCP facilitated epithelial healing and vision recovery within 2 weeks, maintained graft structural stability, and inhibited stromal scarring at 4 weeks post-operation. The ideal performance of the SRCP makes it a promising humanized corneal equivalent for sutureless clinical applications.

Reconstruction of traumatic tibial nerve defect with two parallel conduit strands: a case report.

We herein report a case of traumatic tibial nerve defect involving the ankle joint. A 16-mm-long defect was observed in a 5-mm-diameter tibial nerve. Two 3-mm-inner-diameter PGA-collagen tubes were transferred to the bifurcated tibial nerve. Satisfactory recovery was achieved at 3 year and 9 months postoperatively.

Geometric characteristics of stromal collagen fibres in breast cancer using differential interference contrast microscopy.

Breast cancer (BC) is characterised by a high level of heterogeneity, which is influenced by the interaction of neoplastic cells with the tumour microenvironment. The diagnostic and prognostic role of the tumour stroma in BC remains to be defined. Differential interference contrast (DIC) microscopy is a label-free imaging technique well suited to visualise weak optical phase objects such as cells and tissue. This study aims to compare stromal collagen fibre characteristics between in situ and invasive breast tumours using DIC microscopy and investigate the prognostic value of collagen parameters in BC. A tissue microarray was generated from 200 cases, comprising ductal carcinoma in situ (DCIS; n = 100) and invasive tumours (n = 100) with an extra 50 (25 invasive BC and 25 DCIS) cases for validation was utilised. Two sections per case were used: one stained with haematoxylin and eosin (H&E) stain for histological review and one unstained for examination using DIC microscopy. Collagen fibre parameters including orientation angle, fibre alignment, fibre density, fibre width, fibre length and fibre straightness were measured. Collagen fibre density was higher in the stroma of invasive BC (161.68 ± 11.2 fibre/µm2) compared to DCIS (p < 0.0001). The collagen fibres were thinner (13.78 ± 1.08 µm), straighter (0.96 ± 0.006, on a scale of 0-1), more disorganised (95.07° ± 11.39°) and less aligned (0.20 ± 0.09, on a 0-1 scale) in the invasive BC compared to DCIS (all p < 0.0001). A model considering these features was developed that could distinguish between DCIS and invasive tumours with 94% accuracy. There were strong correlations between fibre characteristics and clinicopathological parameters in both groups. A statistically significant association between fibre characteristics and patients' outcomes (breast cancer specific survival, and recurrence free survival) was observed in the invasive group but not in DCIS. Although invasive BC and DCIS were both associated with stromal reaction, the structural features of collagen fibres were significantly different in the two disease stages. Analysis of the stroma fibre characteristics in the preoperative core biopsy specimen may help to differentiate pure DCIS from those associated with invasion.

The influence of radiation-induced collagen chain fragmentation, crosslinking, and sequential irradiation on the high-cycle fatigue life of human cortical bone.

Both high-cycle fatigue life and fatigue crack propagation resistance of human cortical bone allograft are radiation dose-dependent between 0 and 25 kGy such that higher doses exhibit progressively shorter lifetimes. Recently, we have shown that collagen chain fragmentation and stable crosslink accumulation may contribute to the radiation dose-dependent loss in fatigue crack propagation resistance of human cortical bone. To our knowledge, the influence of these mechanisms on high-cycle fatigue life of cortical bone have not been established. Sequential irradiation has also been shown to mitigate the loss of fatigue life of tendons, however, whether this mitigates losses in fatigue life of cortical bone has not been explored. Our objectives were to evaluate the influence of radiation-induced collagen chain fragmentation and crosslinking on the high-cycle fatigue life of cortical bone in the dose range of 0-15 kGy, and to evaluate the capability of sequential irradiation at 15 kGy to mitigate the loss of high-cycle fatigue life and radiation-induced collagen damage. High-cycle fatigue life specimens from four male donor femoral pairs were divided into 5 treatment groups (0 kGy, 5 kGy, 10 kGy, 15 kGy, and 15 kGy sequentially irradiated) and subjected to high-cycle fatigue life testing with a custom rotating-bending apparatus at a cyclic stress of 35 MPa. Following fatigue testing, collagen was isolated from fatigue specimens, and collagen chain fragmentation and crosslink accumulation were quantified using SDS-PAGE and a fluorometric assay, respectively. Both collagen chain fragmentation (p = 0.006) and non-enzymatic crosslinking (p < 0.001) influenced high-cycle fatigue life, which decreased with increasing radiation dose from 0 to 15 kGy (p = 0.016). Sequential irradiation at 15 kGy did not offer any mitigation in high-cycle fatigue life (p = 0.93), collagen chain fragmentation (p = 0.99), or non-enzymatic crosslinking (p ≥ 0.10) compared to a single radiation dose of 15 kGy. Taken together with our previous findings on the influence of collagen damage on fatigue crack propagation resistance, collagen chain fragmentation and crosslink accumulation both contribute to radiation-induced losses in notched and unnotched fatigue life of cortical bone. To maximize the functional lifetime of radiation sterilized structural cortical bone allografts, pathways other than sequential radiation should be explored to mitigate collagen matrix damage.

The impact of collagen membrane fixation protocols on volume stability in horizontal ridge augmentation in the aesthetic area: A retrospective study.

OBJECTIVES: This study aimed to evaluate the impact of different collagen membran fixation protocols on the volume stability in horizontal ridge augmentation in the aesthetic area. METHODS: A total of 48 patients with 65 augmented sites were included in this study. Implants were placed in the aesthetic region, and simultaneous guided bone regeneration (GBR) surgery was performed for horizontal ridge augmentation. Participants were divided into four groups, each comprising 12 patients, based on different absorbable collagen membrane fixation protocols. Group 1: without fixation; Group 2: fixation with absorbable sutures; Group 3: fixation with titanium pins; Group 4: fixation with titanium pins and absorbable sutures. Cone beam computed tomography (CBCT) was performed immediately after surgery and at 6 months post-surgery, respectively. The horizontal thickness of the augmented region was analyzed for volume stability at the implant shoulder (H0) and 1-5 mm apical to the implant shoulder (H1-H5). Changes in labial thickness during bone healing were calculated as absolute values (mm) and relative values (%). RESULTS: After 6 months of bone healing, horizontal thickness was significantly reduced at all levels (H0-H5) in all groups compared to immediate post-surgery results (p < 0.05). At H1-H5, horizontal bone loss in group 1 was significantly higher than in the other three groups (p < 0.05). Group 4 exhibited significantly less horizontal bone loss compared to group 2 at H0-H2 (p < 0.05) and group 4 compared to group 3 at H0-H1 (p < 0.05). No significant difference in horizontal bone loss between groups 2 and 3 was detected at H0-H5 (p > 0.05). CONCLUSION: Guided bone regeneration in the aesthetic area with additional membrane fixation demonstrated superior volume stability of the augmented region compared to cases without fixation. There was no significant difference in bone volume stability between membrane fixation with titanium pins and fixation with absorbable sutures. However, the combined use of pins and absorbable sutures yielded superior volume stability.

Excessive collagen fiber deposition in idiopathic scrotal calcinosis: a case report.

BACKGROUND: Idiopathic scrotal calcinosis (ISC) is a manifestation of idiopathic calcinosis cutis, and its etiology is still unknown. CASE PRESENTATION: We report a 36-year-old patient manifested multiple gradually increasing yellowish-white scrotal nodules with occasional itching and stinging in the past 6 years and was successfully cured via surgical excision. The laboratory test combined with pathological analysis confirmed the diagnosis of ISC. Like pathological calcinosis in other soft tissues, a large amount of collagen fiber deposition was observed around the calcification nodule, suggesting that abnormal collagen fiber deposition might be an important factor leading to idiopathic calcinosis in the scrotum. Moreover, koilocytes, which indicate human papillomavirus (HPV) infection, were also detected around calcified nodules, indicating the potential pathogenic role of HPV infection in ISC. CONCLUSIONS: Here, we report that ISC shows abnormal excessive deposition of collagen fibers around calcified nodules, which may be a vital factor contributing to the disease. Furthermore, combined with the literature review, a new pathogenic mechanism of ISC is proposed, and the site specificity of scrotal calcinosis is explained, providing a basis for further exploration of the pathogenic mechanism of ISC.

Machine learning-assisted mid-infrared spectrochemical fibrillar collagen imaging in clinical tissues.

Significance: Label-free multimodal imaging methods that can provide complementary structural and chemical information from the same sample are critical for comprehensive tissue analyses. These methods are specifically needed to study the complex tumor-microenvironment where fibrillar collagen's architectural changes are associated with cancer progression. To address this need, we present a multimodal computational imaging method where mid-infrared spectral imaging (MIRSI) is employed with second harmonic generation (SHG) microscopy to identify fibrillar collagen in biological tissues. Aim: To demonstrate a multimodal approach where a morphology-specific contrast mechanism guides an MIRSI method to detect fibrillar collagen based on its chemical signatures. Approach: We trained a supervised machine learning (ML) model using SHG images as ground truth collagen labels to classify fibrillar collagen in biological tissues based on their mid-infrared hyperspectral images. Five human pancreatic tissue samples (sizes are in the order of millimeters) were imaged by both MIRSI and SHG microscopes. In total, 2.8 million MIRSI spectra were used to train a random forest (RF) model. The other 68 million spectra were used to validate the collagen images generated by the RF-MIRSI model in terms of collagen segmentation, orientation, and alignment. Results: Compared with the SHG ground truth, the generated RF-MIRSI collagen images achieved a high average boundary F -score (0.8 at 4-pixel thresholds) in the collagen distribution, high correlation (Pearson's R 0.82) in the collagen orientation, and similarly high correlation (Pearson's R 0.66) in the collagen alignment. Conclusions: We showed the potential of ML-aided label-free mid-infrared hyperspectral imaging for collagen fiber and tumor microenvironment analysis in tumor pathology samples.

Escherichia coli induced matrix metalloproteinase-9 activity and type IV collagen degradation is regulated by progesterone in human maternal decidual.

BACKGROUND: Escherichia coli (E. coli) is one of the main bacteria associated with preterm premature rupture of membranes by increasing pro-matrix metalloproteinase 9 (proMMP-9) and degradation of type IV collagen in human feto-maternal interface (HFMi). proMMP-9 is regulated by progesterone (P4) but it is unclear whether P4 inhibits proMMP in human maternal decidual (MDec). This study aimed to determine a role of P4 on proMMP-2 and - 9 and type IV collagen induced by E. coli infection in MDec. METHODS: Nine HFMi were mounted in a Transwell system. MDec was stimulated with P4 or E. coli for 3-, 6-, or 24-hours. proMMP-2, -9 and type IV collagen were assessed. RESULTS: Gelatin zymography revealed an increase in proMMP-9 after 3, 6, and 24 h of stimulating MDec with E. coli. Using immunofluorescence, it was confirmed the increase in the HFMi tissue and a reduction on the amount of type IV collagen leading to the separation of fetal amniochorion and MDEc. The degradative activity of proMMP-9 was reduced by 20% by coincubation with P4. CONCLUSIONS: P4 modulates the activity of proMMP-9 induced by E. coli stimulation but it was unable to completely reverse the degradation of type IV collagen in human MDec tissue.

The major vault protein integrates adhesion-driven signals to regulate collagen remodeling.

DDR1 interacts with fibrillar collagen and can affect ß1 integrin-dependent signaling, but the mechanism that mediates functional interactions between these two different receptors is not defined. We searched for molecules that link DDR1 and ß1 integrin-dependent signaling in response to collagen binding. The activation of DDR1 by binding to fibrillar collagen reduced by 5-fold, ß1 integrin-dependent ERK phosphorylation that leads to MMP1 expression. In contrast, pharmacological inhibition of DDR1 or culturing cells on fibronectin restored ERK phosphorylation and MMP1 expression mediated by the ß1 integrin. A phospho-site screen indicated that collagen-induced DDR1 activation inhibited ß1 integrin-dependent ERK signaling by regulating autophosphorylation of focal adhesion kinase (FAK). Immunoprecipitation, mass spectrometry, and protein-protein interaction mapping showed that while DDR1 and FAK do not interact directly, the major vault protein (MVP) binds DDR1 and FAK depending on the substrate. MVP associated with DDR1 in cells expressing ß1 integrin that were cultured on collagen. Knockdown of MVP restored ERK activation and MMP1 expression in DDR1-expressing cells cultured on collagen. Immunostaining of invasive cancers in human colon showed colocalization of DDR1 with MVP. These data indicate that MVP interactions with DDR1 and FAK contribute to the regulation of ß1 integrin-dependent signaling pathways that drive collagen degradation.

The collagen-augmented chondrogenesis technique demonstrates superior cartilage repair compared to microfracture for cartilage defects of the knee joint, regardless of age.

PURPOSE: This study investigated whether age affects clinical outcomes and cartilage repair quality in patients who underwent collagen-augmented chondrogenesis. METHODS: The study included patients who underwent either the collagen-augmented chondrogenesis technique or microfracture for cartilage defects of the knee joint of International Cartilage Repair Society grade 3 or 4. Patients were categorised according to an age threshold of 50 years and the treatment method, whether collagen-augmented chondrogenesis technique or microfracture. Group 1 comprised 31 patients aged 50 years or older who received the collagen-augmented chondrogenesis technique, Group 2 consisted of 32 patients under the age of 50 years who received the collagen-augmented chondrogenesis technique and Group 3 included 243 patients aged 50 years or older who received microfracture. Clinical outcomes were assessed using the walking visual analogue scale (VAS) for pain and the Western Ontario McMaster University Osteoarthritis Index scale score (WOMAC) two years after surgery. For patients with magnetic resonance imaging results 1 year postoperatively (Group 1: 30 patients; Group 2: 31 patients; and Group 3: 31 patients), Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) assessment was used to evaluate repaired cartilage lesions. RESULTS: There were no significant differences in the VAS and WOMAC scores between the three groups 2 years after surgery (all n.s.). The MOCART score in patients who underwent MRI at 1 year postoperatively showed significant differences in the degree of defect repair, integration with the border zone, surface of the repaired tissue, adhesion and total score among the three groups (all p < 0.05). Post hoc analysis revealed no difference in the total MOCART scores between Groups 1 and 2. However, Groups 1 and 2 had significantly higher MOCART scores than Group 3 1 year after surgery (all p < 0.05). CONCLUSION: The collagen-augmented chondrogenesis technique group showed improved quality of cartilage repair compared to the microfracture group, regardless of patient age. Compared with simple microfracture treatment, there were no differences in clinical outcomes between the patient groups, related to age. LEVEL OF EVIDENCE: Level Ⅲ.

Correction of Infraorbital Dark Circles Using Autologous Adipose-Derived Collagen Filler: A Novel Regenerative Option.

BACKGROUND: Numerous intrinsic and extrinsic factors, notably the aging process, contribute to the development of infraorbital dark circles. These features, commonly associated with old age and fatigue, are caused by a disruption of dermal melanin and impairment of skin barrier function. Common aesthetic concerns affecting patients with infraorbital dark circles are primarily owing to lean and translucent lower eyelid skin overlying the orbicularis oculi muscle. This study aimed to present a novel technique for correcting infraorbital dark circles utilizing an adipose-derived extracellular matrix concentrate-adipose collagen fragment (ACF)-to correct infraorbital dark circles. METHODS: Female patients (n = 94) aged 20-38 who presented infraorbital dark circles were enrolled to assess the efficacy of this technique for an eight-month follow-up. Following intradermal injections with ACF filler, the clinical outcome was determined by responses to GAIS and patient satisfaction surveys. Statistical analysis was performed with the one-way ANOVA test, and a p value of < 0.05 was considered statistically significant. RESULTS: Patients (n = 92) completed a single treatment session and underwent an eight-month follow-up. Eighty patients (86%) reported being "highly satisfied" or "satisfied" with the outcome and responded that the technique resulted in brighter, tighter, and smoother infraorbital skin. Over 97% of patients were rated as "improved," "much improved" and "Very much improved" throughout the follow-up on GAIS by three independent surgeons (p < 0.05). The statistical analyses demonstrated the percentage differences among groups are highly significant (p < 0.0001). No irregularity or lump was observed during the follow-up. Two patients were excluded from the study due to having undergone cosmetic eyelid surgery. CONCLUSION: Intradermal ACF filler represents a novel approach to addressing infraorbital dark circles and yields significantly high patient satisfaction. ACF fillers provide a degree of bio-stimulation, and adipose-derived concentrate is a natural filler with regenerative effects used in periorbital rejuvenation. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. 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 .

Evaluation of the Bone Formation Potential of Collagen/ß-TCP/Ginger Extract Scaffold Loaded with Mesenchymal Stem Cells in Rat Animal model: A Stereological Study.

Tissue engineering offers a new horizon for restoring the function of damaged tissues and organs. Here, bone regeneration potential of three-dimensional (3D) scaffold made of collagen/beta-tricalcium phosphate/ginger hydroalcoholic extract (COL-ß-TCP-GIN) loaded with stem cells was evaluated. The scaffolds with different component ratios were fabricated using a freeze dryer to obtain the optimum composition. The scaffolds' chemical, physical, and biological characteristics were evaluated using scanning electron microscope, fourier transform infrared spectroscopy, tensile testing machine, and cytotoxicity assay. The optimum scaffold's bone repairing potential was assessed with loaded synovial membrane mesenchymal stem cells (SM-MSCs) in mandibular bone defect of a rat animal model after two months. The ß-TCP component up to 30% could increase the tensile strength of the freeze-dried scaffold. In comparison, the GIN up to 5% was selected as a sufficient amount to be incorporated with the scaffolds. The morphology of scaffolds showed a suitable porosity for cells to proliferate and migrate. In vitro cytotoxicity results showed that GIN increased the cell viability up to 7 days. Regarding in vivo bone regeneration study, histopathology and stereology assessments showed the mandibular bone formation in COL/ß-TCP/GIN scaffolds with SM-MSCs group significantly increased compared to COL/ß-TCP/GIN without cells and sham groups. These results demonstrated the effectiveness of COL/ß-TCP/GIN scaffold with SM-MSCs to induce bone formation, and this composite can be applied in dental and reconstructive surgery. Supplementary Information: The online version contains supplementary material available at 10.1007/s12663-022-01829-9.

Distinct muscle regenerative capacity of human induced pluripotent stem cell-derived mesenchymal stromal cells in Ullrich congenital muscular dystrophy model mice.

BACKGROUND: Ullrich congenital muscular dystrophy (UCMD) is caused by a deficiency in type 6 collagen (COL6) due to mutations in COL6A1, COL6A2, or COL6A3. COL6 deficiency alters the extracellular matrix structure and biomechanical properties, leading to mitochondrial defects and impaired muscle regeneration. Therefore, mesenchymal stromal cells (MSCs) that secrete COL6 have attracted attention as potential therapeutic targets. Various tissue-derived MSCs exert therapeutic effects in various diseases. However, no reports have compared the effects of MSCs of different origins on UCMD pathology. METHODS: To evaluate which MSC population has the highest therapeutic efficacy for UCMD, in vivo (transplantation of MSCs to Col6a1-KO/NSG mice) and in vitro experiments (muscle stem cell [MuSCs] co-culture with MSCs) were conducted using adipose tissue-derived MSCs, bone marrow-derived MSCs, and xeno-free-induced iPSC-derived MSCs (XF-iMSCs). RESULTS: In transplantation experiments on Col6a1-KO/NSG mice, the group transplanted with XF-iMSCs showed significantly enhanced muscle fiber regeneration compared to the other groups 1 week after transplantation. At 12 weeks after transplantation, only the XF-iMSCs transplantation group showed a significantly larger muscle fiber diameter than the other groups without inducing fibrosis, which was observed in the other transplantation groups. Similarly, in co-culture experiments, XF-iMSCs were found to more effectively promote the fusion and differentiation of MuSCs derived from Col6a1-KO/NSG mice than the other primary MSCs investigated in this study. Additionally, in vitro knockdown and supplementation experiments suggested that the IGF2 secreted by XF-iMSCs promoted MuSC differentiation. CONCLUSION: XF-iMSCs are promising candidates for promoting muscle regeneration while avoiding fibrosis, offering a safer and more effective therapeutic approach for UCMD than other potential therapies.

"Paper Peel Technique" For Suturing Collagen Membrane Onto Buccal Mucosa- A Technical Note For Beginners.

Manipulation of the collagen membrane has always been cumbersome in the oral cavity because of its rolling tendency. We present a new technique for easy handling and manipulation of the collagen membrane.

OSCC-derived EVs educate fibroblasts and remodel collagen landscape.

Cancer-associated myofibroblasts (mCAFs) represent a significant component of the tumor microenvironment due to their contributions to extracellular matrix (ECM) remodeling. The pro-tumor mechanisms of extracellular vesicles (EVs) by regulating mCAFs and related collagens remain poorly understood in oral squamous cell carcinoma (OSCC). In this study, through analysis of single-cell sequencing data and immunofluorescence staining, we confirmed the increased presence of mCAFs and enrichment of specific collagen types in OSCC tissues. Furthermore, we demonstrated that OSCC-derived EVs promote the transformation of fibroblasts into mCAFs, leading to tumor invasion. Proteomic analysis identified the presence of TGF-ß1 in EVs and revealed its role in inducing mCAFs via the TGF-ß1/Smad3 signaling pathway. Experiments in vivo confirmed that EVs, particularly those carrying TGF-ß1, trigger COL18high COL5high matrix deposition, thereby forming the pro-tumor ECM in OSCC. In summary, our investigation unveils the significant involvement of OSCC-derived EVs in orchestrating the differentiation of fibroblasts into mCAFs and modulating specific collagen types within the ECM. Therefore, this study provides a theoretical basis for targeting the EV-mediated TGF-ß1 signaling pathway as a potential therapeutic strategy for OSCC.

Bridging the Diagnostic Gap for Hypermobile Ehlers-Danlos Syndrome and Hypermobility Spectrum Disorders: Evidence of a Common Extracellular Matrix Fragmentation Pattern in Patient Plasma as a Potential Biomarker.

Diagnosing hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD), common overlapping multisystemic conditions featuring symptomatic joint hypermobility, is challenging due to lack of established causes and diagnostic tools. Currently, the 2017 diagnostic criteria for hEDS are used, with non-qualifying cases classified as HSD, although the distinction remains debated. We previously showed extracellular matrix (ECM) disorganization in both hEDS and HSD dermal fibroblasts involving fibronectin (FN), type I collagen (COLLI), and tenascin (TN), with matrix metalloproteinase-generated fragments in conditioned media. Here, we investigated these fragments in patient plasma using Western blotting across diverse cohorts, including patients with hEDS, HSD, classical EDS (cEDS), vascular EDS (vEDS), rheumatoid arthritis (RA), psoriatic arthritis (PsA), and osteoarthritis (OA), and healthy donors, uncovering distinctive patterns. Notably, hEDS/HSD displayed a shared FN and COLLI fragment signature, supporting their classification as a single disorder and prompting reconsideration of the hEDS criteria. Our results hold the promise for the first blood test for diagnosing hEDS/HSD, present insights into the pathomechanisms, and open the door for therapeutic trials focused on restoring ECM homeostasis using an objective marker. Additionally, our findings offer potential biomarkers also for OA, RA, and PsA, advancing diagnostic and therapeutic strategies in these prevalent joint diseases.

Effect of growth hormone on colonic anastomosis after intraperitoneal administration of 5-fluorouracil, bleomycin and cisplatin: An experimental study.

BACKGROUND: Growth hormone (GH) plays a crucial role in wound healing and tissue repair in postoperative patients. In particular, colonic anastomosis healing following colorectal surgery is impaired by numerous chemotherapy agents. AIM: To investigate whether GH can improve the healing of a colonic anastomosis following the adverse effects of intraperitoneal administration of 5-fluorouracil (5-FU), bleomycin and cisplatin. METHODS: Eighty Wistar rats underwent laparotomy and a 1 cm-resection of the transverse colon, followed by an end-to-end anastomosis under general anesthesia. The rats were blindly allocated into four equal groups and administered a different daily intraperitoneal therapeutic regimen for 6 days. The control group (A) received normal saline. Group B received chemotherapy with 5-FU (20 mg/kg), bleomycin (4 mg/kg) and cisplatin (0.7 mg/kg). Group C received GH (2 mg/kg), and group D received the aforementioned combination chemotherapy and GH, as described. The rats were sacrificed on the 7th postoperative day and the anastomoses were macroscopically and microscopically examined. Body weight, bursting pressure, hydroxyproline levels and inflammation markers were measured. RESULTS: All rats survived until the day of sacrifice, with no infections or other complications. A decrease in the body weight of group D rats was observed, not statistically significant compared to group A (P = 1), but significantly different to groups C (P = 0.001) and B (P < 0.01). Anastomotic dehiscence rate was not statistically different between the groups. Bursting pressure was not significantly different between groups A and D (P = 1.0), whereas group B had a significantly lower bursting pressure compared to group D (P < 0.001). All groups had significantly more adhesions than group A. Hydroxyproline, as a measurement of collagen deposition, was significantly higher in group D compared to group B (P < 0.05), and higher, but not statistically significant, compared to group A. Significant changes in group D were recorded, compared to group A regarding inflammation (3.450 vs 2.900, P = 0.016) and fibroblast activity (2.75 vs 3.25, P = 0.021). Neoangiogenesis and collagen deposition were not significantly different between groups A and D. Collagen deposition was significantly increased in group D compared to group B (P < 0.001). CONCLUSION: Intraperitoneal administration of chemotherapy has an adverse effect on the healing process of colonic anastomosis. However, GH can inhibit the deleterious effect of administered chemotherapy agents and induce colonic healing in rats.

Molecular Mechanisms of Polyphenols in Management of Skin Aging.

The natural process of skin aging is influenced by a variety of factors, including oxidative stress, inflammation, collagen degradation, and UV radiation exposure. The potential of polyphenols in controlling skin aging has been the subject of much investigation throughout the years. Due to their complex molecular pathways, polyphenols, a broad class of bioactive substances present in large quantities in plants, have emerged as attractive candidates for skin anti-aging therapies. This review aims to provide a comprehensive overview of the molecular mechanisms through which polyphenols exert their anti-aging effects on the skin. Various chemical mechanisms contribute to reducing skin aging signs and maintaining a vibrant appearance. These mechanisms include UV protection, moisturization, hydration, stimulation of collagen synthesis, antioxidant activity, and anti-inflammatory actions. These mechanisms work together to reduce signs of aging and keep the skin looking youthful. Polyphenols, with their antioxidant properties, are particularly noteworthy. They can neutralize free radicals, lessening oxidative stress that might otherwise cause collagen breakdown and DNA damage. The anti-inflammatory effects of polyphenols are explored, focusing on their ability to suppress pro-inflammatory cytokines and enzymes, thereby alleviating inflammation and its detrimental effects on the skin. Understanding these mechanisms can guide future research and development, leading to the development of innovative polyphenol-based strategies for maintaining healthy skin.

N6-methyladenosine (m6A) RNA modification in fibrosis and collagen-related diseases.

Fibrosis is an abnormal tissue healing process characterized by the excessive accumulation of ECM components, such as COL I and COL III, in response to tissue injury or chronic inflammation. Recent advances in epitranscriptomics have underscored the importance of m6A modification in fibrosis. m6A, the most prevalent modification in eukaryotic RNA, is catalyzed by methyltransferases (e.g., METTL3), removed by demethylases (e.g., FTO), and recognized by reader proteins (e.g., YTHDF1/2). These modifications are crucial in regulating collagen metabolism and associated diseases. Understanding the role of m6A modification in fibrosis and other collagen-related conditions holds promise for developing targeted therapies. This review highlights the latest progress in this area.

Spectrum of Alport syndrome in an Indian cohort.

BACKGROUND: Next-generation sequencing has enabled non-invasive diagnosis of type IV collagen disease in clinical settings other than the typical presentation of Alport syndrome (AS). METHODS: We reviewed the clinical and histological records of children diagnosed with Alport syndrome based on next-generation sequencing. Variants on clinical exome sequencing were categorized using ACMG 2015 criteria. RESULTS: During 2015-2023, we found 43 patients (34 boys) with 39 variants in COL4A5 (n = 27), COL4A4 (n = 7), and COL4A3 (n = 5). Thirty, 8, and 5 patients had X-linked, autosomal recessive, and autosomal dominant disease, respectively. The median (IQR) age and eGFR at diagnosis were 10 (7-13) years and 100.1 (59-140) ml/min/1.73 m2, respectively. Fifteen patients were initially diagnosed with steroid-resistant nephrotic syndrome. Alport syndrome was suspected in these patients due to persistent microscopic hematuria, eGFR < 90 ml/min/1.73 m2, characteristic histology, and/or non-response to immunosuppression. Of 26 patients who underwent kidney biopsy, light microscopy revealed focal segmental glomerulosclerosis, minimal change disease, and mesangial proliferative glomerulonephritis in 9, 9, and 8 patients, respectively. Electron microscopy (n = 18) showed characteristic glomerular basement membrane changes and/or foot process effacement in 12 and 16 cases, respectively. Twenty-one patients (48.8%) had high-frequency sensorineural hearing loss, while two had lenticonus. Twelve patients progressed to chronic kidney disease stages 4-5. Median survival (IQR) with eGFR > 30 ml/min/1.73 m2 was 15.6 (13-18) years. CONCLUSIONS: The phenotype of Alport syndrome varies from asymptomatic urinary abnormalities to hematuria, proteinuria and/or low eGFR, and steroid-resistant nephrotic syndrome. Adverse outcomes are common, especially in boys with X-linked disease.