Alterations of Dermal Connective Tissue Collagen in Diabetes: Molecular Basis of Aged-Appearing Skin

Comprehensive analysis of biological landscape of oxidative stress-related genes in diabetic erectile dysfunction

Oxidative stress plays a pivotal role in the pathogenesis of diabetic erectile dysfunction, while specific mechanisms have not been illuminated. The study aims to reveal the genetic expression patterns of oxidative stress in diabetic erectile dysfunction. Transcriptome data of diabetic erectile dysfunction and oxidative stress-related genes (OSRGs) in the Gene Expression Omnibus database were downloaded and analyzed based on differential expression. Functional enrichment analyses were conducted to clarify the biological functions. A protein interaction framework was established, and significant gene profiles were validated in the cavernous endothelial cells, clinical patients, and rat models. A miRNA-OSRGs network was predicted and validated. The results were analyzed using Student's t-test. The analysis screened 203 differentially expressed OSRGs (p < 0.05), which had a close association with oxidoreductase activities, glutathione metabolism, and autophagy. A four-gene signature comprised of EPS8L2 (p = 0.044), GSTA3 (p = 0.015), LOX (p < 0.001) and MGST1 (p = 0.002) was well validated and regarded as the hub OSRGs. Compared with the control group, notable increases and decreases were observed in the expressions of GSTA3 (3.683 ± 0.636 vs. 0.416 ± 0.507) and LOX (2.104 ± 1.895 vs. 18.804 ± 2.751) in the validated diabetic erectile dysfunction group. The hub OSRGs-related miRNAs participated in smooth muscle cell proliferation. Besides, miR-125a-3p (p = 0.034) and miR-138-2-3p (p = 0.012) were validated as promising oxidative stress-related miRNA biomarkers. Our findings revealed the genetic alternations of oxidative stress in diabetic erectile dysfunction. These results will be instructive to explore the molecular landscape and the potential treatment for diabetic erectile dysfunction.

Ghrelin induced by ultraviolet B exposure promotes the restoration of diabetic cutaneous wound healing

BACKGROUND

Diabetes mellitus (DM) presents impediment to wound healing. While ultraviolet B (UVB) exposure showed therapeutic potential in various skin conditions, its capacity to mediate diabetic wound healing remains unclear. To investigate the efficacy of UVB on wound healing and its underlying basis.

MATERIALS AND METHODS

Male C57BL/6 mice were subjected to the high-fat diet followed by streptozotocin administration to establish the diabetic model. Upon confirmation of diabetes, full-thickness wounds were inflicted and the treatment group received UVB radiation at 50 mJ/cm2 for 5 min every alternate day for 2 weeks. Wound healing rate was then assessed, accompanied by evaluations of blood glucose, lipid profiles, CD31 expression, and concentrations of ghrelin and leptin. Concurrently, in vitro studies were executed to evaluate the protective role of ghrelin on human umbilical vein endothelial cells (HUVEC) under high glucose (HG) conditions.

RESULTS

Post UVB exposure, there was a marked acceleration in wound healing in DM mice without alterations in hyperglycemia and lipid profiles. Compared to non-UVB-exposed mice, the UVB group showed enhanced angiogenesis manifested by a surge in CD31 expression. This trend appeared to be in harmony with the elevated ghrelin levels. In vitro experiments indicated that ghrelin significantly enhanced the migratory pace and angiogenic properties of HUVEC under HG-induced stress, potentially mediated by an upregulation in vascular endothelial growth factor expression.

CONCLUSION

UVB exposure bolstered wound healing in diabetic mice, plausibly mediated through augmented angiogenesis induced by ghrelin secretion. Such findings underscore the vast potential of UVB-induced ghrelin in therapeutic strategies targeting diabetic wound healing.

Incremental residual polarization caused by aging in human skin

Significance

The study of the effect of aging on the optical properties of biological tissues, in particular polarization, is important in the development of new diagnostic approaches.

Aim

This work aims to provide a comprehensive analysis of the factors and mechanisms that contribute to the alteration of skin polarization properties caused by aging, using polarization-sensitive hyperspectral imaging measurements and Monte Carlo simulation.

Approach

Our investigation involved both experimental studies of in vivo human skin of volunteers of different ages and computational modeling that accounted for changes in the absorption and scattering properties of the skin model. Specifically, we analyzed alterations in the degree of linear polarization (DOLP) to better understand the impact of aging on skin polarization properties.

Results

A statistically significant increase in the DOLP was found for the elderly group. At the same time, there was no correlation between changes in polarization and the calculated blood volume fraction parameter for different ages. According to the simulation results, it was also found that a change in the scattering properties of biological tissues has a more significant effect on the change in polarizing light compared to the change in absorption.

Conclusions

The results of the work prove that the sensitivity of polarization imaging to age- or pathological-related skin changes may be primarily due to changes in scattering, which in turn is associated with changes in the collagen fibers of the dermis. The proposed technique shows promise for in vivo non-invasive real-time assessment of age-associated skin changes and can also be extended to monitor changes associated with the development of age-related pathologies.

Short-Term l-arginine Treatment Mitigates Early Damage of Dermal Collagen Induced by Diabetes

Changes in the structural properties of the skin due to collagen alterations are an important factor in diabetic skin complications. Using a combination of photonic methods as an optic diagnostic tool, we investigated the structural alteration in rat dermal collagen I in diabetes, and after short-term l-arginine treatment. The multiplex approach shows that in the early phase of diabetes, collagen fibers are partially damaged, resulting in the heterogeneity of fibers, e.g., "patchy patterns" of highly ordered/disordered fibers, while l-arginine treatment counteracts to some extent the conformational changes in collagen-induced by diabetes and mitigates the damage. Raman spectroscopy shows intense collagen conformational changes via amides I and II in diabetes, suggesting that diabetes-induced structural changes in collagen originate predominantly from individual collagen molecules rather than supramolecular structures. There is a clear increase in the amounts of newly synthesized proline and hydroxyproline after treatment with l-arginine, reflecting the changed collagen content. This suggests that it might be useful for treating and stopping collagen damage early on in diabetic skin. Our results demonstrate that l-arginine attenuates the early collagen I alteration caused by diabetes and that it could be used to treat and prevent collagen damage in diabetic skin at a very early stage.

Dental pulp stones and their correlation with metabolic diseases

Background

Dental pulp calcifications or pulp stones are calcified structures found in dental pulp, mostly around or enclosing a blood vessel. The formation of these calcifications begins with concentric layers of calcified tissue within which remnants of necrotic and calcified cells may be present. The calcifications of thrombi in blood vessels, called phleboliths, may also serve as nidi for denticles. In metabolic diseases such as diabetes, hypertension or poor periodontal health, there are obvious changes in blood vessels and vascularization. In our study, we observed histopathological sections of dental pulp and correlated systemic diseases such as diabetes and hypertension with poor periodontal health and dental pulp stones.

Aim

The aim of our study was to evaluate the histopathology of dental pulp stones, their distribution among various age groups and sexes and to identify any correlations between pulp stone formation and systemic diseases such as type II diabetes and hypertension.

Materials and Methods

Samples from 100 patients with metabolic diseases such as type II diabetes and hypertension were collected. The pulp was extirpated from the teeth that were undergoing root canal treatment, and the teeth were extracted. The collected pulp sample was fixed in 10% formaline neutral buffer, subjected to routine histopathological procedures and stained with haematoxylin and eosin. The pulp of teeth extracted for orthodontic treatment was considered a control for patients with no metabolic disease.

Results

There was a definite relationship between increased pulp stones and metabolic diseases such as type II diabetes and hypertension; likewise, poor periodontal health was significantly related to pulp stones.

Skin characterization of diabetes mellitus revealed by polarization-sensitive optical coherence tomography imaging

Significance

Diabetes can lead to the glycation of proteins and dysfunction of skin collagen. Skin lesions are a prevalent clinical symptom of diabetes mellitus (DM). Early diagnosis and assessing the efficacy of treatment for DM are crucial for patient health management. However, performing a non-invasive skin assessment in the early stages of DM is challenging.

Aim

By using the polarization-sensitive optical coherent tomography (PS-OCT) imaging technique, it is possible to noninvasively assess the skin changes caused by diabetes.

Approach

The PS-OCT was used to monitor the polarization characteristics of mouse skin at different stages of diabetes.

Results

Based on a multi-layered adhesive tape model, we found that the polarization characteristics (retardation, optic axis, and polarization uniformity) were sensitive to the microstructure changes in the samples. Through this method, we observed significant changes in the polarization states of the skin as diabetes progressed. This was in line with the detected microstructure changes in skin collagen fibers using scanning electron microscopy.

Conclusions

This study presents a highly useful approach for non-invasive skin assessment of diabetes.

3D-Printed Alginate/Pectin-Based Patches Loaded with Olive Leaf Extracts for Wound Healing Applications: Development, Characterization and In Vitro Evaluation of Biological Properties

Traditional wound dressings may lack suitability for diverse wound types and individual patient requirements. In this context, this study aimed to innovate wound care by developing a 3D-printed patch using alginate and pectin and incorporating Olive Leaf Extract (OLE) as an active ingredient. Different polymer-to-plasticizer ratios were systematically examined to formulate a printable ink with optimal viscosity. The resultant film, enriched with OLE, exhibited a substantial polyphenolic content of 13.15 ± 0.41 mg CAE/g, showcasing significant antioxidant and anti-inflammatory properties. Notably, the film demonstrated potent scavenging abilities against DPPH, ABTS, and NO radicals, with IC50 values of 0.66 ± 0.07, 0.47 ± 0.04, and 2.02 ± 0.14 mg/mL, respectively. In vitro release and diffusion studies were carried out and the release profiles revealed an almost complete release of polyphenols from the patch within 48 h. Additionally, the fabricated film exhibited the capacity to enhance cell motility and accelerate wound healing, evidenced by increased collagen I expression in BJ fibroblast cells. Structural assessments affirmed the ability of the patch to absorb exudates and maintain the optimal moisture balance, while biocompatibility studies underscored its suitability for biomedical applications. These compelling findings endorse the potential application of the developed film in advanced wound care, with the prospect of tailoring patches to individual patient needs.

Effects of glycation end-products on the dental pulp in patients with type 2 diabetes

AIM

This ex vivo study aimed to compare protein expression of advanced glycation end-products (AGE) and receptor (RAGE), and the levels of selected genes associated with inflammation and collagen within dental pulp tissue from patients with type 2 (T2D) diabetes and non-T2D.

METHODOLOGY

Noncarious extracted permanent molar teeth from patients with well-controlled T2D (n = 19) and non-T2D (controls) (n = 19) were collected and compared. The coronal pulp was examined using immunohistochemistry (IHC) (n = 10 per group) for anti-AGE and anti-RAGE. Quantitative PCR (n = 9 per group) was used to analyse the gene expression levels of NFKB, S100A12 and COLIA1. Data analyses were performed between the groups using GraphPad Prism using Pearson correlation, Shapiro-Wilk and Mann-Whitney U-tests, and multiple regression using SPSS.

RESULTS

AGEs were distributed diffusely throughout the pulp extracellular matrix associated with collagen fibres and were present on several cell types. RAGE was expressed at the pulp-dentine interface and was observed on odontoblasts, immune cells, endothelial cells and fibroblasts. Semi-quantitative analysis of IHC samples showed significantly increased expression of AGE (p < .0001) and RAGE (p = .02) in T2D samples compared with controls. The expression of NFKB (p < .0001), S100A12 (p < .0001) and COLIA1 (p = .01) genes were significantly higher in the T2D pulp, and multivariate logistic regression analysis showed that these findings were not affected by age.

CONCLUSION

T2D may exert a similar glycation response in the dental pulp to other body sites. This could occur through activation of NF-κB pathways with a concomitant increase in genes associated with inflammation and collagen.

Current status and progress in research on dressing management for diabetic foot ulcer

Diabetic foot ulcer (DFU) is a major complication of diabetes and is associated with a high risk of lower limb amputation and mortality. During their lifetime, 19%-34% of patients with diabetes can develop DFU. It is estimated that 61% of DFU become infected and 15% of those with DFU require amputation. Furthermore, developing a DFU increases the risk of mortality by 50%-68% at 5 years, higher than some cancers. Current standard management of DFU includes surgical debridement, the use of topical dressings and wound decompression, vascular assessment, and glycemic control. Among these methods, local treatment with dressings builds a protective physical barrier, maintains a moist environment, and drains the exudate from DFU wounds. This review summarizes the development, pathophysiology, and healing mechanisms of DFU. The latest research progress and the main application of dressings in laboratory and clinical stage are also summarized. The dressings discussed in this review include traditional dressings (gauze, oil yarn, traditional Chinese medicine, and others), basic dressings (hydrogel, hydrocolloid, sponge, foam, film agents, and others), bacteriostatic dressings, composite dressings (collagen, nanomaterials, chitosan dressings, and others), bioactive dressings (scaffold dressings with stem cells, decellularized wound matrix, autologous platelet enrichment plasma, and others), and dressings that use modern technology (3D bioprinting, photothermal effects, bioelectric dressings, microneedle dressings, smart bandages, orthopedic prosthetics and regenerative medicine). The dressing management challenges and limitations are also summarized. The purpose of this review is to help readers understand the pathogenesis and healing mechanism of DFU, help physicians select dressings correctly, provide an updated overview of the potential of biomaterials and devices and their application in DFU management, and provide ideas for further exploration and development of dressings. Proper use of dressings can promote DFU healing, reduce the cost of treating DFU, and reduce patient pain.

CCN1 is predominantly elevated in human skin dermis by solar-simulated ultraviolet irradiation and accumulated in dermal extracellular matrix

Skin primarily comprises a collagen-rich extracellular matrix (ECM) that provides structural and functional support to the skin. Aging causes progressive loss and fragmentation of dermal collagen fibrils, leading to thin and weakened skin (Dermal aging). We previously reported that CCN1 is elevated in naturally aged human skin, photoaged human skin, and acute UV-irradiated human skin dermal fibroblasts in vivo. Elevated CCN1 alters the expression of numerous secreted proteins that have deleterious effects on the dermal microenvironment, impairing the structural integrity and function of the skin. Here we show that CCN1 is predominantly elevated in the human skin dermis by UV irradiation and accumulated in the dermal extracellular matrix. Laser capture microdissection indicated that CCN1 is predominantly induced in the dermis, not in the epidermis, by acute UV irradiation in human skin in vivo. Interestingly, while UV-induced CCN1 in the dermal fibroblasts and in the medium is transient, secreted CCN1 accumulates in the ECM. We explored the functionality of the matrix-bound CCN1 by culturing dermal fibroblasts on an acellular matrix plate that was enriched with a high concentration of CCN1. We observed that matrix-bound CCN1 activates integrin outside-in signaling resulting in the activation of FAK and its downstream target paxillin and ERK, as well as elevated MMP-1 and inhibition of collagen, in human dermal fibroblasts. These data suggest that accumulation of CCN1 in the dermal ECM is expected to progressively promote the aging of the dermis and thereby negatively impact the function of the dermis.

Addition of Resolvins D1 or E1 to Collagen Membranes Mitigates Their Resorption in Diabetic Rats

Uncontrolled diabetes is characterized by aberrant inflammatory reactions and increased collagenolysis. We have reported that it accelerates the degradation of implanted collagen membranes (CM), thus compromising their function in regenerative procedures. In recent years, a group of physiological anti-inflammatory agents called specialized pro-resolving lipid mediators (SPMs) have been tested as a treatment for various inflammatory conditions, either systemically or locally, via medical devices. Yet, no study has tested their effect on the fate of the biodegradable material itself. Here, we measured the in vitro release over time of 100 or 800 ng resolvin D1 (RvD1) incorporated into CM discs. In vivo, diabetes was induced in rats with streptozotocin, while buffer-injected (normoglycemic) rats served as controls. Resolvins (100 or 800 ng of RvD1 or RvE1) were added to biotin-labeled CM discs, which were implanted sub-periosteally over the calvaria of rats. Membrane thickness, density, and uniformity were determined by quantitative histology after 3 weeks. In vitro, significant amounts of RvD1 were released over 1-8 days, depending on the amount loaded. In vivo, CMs from diabetic animals were thinner, more porous, and more variable in thickness and density. The addition of RvD1 or RvE1 improved their regularity, increased their density, and reduced their invasion by the host tissue significantly. We conclude that addition of resolvins to biodegradable medical devices can protect them from excessive degradation in systemic conditions characterized by high degree of collagenolysis.

Visualizing dynamic three-dimensional changes of human reticular dermal collagen under mechanical strain

In clinical practice, plastic surgeons are often faced with large skin defects that are difficult to close primarily. Management of large skin wounds e.g. burns or traumatic lacerations requires knowledge of skin biomechanic properties. Research into skin microstructural adaptation to mechanical deformation has only been performed using static regimes due to technical limitations. Here, we combine uniaxial stretch tests with fast second harmonic generation imaging and we apply this for the first time to investigate dynamic collagen rearrangement in reticular human dermis.Ex vivohuman skin from the abdomen and upper thigh was simultaneously uniaxially stretched while either periodically visualizing 3D reorganization, or visualizing 2D changes in real time. We determined collagen alignment via orientation indices and found pronounced variability across samples. Comparing mean orientation indices at the different stages of the stress strain curves (toe, heel, linear) showed a significant increase in collagen alignment during the linear part of the mechanical response. We conclude that fast SHG imaging during uni-axial extension is a promising research tool for future studies on skin biomechanic properties.

The multiscale characterization and constitutive modeling of healthy and type 2 diabetes mellitus Sprague Dawley rat skin

In type 2 diabetes mellitus (T2DM), elevated glucose level impairs the biochemistry of the skin which may result in alteration of its mechanical and structural properties. The several aspects of structural and mechanical changes in skin due to T2DM remain poorly understood. To fill these research gaps, we developed a non-obese T2DM rat (Sprague Dawley (SD)) model for investigating the effect of T2DM on the in vivo strain stress state, mechanical and structural properties of skin. In vivo strain and mechanical anisotropy of healthy and T2DM skin were measured using the digital imaging correlation (DIC) technique and DIC coupled bulge experiment, respectively. Fluorescence microscopy and histology were used to assess the collagen and elastin fibers microstructure whereas nanoscale structure was captured through atomic force microscopy (AFM). Based on the microstructural observations, skin was modeled as a multilayer membrane where in and out of plane distribution of collagen fibers and planar distribution of elastin fibers were cast in constitutive model. Further, the state of in vivo stresses of healthy and T2DM were measured using model parameters and in vivo strain in the constitutive model. The results showed that T2DM causes significant loss in in vivo stresses (p < 0.01) and increase in anisotropy (p < 0.001) of skin. These changes were found in good correlation with T2DM associated alteration in skin microstructure. Statistical analysis emphasized that increase in blood glucose concentration (HbA1c) was the main cause of impaired biomechanical properties of skin. The presented data in this study can help to understand the skin pathology and to simulate the skin related clinical procedures. STATEMENT OF SIGNIFICANCE: Our study is significant as it presents findings related to the effect of T2DM on the physiologic stress strain, structural and mechanical response of SD rat skin. In this study, we developed a non-obese T2DM SD rat model which mimics the phenotype of Asian type 2 diabetics (non-obese). Several structural and mechanical characterization techniques were explored for multiscale characterization of healthy and T2DM skin. Further, based on microstructural information, we presented the constitutive models that incorporate the real microstructure of skin. The presented results can be helpful to simulate the realistic mechanical response of skin during various clinical trials.

Promotion of cutaneous diabetic wound healing by subcutaneous administration of Wharton's jelly mesenchymal stem cells derived from umbilical cord

Wound healing is a major problem in diabetic patients, and current treatments have been confronted with limited success. The present study examined the benefit of Wharton's jelly mesenchymal stem cells (WJ-MSCs) derived from the human umbilical cord (UC) in wound healing in diabetic rats. Thirty days after inducing diabetes, a circular excision was created in the skin of rats, and the treatments were performed for 21 days. Two groups were studied, which included the Control group and WJ-MSCs group. The studied groups were sampled on the 7th, 14th, and 21st days after wounding. Histological ultrasound imaging of dermis and epidermis in the wound area for thickness and density measurement and skin elasticity were evaluated. Our results on post-wounding days 7, 14, and 21 showed that the wound closure, thickness, and density of new epidermis and dermis, as well as skin elasticity in the healed wound, were significantly higher in the WJ-MSCs group compared to the Control group. Subcutaneous administration of WJ-MSCs in diabetic wounds can effectively accelerate healing. Based on this, these cells can be used along with other treatment methods in the healing of different types of chronic wounds.

Identification of hub biomarkers and exploring the roles of immunity, M6A, ferroptosis, or cuproptosis in rats with diabetic erectile dysfunction

BACKGROUND

Currently, patients with diabetic erectile dysfunction (DMED) were not satisfied with the effects of first-line phosphodiesterase type 5 inhibitors (PDE5Is). Hence, this paper was designed to mine hub biomarkers in DMED and explore its potential mechanisms.

METHODS

Gene expression matrix of DMED was downloaded from the gene expression omnibus (GEO; GSE2457) dataset. The top 20 genes were selected based on the connectivity degrees in protein-protein interaction (PPI) network. Functional enrichment analysis was utilized to reveal DMED-related signaling pathways. We also explored the roles of immunity, m6A, ferroptosis, or cuproptosis in DMED and constructed Sprague Dawley (SD) rats DMED model to verify gene expressions by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Based on the threshold, a total of 122 differently expressed genes (DEGs) were identified in DMED, including 39 up-regulated and 83 down-regulated genes. Functional enrichment analysis implied that these DEGs were significantly enriched in peroxisome proliferator-activated receptors, ferroptosis, hypoxia-inducible factor 1 signaling pathways, and so on. SD rats DMED model was also successfully established by us and validated by intracavernous pressure/mean arterial pressure, Masson's trichrome staining, and immunohistochemical analysis. We further verified the expression of these top 20 genes from the PPI network by qRT-PCR in the SD rats DMED model and finally identified Sparc, Lox, Srebf1, and Mmp3 as hub biomarkers (all p < 0.05). As for immunity and cuproptosis, our analysis indicated that DMED had nothing to do with them (all p > 0.05). Actually, DMED was markedly associated with m6A regulators and ferroptosis.

CONCLUSIONS

We identified Sparc, Lox, Srebf1, and Mmp3 as potential hub biomarkers in the SD rats DMED model for future drug development and found its significant associations with m6A regulators and ferroptosis, but not with immunity or cuproptosis.

Histological Manifestations of Diabetic Kidney Disease and its Relationship with Insulin Resistance

Histological manifestations of diabetic kidney disease (DKD) include mesangiolysis, mesangial matrix expansion, mesangial cell proliferation, thickening of the glomerular basement membrane, podocyte loss, foot process effacement, and hyalinosis of the glomerular arterioles, interstitial fibrosis, and tubular atrophy. Glomerulomegaly is a typical finding. Histological features of DKD may occur in the absence of clinical manifestations, having been documented in patients with normal urinary albumin excretion and normal glomerular filtration rate. Furthermore, the histological picture progresses over time, while clinical data may remain normal. Conversely, histological lesions of DKD improve with metabolic normalization following effective pancreas transplantation. Insulin resistance has been associated with the clinical manifestations of DKD (nephromegaly, glomerular hyperfiltration, albuminuria, and kidney failure). Likewise, insulin resistance may underlie the histological manifestations of DKD. Morphological changes of DKD are absent in newly diagnosed type 1 diabetes patients (with no insulin resistance) but appear afterward when insulin resistance develops. In contrast, structural lesions of DKD are typically present before the clinical diagnosis of type 2 diabetes. Several heterogeneous conditions that share the occurrence of insulin resistance, such as aging, obesity, acromegaly, lipodystrophy, cystic fibrosis, insulin receptor dysfunction, and Alström syndrome, also share both clinical and structural manifestations of kidney disease, including glomerulomegaly and other features of DKD, focal segmental glomerulosclerosis, and C3 glomerulopathy, which might be ascribed to the reduction in the synthesis of factor H binding sites (such as heparan sulfate) that leads to uncontrolled complement activation. Alström syndrome patients show systemic interstitial fibrosis markedly similar to that present in diabetes.

Dysregulation of TSP2-Rac1-WAVE2 axis in diabetic cells leads to cytoskeletal disorganization, increased cell stiffness, and dysfunction

Fibroblasts are a major cell population that perform critical functions in the wound healing process. In response to injury, they proliferate and migrate into the wound space, engaging in extracellular matrix (ECM) production, remodeling, and contraction. However, there is limited knowledge of how fibroblast functions are altered in diabetes. To address this gap, several state-of-the-art microscopy techniques were employed to investigate morphology, migration, ECM production, 2D traction, 3D contraction, and cell stiffness. Analysis of cell-derived matrix (CDM) revealed that diabetic fibroblasts produce thickened and less porous ECM that hindered migration of normal fibroblasts. In addition, diabetic fibroblasts were found to lose spindle-like shape, migrate slower, generate less traction force, exert limited 3D contractility, and have increased cell stiffness. These changes were due, in part, to a decreased level of active Rac1 and a lack of co-localization between F-actin and Waskott-Aldrich syndrome protein family verprolin homologous protein 2 (WAVE2). Interestingly, deletion of thrombospondin-2 (TSP2) in diabetic fibroblasts rescued these phenotypes and restored normal levels of active Rac1 and WAVE2-F-actin co-localization. These results provide a comprehensive view of the extent of diabetic fibroblast dysfunction, highlighting the regulatory role of the TSP2-Rac1-WAVE2-actin axis, and describing a new function of TSP2 in regulating cytoskeleton organization.

Single nucleotide variations in the development of diabetic foot ulcer: A narrative review

Diabetes mellitus has become a global health problem, and the number of patients with diabetic foot ulcers (DFU) is rapidly increasing. Currently, DFU still poses great challenges to physicians, as the treatment is complex, with high risks of infection, recurrence, limb amputation, and even death. Therefore, a comprehensive understanding of DFU pathogenesis is of great importance. In this review, we summarized recent findings regarding the DFU development from the perspective of single-nucleotide variations (SNVs). Studies have shown that SNVs located in the genes encoding C-reactive protein, interleukin-6, tumor necrosis factor-alpha, stromal cell-derived factor-1, vascular endothelial growth factor, nuclear factor erythroid-2-related factor 2, sirtuin 1, intercellular adhesion molecule 1, monocyte chemoattractant protein-1, endothelial nitric oxide synthase, heat shock protein 70, hypoxia inducible factor 1 alpha, lysyl oxidase, intelectin 1, mitogen-activated protein kinase 14, toll-like receptors, osteoprotegerin, vitamin D receptor, and fibrinogen may be associated with the development of DFU. However, considering the limitations of the present investigations, future multi-center studies with larger sample sizes, as well as in-depth mechanistic research are warranted.

Research Advances on the Damage Mechanism of Skin Glycation and Related Inhibitors

Our skin is an organ with the largest contact area between the human body and the external environment. Skin aging is affected directly by both endogenous factors and exogenous factors (e.g., UV exposure). Skin saccharification, a non-enzymatic reaction between proteins, e.g., dermal collagen and naturally occurring reducing sugars, is one of the basic root causes of endogenous skin aging. During the reaction, a series of complicated glycation products produced at different reaction stages and pathways are usually collectively referred to as advanced glycation end products (AGEs). AGEs cause cellular dysfunction through the modification of intracellular molecules and accumulate in tissues with aging. AGEs are also associated with a variety of age-related diseases, such as diabetes, cardiovascular disease, renal failure (uremia), and Alzheimer's disease. AGEs accumulate in the skin with age and are amplified through exogenous factors, e.g., ultraviolet radiation, resulting in wrinkles, loss of elasticity, dull yellowing, and other skin problems. This article focuses on the damage mechanism of glucose and its glycation products on the skin by summarizing the biochemical characteristics, compositions, as well as processes of the production and elimination of AGEs. One of the important parts of this article would be to summarize the current AGEs inhibitors to gain insight into the anti-glycation mechanism of the skin and the development of promising natural products with anti-glycation effects.

Evaluation of Skin Biophysical Parameters and Angiogenesis Using CD34 as a Biomarker in Older Diabetic Women Treated with Radiofrequency

Background

The prevalence of type 2 diabetes mellitus (t2DM) has been steadily increasing. Patients with t2DM need to slow down the skin ageing processes and to obtain a rejuvenating effect. Treatments that do not damage the superficial layers of the epidermis could be a promising solution for those patients.

Purpose

The aim of this study was to evaluate the effects of radiofrequency therapy on the biophysical parameters and angiogenesis of facial skin, using CD34 as a biomarker in older diabetic women treated with metformin.

Patients and Methods

A total of 45 subjects with phototype 2 or 3 (Fitzpatrick scale) were investigated (25 t2DM – study group, 20 – healthy controls). A series of 6 treatments (once a week) with a Radio Frequency Skin Rejuvenation System device was used on facial skin. Measurements of skin hydration, transepidermal water loss (TEWL), melanin and erythema index, temperature, and pH, at baseline and after radiofrequency therapy were performed with the Courage + Khazaka MPA-9 device. Immunohistochemistry on paraffin-embedded sections was used to evaluate the intensity of CD34 expression.

Results

Radiofrequency treatment significantly improved facial skin hydration (p < 0.0001). Enhancement of the epidermal barrier observed, by reduced TEWL as a result of a series of treatments with radiofrequency on the facial skin (p < 0.0001), was observed. CD34 was more abundantly expressed after radiofrequency treatment. No side effects were observed.

Conclusion

Treatment with radiofrequency is an effective and non-invasive method of facial skin rejuvenation in older women with t2DM, with a relatively short post-procedure recovery time and low potential for severe adverse effects.

Dieckol Inhibits the Effects of Particulate Matter 10 on Sebocytes, Outer Root Sheath Cells, and Cutibacterium Acnes-Pretreated Mice

Background

Particulate matter (PM) is an air pollutant that can impair the human skin. Antioxidants have been tested to improve PM-induced skin inflammation.

Objective

In this study, we investigated the effects of dieckol on PM-induced inflammation on cultured human sebocytes, outer root sheath (ORS) cells, and mice pretreated with Cutibacterium acnes.

Methods

We cultured and treated the sebocytes and ORS cells with 5 µM of dieckol and 100 µg/ml of PM10 for 24 h. The C. acnes-pretreated mice received 5 µM of dieckol and 100 µg/ml of PM10. We measured cell viability using MTT assay. Real-time PCR and measurement of reactive oxygen species (ROS) and sebum production analyzed the effects.

Results

Dieckol inhibited the upregulation of the gene expression of the inflammatory cytokines, matrix metalloproteinase (MMP), aryl hydrocarbon receptor, and nuclear factor kappa-light-chain-enhancer of activated B cells by PM10 in the cultured sebocytes and ORS cells and inhibited an increase in ROS production by PM10 in the cultured sebocytes. In addition, dieckol decreased the inflammatory cytokines, MMP, and sebum production in C. acnes-pretreated mice.

Conclusion

Dieckol effectively reduced the expression of inflammatory biomarkers and the production of sebum in cultured sebocytes, ORS cells, and C. acnes-pretreated mice.

Effect of Cirsium japonicum Flower Extract on Skin Aging Induced by Glycation

Advanced glycation end products (AGEs) have recently been increasingly discussed as one factor of skin aging. In this study, we investigated the effects of Cirsium japonicum flower (CFE) extract on glycation in relation to skin aging and skin elasticity. Moreover, we learned the main active constituent of CFE that has effects against glycation. To demonstrate the effects of CFE on glycation, we carried out an in vitro glycation study, 3-dimensional culture, and clinical study. As a result, CFE inhibited formation of AGEs in both bovine serum albumin (BSA)/glucose glycation system and aldehyde-derived glycation system. Moreover, CFE reduced Nε-(carboxymethyl), lysine (CML), and carbonylated proteins that increased by glycation. Furthermore, CFE broke crosslinks of collagen–AGEs and inhibited the increase of matrix metalloproteinase-1 (MMP-1) gene expression by AGEs. In the 3D culture condition, CFE restored the reduction of collagen gel contraction by glycation. Moreover, apigenin was detected as the main active constituent in CFE that has anti-glycation effects. In the clinical study, we confirmed that CFE has effects on skin wrinkles and skin elasticity. Our findings suggest that CFE can be used as a cosmetic or cosmeceutical ingredient for improving skin elasticity and wrinkles. Regulation of AGEs can be an interesting target for anti-aging.

Type 2 diabetes and the clinically normal pulp - An in-vitro study

Aim

The aim of this study was to investigate the effect of type 2 diabetes (T2D) on clinically normal dental pulp tissue by using special stains and immunohistochemistry (IHC) to determine the morphology of the coronal pulp and distribution of immune markers in non‐T2D and T2D groups.

Methodology

Ethics approval for this in vitro pilot study was obtained from the University of Otago Human Ethics Committee (16/069). Twenty extracted permanent molar teeth diagnosed as having clinically normal pulp status were collected. Ten teeth were from participants with well‐controlled T2D and ten from participants without diabetes (non‐T2D). Each tooth was sectioned transversely at the cemento‐enamel junction before the crowns were decalcified and embedded in paraffin. Sections were stained with haematoxylin and eosin, Massons trichrome, and van Gieson stains for histological and morphological evaluation. IHC using anti‐CD4, anti‐CD68 and anti‐CD83 and anti‐IL1β, anti‐IL6, anti‐IL17, anti‐TNF‐α, anti‐TLR2, anti‐TLR4 and anti‐FOXP3 identified proteins of interest. Qualitative and semi‐quantitative analyses evaluated the morphology of the dental pulp and protein expression. Data analyses were performed with GraphPad Prism, using Student's t‐test and multiple regression using SPSS at p < .05.

Results

Special stains demonstrated morphological differences in the T2D dental pulp compared with non‐T2D. Qualitative analysis indicated that the pulp in the T2D samples was consistently less cellular, less vascular, showed evidence of thickened blood vessel walls, increased pulp calcification and collagen deposition. Semi‐quantitative analysis of IHC samples showed the T2D pulp had significantly increased expression of macrophage and dendritic cell markers CD68 (p < .001) and CD83 (p = .04), and there was significantly greater expression of inflammatory cytokines IL1β (p = .01), IL6 (p < .0001), IL17 (p < .0001) and TNF‐α (p = .01). T2D samples showed a significant increase in markers of innate inflammation, TLR2 (p < .001) and TLR4 (p < .001) and decreased expression of regulatory T‐cell marker, FOXP3 (p = .01). Multiple regression showed that age‐corrected differences were statistically significant.

Conclusion

Preliminary findings suggest that T2D may exert a similar response in the pulp to complications in other body sites. Hyperglycaemia is associated with changes in the morphology of the clinically normal dental pulp with altered immune cell and cytokine expression.

Decellularized extracellular matrix mediates tissue construction and regeneration

Contributing to organ formation and tissue regeneration, extracellular matrix (ECM) constituents provide tissue with three-dimensional (3D) structural integrity and cellular-function regulation. Containing the crucial traits of the cellular microenvironment, ECM substitutes mediate cell-matrix interactions to prompt stem-cell proliferation and differentiation for 3D organoid construction in vitro or tissue regeneration in vivo. However, these ECMs are often applied generically and have yet to be extensively developed for specific cell types in 3D cultures. Cultured cells also produce rich ECM, particularly stromal cells. Cellular ECM improves 3D culture development in vitro and tissue remodeling during wound healing after implantation into the host as well. Gaining better insight into ECM derived from either tissue or cells that regulate 3D tissue reconstruction or organ regeneration helps us to select, produce, and implant the most suitable ECM and thus promote 3D organoid culture and tissue remodeling for in vivo regeneration. Overall, the decellularization methodologies and tissue/cell-derived ECM as scaffolds or cellular-growth supplements used in cell propagation and differentiation for 3D tissue culture in vitro are discussed. Moreover, current preclinical applications by which ECM components modulate the wound-healing process are reviewed.

Preventative effects of antioxidants on changes in sebocytes, outer root sheath cells, and Cutibacterium acnes-pretreated mice by particulate matter: No significant difference among antioxidants

OBJECTIVES

Particulate matter (PM) is an air pollutant that can damage human skin; antioxidants have shown some efficacy in alleviating PM-induced skin inflammation. We investigated the antioxidant effects of punicalagin, epigallocatechin-3-gallate (EGCG), and resveratrol on PM-induced changes in cultured human sebocytes, outer root sheath (ORS) cells, and Cutibacterium acnes-pretreated mice.

METHODS

Sebocytes and ORS cells were cultured with 100 μg/mL PM10 and 5 μM punicalagin, 1 μM EGCG, or 1 μM resveratrol for 24 h. In C. acnes-pretreated mice, inflammatory nodules were treated with 100 μg/mL PM10 and 5 μM punicalagin, 1 μM EGCG, or 1 μM resveratrol. Cell viability was measured using an MTT assay. Antioxidant effects were analyzed according to RNA expression, using real-time PCR, as well as reactive oxygen species (ROS) and sebum measurements.

RESULTS

Antioxidants inhibited the upregulation of inflammatory cytokines, matrix metalloproteinase, aryl hydrocarbon receptor, and NF-kB as well as the production of ROS induced by PM10 in cultured sebocytes and ORS cells. The preventative effects of punicalagin and EGCG on biomarker expression in cultured sebocytes and ORS cells were slightly greater than those of resveratrol, though the difference was not significant. In C. acnes-pretreated mice, the antioxidants inhibited inflammatory cytokine and matrix metalloproteinase expression as well as sebum production.

CONCLUSIONS

Antioxidants effectively reduced the expression of inflammatory biomarkers and sebum production in cultured sebocytes, ORS cells, and C. acnes-pretreated mice.

Structural, functional and molecular pathogenesis of pelvic organ prolapse in patient and Loxl1 deficient mice

Pelvic organ prolapse is a worldwide health problem to elderly women. Understanding its pathogenesis and an ideal animal model are crucial to developing promising treatments. The present study aimed to investigate new clinical significance and detailed mechanism of pelvic organ prolapse by comparing the structural, functional and molecular dysfunctions of pelvic organ prolapse in patient and Loxl1 deficient mice. Our results showed that human vagina tissues from prolapsed site showed disarranged collagen and elastic fibers compared with the non-prolapse tissue. A gene ontology (GO) analysis of differentially expressed genes revealed molecular changes mainly related to inflammatory response and extracellular matrix (ECM) organization. While the mice lacking Loxl1 developed stable POP phenotype and disordered ECM structure in histology. Such Loxl1 knockout mice exhibited a significantly urinary dysfunction and decreased mechanical properties of the pelvic floor tissues, implying that POP in human condition might be induced by progressively decreased mechanics of pelvic tissues following ECM catabolism. Similarly, we not only identified significant up-regulated ECM catabolism processes and down-regulated ECM synthesis processes, but also characterized high level of inflammatory response in vagina tissue of the Loxl1 deficient mice. Thus, all these pathological changes in the POP mice model was consistent with those of the clinical elderly patients. These findings provide new insight into remodeling of POP by LOXL1 regulation and be of great importance to develop combination treatments of ECM metabolism and inflammation regulation strategy.

Evaluation of Gallic Acid-Coated Gold Nanoparticles as an Anti-Aging Ingredient

Hyperglycemic environment-induced oxidative stress-mediated matrix metalloproteinase-1 (MMP-1) plays a crucial role in the degradation of the extracellular matrix (ECM), which might contribute to premature skin aging. Synthesized, environmentally friendly gallic acid-coated gold nanoparticles (GA–AuNPs) have been evaluated as an anti-aging antioxidant. Their microstructure was characterized by transmission electron microscopy (TEM), which showed that GA–AuNPs are spherical when prepared at pH 11. Dynamic light scattering (DLS) analysis revealed that the average hydrodynamic diameter of a GA–AuNP is approximately 40 nm and with a zeta potential of −49.63 ± 2.11 mV. Additionally, the present data showed that GA–AuNPs have a superior ability to inhibit high glucose-mediated MMP-1-elicited type I collagen degradation in dermal fibroblast cells. Collectively, our data indicated that high-glucose-mediated ROS production was reduced upon cell treatment with GA–AuNPs, which blocked p38 MAPK/ERK-mediated c-Jun, c-Fos, ATF-2 phosphorylation, and the phosphorylation of NFκB, leading to the down-regulation of MMP-1 mRNA and protein expression in high glucose-treated cells. Our findings suggest that GA-AuNPs have a superior ability to inhibit high-glucose-mediated MMP-1-elicited ECM degradation, which highlights its potential as an anti-aging ingredient.

Diabetes and Cannabinoid CB1 receptor deficiency promote similar early onset aging-like changes in the skin

BACKGROUND

The cannabinoid receptor type-1 (CB₁R) is a major regulator of metabolism, growth and inflammation. Yet, its potential role in the skin is not well understood. Our aim was to evaluate the role of CB₁R in aging-like diabetic skin changes by using a CB₁R knockout mouse model.

METHODS

We evaluated several signals of skin aging in wild-type control (WT), WT streptozotocin-induced type 1 diabetic mice (WT DM), CB₁R knockout (CB₁RKO) and CB₁RKO DM mice. We quantified markers of inflammation, angiogenesis, antioxidant enzymes and collagen content. Moreover, we evaluate reactive oxygen species (ROS) levels and macrophage phenotype, M1 and M2.

RESULTS

CB₁R expression is decreased in the skin of WT DM mice and collagen levels are decreased in the skin of WT DM, CB₁RKO and CB₁RKO DM mice. Additionally, the absence of CB₁R correlated with higher expression of pro-inflammatory markers, also evident in WT DM or CB₁RKO DM mice. Moreover, the M1/M2 macrophage ratio and ROS levels were significantly elevated but in the diabetic WT and the CB₁RKO mice, consistent with a significant decrease in the antioxidant capacity of the skin.

CONCLUSIONS

Our results indicate that CB₁R deficiency in the skin may lead to accelerated skin aging due to the increased production of ROS, a decrease in the antioxidant defenses and a higher pro-inflammatory environment. A significant decrease in the CB₁R expression may be a significant contributing factor to the early aging-like changes in diabetes.

Autologous platelet-rich fibrin (PRF) augmentation as an add-on therapy in deep surgical site infections (dSSIs) after instrumented spinal surgery: preliminary results of a single institution case series

BACKGROUND

Deep surgical site infections (dSSIs) after instrumented spinal surgery pose major therapeutic challenges. Standard treatment involves surgical debridement, wound drainage, and long-term antibiotic administration. Autologous platelet-rich fibrin (PRF) constitutes a biomaterial obtained from patients' own blood that contains leukocytes, chemokines and growth factors boosting cicatrization. Due to favorable results reported from other surgical disciplines such as dentistry, orthopedics, maxillofacial and plastic surgery using PRF, the authors hypothesized that PRF augmentation will promote wound healing in dSSIs.

OBJECTIVE

To report our preliminary results on the safety and efficacy of autologous-PRF as an add-on therapy on a pilot case series of persistent dSSI after instrumented spinal surgery.

METHODS

Among the 293 patients who underwent dorsal decompression and stabilization of the cervical, thoracic, and lumbar spine due to degenerative diseases in our department, 12 patients (4%) presented persisting dSSI after standard wound debridement and antibiotic treatment. PRF augmentation was used during a second surgical revision as an add-on therapy to standard debridement. In all cases, the wound was primarily closed without drains.

RESULTS

Wound healing was completed between 14 and 21 days after the second surgical revision in all patients. At a median follow-up of 8 months (range: 6 to 18 months), no recurrence of dSSI nor complications were encountered in any case.

CONCLUSIONS

Our preliminary results suggest that PRF augmentation in persistent dSSI after instrumented spinal surgery appears to be a safe and effective strategy to promote wound healing. Prospective controlled studies are required to define the efficiency of PRF more clearly in both treating and preventing dSSI.

Cutaneous innervation in impaired diabetic wound healing

Type 2 diabetes is associated with several potential comorbidities, among them impaired wound healing, chronic ulcerations, and the requirement for lower extremity amputation. Disease-associated abnormal cellular responses, infection, immunological and microvascular dysfunction, and peripheral neuropathy are implicated in the pathogenesis of the wound healing impairment and the diabetic foot ulcer. The skin houses a dense network of sensory nerve afferents and nerve-derived modulators, which communicate with epidermal keratinocytes and dermal fibroblasts bidirectionally to effect normal wound healing after trauma. However, the mechanisms through which cutaneous innervation modulates wound healing are poorly understood, especially in humans. Better understanding of these mechanisms may provide the basis for targeted treatments for chronic diabetic wounds. This review provides an overview of wound healing pathophysiology with a focus on neural involvement in normal and diabetic wound healing, as well as future therapeutic perspectives to address the unmet needs of diabetic patients with chronic wounds.

Balanitis Xerotica Obliterans Associated With Differentiated Penile Intraepithelial Neoplasia and "Bramble-Bush" Elastic Fibers Accumulation: A Finding Not Specific for Penicillamine Intake

We describe the association of balanitis xerotica obliterans and differentiated penile intraepithelial neoplasia (PeIN) with dermal elastosis and "bramble-bush" elastic fibers in a diabetic patient with no history of penicillamine intake. An 84-year-old man presented with urethral obstruction syndrome that required postectomy, meatotomy, and foreskin excision. Histopathological examination revealed changes of lichen sclerosus and differentiated PeIN. Orcein staining showed striking dermal elastosis and transepidermal elimination of elastic fibers. At higher magnification, multiple serrations and buds arising from the borders of the elastic fibers were observed giving the so-called bramble-bush appearance. Balanitis xerotica obliterans is considered a premalignant disease, and 14% of patients have evidence of PeIN. The differentiated subtype can be difficult to diagnose because of the minimal basal cell atypia, so a striking dermal elastosis, which may even occur before the neoplasm becomes invasive, may facilitate its diagnosis. The term "acquired perforating dermatosis" seems appropriate to describe those cases of perforating elastosis that occurs in adults with systemic diseases. The bramble-bush appearance of elastic fibers is not specific for penicillamine-induced elastopathy, and it may occur in other diseases, such as diabetes mellitus. This peculiar morphology of elastic fibers may be related to the enzymatic imbalance between matrix metalloproteinases and lysyl oxidase, an enzyme required for the cross-linking of elastic fibers.

Ultraviolet light-induced collagen degradation inhibits melanoma invasion

Ultraviolet radiation (UVR) damages the dermis and fibroblasts; and increases melanoma incidence. Fibroblasts and their matrix contribute to cancer, so we studied how UVR modifies dermal fibroblast function, the extracellular matrix (ECM) and melanoma invasion. We confirmed UVR-damaged fibroblasts persistently upregulate collagen-cleaving matrix metalloprotein-1 (MMP1) expression, reducing local collagen (COL1A1), and COL1A1 degradation by MMP1 decreased melanoma invasion. Conversely, inhibiting ECM degradation and MMP1 expression restored melanoma invasion. Primary cutaneous melanomas of aged humans show more cancer cells invade as single cells at the invasive front of melanomas expressing and depositing more collagen, and collagen and single melanoma cell invasion are robust predictors of poor melanoma-specific survival. Thus, primary melanomas arising over collagen-degraded skin are less invasive, and reduced invasion improves survival. However, melanoma-associated fibroblasts can restore invasion by increasing collagen synthesis. Finally, high COL1A1 gene expression is a biomarker of poor outcome across a range of primary cancers.

Skin Complications of Diabetes Mellitus Revealed by Polarized Hyperspectral Imaging and Machine Learning

Aging and diabetes lead to protein glycation and cause dysfunction of collagen-containing tissues. The accompanying structural and functional changes of collagen significantly contribute to the development of various pathological malformations affecting the skin, blood vessels, and nerves, causing a number of complications, increasing disability risks and threat to life. In fact, no methods of non-invasive assessment of glycation and associated metabolic processes in biotissues or prediction of possible skin complications, e.g., ulcers, currently exist for endocrinologists and clinical diagnosis. In this publication, utilizing emerging photonics-based technology, innovative solutions in machine learning, and definitive physiological characteristics, we introduce a diagnostic approach capable of evaluating the skin complications of diabetes mellitus at the very earlier stage. The results of the feasibility studies, as well as the actual tests on patients with diabetes and healthy volunteers, clearly show the ability of the approach to differentiate diabetic and control groups. Furthermore, the developed in-house polarization-based hyperspectral imaging technique accomplished with the implementation of the artificial neural network provides new horizons in the study and diagnosis of age-related diseases.

Dermal Drivers of Injury-Induced Inflammation: Contribution of Adipocytes and Fibroblasts

Irregular inflammatory responses are a major contributor to tissue dysfunction and inefficient repair. Skin has proven to be a powerful model to study mechanisms that regulate inflammation. In particular, skin wound healing is dependent on a rapid, robust immune response and subsequent dampening of inflammatory signaling. While injury-induced inflammation has historically been attributed to keratinocytes and immune cells, a vast body of evidence supports the ability of non-immune cells to coordinate inflammation in numerous tissues and diseases. In this review, we concentrate on the active participation of tissue-resident adipocytes and fibroblasts in pro-inflammatory signaling after injury, and how altered cellular communication from these cells can contribute to irregular inflammation associated with aberrant wound healing. Furthering our understanding of how tissue-resident mesenchymal cells contribute to inflammation will likely reveal new targets that can be manipulated to regulate inflammation and repair.

Dermal fibroblasts cultured from donors with type 2 diabetes mellitus retain an epigenetic memory associated with poor wound healing responses

The prevalence of Type 2 diabetes mellitus (T2DM) is escalating globally. Patients suffer from multiple complications including the development of chronic wounds that can lead to amputation. These wounds are characterised by an inflammatory environment including elevated tumour necrosis factor alpha (TNF-α). Dermal fibroblasts (DF) are critical for effective wound healing, so we sought to establish whether there were any differences in DF cultured from T2DM donors or those without diabetes (ND-DF). ND- and T2DM-DF when cultured similarly in vitro secreted comparable concentrations of TNF-α. Functionally, pre-treatment with TNF-α reduced the proliferation of ND-DF and transiently altered ND-DF morphology; however, T2DM-DF were resistant to these TNF-α induced changes. In contrast, TNF-α inhibited ND- and T2DM-DF migration and matrix metalloprotease expression to the same degree, although T2DM-DF expressed significantly higher levels of tissue inhibitor of metalloproteases (TIMP)-2. Finally, TNF-α significantly increased the secretion of pro-inflammatory cytokines (including CCL2, CXCL1 and SERPINE1) in ND-DF, whilst this effect in T2DM-DF was blunted, presumably due to the tendency to higher baseline pro-inflammatory cytokine expression observed in this cell type. Collectively, these data demonstrate that T2DM-DF exhibit a selective loss of responsiveness to TNF-α, particularly regarding proliferative and secretory functions. This highlights important phenotypic changes in T2DM-DF that may explain the susceptibility to chronic wounds in these patients.

The Imbalance of MMP-2/TIMP-2 and MMP-9/TIMP-1 Contributes to Collagen Deposition Disorder in Diabetic Non-Injured Skin

The importance of the early diagnosis and treatment of diabetes and its cutaneous complications has become increasingly recognized. When diabetic non-injured skin was stained with Masson's trichrome, its dermal collagen was found to be disordered, its density was variable, and it was dispersed or arranged in vague fascicles. The collagen type I sequencing results of RNA sequencing-based transcriptome analysis of three primary human skin cell types-dermal fibroblasts, dermal microvascular endothelial cells, and epidermal keratinocytes-under high glucose were analyzed. The results showed that both COL1A1 and COL1A2 mRNA expressions were reduced in human dermal fibroblasts (HDFs). The ratio of matrix metalloproteinase (MMP)-2/tissue inhibitors of metalloproteinase (TIMP)-2 and MMP-9/TIMP-1 in HDFs increased when treated with high glucose. By inhibiting MMP-2 and MMP-9 with SB-3CT, collagen deposition disorder of the skin in streptozotocin-induced diabetes mice was alleviated. The imbalance of MMP2/TIMP2 and MMP9/TIMP1 contributes to the non-injured skin disorder of collagen deposition in diabetes, suggesting a possibility for early treatment of diabetes skin complications.

Insights into the effect of artificial sweeteners on the structure, stability, and fibrillation of type I collagen

Artificial sweeteners (AS) are widely used as sugar substitutes because natural sweetener (sugar) leads to a number of health issues, including diabetes, obesity, and tooth decay. Since natural sugar (sucrose), diabetes and skin are highly interlinked, and also sucrose is known to inhibit the fibrillation of collagen, the major protein of the skin, a study on the impact of AS on collagen is important and essential. Herein, we have studied the influence of commonly used AS such as Sucralose (SUC), Aspartame (APM), and Saccharin (SAC) on the structure, stability, and fibrillation of collagen using various spectroscopic methods. The circular dichroism and turbidity results suggest that the AS does not disrupt the triple helix structure and also the fibrillar property of collagen, respectively. The fibrillar morphology was sustained, although there was a trivial difference in the entanglement of fibrils in the presence of SAC, compared to native collagen fibrils. The thermal stability of collagen is maintained in the presence of AS. Fluorescence and STD-NMR results indicate that the interaction between AS and collagen was weak, which supports the intact structure, stability, and fibrillation property of collagen. The current study thus suggests that the chosen AS does not influence collagen properties.

Biophotonics methods for functional monitoring of complications of diabetes mellitus

The prevalence of diabetes complications is a significant public health problem with a considerable economic cost. Thus, the timely diagnosis of complications and prevention of their development will contribute to increasing the length and quality of patient life, and reducing the economic costs of their treatment. This article aims to review the current state-of-the-art biophotonics technologies used to identify the complications of diabetes mellitus and assess the quality of their treatment. Additionally, these technologies assess the structural and functional properties of biological tissues, and they include capillaroscopy, laser Doppler flowmetry and hyperspectral imaging, laser speckle contrast imaging, diffuse reflectance spectroscopy and imaging, fluorescence spectroscopy and imaging, optical coherence tomography, optoacoustic imaging and confocal microscopy. Recent advances in the field of optical noninvasive diagnosis suggest a wider introduction of biophotonics technologies into clinical practice and, in particular, in diabetes care units.

Extracellular matrix-derived biomaterials in engineering cell function

Extracellular matrix (ECM) derived components are emerging sources for the engineering of biomaterials that are capable of inducing desirable cell-specific responses. This review explores the use of biomaterials derived from naturally occurring ECM proteins and their derivatives in approaches that aim to regulate cell function. Biomaterials addressed are grouped into six categories: purified single ECM proteins, combinations of purified ECM proteins, cell-derived ECM, tissue-derived ECM, diseased and modified ECM, and ECM-polymer coupled biomaterials. Purified ECM proteins serve as a material coating for enhanced cell adhesion and biocompatibility. Cell-derived and tissue-derived ECM, generated by cell isolation and decellularization technologies, can capture the native state of the ECM environment and guide cell migration and alignment patterns as well as stem cell differentiation. We focus primarily on recent advances in the fields of soft tissue, cardiac, and dermal repair, and explore the utilization of ECM proteins as biomaterials to engineer cell responses.

Galactose-Induced Skin Aging: The Role of Oxidative Stress

Skin aging has been associated with a higher dietary intake of carbohydrates, particularly glucose and galactose. In fact, the carbohydrates are capable of damaging the skin's vital components through nonenzymatic glycation, the covalent attachment of sugar to a protein, and subsequent production of advanced glycation end products (AGEs). This review is focused on the role of D-galactose in the development of skin aging and its relation to oxidative stress. The interest in this problem was dictated by recent findings that used in vitro and in vivo models. The review highlights the recent advances in the underlying molecular mechanisms of D-galactose-mediated cell senescence and cytotoxicity. We have also proposed the possible impact of galactosemia on skin aging and its clinical relevance. The understanding of molecular mechanisms of skin aging mediated by D-galactose can help dermatologists optimize methods for prevention and treatment of skin senescence and aging-related skin diseases.

Role of the lysyl oxidase family in organ development (Review)

Lysyl oxidase proteins (LOXs) are amine oxidases, which are mainly located in smooth muscle cells and fibroblasts and serve an important role in the formation of the extracellular matrix (ECM) in a copper-dependent manner. Owing to the ability of LOX proteins to modulate crosslinking between collagens and to promote the deposition of other fibers, they serve crucially in organogenesis and the subsequent organ development, as well as disease initiation and progression. In addition, ECM formation significantly influences organ morphological formation in both cancer- and non-tumor-related diseases, in addition to cellular epigenetic transformation and migration, under the influence of LOXs. A number of different signaling pathways regulate the LOXs expression and their enzymatic activation. The tissue remodeling and transformation process shares some resemblance between oncogenesis and embryogenesis. Additionally the roles that LOXs serve appeared to be stressed during oncogenesis and tumor metastasis. It has also been indicated LOXs have a noteworthy role in non-tumor diseases. Nonetheless, the role of LOXs in systemic or local organ development and disease control remains unknown. In the present study, the essential roles that LOXs play in embryogenesis were unveiled partially, whereas the role of LOXs in organ or systematic development requires further investigations. The present review aimed to discuss the roles of members of the LOX family in the context of the remodeling of organogenesis and organ development. In addition, the consequences of the malfunction of these proteins related to the development of abnormalities and resulting diseases is discussed.

The role of extracellular matrix in the pathophysiology of diabetic wounds

Impaired healing leading to the formation of ulcerated wounds is a critical concern in patients with diabetes. Abnormalities in extracellular matrix (ECM) production and remodeling contribute to tissue dysfunction and delayed healing. Specifically, diabetes-induced changes in the expression and/or activity of structural proteins, ECM-modifying enzymes, proteoglycans, and matricellular proteins have been reported. In this review, we provide a summary of the key ECM molecules and associated changes in skin and diabetic wounds. Such information should allow for new insights in the understanding of impaired wound healing and lead to the development of ECM-based therapeutic strategies.

Wound senescence: A functional link between diabetes and ageing?

Arguably, the two most important causes of pathological healing in the skin are diabetes and ageing. While these factors have historically been considered independent modifiers of the healing process, recent studies suggest that they may be mechanistically linked. The primary contributor to diabetic pathology is hyperglycaemia, which accelerates the production of advanced glycation end products, a characteristic of ageing tissue. Indeed, advanced age also leads to mild hyperglycaemia. Here, we discuss emerging literature that reveals a hitherto unappreciated link between cellular senescence, diabetes and wound repair. Senescent cells cause widespread destruction of normal tissue architecture in ageing and have been shown to be increased in chronic wounds. However, the role of senescence remains controversial, with several studies reporting beneficial effects for transiently induced senescence in wound healing. We recently highlighted a direct role for senescence in diabetic healing pathology, mediated by the senescence receptor, CXCR2. These findings suggest that targeting local tissue senescence may provide a therapeutic strategy applicable to a broad range of chronic wound types.

Accelerated degradation of collagen membranes in type 1 diabetic rats is associated with increased expression and production of several inflammatory molecules

BACKGROUND

Membrane durability is critical for regenerative procedures. We reported previously that type 1-like diabetes in rats accelerates the degradation of collagen membranes and we tested here whether this is associated with increased local production of inflammatory molecules as part of a diabetes-induced chronic inflammation around and within the membranes.

METHODS

Collagen membrane discs were implanted under the scalp in diabetic (streptozotocin-induced) and control rats, which were sacrificed after 2 or 3 weeks. Total RNA and proteins were isolated from the membrane and its surrounding tissues and the expression and production of six inflammatory molecules (interleukin-6 [IL-6], tumor necrosis factor alpha [TNFα], matrix metalloproteinase [MMP]-9, macrophage migration inhibitory factor [MIF], MIP-1α, and MIP-2α) was measured using real-time PCR and western blotting, respectively. Minimal histological analysis of the membranes was conducted to conform to previous studies.

RESULTS

Hyperglycemia resulted in reduced membrane thickness (by 10% to 25%) and increased mononuclear infiltrate inside the membrane. mRNA and protein levels of IL-6, TNFα, and MMP-9 were elevated in diabetic rats both 2 and 3 weeks post-surgery. The levels (both mRNA and protein) of MIF were increased at 2 weeks post-surgery and those of MIP-1α and MIP-2α at 3 weeks. There was a very good match in the temporal changes of all examined genes between the mRNA and protein levels.

CONCLUSIONS

Elevated local production of inflammatory cytokines and MMPs, together with apparent mononuclear infiltrate and increased collagenolysis confirm that hyperglycemia leads to a chronic inflammation in and around the implanted collagen membranes, which reduces membrane longevity.

Cellular Senescence as the Pathogenic Hub of Diabetes-Related Wound Chronicity

Diabetes is constantly increasing at a rate that outpaces genetic variation and approaches to pandemic magnitude. Skin cells physiology and the cutaneous healing response are progressively undermined in diabetes which predisposes to lower limb ulceration, recidivism, and subsequent lower extremities amputation as a frightened complication. The molecular operators whereby diabetes reduces tissues resilience and hampers the repair mechanisms remain elusive. We have accrued the notion that diabetic environment embraces preconditioning factors that definitively propel premature cellular senescence, and that ulcer cells senescence impair the healing response. Hyperglycemia/oxidative stress/mitochondrial and DNA damage may act as major drivers sculpturing the senescent phenotype. We review here historical and recent evidences that substantiate the hypothesis that diabetic foot ulcers healing trajectory, is definitively impinged by a self-expanding and self-perpetuative senescent cells society that drives wound chronicity. This society may be fostered by a diabetic archetypal secretome that induces replicative senescence in dermal fibroblasts, endothelial cells, and keratinocytes. Mesenchymal stem cells are also susceptible to major diabetic senescence drivers, which accounts for the inability of these cells to appropriately assist in diabetics wound healing. Thus, the use of autologous stem cells has not translated in significant clinical outcomes. Novel and multifaceted therapeutic approaches are required to pharmacologically mitigate the diabetic cellular senescence operators and reduce the secondary multi-organs complications. The senescent cells society and its adjunctive secretome could be an ideal local target to manipulate diabetic ulcers and prevent wound chronification and acute recidivism. This futuristic goal demands harnessing the diabetic wound chronicity epigenomic signature.

Experimental Investigation on the Tissue Response Induced by Face-Lifting Mesh Suspension Thread in Rats

Background

Face-lifting procedures are often performed to hide the effects of aging. Thread-lifting, a minimally invasive technique for the correction of facial aging, has become increasingly popular, and various materials for the procedure have been developed.

Objective

This study compared tissue responses to two types of threading sutures placed under rat skin: polypropylene (PP) monofilament mesh suspension thread (a novel face-lifting material) and polydioxanone (PDO) barbed thread.

Methods

Eight rats each were assigned to the PP monofilament mesh suspension, PDO barbed thread, and control groups. Tissue reactions were evaluated 28 days after subcutaneous loading of the materials.

Results

Significant increases in tensile strength and the mean area occupied by collagen fibers were evident in skin loaded with PDO barbed thread and PP monofilament mesh suspension thread compared to control skin (p<0.05). Compared to sites loaded with PDO barbed thread, those loaded with PP monofilament mesh suspension thread showed a significant increase in the number of collagen fibers and a lower grade of inflammation (p<0.05).

Conclusion

PP monofilament mesh suspension thread has skin-rejuvenating effects comparable to those of PDO barbed thread, but induces a less severe inflammatory response. This indicates that it is a safe and effective material for use in thread-lifting procedures on aging skin.

When Wounds Are Good for You: The Regenerative Capacity of Fractional Resurfacing and Potential Utility in Chronic Wound Prevention

Significance: Fractional resurfacing involves producing arrays of microinjuries on the skin, by thermal or mechanical means, to trigger tissue regeneration. Originally developed for cosmetic enhancement, fractional resurfacing induces a broad array of improvements in the structural and functional qualities of the treated skin and is especially effective at returning defective skin to a more normal state. In addition to fascinating questions about the nature of this remarkable regenerative capacity, there may be potential utility in ulcer prevention by halting or even reversing the progressive decline in overall skin quality that usually precedes chronic wound development. Recent Advances: Photoaging and scarring are the two skin defects most commonly treated by fractional resurfacing, and the treatment produces profound and long-lasting improvements in skin quality, both clinically and at the cellular/histologic level. Chronic wounds usually occur in skin that is compromised by various pathologic factors, and many of the defects found in this ulcer-prone skin are similar to those that have seen improvements after fractional resurfacing. Critical Issues: The mechanisms responsible for the regenerative capacity of fractional resurfacing are mostly unknown, as is how ulcer-prone skin, which is usually afflicted by stressors external to the skin tissue itself, would respond to fractional resurfacing. Future Directions: Better understanding of the cellular and molecular mechanisms underlying the unique healing response to fractional resurfacing could reveal fundamental information about adult tissue regeneration, lead to improvements in current applications, as well as new therapies in other pathologic conditions.

In vitro modulation of extracellular matrix genes by stingless bee honey in cellular aging of human dermal fibroblast cells

This study determined the antiaging effect of stingless bee honey on the expression of extracellular matrix genes. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was performed for determination of optimum concentration and incubation time of stingless bee honey. Gene expression of matrix metalloproteinase-1 (MMP-1) and collagen type Ⅰ (COL1A1) were analyzed using real time reverse transcriptase polymerase chain reaction technique. Incubation with stingless bee honey at concentration of 0.02% for 72 hr showed significant increase in the viability of human fibroblast cells. Stingless bee honey significantly downregulates metalloproteinase-1 gene expression in both pre-senescence and senescence fibroblast cells and upregulates collagen type Ⅰ gene expression in senescence fibroblast cells. In conclusion, stingless bee honey potentially delayed skin aging through modulation of extracellular matrix genes. PRACTICAL APPLICATIONS: Changes of the extracellular matrix regulation promote skin aging. Stingless bee honey is a good source of natural antioxidant which potentially delays skin aging. This study demonstrated that stingless bee honey beneficially increases collagen type Ⅰ expression and decreases MMP-1 expression during cellular aging of human dermal fibroblast cells.

Amelioration of Cavernosal Fibrosis and Erectile Function by Lysyl Oxidase Inhibition in a Rat Model of Cavernous Nerve Injury

BACKGROUND

Cavernous nerve injury (CNI) causes fibrosis and loss of smooth muscle cells (SMCs) in the corpus cavernosum and leads to erectile dysfunction, and lysyl oxidase (LOX) activation has been found to play an important role in fibrotic diseases.

AIM

To evaluate the role of LOX in penile fibrosis after bilateral CNI (BCNI).

METHODS

Rats underwent BCNI or a sham operation and were treated with vehicle or β-aminopropionitrile, a specific LOX activity inhibitor. 30 days after BCNI, rats were tested for erectile function before penile tissue harvest. LOX and extracellular matrix component expression levels in the corpus cavernosum, including matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), fibronectin (FN), collagen (COL) I, and COL IV, were evaluated by real-time quantitative polymerase chain reaction and western blot. Corporal fibrosis was evaluated by Masson trichrome staining. Localization of LOX and SMC content in the corpus cavernosum were assessed by immunohistochemistry.

OUTCOMES

Ratio of intracavernous pressure to mean arterial blood pressure; LOX, MMPs, TIMPs, COL I, COL IV, and FN expression; penile fibrosis; penile SMC content.

RESULTS

After BCNI, there was an increase in penile LOX expression and activity, increased penile fibrosis, decreased SMC content, and impaired erectile function. TIMP1, TIMP2, COL I, COL IV, and FN expression was markedly upregulated, whereas the enzyme activity of MMPs was decreased after BCNI. β-Aminopropionitrile treatment, at least in part, prevented a decrease in the ratio of intracavernous pressure to mean arterial blood pressure, decreased penile expression of TIMP1, TIMP2, COL I, COL IV, and FN, increased MMP activity, prevented corporal fibrosis, and preserved SMC content.

CLINICAL TRANSLATION

LOX over-activation contributes to penile fibrosis and LOX inhibition could be a promising strategy in preventing the progression of CNI-induced erectile dysfunction.

STRENGTHS AND LIMITATIONS

This is the 1st study to demonstrate the role of LOX activation in penile fibrosis. However, the exact mechanism of how LOX influences extracellular matrix protein synthesis and SMC content preservation awaits further investigation.

CONCLUSION

CNI induced LOX over-activation in cavernous tissue, and inhibition of LOX preserved penile morphology and improved erectile function in a rat model of BCNI. Wan Z-H, Li G-H, Guo Y-L, et al. Amelioration of Cavernosal Fibrosis and Erectile Function by Lysyl Oxidase Inhibition in a Rat Model of Cavernous Nerve Injury. J Sex Med 2018;15:304-313.

Quantitative evaluation of skin disorders in type 1 diabetic mice by in vivo optical imaging

Diabetes can affect the skin structure as well as the cutaneous vascular permeability. However, effective methods to quantitatively evaluate diabetes-induced skin disorders in vivo are still lacking. Here, we visualized the skin by using in vivo two-photon imaging and quantitatively evaluated the collagen morphology. The results indicated that diabetes could cause a significant reduction in the number of collagen fibers and lead to the disorder of skin collage fibers. And, the classic histological analysis also showed diabetes did lead to the change of skin filamentous structure. Additionally, the Evans Blue dye was used as an indicator to evaluate vascular permeability. We in vivo monitored cutaneous microvascular permeability by combining spectral imaging with the skin optical clearing method. This work is very useful for quantitative evaluation of skin disorders based on in vivo optical imaging, which has a great reference value in the clinical diagnosis.