A new mechanism in negative pressure wound therapy: interleukin-17 alters chromatin accessibility profiling.

Negative pressure wound therapy (NPWT) is extensively used in clinical settings to enhance the healing of wounds. Despite its widespread use, the molecular mechanisms driving the efficacy of NPWT have not been fully elucidated. In this study, skin wound-healing models were established, with administration of NPWT. Vimentin, collagen I, and MMP9 of skin tissues were detected by immunofluorescence (IF). Gene expression analysis of skin wound tissues was performed by RNA-sequencing (RNA-seq). Protein expression was assayed by a Western blotting or IF assay, and mRNA levels were quantified by quantitative PCR. Chromatin accessibility profiles of fibroblasts following NPWT or IL-17 exposure were analyzed by ATAC-seq. In rat wound-healing models, NPWT promoted wound repair by promoting reepithelialization, extracellular matrix (ECM) synthesis, and proliferation, which mainly occurred in the early stage of wound healing. These differentially expressed genes (DEGs) in NPWT wounds versus control wounds were enriched in the IL-17 signaling pathway. IL-17 was identified as an upregulated factor following NPWT in skin wounds. Moreover, the IL-17 inhibitor secukinumab (SEC) could abolish the promoting effect of NPWT on wound healing. Importantly, chromatin accessibility profiles were altered following NPWT and IL-17 stimulation in skin fibroblasts. Our findings suggest that NPWT upregulates IL-17 to promote wound healing by altering chromatin accessibility, which is a novel mechanism for NPWT's efficacy in wound healing.NEW & NOTEWORTHY To our knowledge, this is the first report of the efficacy of negative pressure wound therapy (NPWT) in promoting wound healing via IL-17. Moreover, NPWT and IL-17 can alter chromatin accessibility. Our study identifies a novel mechanism for NPWT's efficacy in wound healing.

Epidemiology and Prognostic Factors Analysis of Electrical Injuries in Shaanxi, China: A Single-Center Observational Study of 385 Cases.

The objective of this research is to investigate the epidemiological features of electrical injuries in Shaanxi Province, China, examine their prognosis, and ascertain the factors that impact the outcomes. Telephone follow-ups were conducted with electrical injury patients at our hospital between 2011 and 2021, yielding the following results: Most electrical injuries occur in males (94.3%) and younger or middle-aged individuals. The most common voltages involved are 220V and 380V. Since 2016, there has been a 20.1% annual decrease in electrical injuries, with most cases occurring from April to September. Patients typically undergo 1 surgical procedure (0,3), with a 14.8% amputation rate and an average hospital stay of 21 days (9,43). 1.8% of electrical injury patients have died, 17.1% have permanent nerve damage, and 10.8% need help with daily tasks. 18.5% have psychological issues and 9.6% have PTSD. 93.7% return to work in an average of 6 months (2,12). Amputation risk is influenced by voltage, muscle injury, and current pathway; skin grafting risk is mainly due to voltage. Heart injuries are affected by unconsciousness and current pathways; labor loss risk factors include voltage, falls from heights, and muscle injury; nerve damage is linked to muscle injury. Cataract development risk is associated with electric shock to the head and neck. It is crucial to address the psychological well-being of patients and provide necessary support. Patient input should be taken into account when deciding on treatment for non-functional limbs. Physicians should evaluate prognostic factors and provide appropriate treatment to enhance patient outcomes.

Split-level folding, step-type tension-relieving suture technique, and the evaluation on scar minimization.

BACKGROUND: Prevailing tension-reducing suture methods have a spectrum of issues. This study presents a straightforward yet highly efficacious suture technique known as the Split-level Folding, Step-type Tension-relieving Suture technique, which could play a pivotal role in preempting incisional scarring. AIMS: To introduce Split-level Folding, Step-type Tension-relieving Suture technique and assess its effect on scar minimization. METHODS: A retrospective analysis of 64 patients who underwent treatment utilizing the proposed suturing methodology. Assessment parameters included the Patient and Observer Scar Assessment Scale (POSAS), the Vancouver Scar Scale (VSS), scar width, complications, and all evaluated at 6- and 12-month postoperatively. RESULTS: At 12-month follow-up, the POSAS and VSS scores in the normal suture group (32.58 ± 5.43, 3.58 ± 1.39) were considerably higher than the step-type suture group (29.75 ± 3.56, p = 0.0007; 2.78 ± 1.17, p = 0.0006). Moreover, the step-type suture group showcased a significantly narrower average incision scar width (1.62 ± 0.36) than the normal suture group (1.87 ± 0.42, p = 0.0004). This novel tension-relieving suture technique that effectively circumvents the occurrence of persistent localized eversion and other complications often associated with traditional tension-relieving sutures. CONCLUSIONS: The Split-level Folding, Step-type Tension-relieving Suture technique emerges as a highly promising option for averting incisional scarring. This suture method works well for incisions on the chest, back, and extremities, resulting in significantly better long-term outcomes.

MicroRNA-137 promoter methylation in oral lichen planus and oral squamous cell carcinoma.

Oral lichen planus (OLP) is a common oral mucosal disease, which is generally considered a potentially malignant lesion. To identify efficiently prognostic biomarker, we investigated the microRNA-137 (miR-137) promoter methylation in OLP and compared with the samples from healthy volunteers and patients with oral squamous cell carcinoma (OSCC). A total of 20 OLP and 12 patients with OSCC as well as 10 healthy subjects were subjected to miR-137 promoter methylation analysis using methylation-specific PCR (MSP). To address the malignancy prediction potential from miR-137 promoter methylation status, methylation of the p16 gene, a well-known tumor suppressor, was investigated in the same samples. The p16 methylation and miR-137 promoter methylation were found to be 25% and 35% in patients with OLP, 50% and 58.3% in patients with OSCC, and 0% and 0% in healthy subjects, respectively. The differences between miR-137 and p16 methylation levels were statistically significant between healthy controls and patients. Methylation levels of the two promoters were also influenced by age, gender, and lesion duration. Interestingly, aberrant promoter methylation of the p16 and miR-137 genes was only found in the epithelium but not in the connective tissue from patients with OLP. This raises the possibility to use miR-137 methylation as a biomarker for malignant prediction in patients with OLP.

Downregulation of tumor suppressor QKI in gastric cancer and its implication in cancer prognosis.

Gastric cancer (GC) is the fourth most common cancer and second leading cause of cancer-related death worldwide. RNA-binding protein Quaking (QKI) is a newly identified tumor suppressor in multiple cancers, while its role in GC is largely unknown. Our study here aimed to clarify the relationship between QKI expression with the clinicopathologic characteristics and the prognosis of GC. In the 222 GC patients' specimens, QKI expression was found to be significantly decreased in most of the GC tissues, which was largely due to promoter hypermethylation. QKI overexpression reduced the proliferation ability of GC cell line in vitro study. In addition, the reduced QKI expression correlated well with poor differentiation status, depth of invasion, gastric lymph node metastasis, distant metastasis, advanced TNM stage, and poor survival. Multivariate analysis showed QKI expression was an independent prognostic factor for patient survival.

MicroRNA-320a suppresses human colon cancer cell proliferation by directly targeting ß-catenin.

Recent profile studies of microRNA (miRNA) expression have documented a deregulation of miRNA (miR-320a) in human colorectal carcinoma. However, its expression pattern and underlying mechanisms in the development and progression of colorectal carcinoma has not been elucidated clearly. Here, we performed real-time PCR to examine the expression levels of miR-320a in colon cancer cell lines and tumor tissues. And then, we investigated its biological functions in colon cancer cells by a gain of functional strategy. Further more, by the combinational approaches of bioinformatics and experimental validation, we confirmed target associations of miR-320a in colorectal carcinoma. Our results showed that miR-320a was frequently downregulated in cancer cell lines and colon cancer tissues. And we demonstrated that miR-320a restoration inhibited colon cancer cell proliferation and ß-catenin, a functionally oncogenic molecule was a direct target gene of miR-320a. Finally, the data of real-time PCR showed the reciprocal relationship between miR-320a and ß-catenin's downstream genes in colon cancer tissues. These findings indicate that miR-320a suppresses the growth of colon cancer cells by directly targeting ß-catenin, suggesting its application in prognosis prediction and cancer treatment.

pH regulates the lumen diameter of tissue-engineered capillaries.

Angiogenesis is vital in tissue engineering and the size of the capillary lumen diameter directly affects vascular function. Therefore, the involvement of the pH in the regulation of the capillary lumen diameter was investigated in the present study. The cytosolic pH of different pH medium groups was measured using flow cytometry. Bromodeoxyuridine staining and wound-healing assays were performed to detect cell proliferation and migration, respectively. The expression of angiogenesis-related genes was detected using reverse transcription-quantitative PCR. In addition, cell tube formation under different pH conditions was assessed using a tube formation assay and a 3D Matrigel® model. The results indicated that a change in the pH value of the culture medium affected the cytosolic pH of the endothelial cells, which then led to a change in vascular diameter. When the medium's pH ranged from 7.4 to 7.6, the diameter of the lumen formed in the Matrigel was suitable for capillary formation in tissue engineering. The present results revealed an important role for the pH in the process of capillary formation and provided insight for pH regulation during endothelial cell tube formation and angiogenesis in tissue engineering.

A Biomimetic Basement Membrane Substitute Based on Tri-Layered Nanofibrous Scaffold for Skin Reconstruction.

Developing basement membranes (BMs) substitute remains major problem for constructing functional tissue engineered skin because of its complex structure and multifunction of regulating cellular behavior. Herein, a stable electrospinning method was employed to generate a biomimetic model of natural BMs based on novel scaffold electrospun from Poly(ɛ-caprolactone) (PCL) and cellulose acetate (CA) incorporated with chitosan (CS). The morphology, structure, surface hydrophilicity, roughness and mechanical tensile strength of prepared monolayer and tri-layered scaffold were comprehensively compared. Besides, co-culture system via seeding keratinocytes (Kcs) and fibroblasts (Fbs) on opposite side of tri-layered scaffold revealed more effective segregation of both cell types within the central nanofibrous barrier together with enhanced cell attachment and proliferation than that on the monolayer scaffold. Moreover, the deposition of type VII collagen and laminin-5 was examined in comparison with normal skin BMs. Furthermore, the histological studies revealed characteristics of reconstructing BM zone at the junction of dermis-epidermis after in vivo implantation for 2 weeks, and wound healing while the seeded cells interacted with the endogenous cells. Additionally, the expression of active integrin ß1 and phosphorylated focal adhesion kinase (FAK) was promoted with treatment of tri-layered scaffold. This study stressed that this tri-layer scaffold might provoke biomimetic responses of Kcs and Fbs and thus be applied for future development of BMs containing tissues.

Precise and Arbitrary Deposition of Biomolecules onto Biomimetic Fibrous Matrices for Spatially Controlled Cell Distribution and Functions.

Advances in nano-/microfabrication allow the fabrication of biomimetic substrates for various biomedical applications. In particular, it would be beneficial to control the distribution of cells and relevant biomolecules on an extracellular matrix (ECM)-like substrate with arbitrary micropatterns. In this regard, the possibilities of patterning biomolecules and cells on nanofibrous matrices are explored here by combining inkjet printing and electrospinning. Upon investigation of key parameters for patterning accuracy and reproducibility, three independent studies are performed to demonstrate the potential of this platform for: i) transforming growth factor (TGF)-ß1-induced spatial differentiation of fibroblasts, ii) spatiotemporal interactions between breast cancer cells and stromal cells, and iii) cancer-regulated angiogenesis. The results show that TGF-ß1 induces local fibroblast-to-myofibroblast differentiation in a dose-dependent fashion, and breast cancer clusters recruit activated stromal cells and guide the sprouting of endothelial cells in a spatially resolved manner. The established platform not only provides strategies to fabricate ECM-like interfaces for medical devices, but also offers the capability of spatially controlling cell organization for fundamental studies, and for high-throughput screening of various biomolecules for stem cell differentiation and cancer therapeutics.

A Comparative Study on the Biological Characteristics of Human Adipose-Derived Stem Cells from Lipectomy and Liposuction.

PURPOSES: To compare the biological behaviors of human adipose-derived stem cells (ADSCs) isolated from adipose tissue by lipectomy and liposuction, with the purpose of providing the basis for clinical application. METHODS: The proliferation and apoptosis of ADSCs were analyzed by CCK-8 assay and flow cytometry. Cell migration was measured by a wound healing assay. An ELISA assay was used to evaluate paracrine functions. SOD and MDA were tested by xanthine oxidase and thiobarbituric acid reactions, respectively. In addition, we used a CCK-8, LDH assay and flow cytometry to analyze the proliferation and apoptosis of ADSCs treated with lidocaine or adrenaline. RESULTS: The viable ADSCs yield from liposuction was significantly lower than that from lipectomy, while the apoptosis of cells from liposuction was significantly higher than from lipectomy. The paracrine secretion of the two sources of ADSCs was highest when treated with 10-7 mol/L insulin and 10 ng/mL TGF-α, but there were no significant differences in VEGF, IL-6, IL-8 or HGF levels. The ADSCs from lipectomy migrated faster than those from liposuction, and SOD in the lipectomy group was higher than in the liposuction group, whereas MDA of the lipectomy group was lower than that of the liposuction group. The proliferation ADSCs treated with lidocaine or adrenaline was greatly decreased, while apoptosis was significantly increased, and cytotoxicity of lidocaine or adrenaline to ADSCs was dose-dependent. CONCLUSIONS: Compared with ADSCs from liposuction, the ADSCs from lipectomy have better biological characteristics. Lidocaine and adrenaline decreased the viability of ADSCs, and their cytotoxicity to ADSCs was dose-dependent.

Wound-healing improvement by resurfacing split-thickness skin donor sites with thin split-thickness grafting.

INTRODUCTION: Split-thickness skin graft (STSG) donor site dressing has been controversial until now. Our study aimed to assess the patient comfort and wound-healing efficacy with the application of thin split-thickness skin grafts regrafting on STSG donor sites. METHODS: One hundred ninety-two consecutive patients undergoing split-thickness skin grafting were included in the study, and the participants were randomly divided into the following three groups: group A was regrafted with thin STSGs and groups B and C were covered with occlusive hydrocellular dressing and paraffin gauze, respectively. The participants were compared according to the epithelialization time, pain and scar formation. RESULTS: The average time of epithelialization was 6.2 ± 1.1 days in group A, 11.1 ± 2.1 days in group B and 13.5 ± 2.5 days in group C. The pain scores on days 2 and 5 after operation were 2.3 ± 0.8 and 1.9 ± 0.8 in group A, 2.5 ± 1.1 and 3.9 ± 1.3 in group B, and 3.8 ± 1.4 and 5.9 ± 2.1 in group C. The scar scores at half a year and one year after operation were 4.3 ± 0.6 and 2.50 ± 0.6 in group A, 7.4 ± 0.6 and 6.2 ± 0.6 in group B, and 11.8 ± 0.4 and 10.9 ± 1.0 in group C, separately. The difference in the three groups was significant. CONCLUSION: Utilizing thin STSGs regrafting on donor sites could significantly shorten the epithelialization time, reduce pain and prevent hyperplastic scar formulation.

Biomimetic LBL structured nanofibrous matrices assembled by chitosan/collagen for promoting wound healing.

This paper reports the fabrication of biomimetic nanofibrous matrices via co-electrospinning of polycaprolactone (PCL)/cellulose acetate (CA) and layer-by-layer self-assembly (LBL) of positively charged chitosan (CS) and negatively charged Type Ⅰ collagen on the nanofibrous matrix. FE-SEM images indicate that the average fiber diameter increased from 392 to 541 nm when the coating bilayers varied from 5 to 20.5. Besides, the excellent biocompatibility and enhanced attachment and spreading of normal human dermal fibroblasts (NHDFs) of prepared nanofibrous mats are confirmed by MTT and SEM results. Furthermore, the LBL structured (CS/collagen)n nanofibrous mats greatly improve the cell migration in vitro, promote re-epithelialization and vascularization in vivo, and up-regulate the expression of collagen Ⅳ and α-tubulin, as well as the Integrin ß1 and phosphorylation of focal adhesion kinase (FAK) at Tyr-397. The levels of expressed protein are significantly enhanced with increasing coating bilayers via immunohistochemistry and western blotting analyses. Collectively, these results suggest that the LBL structured biomimetic nanofibrous matrices may enhance cell migration and further promote the skin regeneration by up-regulating the secretion of ECM protein and triggering Integrin/FAK signaling pathway, which demonstrate the potential use of the nanofibrous mats to rapidly restore the structural and functional properties of wounded skin.

E2F1 and RNA binding protein QKI comprise a negative feedback in the cell cycle regulation.

pRb/E2F1 activity is coordinately regulated during the cell cycle progression, while the molecular strategies safeguarding this pathway are not fully understood. We have previously shown that RNA binding protein QKI inhibits the cell proliferation and promotes the differentiation of gastrointestinal epithelium, suggesting a role of QKI in cell cycle regulation. Here we found that with the cell entry into S phase, QKI expression increased both at the mRNA and protein levels, which was reminiscent of cyclin E expression. Forced expression of E2F1 increased the endogenous level of QKI. Promoter luciferase assay and ChIP analysis identified that the -542~-538 E2F1 binding site was responsible for the upregulation. Increased QKI expression by E2F1, in turn, reduced the E2F1 activity and delayed S-phase entry, forming a negative feedback. As a gene expression regulator, QKI overexpression increased p27, while it decreased cyclin D1 and c-fos expression. Molecularly, p27 and c-fos were direct targets of QKI, while cyclin D1 reduction might be an indirect effect. Taken together, our results reveal that E2F1 directly transcribes QKI, which, in turn, negatively regulates the cell cycle by targeting multiple cell cycle regulators, forming an E2F1-QKI-pRb/E2F1 negative feedback loop.