Combined analysis of single-cell sequencing and bulk transcriptome sequencing reveals new mechanisms for non-healing diabetic foot ulcers.

Diabetic foot ulcers (DFUs) pose a significant challenge in diabetes care. Yet, a comprehensive understanding of the underlying biological disparities between healing and non-healing DFUs remains elusive. We conducted bioinformatics analysis of publicly available transcriptome sequencing data in an attempt to elucidate these differences. Our analysis encompassed differential analysis to unveil shifts in cell composition and gene expression profiles between non-healing and healing DFUs. Cell communication alterations were explored employing the Cellchat R package. Pseudotime analysis and cytoTRACE allowed us to dissect the heterogeneity within fibroblast subpopulations. Our findings unveiled disruptions in various cell types, localized low-grade inflammation, compromised systemic antigen processing and presentation, and extensive extracellular matrix signaling disarray in non-healing DFU patients. Some of these anomalies partially reverted in healing DFUs, particularly within the abnormal ECM-receptor signaling pathway. Furthermore, we distinguished distinct fibroblast subpopulations in non-healing and healing DFUs, each with unique biological functions. Healing-associated fibroblasts exhibited heightened extracellular matrix (ECM) remodeling and a robust wound healing response, while non-healing-associated fibroblasts showed signs of cellular senescence and complement activation, among other characteristics. This analysis offers profound insights into the wound healing microenvironment, identifies pivotal cell types for DFU healing promotion, and reveals potential therapeutic targets for DFU management.

Time-course study of genetic changes in periodontal ligament regeneration after tooth replantation in a mouse model.

This research focused on analyzing gene expression changes in the periodontal ligament (PDL) after tooth re-plantation to identify key genes and pathways involved in healing and regeneration. Utilizing a mouse model, mRNA was extracted from the PDL at various intervals post-replantation for RNA sequencing analysis, spanning from 3 to 56 days. The results revealed significant shifts in gene expression, particularly notable on day 28, supported by hierarchical clustering and principal component analysis. Gene ontology (GO) enrichment analysis highlighted an upregulation in olfactory receptor and G protein-coupled receptor signaling pathways at this time point. These findings were validated through reverse transcription-quantitative PCR (RT-qPCR), with immunochemical staining localizing olfactory receptor gene expression to the PDL and surrounding tissues. Moreover, a scratch assay indicated that olfactory receptor genes might facilitate wound healing in human PDL fibroblasts. These results underscore the importance of the 28-day post-transplant phase as a potential "tipping point" in PDL healing and regeneration. In conclusion, this research sheds light on the potential role of olfactory receptor genes in PDL regeneration, providing a foundation for developing new therapeutic approaches in tooth replantation and transplantation, with broader implications for regenerative medicine in oral health.

Upregulation of circ-IGF1R increased therapeutic effect of hypoxia-pretreated ADSC-derived extracellular vesicle by regulating miR-503-5p/HK2/VEGFA axis.

Diabetes mellitus is a major cause of blindness and chronic ulcers in the working-age population worldwide. Wound healing is deeply dependent on neovascularization to restore blood flow. Former research has found that differentially expressed circular RNAs (circRNAs) are associated with hyperglycaemia-induced endothelial cell damage, and hypoxia-pretreated adipose-derived stem cells (ADSCs)-extracellular vesicle (HEV) transplants have a more therapeutic effect to enhance wound healing in diabetic mice by delivery circRNA. The current investigation employed high-throughput sequencing to identify circRNAs that are abnormally expressed between EV and HEV. The regulatory mechanism and predicted targets of one differentially expressed circRNA, circ-IGF1R, were investigated utilizing bioinformatics analyses, luciferase reporter assays, angiogenic differentiation assays, flow cytometric apoptosis analysis and RT-qPCR. Circ-IGF1R expression increased in HEV, and downregulation of circ-IGF1R suppressed and reversed the promotion effect of HEV on angiogenesis in ulcerated tissue. Bioinformatics analyses and luciferase reporter assays confirmed that miR-503-5p was the downstream target of circ-IGF1R, and inhibiting miR-503-5p restored the promotion effect of HEV on angiogenesis after circ-IGF1R silence. The study also found that miR-503-5p can interact with 3'-UTR of both HK2 and VEGFA. Overexpression of HK2 or VEGFA restored the promotion effect of HExo on angiogenesis after circ-IGF1R silence. Overexpression miR-503-5p or silence HK2/VEGFA reversed the protective effect of circ-IGF1R to MLMECs angiogenic differentiation. Overexpression of circ-IGF1R increased the protective effect of HEV on the promotion of wound healing in mice with diabetes. Circ-IGF1R promotes HIF-1α expression through miR-503-5p sponging. Our data demonstrate that circ-IGF1R overexpression EVs from ADSCs suppress high glucose-induced endothelial cell damage by regulating miR-503-5p/HK2/VEGFA axis.

New Perspectives and Prospects of microRNA Delivery in Diabetic Wound Healing.

The remarkable potential of microRNAs (miRNAs) as a class of biotherapeutic agents in the treatment of diverse pathological conditions has garnered significant interest in recent years. To heal both acute and chronic wounds, miRNAs work by post-transcriptionally controlling various proteins and the pathways that are linked to them. Diabetes mellitus predisposes to several macro- and microvascular defects of end organs such as atherosclerosis, peripheral artery disease, retinopathy, nephropathy, neuropathy, and impaired wound healing. Here, miRNAs emerge as a beacon of hope, with the capacity to heal diabetic wounds by precisely modulating the expression of genes involved in the healing process. Despite the therapeutic promise, the journey to realizing the full potential of miRNAs is fraught with challenges. Their intrinsic instability and the inefficient delivery into target cells pose significant barriers to their clinical application. Consequently, a major focus of current research is the discovery of novel miRNAs and the development of innovative delivery systems that can effectively transport these nucleic acids into the cells where they are needed most. This review delves into the intricate roles that miRNAs play at various stages of diabetic wound healing, providing a comprehensive overview of the latest research findings. The review also addresses the obstacles and opportunities that come with translating miRNA-based strategies into clinical practice, offering a critical assessment of the field's advancements and the hurdles that remain to be overcome. SIGNIFICANCE STATEMENT: The potential of microRNA delivery using new biological or nonbiological carriers may create a revolutionary treatment method for chronic wounds of diabetes.

Decoding cellular plasticity and niche regulation of limbal stem cells during corneal wound healing.

BACKGROUND: Dysfunction or deficiency of corneal epithelium results in vision impairment or blindness in severe cases. The rapid and effective regeneration of corneal epithelial cells relies on the limbal stem cells (LSCs). However, the molecular and functional responses of LSCs and their niche cells to injury remain elusive. METHODS: Single-cell RNA sequencing was performed on corneal tissues from normal mice and corneal epithelium defect models. Bioinformatics analysis was performed to confirm the distinct characteristics and cell fates of LSCs. Knockdown of Creb5 and OSM treatment experiment were performed to determine their roles of in corneal epithelial wound healing. RESULTS: Our data defined the molecular signatures of LSCs and reconstructed the pseudotime trajectory of corneal epithelial cells. Gene network analyses characterized transcriptional landmarks that potentially regulate LSC dynamics, and identified a transcription factor Creb5, that was expressed in LSCs and significantly upregulated after injury. Loss-of-function experiments revealed that silencing Creb5 delayed the corneal epithelial healing and LSC mobilization. Through cell-cell communication analysis, we identified 609 candidate regeneration-associated ligand-receptor interaction pairs between LSCs and distinct niche cells, and discovered a unique subset of Arg1+ macrophages infiltrated after injury, which were present as the source of Oncostatin M (OSM), an IL-6 family cytokine, that were demonstrated to effectively accelerate the corneal epithelial wound healing. CONCLUSIONS: This research provides a valuable single-cell resource and reference for the discovery of mechanisms and potential clinical interventions aimed at ocular surface reconstruction.

Effect of Bovine Lactoferrin Treatment on Iron Homeostasis and Gene Expression Changes in Multiple Organ Dysfunctions During Wound Healing Process in Rats.

BACKGROUND: Injury systemically disrupts the homeostatic balance and can cause organ failure. LF mediates both iron-dependent and iron-independent mechanisms, and the role of LF in regulating iron homeostasis is vital in terms of metabolism. OBJECTIVES: In this study, we evaluated the organ-level effect and gene expression change of bLf in the cutaneous repair process. MATERIALS AND METHODS: An excisional full-thickness skin defect (FTSD) wound model was created in male Sprague Dawley rats (180-250 g) (n = 48) fed a high-fat diet (HFD) and the PHGPx, SLC7A11 and SLC40A1 genes and iron metabolism were evaluated. The animals were randomly divided into 6 groups: 1- Control, 2- bLf (200 mg/kg/day, oral), 3- FTSD (12 mm in diameter, dorsal), 4- HFD + bLf, 5- HFD + FTSD, 6- HFD + FTSD + bLf. Histologically, iron accumulation was demonstrated by Prussian blue staining in the liver, kidney, and intestinal tissues. Gene expression analysis was performed with qPCR. RESULTS: Histologically, iron accumulation was demonstrated by Prussian blue staining in the liver, kidney, and intestinal tissues. Prussian blue reactions were detected in the kidney. PHPGx and SLC7A11 genes in kidney and liver tissue were statistically significant (P < 0.05) except for the SLC40A1 gene (P > 0.05). Expression changes of the three genes were not statistically significant in analyses of rat intestinal tissue (P = 0.057). CONCLUSION: In the organ-level ferroptotic damage mechanism triggered by wound formation. BLf controls the expression of three genes and manages iron deposition in these three tissues. In addition, it suppressed the increase in iron that would drive the cell to ferroptosis and anemia caused by inflammation, thereby eliminating iron deposition in the tissues.

Profiling microRNAs of earthworm, Perionyx excavatus and deciphering the expression of distinct novel miRNAs regulating epimorphosis regeneration.

Earthworm, P. excavatus, is an ideal model organism for studying regeneration. Due to its prodigious regeneration capability, the amputated head part of the earthworm can regenerate completely within 22 days. MicroRNAs (miRNAs) regulate specific genes and are involved in essential biological processes, including regeneration. In this study, we conducted a comprehensive analysis of miRNA profiling of the earthworm, P. excavatus, during the process of anterior regeneration. Our investigation involved in the identification of 55 miRNAs from 30 distinct miRNA families that exhibit significant relevance to wound healing and regeneration. Notably, we have identified 50 novel miRNAs and predicted their pre-miRNA secondary structures using MIREAP. Both Known and Novel miRNAs are validated using qPCR. In addition, we employed the miRanda algorithm to predict the interactions between these miRNAs and their target mRNA transcripts. Based on the miRanda target prediction results, we identified the target genes such as Wnt, Myc, MAPK, SoxB, IHH, Hox, and Notch. These findings indicate that the potential targets of these miRNAs might play crucial roles in various functions related to wound healing, tissue restoration, and regeneration. Furthermore, the acquisition of these findings provides a unique perspective on understanding the molecular mechanisms driving epimorphosis regeneration in connection with miRNAs for the development of miRNA-based therapeutics.

Time-course swRNA-seq uncovers a hierarchical gene regulatory network in controlling the response-repair-remodeling after wounding.

Wounding initiates intricate responses crucial for tissue repair and regeneration. Yet, the gene regulatory networks governing wound healing remain poorly understood. Here, employing single-worm RNA sequencing (swRNA-seq) across 12 time-points, we delineated a three-stage wound repair process in C. elegans: response, repair, and remodeling. Integrating diverse datasets, we constructed a dynamic regulatory network comprising 241 transcription regulators and their inferred targets. We identified potentially seven autoregulatory TFs and five cross-autoregulatory loops involving pqm-1 and jun-1. We revealed that TFs might interact with chromatin factors and form TF-TF combinatory modules via intrinsically disordered regions to enhance response robustness. We experimentally validated six regulators functioning in transcriptional and translocation-dependent manners. Notably, nhr-76, daf-16, nhr-84, and oef-1 are potentially required for efficient repair, while elt-2 may act as an inhibitor. These findings elucidate transcriptional responses and hierarchical regulatory networks during C. elegans wound repair, shedding light on mechanisms underlying tissue repair and regeneration.

Sirtuin-6 knockout causes exacerbated stalled healing of diabetic ulcers in mice.

BACKGROUND: Diabetic ulcers (DUs) are characterized by chronic inflammation and delayed re-epithelialization, with a high incidence and weighty economic burden. The primary therapeutic strategies for refractory wounds include surgery, non-invasive wound therapy, and drugs, while the optimum regimen remains controversial. Sirtuin-6 (SIRT6) is a histone deacetylase and a key epigenetic factor that exerts anti-inflammatory and pro-proliferatory effects in wound healing. However, the exact function of SIRT6 in DUs remains unclear. METHODS: We generated tamoxifen-inducible SIRT6 knockout mice by crossing SIRT6flox/flox homozygous mice with UBC-creERT2+ transgenic mice. Systemic SIRT6 null mice, under either normal or diabetic conditions, were utilized to assess the effects of SIRT6 in DUs treatment. Gene and protein expressions of SIRT6 and inflammatory cytokines were measured by Western blotting and RT-qPCR. Histopathological examination confirmed the altered re-epithelialization (PCNA), inflammation (NF-κB p50 and F4/80), and angiogenesis (CD31) markers during DUs restoration. RESULTS: Knockout of SIRT6 inhibited the healing ability of DUs, presenting attenuated re-epithelialization (PCNA), exacerbated inflammation responses (NF-κB p50, F4/80, Il-1ß, Tnf-α, Il-6, Il-10, and Il-4), and hyperplasia vascular (CD31) compared with control mice. CONCLUSIONS: SIRT6 could boost impaired wound healing through improving epidermal proliferation, inflammation, and angiogenesis. Our study highlighted the therapeutic potential of the SIRT6 agonist for DUs treatment.

mir-182-5p regulates all three phases of inflammation, proliferation, and remodeling during cutaneous wound healing.

Wound healing is a highly programmed process, in which any abnormalities result in scar formation. MicroRNAs are potent regulators affecting wound repair and scarification. However, the function of microRNAs in wound healing is not fully understood. Here, we analyzed the expression and function of microRNAs in patients with cutaneous wounds. Cutaneous wound biopsies from patients with either hypertrophic scarring or normal wound repair were collected during inflammation, proliferation, and remodeling phases. Fourteen candidate microRNAs were selected for expression analysis by qRT-PCR. The expression of genes involved in inflammation, angiogenesis, proliferation, and migration were measured using qRT-PCR. Cell cycle and scratch assays were used to explore the proliferation and migration rates. Flow cytometry analysis was employed to examine TGF-ß, αSMA and collagen-I expression. Target gene suggestion was performed using Enrichr tool. The results showed that miR-16-5p, miR-152-3p, miR-125b-5p, miR-34c-5p, and miR-182-5p were revealed to be differentially expressed between scarring and non-scarring wounds. Based on the expression patterns obtained, miR-182-5p was selected for functional studies. miR-182-5p induced RELA expression synergistically upon IL-6 induction in keratinocytes and promoted angiogenesis. miR-182-5p prevented keratinocyte migration, while overexpressed TGF-ß3 following induction of inflammation. Moreover, miR-182-5p enhanced fibroblast proliferation, migration, differentiation, and collagen-1 expression. FoxO1 and FoxO3 were found to potentially serve as putative gene targets of miR-182-5p. In conclusion, miR-182-5p is differentially expressed between scarring and non-scarring wounds and affect the behavior of cells involved in cutaneous wound healing. Deregulated expression of miR-182-5p adversely affects the proper transition of wound healing phases, resulting in scar formation.

Twist2 contributes to skin regeneration and hair follicle formation in mouse fetuses.

Unlike adult mammalian wounds, early embryonic mouse skin wounds completely regenerate and heal without scars. Analysis of the underlying molecular mechanism will provide insights into scarless wound healing. Twist2 is an important regulator of hair follicle formation and biological patterning; however, it is unclear whether it plays a role in skin or skin appendage regeneration. Here, we aimed to elucidate Twist2 expression and its role in fetal wound healing. ICR mouse fetuses were surgically wounded on embryonic day 13 (E13), E15, and E17, and Twist2 expression in tissue samples from these fetuses was evaluated via in situ hybridization, immunohistochemistry, and reverse transcription-quantitative polymerase chain reaction. Twist2 expression was upregulated in the dermis of E13 wound margins but downregulated in E15 and E17 wounds. Twist2 knockdown on E13 left visible marks at the wound site, inhibited regeneration, and resulted in defective follicle formation. Twist2-knockdown dermal fibroblasts lacked the ability to undifferentiate. Furthermore, Twist2 hetero knockout mice (Twist + /-) formed visible scars, even on E13, when all skin structures should regenerate. Thus, Twist2 expression correlated with skin texture formation and hair follicle defects in late mouse embryos. These findings may help develop a therapeutic strategy to reduce scarring and promote hair follicle regeneration.

Age-Related Differences in the Mouse Corneal Epithelial Transcriptome and Their Impact on Corneal Wound Healing.

Purpose: Aging is a risk factor for dry eye. We sought to identify changes in the aged mouse corneal epithelial transcriptome and determine how age affects corneal sensitivity, re-epithelialization, and barrier reformation after corneal debridement. Methods: Corneal epithelium of female C57BL/6J (B6) mice of different ages (2, 12, 18, and 24 months) was collected, RNA extracted, and bulk RNA sequencing performed. Cornea sensitivity was measured with an esthesiometer in 2- to 3-month-old, 12- to 13-month-old, 18- to 19-month-old, and 22- to 25-month-old female and male mice. The 2-month-old and 18-month-old female and male mice underwent unilateral corneal debridement using a blunt blade. Wound size and fluorescein staining were visualized and photographed at different time points, and a re-epithelialization rate curve was calculated. Results: There were 157 differentially expressed genes in aged mice compared with young mice. Several pathways downregulated with age control cell migration, proteoglycan synthesis, and collagen trimerization, assembly, biosynthesis, and degradation. Male mice had decreased corneal sensitivity compared with female mice at 12 and 24 months of age. Aged mice, irrespective of sex, had delayed corneal re-epithelialization in the first 48 hours and worse corneal fluorescein staining intensity at day 14 than young mice. Conclusions: Aged corneal epithelium has an altered transcriptome. Aged mice regardless of sex heal more slowly and displayed more signs of corneal epithelial defects after wounding than young mice. These results indicate that aging significantly alters the corneal epithelium and its ability to coordinate healing.

Exclusive expression of KANK4 promotes myofibroblast mobility in keloid tissues.

Keloids are characterized by abnormal wound healing with excessive accumulation of extracellular matrix. Myofibroblasts are the primary contributor to extracellular matrix secretion, playing an essential role in the wound healing process. However, the differences between myofibroblasts involved in keloid formation and normal wound healing remain unclear. To identify the specific characteristics of keloid myofibroblasts, we initially assessed the expression levels of well-established myofibroblast markers, α-smooth muscle actin (α-SMA) and transgelin (TAGLN), in scar and keloid tissues (n = 63 and 51, respectively). Although myofibroblasts were present in significant quantities in keloids and immature scars, they were absent in mature scars. Next, we conducted RNA sequencing using myofibroblast-rich areas from keloids and immature scars to investigate the difference in RNA expression profiles among myofibroblasts. Among significantly upregulated 112 genes, KN motif and ankyrin repeat domains 4 (KANK4) was identified as a specifically upregulated gene in keloids. Immunohistochemical analysis showed that KANK4 protein was expressed in myofibroblasts in keloid tissues; however, it was not expressed in any myofibroblasts in immature scar tissues. Overexpression of KANK4 enhanced cell mobility in keloid myofibroblasts. Our results suggest that the KANK4-mediated increase in myofibroblast mobility contributes to keloid pathogenesis.

Deciphering the role of wound healing genes in skin cutaneous melanoma: Insights into expression, methylation, mutations, and therapeutic implications.

Skin Cutaneous Melanoma (SKCM) is a form of cancer that originates in the pigment-producing cells, known as melanocytes, of the skin. Delay wound healing is often correlated with the occurrence of and progression of SKCM. In this comprehensive study, we investigated the intricate roles of two important wound healing genes in SKCM, including Matrix Metalloproteinase-2 (MMP2) and Matrix Metalloproteinase-9 (MMP9). Through a multi-faceted approach, we collected clinical samples, conducted molecular experiments, including RT-qPCR, bisulphite sequencing, cell culture, cell Counting Kit-8, colony formation, and wound healing assays. Beside this, we also used various other databases/tools/approaches for additional analysis including, UALCAN, GEPIA, HPA, MEXPRESS, cBioPortal, KM plotter, DrugBank, and molecular docking. Our results revealed a significant up-regulation of MMP2 and MMP9 in SKCM tissues compared to normal counterparts. Moreover, promoter methylation analysis suggested an epigenetic regulatory mechanism. Validations using TCGA datasets and immunohistochemistry emphasized the clinical relevance of MMP2 and MMP9 dysregulation. Functional assays demonstrated their synergistic impact on proliferation and migration in SKCM cells. Furthermore, we identified potential therapeutic candidates, Estradiol and Calcitriol, through drug prediction and molecular docking analyses. These compounds exhibited binding affinities, suggesting their potential as MMP2/MMP9 inhibitors. Overall, our study elucidates the diagnostic, prognostic, and therapeutic implications of MMP2 and MMP9 in SKCM, shedding light on their complex interplay in SKCM occurrence and progression.

MicroRNA-221-3p inhibits the inflammatory response of keratinocytes by regulating the DYRK1A/STAT3 signaling pathway to promote wound healing in diabetes.

Diabetic foot ulcer (DFU), a serious complication of diabetes, remains a clinical challenge. MicroRNAs affect inflammation and may have therapeutic value in DFU. Here, we find that an miR-221-3p mimic reduces the inflammatory response and increases skin wound healing rates in a mouse model of diabetes, whereas miR-221-3p knockout produced the opposite result. In human keratinocytes cells, miR-221-3p suppresses the inflammatory response induced by high glucose. The gene encoding DYRK1A is a target of miR-221-3p. High glucose increases the expression of DYRK1A, but silencing DYRK1A expression decreases high glucose-induced inflammatory cytokine release via dephosphorylation of STAT3, a substrate of DYRK1A. Application of miR-221-3p mimic to human keratinocytes cells not only decreases DYRK1A expression but also inhibits high glucose-induced production of inflammatory cytokines to promote wound healing. This molecular mechanism whereby miR-221-3p regulates inflammation through the DYRK1A/STAT3 signaling pathway suggests targets and therapeutic approaches for treating DFU.

Photobiomodulation preconditioned diabetic adipose derived stem cells with additional photobiomodulation: an additive approach for enhanced wound healing in diabetic rats with a delayed healing wound.

In this preclinical investigation, we examined the effects of combining preconditioned diabetic adipose-derived mesenchymal stem cells (AD-MSCs) and photobiomodulation (PBM) on a model of infected ischemic delayed healing wound (injury), (IIDHWM) in rats with type I diabetes (TIDM). During the stages of wound healing, we examined multiple elements such as stereology, macrophage polarization, and the mRNA expression levels of stromal cell-derived factor (SDF)-1α, vascular endothelial growth factor (VEGF), hypoxia-induced factor 1α (HIF-1α), and basic fibroblast growth factor (bFGF) to evaluate proliferation and inflammation. The rats were grouped into: (1) control group; (2) diabetic-stem cells were transversed into the injury site; (3) diabetic-stem cells were transversed into the injury site then the injury site exposed to PBM; (4) diabetic stem cells were preconditioned with PBM and implanted into the wound; (5) diabetic stem cells were preconditioned with PBM and transferred into the injury site, then the injury site exposed additional PBM. While on both days 4, and 8, there were advanced histological consequences in groups 2-5 than in group 1, we found better results in groups 3-5 than in group 2 (p < 0.05). M1 macrophages in groups 2-5 were lower than in group 1, while groups 3-5 were reduced than in group 2 (p < 0.01). M2 macrophages in groups 2-5 were greater than in group 1, and groups 3-5 were greater than in group 2. (p ≤ 0.001). Groups 2-5 revealed greater expression levels of bFGF, VEGF, SDF- 1α, and HIF- 1α genes than in group 1 (p < 0.001). Overall group 5 had the best results for histology (p < 0.05), and macrophage polarization (p < 0.001). AD-MSC, PBM, and AD-MSC + PBM treatments all enhanced the proliferative stage of injury repairing in the IIDHWM in TIDM rats. While AD-MSC + PBM was well than the single use of AD-MSC or PBM, the best results were achieved with PBM preconditioned AD-MSC, plus additional PBM of the injury.

Enhancing Skin Injury Repair: Combined Application of PF-127 Hydrogel and hADSC-Exos Containing miR-148a-3p.

The use of exosomes to relieve skin injuries has received considerable attention. The PluronicF-127 hydrogel (PF-127 hydrogel) is a novel biomaterial that can be used to carry biomolecules. This study sought to investigate the impact of exosomes originating from human mesenchymal stem cells (MSCs) developed from adipose tissue (hADSC-Exos) combined with a PF-127 hydrogel on tissue repair and explore the underlying mechanism using in vitro and in vivo experiments. miR-148a-3p is the most expressed microRNA (miRNA) in hADSC-Exos. We found that exosomes combined with the PF-127 hydrogel had a better efficacy than exosomes alone; moreover, miR-148a-3p knockdown lowered its efficacy. In vitro, we observed a significant increase in the tumor-like ability of HUVECs after exosome treatment, which was attenuated after miR-148a-3p knockdown. Furthermore, the effects of miR-148a-3p on hADSC-Exos were achieved through the prevention of PTEN and the triggering of phosphatidylinositol 3-kinase (PI3K)/Akt signaling. In conclusion, our results demonstrated that hADSC-Exos can promote angiogenesis and skin wound healing by delivering miR-148a-3p and have a better effect when combined with the PF-127 hydrogel, which may be an alternative strategy to promote wound healing.

Macrophage Polarization Dynamics in Biomaterials: Implications for in Vitro Wound Healing.

The interaction between biomaterials and the immune system plays a pivotal role in determining the success or failure of implantable devices. Macrophages, as key orchestrators of immune responses, exhibit diverse reactions that influence tissue integration or lead to implant failure. This study focuses on unraveling the intricate relationship between macrophage phenotypes and biomaterials, specifically hydrogels, by employing THP-1 cells as a model. Through a comprehensive investigation using polysaccharide, polymer, and protein-based hydrogels, our research sheds light on how the properties of hydrogels influence macrophage polarization. Phenotypic observations, biochemical assays, surface marker expression, and gene expression profiles collectively demonstrate the differential macrophage polarization abilities of polysaccharide-, polymer-, and protein-based hydrogels. Moreover, our indirect coculture studies reveal that hydrogels fostering M2 polarization exhibit exceptional wound-healing capabilities. These findings highlight the crucial role of the hydrogel microenvironment in adjusting macrophage polarization, offering a fresh avenue for refining biomaterials to bolster advantageous immune responses and improve tissue integration. This research contributes valuable insights for designing biomaterials with tailored properties that can guide macrophage behavior, ultimately improving the overall success of implantable devices.

Genetic analysis of impaired healing responses after periodontal therapy in type 2 diabetes: Clinical and in vivo studies.

OBJECTIVE: This study aims to investigate the mechanisms underlying the impaired healing response by diabetes after periodontal therapy. BACKGROUND: Outcomes of periodontal therapy in patients with diabetes are impaired compared with those in patients without diabetes. However, the mechanisms underlying impaired healing response to periodontal therapy have not been sufficiently investigated. MATERIALS AND METHODS: Zucker diabetic fatty (ZDF) and lean (ZL) rats underwent experimental periodontitis by ligating the mandibular molars for one week. The gingiva at the ligated sites was harvested one day after ligature removal, and gene expression was comprehensively analyzed using RNA-Seq. In patients with and without type 2 diabetes (T2D), the corresponding gene expression was quantified in the gingiva of the shallow sulcus and residual periodontal pocket after non-surgical periodontal therapy. RESULTS: Ligation-induced bone resorption and its recovery after ligature removal were significantly impaired in the ZDF group than in the ZL group. The RNA-Seq analysis revealed 252 differentially expressed genes. Pathway analysis demonstrated the enrichment of downregulated genes involved in the peroxisome proliferator-activated receptor (PPAR) signaling pathway. PPARα and PPARγ were decreased in mRNA level and immunohistochemistry in the ZDF group than in the ZL group. In clinical, probing depth reduction was significantly less in the T2D group than control. Significantly downregulated expression of PPARα and PPARγ were detected in the residual periodontal pocket of the T2D group compared with those of the control group, but not in the shallow sulcus between the groups. CONCLUSIONS: Downregulated PPAR subtypes expression may involve the impaired healing of periodontal tissues by diabetes.