Project description:The wounds were made on the back skin of Snhg26 knockout (KO) and wild type (WT) mice. The wound edge and skin tissue were collected and the epidermis were separated by incubate the tissue with dispaseII. Total RNA was extracted from the epidermis. The global transcriptome analysis of the epidermis were performed by using Affymetrix arrays.
Project description:The epidermal stem cell transition from inflammation to proliferation is a crucial process in tissue repair. However, the molecular mechanism underlying this process is poorly understood. Combined with lncRNA expression profiling of human acute wounds and functional screening, we identified SNHG26 as a pivotal regulator of inflammatory to proliferative state transition of keratinocyte progenitor cells. Snhg26-deficient mice showed impaired wound healing characterized by increased inflammatory response and decreased reepithelization in the wound. Consistently, single-cell transcriptomic analysis of the wound-edge tissue identified proliferative, migratory, and proinflammatory basal progenitors, which were dramatically changed in Snhg26 deficient mice. Mechanically, SNHG26 binds with ILF2 to relocate this transcription factor from the inflammatory gene loci (such as JUN) to the LAMB3 genomic loci. Collectively, this work identified a conserved lncRNA SNHG26 as a master regulator of epidermal stem cell state transition from inflammation to proliferation, highlighting the importance of lncRNAs in tissue repair and regeneration.
Project description:The cell transition from an inflammatory phase to a subsequent proliferative phase is crucial for wound healing, yet the driving mechanism remains unclear. By profiling lncRNA expression changes during human skin wound healing and screening lncRNA functions, we identified SNHG26 as a pivotal regulator in keratinocyte progenitors underpinning this phase transition. To study the proteins interact with SNHG26, we performed RNA pull-down assay in human keratinocyte progenitors. The mass spectrometry (MS) analysis was performed to identify the proteins interacted with SNHG26.
Project description:Analysis the transcriptome of keratinocyte after SNHG26 silencing with or without TNFa treatment for 3 hours. SNHG26 is a conseved lncRNA which is upregulated in the epidermis of human and mouse acute wound. Results of this profiling provide insight into the biological role of SNHG26 in keratinocytes.
Project description:Impaired skin wound healing is a significant global health issue, especially among the elderly. Wound healing is a well-orchestrated process involving the sequential phases of inflammation, proliferation, and tissue remodeling. Although wound healing is a highly dynamic and energy-requiring process, the role of metabolism remains largely unexplored. By combining transcriptomics and metabolomics of human skin biopsy samples, we mapped the core bioenergetic and metabolic changes in normal acute as well as chronic wounds in elderly subjects. We found upregulation of glycolysis, the tricarboxylic acid cycle, glutaminolysis, and β-oxidation in the later stages of acute wound healing and in chronic wounds. To ascertain the role of these metabolic pathways on wound healing, we targeted each pathway in a wound healing assay as well as in a human skin explant model using metabolic inhibitors and stimulants. Enhancement or inhibition of glycolysis and, to a lesser extent, glutaminolysis had a far greater impact on wound healing than similar manipulations of oxidative phosphorylation and fatty acid β-oxidation. These findings increase the understanding of wound metabolism and identify glycolysis and glutaminolysis as potential targets for therapeutic intervention.
Project description:Wound healing is facilitated by neoangiogenesis, a complex process that is essential to tissue repair in response to injury. MicroRNAs are small, non-coding RNAs that can regulate the wound healing process including stimulation of impaired angiogenesis that is associated with Type-2 diabetes (T2D). Expression of miR-409-3p was significantly increased in the non-healing skin wounds of patients with T2D compared to the non-wounded normal skin, and in the skin of a murine model with T2D. In response to high glucose, neutralization of miR-409-3p markedly improved EC growth and migration in human umbilical vein endothelial cells (HUVECs), promoted wound closure and angiogenesis as measured by increased CD31 in human skin organoids, while overexpression attenuated EC angiogenic responses. Bulk mRNA-Seq transcriptomic profiling revealed BTG2 as a target of miR-409-3p, where overexpression of miR-409-3p significantly decreased BTG2 mRNA and protein expression. A 3′ untranslated region (3′-UTR) luciferase assay of BTG2 revealed decreased luciferase activity with overexpression of miR-409-3p, while inhibition had opposite effects. Mechanistically, in response to high glucose, miR-409-3p deficiency in ECs resulted in increased mTOR phosphorylation meanwhile BTG2 silencing significantly decreased mTOR phosphorylation. Endothelial specific and tamoxifen-inducible miR-409-3p knock out mice (MiR-409IndECKO) with hyperglycemia that underwent dorsal skin wounding showed significant improvement of wound closure, increased blood flow, granulation tissue thickness (GTT), and CD31 that correlated with increased BTG2 expression. Taken together, our results show that miR-409-3p is a critical mediator of impaired angiogenesis in diabetic skin wound healing.
Project description:Adalimumab, but neither etanercept nor certolizumab-pegol, has been reported to induce a wound healing profile in the circulation of patients with hidradenitis suppurativa (HS), a chronic inflammatory skin disease. However, the role of tumor necrosis factor alpha (TNF) inhibitors in cutaneous wound healing in vivo is still unclear. To examine and compare the efficacy of various TNF inhibitors in cutaneous wound healing in vivo, a human TNF knock-in Leprdb/db mouse model was established to model the impaired cutaneous wound healing as seen in HS. The vehicle group exhibited severe impairments in cutaneous wound healing. In contrast, adalimumab significantly accelerated healing, confirmed by both histologic assessment and a unique healing transcriptional profile. Moreover, adalimumab and infliximab showed similar levels of efficacy, but golimumab was less effective, along with etanercept and certolizumab-pegol. In line with histologic assessments, proteomics analyses from healing wounds exposed to various TNF inhibitors revealed distinct and differential wound healing signatures that may underlie the differential efficacy of these inhibitors in accelerating cutaneous wound healing. Taken together, these data revealed that TNF inhibitors exhibited differential levels of efficacy in accelerating cutaneous wound healing in the impaired wound healing model in vivo likely through distinct mechanisms of action related to the structure of the biologic or its ability to bind TNF.
Project description:Wound healing is impaired by infection; however, how microbe-induced inflammation modulates tissue repair remains unclear. We took advantage of the optical transparency of zebrafish and a genetically tractable microbe, Listeria monocytogenes, to probe the role of infection and inflammation in wound healing. We found a critical window of microbial clearance necessary to limit persistent inflammation and enable efficient wound repair. Infection with bacteria engineered to activate the inflammasome, Lm-Pyro, induced persistent inflammation and impaired healing despite low bacterial burden. In contrast, infection with an anti-inflammatory, apoptosis inducing strain, Lm-Apo, had similar infectious burden but was associated with rapid wound repair. Inflammatory infections induced il-1b expression and blocking IL-1R signaling partially rescued wound healing in the presence of persistent infection. Taken together, our findings suggest that the dynamics of microbe-induced tissue inflammation impacts repair in complex tissue damage independent of bacterial load, with a critical early window for efficient tissue repair.
Project description:Wound healing is a multi-step process to rapidly restore barrier function. This process is often impaired in diabetic patients resulting in chronic wounds and amputation. We previously found that paradoxical activation of the mitogen-activated protein kinase (MAPK) pathway via topical administration of the BRAF inhibitor vemurafenib accelerates wound healing by activating keratinocyte proliferation and reepithelialization pathways in healthy mice. Herein, we investigated whether this wound healing acceleration also occurs in impaired diabetic wounds and found that topical vemurafenib not only improves wound healing in a murine diabetic wound model, but unexpectedly promotes hair follicle regeneration. Neogenic hair follicles expressing Sox-9, CD34 and K15 were found in wounds of diabetic and non-diabetic mice, and their formation can be prevented by blocking downstream MEK signaling. Thus, topically applied BRAF inhibitors may accelerate wound healing, and promote the restoration of improved skin architecture in both normal and impaired wounds.