Novel prospects for scarless wound healing: The roles of myofibroblasts and adipocytes.

Disturbances or defects in the process of wound repair can disrupt the delicate balance of cells and molecules necessary for complete wound healing, thus leading to chronic wounds or fibrotic scars. Myofibroblasts are one of the most important cells involved in fibrotic scars, and reprogramming provides a potential avenue to increase myofibroblast clearance. Although myofibroblasts have long been recognized as terminally differentiated cells, recent studies have shown that myofibroblasts have the capacity to be reprogrammed into adipocytes. This review intends to summarize the potential of reprogramming myofibroblasts into adipocytes. We will discuss myofibroblast lineage tracing, as well as the known mechanisms underlying adipocyte regeneration from myofibroblasts. In addition, we investigated different changes in myofibroblast gene expression, transcriptional regulators, signalling pathways and epigenetic regulators during skin wound healing. In the future, myofibroblast reprogramming in wound healing will be better understood and appreciated, which may provide new ideas for the treatment of scarless wound healing.

Dual-Action Icariin-Containing Thermosensitive Hydrogel for Wound Macrophage Polarization and Hair-Follicle Neogenesis.

Bone morphogenetic protein (BMP) pathway is essential for M2 macrophage polarization and hair-follicle neogenesis. Icariin, a flavonoid derived from Epimedium, is a mediator of the BMP pathway. Here, we develop a hydrogel formulation functionalized with icariin for regulation of macrophage polarization to accelerate wound healing and hair-follicle neogenesis. Compared to skin defects without icariin treatment, those treated with icariin+PEG hydrogel healed faster and had new hair follicles. Results in vivo showed that icariin+PEG hydrogel induced a higher level of M2 phenotypic transformation of macrophages. Moreover, icariin+PEG hydrogel significantly accelerated wound-repair process by reducing the invasion of inflammation, excessive deposition of collagen, immoderate activation of myofibroblasts, and increasing the regeneration of hair follicles. Furthermore, studies in vitro demonstrated that the icariin+PEG hydrogel induced macrophages to polarize to the M2 phenotype and dermal papilla cell to hair follicles. Finally, molecular analysis demonstrated that the icariin+PEG hydrogel increased the expression of BMP4 and Smad1/5 phosphorylation in skin wounds. These results demonstrate the therapeutic potential of icariin-containing thermosensitive hydrogels for inducing M2 macrophage polarization to accelerate wound healing and promote hair-follicle neogenesis by regulating the BMP pathway.

The uPA System Differentially Alters Fibroblast Fate and Profibrotic Ability in Skin Fibrosis.

Skin fibrosis is a common pathological feature of various diseases, and few treatment strategies are available because of the molecular pathogenesis is poorly understood. The urokinase-type plasminogen activator (uPA) system is the major serine protease system, and its components uPA, urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitor-1(PAI-1) are widely upregulated in fibrotic diseases, including hypertrophic scars, keloids, and scleroderma. Here, we found that the successful binding of uPA and uPAR activates the downstream peroxisome proliferator-activated receptor (PPAR) signalling pathway to reduce the proliferation, migration, and contraction of disease-derived fibroblasts, contributing to the alleviation of skin fibrosis. However, increased or robust upregulation of the inhibitor PAI-1 inhibits these effects, suggesting of the involvement of PAI-1 in skin fibrosis. Subsequent in vivo studies showed that uPAR inhibitors increased skin fibrosis in mouse models, while uPA agonists and PAI-1 inhibitors reversed these effects. Our findings demonstrate a novel role for the uPA system and highlights its relationships with skin fibrosis, thereby suggesting new therapeutic approaches targeting the uPA system.

Direct and Indirect Roles of Macrophages in Hypertrophic Scar Formation.

Hypertrophic scars are pathological scars that result from abnormal responses to trauma, and could cause serious functional and cosmetic disability. To date, no optimal treatment method has been established. A variety of cell types are involved in hypertrophic scar formation after wound healing, but the underlying molecular mechanisms and cellular origins of hypertrophic scars are not fully understood. Macrophages are major effector cells in the immune response after tissue injury that orchestrates the process of wound healing. Depending on the local microenvironment, macrophages undergo marked phenotypic and functional changes at different stages during scar pathogenesis. This review intends to summarize the direct and indirect roles of macrophages during hypertrophic scar formation. The in vivo depletion of macrophages or blocking their signaling reduces scar formation in experimental models, thereby establishing macrophages as positive regulatory cells in the skin scar formation. In the future, a significant amount of attention should be given to molecular and cellular mechanisms that cause the phenotypic switch of wound macrophages, which may provide novel therapeutic targets for hypertrophic scars.

Toll-like receptor 4 polymorphisms to determine acute pancreatitis susceptibility and severity: a meta-analysis.

AIM: To investigate the correlation of toll-like receptor 4 (TLR4) gene Asp299Gly and Thr399Ile polymorphisms and acute pancreatitis (AP) risk and severity. METHODS: To get a more precise estimation of the relationship, a comprehensive search was performed to examine all the eligible studies of TLR4 Asp299Gly and Thr399Ile polymorphisms and AP risk. The odds ratios with 95% confidence intervals were used to assess the strength of the association. Publication bias was analyzed by Begg's funnel plots. RESULTS: In total, six studies with 1255 cases and 998 controls were included in this meta-analysis. Totally, no significant associations were found between TLR4 Asp299Gly or Thr399Ile polymorphisms and AP risk using five models with high homogeneity (P > 0.05). Furthermore, stratification analysis by ethnicity or assay also found no significant association in these two polymorphisms (P > 0.05), and TLR4 Asp299Gly was not associated with AP severity (P > 0.05). In addition, no publication bias was found in these studies (P > 0.05). CONCLUSION: Our current meta-analysis suggests that TLR4 Asp299Gly and Thr399Ile polymorphisms may not be risk factors to AP susceptibility.

[Design of obstetrical "potential severe disease" score and its application in 3269 pregnant women].

OBJECTIVE: To study the applicability and practicability of "potential severe disease" score in prognosticating severity of potential disease in late pregnancy and puerperal mother and newborn. METHODS: "Potential severe disease" score was designed based on the characters of obstetrical patients, and 3269 puerperal women were surveyed and the condition of mother and child were investigated after delivery. RESULTS: The mean rank of "potential severe disease" score in the group with severe illness (n=137) was extremely higher than that of smooth pregnancy group (n=3132, 2969.390 vs. 1576.630, Z=-18.052, P<0.01). The result indicated the score could evaluate the degree of illness. The area under the receiver operating characteristic curve (AUC) of the "potential severe disease" score was 0.926, the optimal cut-off point of score was 3, with sensibility 73.72%, specificity 92.21%. There was no significant difference in the mean rank of "potential severe disease" score between fetal distress group (n=507) and normal fetus group (n=2726, 1572.920 vs. 1646.400, Z=-1.498, P>0.05), therefore it indicated that the "potential severe disease" score had not the identification ability on fetal distress. CONCLUSION: Obstetrical "potential severe disease" score may be applied for obstetrics because of speediness, simplicity and better identification in evaluating the disease in late pregnancy.

[A new puncture needle with multiple holes for testicular sperm extraction].

OBJECTIVE: To evaluate a new puncture needle with multiple holes (National Invention Patent of China: ZL 2010202466554) in testicular sperm extraction for infertile males. METHODS: This study included 215 azoospermia patients, who underwent testicular sperm extraction with a new puncture needle with multiple holes (group A, n = 133), by open biopsy (group B, n = 37), or with a fine needle (group C, n = 45). RESULTS: The first-time success rate was 100% in group A, 19% in B and 100% in C. The average operation time was obviously shorter in group A ([3 +/- 1] min) than in B ([15 +/- 3] min) and C ([7 +/- 2] min). The rate of postoperative complications was 3.0% in group A, significantly lower than in B (21.6%) and C (11.1%). CONCLUSION: The new puncture needle with multiple holes, with its advantages of accuracy, high first-time success rate, minimal invasiveness and low rate of complications, deserves to be generally applied in testicular sperm extraction.