Process of Hypertrophic Scar Formation: Expression of Eukaryotic Initiation Factor 6

Eukaryotic initiation factor 6 regulates mechanical responses in endothelial cells

The repertoire of extratranslational functions of components of the protein synthesis apparatus is expanding to include control of key cell signaling networks. However, very little is known about noncanonical functions of members of the protein synthesis machinery in regulating cellular mechanics. We demonstrate that the eukaryotic initiation factor 6 (eIF6) modulates cellular mechanobiology. eIF6-depleted endothelial cells, under basal conditions, exhibit unchanged nascent protein synthesis, polysome profiles, and cytoskeleton protein expression, with minimal effects on ribosomal biogenesis. In contrast, using traction force and atomic force microscopy, we show that loss of eIF6 leads to reduced stiffness and force generation accompanied by cytoskeletal and focal adhesion defects. Mechanistically, we show that eIF6 is required for the correct spatial mechanoactivation of ERK1/2 via stabilization of an eIF6-RACK1-ERK1/2-FAK mechanocomplex, which is necessary for force-induced remodeling. These results reveal an extratranslational function for eIF6 and a novel paradigm for how mechanotransduction, the cellular cytoskeleton, and protein translation constituents are linked.

CO2 laser resurfacing for burn and traumatic scars of the hand and upper extremity

Background

Scar formation is a normal part of the proliferative phase in wound healing where collagen is remodelled to better approximate normal skin. When collagen is not effectively redistributed, excessive scarring may occur. Recently, CO₂ laser has emerged as an adjunct in improving scar quality via remodelling and redistribution of dermal collagen fibres. Due to the paucity of literature related to its use in the hands and upper extremities, we created a study to examine its effects on hypertrophic scars focused on the hands and upper extremities.

Methods

Patients treated with CO₂ laser for hypertrophic scars of the hand and upper extremity were included. The Vancouver Scar Scale (VSS) and Patient and Observer Scar Assessment Scale (POSAS) were used to assess the progression of scar quality. Unpaired t-tests were performed to determine statistical difference between pre- and post-treatment scores on each scale. Pearson correlation coefficients were used to understand the relationship between number of treatments and scar quality.

Results

Of the 90 patients enrolled, 54 patients completed serial scar assessment forms. All patient and observer-reported POSAS domains showed improvement (P < 0.05) apart from Itching. All VSS domains showed improvement (P < 0.05). There was moderate correlation between overall patient-reported opinion of scar quality and Discoloration, Stiffness and Thickness, and strong correlation between overall patient opinion and Irregularity (r = 0.715). All observer-reported domains were strongly correlated (r = 7.56–8.74) with overall observer opinion of scar quality.

Conclusion

The results of this study may further substantiate CO₂ laser as a treatment modality for excessive scarring in a variety of surgical subspecialties.

Lay Summary

Complex trauma and burns that impact the skin sometimes result in abnormal healing of the skin called, “hypertrophic scarring”. In our study we assessed how using focused CO₂ laser therapy impacts patients and health care provider assessment of wound progression. Our results were based upon patient reported and healthcare provider observations based upon two standardized forms the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). What we found is that after CO₂ Laser Therapy, our 64 patients with 77 treated scars received on average almost 3 treatments and these treatments helped them with physical function and improved aesthetic appearance of their scars. The health care providers also found that the treatments improved functional and aesthetic end points. Overall, our study helps substantiate the body of evidence that using CO₂ laser therapy improves aesthetics and function of hypertrophic scars in the upper extremity.

Radiation Therapy in Keloids Treatment: History, Strategy, Effectiveness, and Complication

Objective:

Radiation therapy combined with surgical excision was considered as one of the most effective treatment plans for keloid lesions. However, there was no unanimity found over present literatures regarding the issue on optimized treatment strategy for keloids. We here provide a comprehensive review over this issue and emphasize on the influencing factors.

Data Sources:

The data analyzed in this review were searched from articles included in PubMed and EMBASE databases.

Study Selection:

The original articles and critical reviews discussing the application of radiation therapy in keloids treatment were selected for this review.

Results:

The application of radiation therapy has transitioned from simple superficial X-ray irradiation to brachytherapy. Furthermore, several factors including radiation type, dose, fraction, interval, and complications were reviewed, and the results revealed that these factors were significant toward clinical outcome at various levels.

Conclusions:

Both past and present evidence support the idea that combination therapy of radiation and surgical therapy is safe and feasible. However, the optimization of treatment strategy was based on different radiation types and should take dose, fractions, interval, and complications into consideration, which will then decrease the rate of recurrence and increase the level of satisfaction.

Mesenchymal stem cells in the treatment of Cesarean section skin scars: study protocol for a randomized, controlled trial

Background

Cesarean delivery has already become a very common method of delivery around the world, especially in low-income countries. Hypertrophic scars and wound infections have affected younger mothers and frustrated obstetricians for a long time. Mesenchymal stem cells (MSCs) have strong potential for self-renewal and differentiation to multilineage cells. Previous studies have demonstrated that MSCs are involved in enhancing diabetic wound healing. Therefore, this study is designed to investigate the safety and efficacy of using MSCs in the treatment of Cesarean section skin scars.

Methods

This trial is a prospective, randomized, double-blind, placebo-controlled, single-center trial with three parallel groups. Ninety eligible participants will be randomly allocated to placebo, low-dose (transdermal hydrogel MSCs; 3 × 10⁶ cells) or high-dose (transdermal hydrogel MSCs; 6 × 10⁶ cells) groups at a 1:1:1 allocation ratio according to a randomization list, once a day for six consecutive days. Study duration will last for 6 months, comprising a 1 week run-in period and 24 weeks of follow-up. The primary aim of this trial is to compare the difference in Vancouver Scar Scale rating among the three groups at the 6th month. Adverse events, including severe and slight signs or symptoms, will be documented in case report forms. The study will be conducted at the Department of Obstetric of Southern Medical University Affiliated Maternal & Child Health Hospital of Foshan.

Discussion

This trial is the first investigation of the potential for therapeutic use of MSCs for the management of women’s skin scar after Cesarean delivery. The results will give us an effective therapeutic strategy to combat Cesarean section skin scars, even with uterine scarring.

Trial registration

ClinicalTrials.gov, NCT02772289. Registered on 10 May 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2478-x) contains supplementary material, which is available to authorized users.

Involvement of eIF6 in external mechanical stretch-mediated murine dermal fibroblast function via TGF-β1 pathway

External mechanical loading on a wound commonly increases fibrosis. Transforming growth factor-β1 (TGF-β1) has been implicated in fibrosis in various models, including the mechanical force model. However, the underlying mechanism is unclear. Our previous experiments suggested that eukaryotic initiation factor 6 (eIF6) acted as a regulator of TGF-β1 expression, and negatively impact on collagen synthesis. Our current results showed that external mechanical stretching significantly increased COL1A1, TGF-β1 and eIF6 expression as well as dermal fibroblasts proliferation, both in vitro and in vivo. eIF6 –deficient (eIF6^+/−) cells exhibited significantly higher levels of COL1A1, and these levels increased further with external mechanical stretching, suggesting that mechanical stretching plays a synergistic role in promoting COL1A1 expression in eIF6^+/− cells. Inhibition of TGFβR I/II by LY2109761 decreased COL1A1 protein expression in eIF6^+/− dermal fibroblasts in a cell stretching model, and attenuated granulation tissue formation in partial thickness wounds of eIF6^+/− mice. These data suggest that mechanical stretching has a synergistic role in the expression of COL1A1 in eIF6^+/− cells, and is mediated by activation of TGFβRI/II. Taken together, our results indicate that eIF6 may be involved in external mechanical force-mediated murine dermal fibroblast function at least partly through the TGF-β1 pathway.