Blocking the ATR-SerRS-VEGFA pathway targets angiogenesis for UV-induced cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most prevalent form of skin cancer, with an escalating incidence rate and a notable potential (up to 5%) for metastasis. Ultraviolet radiation (UVA and UVB) exposure is the primary risk factor for cSCC carcinogenesis, with literature suggesting ultraviolet radiation (UVR) promotes vascular endothelial growth factor A (VEGFA) expression. This study aims to investigate UVR-induced upregulation of VEGFA and explore combination therapeutic strategies. The skin squamous cell carcinoma cell line A431 was exposed to specific durations of ultraviolet radiation. The effect of emodin on ATR/SerRS/VEGFA pathway was observed. The cell masses were also transplanted subcutaneously into mice (n = 8). ATR inhibitor combined with emodin was used to observe the growth and angiogenesis of the xenografts. The results showed that UV treatment significantly enhanced the phosphorylation of SerRS and the expression level of VEGFA in A431 cells (p < 0.05). Treatment with emodin significantly inhibited this expression (p < 0.05), and the combination of emodin and ATR inhibitor further enhanced the inhibitory effect (p < 0.05). This phenomenon was further confirmed in the xenograft model, which showed that the combination of ATR inhibitor and emodin significantly inhibited the expression of VEGFA to inhibit angiogenesis (p < 0.05), thus showing an inhibitory effect on cSCC. This study innovatively reveals the molecular mechanism of UV-induced angiogenesis in cSCC and confirms SerRS as a novel target to inhibit cSCC angiogenesis and progression in vitro and in vivo studies.

Active Hydrophilic Graphene Oxide Nanocomposites Delivery Mediated by Adipose-Derived Stem Cell for Elevated Photothermal Therapy of Breast Cancer.

Purpose: Graphene oxide (GO) and its derivatives have recently been identified as promising candidates for early disease diagnosis and therapy. However, the physiological stability and precise launch requirements present limitations on further clinical practices. Adipose-derived stem cells (ADSCs) were employed as an unobstructed biological vehicle to address the validate this ADSC-based tumor-targeting system for highly efficient GO delivery combined with two-stage NIR radiation for superior tumor ablation. Methods: GO was modified with poly-ethylene glycol (PEG) and folic acid (FA). Afterward, the GO nanocomposite was internalized into ADSCs. The GO-PEG-FA-laden ADSCs were injected into the tail veins of the tumor-bearing mice. Subsequently, first-stage NIR radiation was utilized to disrupt the ADSCs for GO-PEG-FA release. After this, the heat generated by secondary-stage NIR radiation destroy the malignant cells and shrink the tumor, and the cascade process could be recycled until complete tumor ablation if necessary. Results: The GO-PEG-FA nanocomposite exhibited negligible cytotoxicity and could be internalized into ADSCs to target specific tumor sites after 32 days of intravenous injection. The nanocomposite was released from the ADSCs and taken up into cancer cells again with the assistance of FA after the first dose of near-infrared radiation. Then, the second radiation dose could directly strike the cancer cell for cancer ablation. Conclusion: In summary, we reported a stem cell-based anticancer system that used GO-PEG-FA-laden ADSCs for breast cancer therapy through NIR treatment in mice potentially opens a new avenue not only to address precise drug targeting in tumor therapy, but also future clinical practice in diverse areas.

Polydopamine-assisted tranilast immobilization on a PLA chamber to enhance fat flaps regeneration by reducing tissue fibrosis.

Tissue engineering chambers (TECs) have been shown to be useful in regenerating adipose tissue. However, tissue fibrosis caused by the chambers compromises the final volume of the newly formed adipose tissue. Surface modifications can compensate for the lack of biocompatibility of an implant. Tranilast (Tra) is an antifibrotic drug used to treat fibrotic pathologies, including keloids and scleroderma. In this study, a polydopamine-assisted tranilast coating (pDA + Tra) was prepared on a polylactic acid (PLA) chamber to minimize tissue fibrosis and achieve a large volume of fat flap regeneration. The in vitro results showed that, in contrast to a PLA chamber, roughness increased, and the fibroblast adhesion and smooth muscle antibody-positive immunoreactivity decreased in the PLA + pDA + Tra chamber. In addition, pedicled adipose tissue flaps were separated from the back of the rabbit and inserted into each chamber using the classic TEC procedure. After 16 weeks, the marked attenuation of fibrosis and promotion of fat regeneration was observed in the PLA + pDA + Tra chamber in contrast to the PLA chamber. Moreover, in contrast to the PLA chamber, Q-PCR results showed that fibrotic factor TGF-ß was significantly reduced, associated with a remarkable increase in adipogenic differentiation transcription factors PPAR-γ and C/EBPα in the PLA + pDA + Tra chamber after 16 weeks (p < 0.05). Thus, PLA chambers loaded with pDA + Tra on the surface have good biocompatibility, and chemical anti-fibrosis reagents can synergistically reduce fibrosis formation while excellently promoting adipose tissue regeneration.

The angiogenic and adipogenic modes of adipose tissue after free fat grafting.

BACKGROUND: The major drawback of adipose grafting is its clinical unpredictability, which leads to surgeon and patient dissatisfaction. The mechanisms underlying angiogenesis and regeneration of the graft tissue are still unclear. METHODS: Mouse adipose tissue was processed using two different methods (fragmental and integral) and was used to identify the mode of angiogenesis of the graft. Cross-grafting of tissue from normal mice and transgenic mice expressing green fluorescent protein was used to observe the origin of cells during the adipose regeneration. RESULTS: Almost all the CD31 endothelial cells of the new vessels were derived from the recipient. The new vessels in the graft were mainly formed through recipient vessels growing into the graft rather than the reassembly of donor endothelial cells or the reconnection of recipient and donor vessels. Angiogenesis depends largely on recipient-site environment. The retention of donor-derived tissue dropped to only 10 percent 8 weeks after grafting, and the majority of the key regeneration cells, the CD34 cells, came from the recipient during adipogenesis (p < 0.05). In total, the retention of the recipient-derived tissue was up to 73 percent in the fragmental group and 47.5 percent in the integral group. CONCLUSIONS: The angiogenesis of the graft occurs by the classic "vessel branching" mode, in which the recipient plays a dominant role. The mode of graft tissue retention primarily involves CD34 adipose precursor cells derived from the recipient.

Anti-aging effect of adipose-derived stem cells in a mouse model of skin aging induced by D-galactose.

INTRODUCTION: Glycation products accumulate during aging of slowly renewing tissue, including skin, and are suggested as an important mechanism underlying the skin aging process. Adipose-derived cells are widely used in the clinic to treat ischemic diseases and enhance wound healing. Interestingly, adipose-derived stem cells (ASCs) are also effective in anti-aging therapy, although the mechanism underlying their effects remains unknown. The purpose of the present study was to examine the anti-aging effect of ASCs in a D-galactose-induced aging animal model and to clarify the underlying mechanism. MATERIALS AND METHODS: Six-week-old nude mice were subcutaneously injected with D-gal daily for 8 weeks. Two weeks after completion of treatment, mice were randomized to receive subcutaneous injections of 106 green fluorescent protein (GFP)-expressing ASCs, aminoguanidine (AG) or phosphate-buffered saline (PBS). Control mice received no treatment. We examined tissue histology and determined the activity of senescence-associated molecular markers such as superoxide dismutase (SOD) and malondialdehyde (MDA). RESULTS: Transplanted ASCs were detectable for 14 days and their GFP signal disappeared at day 28 after injection. ASCs inhibited advanced glycation end product (AGE) levels in our animal model as well as increased the SOD level and decreased the MDA level, all of which act to reverse the aging phenotype in a similar way to AG, an inhibitor of AGE formation. Furthermore, ASCs released angiogenic factors in vivo such as vascular endothelial growth factor, suggesting a skin trophic effect. CONCLUSIONS: These results demonstrate that ASCs may contribute to the regeneration of skin during aging. In addition, the data shows that ASCs provide a functional benefit by glycation suppression, antioxidation, and trophic effects in a mouse model of aging.

Tissue engineering chamber promotes adipose tissue regeneration in adipose tissue engineering models through induced aseptic inflammation.

Tissue engineering chamber (TEC) makes it possible to generate significant amounts of mature, vascularized, stable, and transferable adipose tissue. However, little is known about the role of the chamber in tissue engineering. Therefore, to investigate the role of inflammatory response and the change in mechanotransduction started by TEC after implantation, we placed a unique TEC model on the surface of the groin fat pads in rats to study the expression of cytokines and tissue development in the TEC. The number of infiltrating cells was counted, and vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1) expression levels in the chamber at multiple time points postimplantation were analyzed by enzyme-linked immunosorbent assay. Tissue samples were collected at various time points and labeled for specific cell populations. The result showed that new adipose tissue formed in the chamber at day 60. Also, the expression of MCP-1 and VEGF in the chamber decreased slightly from an early stage as well as the number of the infiltrating cells. A large number of CD34+/perilipin- perivascular cells could be detected at day 30. Also, the CD34+/perilipin+ adipose precursor cell numbers increased sharply by day 45 and then decreased by day 60. CD34-/perilipin+ mature adipocytes were hard to detect in the chamber content at day 30, but their number increased and then peaked at day 60. Ki67-positive cells could be found near blood vessels and their number decreased sharply over time. Masson's trichrome showed that collagen was the dominant component of the chamber content at early stage and was replaced by newly formed small adipocytes over time. Our findings suggested that the TEC implantation could promote the proliferation of adipose precursor cells derived from local adipose tissue, increase angiogenesis, and finally lead to spontaneous adipogenesis by inducing aseptic inflammation and changing local mechanotransduction.

The survival condition and immunoregulatory function of adipose stromal vascular fraction (SVF) in the early stage of nonvascularized adipose transplantation.

INTRODUCTION: Adipose tissue transplantation is one of the standard procedures for soft-tissue augmentation, reconstruction, and rejuvenation. However, it is unknown as to how the graft survives after transplantation. We thus seek out to investigate the roles of different cellular components in the survival of graft. MATERIALS & METHODS: The ratios of stromal vascular fraction (SVF) cellular components from human adipose tissue were evaluated using flow cytometry. Human liposuction aspirates that were either mixed with marked SVF cells or PBS were transplanted into nude mice. The graft was harvested and stained on days 1,4,7 and 14. The inflammation level of both SVF group and Fat-only group were also evaluated. RESULTS: Flow cytometric analysis showed SVF cells mainly contained blood-derived cells, adipose-derived stromal cells (ASCs), and endothelial cells. Our study revealed that most cells are susceptible to death after transplantation, although CD34+ ASCs can remain viable for 14 days. Notably, we found that ASCs migrated to the peripheral edge of the graft. Moreover, the RT-PCR and the immuno-fluorescence examination revealed that although the SVF did not reduce the number of infiltrating immune cells (macrophages) in the transplant, it does have an immunoregulatory function of up-regulating the expression of CD163 and CD206 and down-regulating that of IL-1ß, IL-6. CONCLUSIONS: Our study suggests that the survival of adipose tissue after nonvascularized adipose transplantation may be due to the ASCs in SVF cells. Additionally, the immunoregulatory function of SVF cells may be indirectly contributing to the remolding of adipose transplant, which may lead to SVF-enriched adipose transplantation.