M-CSF-Stimulated CD11b+ Myeloid Cells Induce Alopecia Areata in C3H/HeJ Mice

Alopecia areata (AA) is a T cell-mediated autoimmune skin disease with clinical features of hair loss and skin inflammation. It is unclear whether other immune cells except T lymphocytes are also involved in the development of AA. Here, our results reveal that dermal injection of either CD11b+ myeloid cells isolated from AA-affected skin or non-AA splenocyte-derived CD11b+ cells treated with macrophage colony-stimulating factor (M-CSF) induces AA in C3H/HeJ mice. The functional similarity of these cells in induction of AA seems to be due to a higher expression of M-CSF in AA affected skin. To explore the mechanism by which dermal injection of CD11b+ cells induce AA, we co-culture either AA derived skin cells or M-CSF-stimulated CD11b+ cells with naïve splenocytes. The results of splenocyte proliferation assay and immunoglobulin release in conditioned medium show a significant increase of splenocyte proliferation and IgG level in conditioned medium under both conditions as compared to controls. Most activated splenocytes induced by M-CSF-stimulated myeloid cells are B lymphocytes. B cell activation are further confirmed in AA-affected skin and skin draining lymph nodes of AA mice. In conclusion, in this study, we have provided evidence that M-CSF stimulated CD11b+ cells are able to induce AA in C3H/HeJ mice through a possible mechanism by activating B lymphocytes. This finding may provide insight for understanding the pathogenesis of AA.

Fibronectin meshwork controls epithelial stem cell fate

Adult stem cell fate is tightly balanced by the local microenvironment called niche and sustain tissue regeneration. How niche signals are integrated and regulate regeneration remains largely unexplored. The extracellular matrix and integrin ligand fibronectin is a crucial and well-characterized wound healing actor that has never been involved in skin regeneration. Here, we show that fibronectin displays a highly specific enrichment in hair follicle stem cells (HFSC) at the onset of regeneration. Conditional deletion of fibronectin in HFSC compartment (Lrig1, K19) leads to hair regeneration blockade, impaired stem cell location and fate. Dermal injection of exogenous fibronectin rescues these phenotypes. To elucidate molecular mechanism underlying fibronectin function, we used conditional deletion models of SLC3A2, the main integrin coreceptor. We show that, via its role in integrin-dependent assembly of fibronectin matrix, SLC3A2 acts as molecular relay of niche signals. Thus, fibronectinintegrin-SLC3A2 cascade finely tunes HFSC fate and tissue regenerative power.

Dermal bacterial LPS-stimulation reduces susceptibility to intradermal Trypanosoma brucei infection

Infections with Trypanosoma brucei sp. are established after the injection of metacyclic trypomastigotes into the skin dermis by the tsetse fly vector. The parasites then gain access to the local lymphatic vessels to infect the local draining lymph nodes and disseminate systemically via the bloodstream. Macrophages are considered to play an important role in host protection during the early stage of systemic trypanosome infections. Macrophages are abundant in the skin dermis, but relatively little is known of their impact on susceptibility to intradermal (ID) trypanosome infections. We show that although dermal injection of colony stimulating factor 1 (CSF1) increased the local abundance of macrophages in the skin, this did not affect susceptibility to ID T. brucei infection. However, bacterial LPS-stimulation in the dermis prior to ID trypanosome infection significantly reduced disease susceptibility. In vitro assays showed that LPS-stimulated macrophage-like RAW264.7 cells had enhanced cytotoxicity towards T. brucei, implying that dermal LPS-treatment may similarly enhance the ability of dermal macrophages to eliminate ID injected T. brucei parasites in the skin. A thorough understanding of the factors that reduce susceptibility to ID injected T. brucei infections may lead to the development of novel strategies to help reduce the transmission of African trypanosomes.

Topical platelets rich plasma implications in management of burn

Background: Burn injury is a major cause of trauma to the human body, causing death and disability with a long healing period and high health care costs. The mortality rate of burn injury is decreasing with new treatment modalities.Methods: Fifty patients who underwent to use or not use the platelet rich plasma (PRP) technique in improving the process of healing in burn scars and graft either by physiological dressing or sub dermal injection between 2 groups. The study was conducted on patients presented to Plastic and Reconstructive Surgery Department of Abou Qir General Hospital and Menuofia University in the period from October 2017 to October 2018.Results: On treating the burned area with PRP injection and conventional dressing, the minimal time taken for complete healing was 10 days, while the maximal time taken was 24 days with median 18 days while on treating the burned area with conventional dressing without PRP injection, the minimal time taken for complete healing was 14 days, while the maximum time taken was 32 days.Conclusions: With application of PRP decreased the need of grafting through promoting the healing process of the wound of burned areas than areas not applied with PRP.

Successful Management of Treatment-Resistant Alopecia Areata with Platelet Rich Plasma: A Case Series

Introduction. Alopecia areata (AA) is an autoimmune disease-causing non-scarring alopecia. It is usually treated with immunosuppressive agents, to which some patients fail to respond adequately. Material and Methods. Three patients with AA refractory to standard therapy were treated with intra-dermal injection of autologous platelet rich plasma (PRP) every four weeks. Results. All three patients showed remarkable improvement after multiple sessions of PRP treatment. Conclusion. Autologous PRP is safe and effective in treatment-resistant forms of AA demonstrated in many case reports; therefore it deserves further study with randomized, placebo-controlled trials.