Androgenic alopecia(AGA)is the most common type of clinical alopecia.Androgen receptor(AR)is the most logical candidate gene for regulating the occurrence of AGA.Dermal papilla cells(DPCs)are a special kind of mesen-chymal cells,located in the hair bulb of hair follicles.DPCs play a role in maintaining and inducing the periodic cycling of hair follicles,and are considered as a key cell target of androgen in hair follicles.Tcf4 is a positive regulator of the maintenance of DPC biological features.Previously,we reported that Twist1 can enhance the inductive effect of Tcf4.1 As a transcription factor,AR can bind with Tcf4 to regulate the proliferation in prostate growth and tumori-genesis.2,3 However,whether and how AR interacts with Tcf4 in DPCs remains unknown.

Ureaplasma urealyticum (U. urealyticum) is a normal commensal that colonizes the human genital tract and usually of low virulence; however, it can trigger serious extragenital infections in immunocompromised patient. In this case, a 48-year-old female immunocompromised patient with a four-year history of recurrent ulcer on extremities was presented to our hospital due to aggravation of lesions 10 months before. She was initially diagnosed as Pseudomonas aeruginosa infection secondary to lupus panniculitis and slightly responded to ceftazidime treatment; however, a new rash appeared on her left hip 16 days after admission, which was aggravated even under antibiotic treatment. After multiple negative cultures, U. urealyticum was identified in her left hip tissue using metagenomic next-generation sequencing (mNGS). U. urealyticum was also confirmed in her secretion samples from left hip, left thigh, right calf and uterine neck using mycoplasma culture and quantitative real-time polymerase chain reaction. Her lesions, especially the new rash, were positively responded to sensitive antibiotic treatment. To the best of our knowledge, this is the first case of U. urealyticum induced recurrent skin and soft-tissue infections (SSTIs) in an immunocompromised adult patient. This case suggests that the prevalence of this kind of infections may be underestimated because of the limitation of routine culture. mNGS may be considered to look for atypical pathogens to improve the antimicrobial treatment of complicated infections.

ObjectiveDuring hair follicle regeneration, hair follicle stem cells (HFSCs) are regulated by signals from dermal papilla cells (DPCs). Previously we found that Tcf4 could promote the proliferation of DPCs. In this study, we focused on whether and how the biological properties of Tcf4-induced DPCs were regulated by Twist1.MethodsTwist1 was overexpressed or knocked down in DPCs following different adenovirus or lentivirus infection. Phase-contrast microscopy was used to observe the agglutinative growth of DPCs. The CCK-8 assay was used to test the proliferation of DPCs. Western blot and qPCR experiments were used to determine the expression of HGF, IGF-1, VEGF, c-myc, survivin, and CyclinD1 in DPCs. ELISAs were used to test the growth factors secreted by DPCs. Conditional medium culture was used to detect the inductive ability of DPCs. Co-immunoprecipitation and immunofluorescence were used to test the binding of Twist1, Tcf4, and β-catenin in DPCs. Immunofluorescence was also used to test the expression of Twist1, Tcf4, and KRT15 in hair follicles.ResultsTwist1 induced DPC agglutinative growth and proliferation. Twist1 upregulated the expression of downstream target genes downstream of Tcf4, c-myc, survivin, in Tcf4-induced DPCs, as well as the expression and secretion of growth factors HGF, IGF-1, VEGF, which had the ability to induce hair follicle growth. The conditional medium from Twist1-treated DPCs increased the expression of KRT40 and MSX2 in HaCaT cells. Twist1 and Tcf4 co-localized in DPCs both in vitro and in vivo. Anti-Twist1 precipitated Tcf4 and β-catenin.ConclusionThese results indicate that Tcf4 and Twist1 play a synergistic role in regulating the hair follicle induction ability of DPCs. Twist1 functions by forming a ternary complex with Tcf4 and β-catenin. Thus, we report new data that elucidate whether and how Twist1 regulates some biological properties of DPCs.

Objective:To develop an efficient and rapid method for the isolation and cultivation of human scalp dermal papilla cells from small specimens.Methods:Hair-bearing skin specimens measuring 0.5 cm × 0.5 cm -0.5 cm × 1 cm in size were obtained from the scalp of 3 patients with pigmented nevus and 6 with sebaceous nevus during surgery in Department of Dermatology, the First Hospital Affiliated to Army Medical University from September 2018 to January 2019. The subcutaneous fat layer containing hair follicles was cut out of the specimens, and hair follicles were sorted with ophthalmic forceps, which were subsequently digested with 0.6% dispase Ⅱ for 30 minutes, then with 0.2% collagenase Ⅳ at 37 ℃ for 30 - 60 minutes, and were centrifuged to obtain hair papillae. Morphological observation was performed on the isolated hair papillae, and dermal papilla cells were cultured, passaged and identified.Results:Under the microscope, the hair papillae isolated by two-step enzyme digestion of small scalp specimens were intact, and showed an inverted pear-like shape, and residual dermal sheaths could be observed around some hair papillae. However, no hair papilla was isolated by one-step enzyme digestion. With the two-step enzyme digestion method, the hair papilla separation rate was 60.8% ± 2.1%, the adherence rate of the dermal papilla cells at 72 hours was 86.6% ± 3.9%, the time for cells to emigrate out of hair papillae was 0.5 - 3.0 days, the total operation duration was 2.0 - 3.0 hours, and the actual operation duration after subtraction of digestion duration was 1.0 - 1.5 hours. The dermal papilla cells isolated by the two-step enzyme digestion method could grow in an aggregative pattern in early stage, but grew in a non-aggregative pattern after 8 passages.Conclusion:The two-step enzyme digestion of small specimens is a simple and efficient method for isolating human scalp dermal papilla cells.