Murine type VII collagen distorts outcome in human skin graft mouse model for dystrophic epidermolysis bullosa

Human skin graft mouse models are widely used to investigate and develop therapeutic strategies for the severe generalized form of recessive dystrophic epidermolysis bullosa (RDEB), which is caused by biallelic null mutations in COL7A1 and the complete absence of type VII collagen (C7). Most therapeutic approaches are focused on reintroducing C7. Therefore, C7 and anchoring fibrils are widely used as readouts in therapeutic research with skin graft models. In this study, we investigated the expression pattern of human and murine C7 in a grafting model, in which human skin is reconstituted out of in vitro cultured keratinocytes and fibroblasts. The model revealed that murine C7 was deposited in both human healthy control and RDEB skin grafts. Moreover, we found that murine C7 is able to form anchoring fibrils in human grafts. Therefore, we advocate the use of human‐specific antibodies when assessing the reintroduction of C7 using RDEB skin graft mouse models.     

Hair hormones in male youth with internet gaming disorder

Objectives: Internet gaming disorder (IGD) is associated with altered physiological reactivity to psychosocial stress. Findings from a previous study on alterations of basal hypothalamic–pituitary–adrenal (HPA) axis functioning, indexed by differences in hair hormone levels (i.e., cortisol) in IGD patients compared to matched controls, were limited by a small sample size.

Methods: Following the protocol of the previous study, male patients with IGD (n?=?31) and controls (n?=?31) matched for age, educational status and smoking were recruited. Sociodemographic and clinical characteristics were assessed using structured interviews and self-reports. Hair samples were taken for the analysis of cortisol, cortisone, testosterone, progesterone, dehydroepiandrosterone (DHEA), and corticosterone.

Results: Groups showed no significant differences on cortisol (d?=??0.10, 95%CI (?0.60; 0.40)), cortisone (d?=??0.10, 95%CI (?0.60; 0.40)), testosterone (d?=??0.00, 95%CI (?0.51; 0.51)), progesterone (d?=??0.46, 95%CI (?0.96; 0.05)), DHEA (d?=??0.04, 95%CI (?0.54; 0.47)) or corticosterone (d?=??0.19, 95%CI (?0.69; 0.32)). Associations between hair hormone concentrations, symptom severity and sociodemographic variables were weak and did not survive correction for multiple testing.

Conclusions: Unlike other psychiatric disorders, effects of IGD and associated psychopathology on basal HPA axis functioning, indexed by hair hormone levels, are negligible. Future studies need to rule out potential effects of sex, age and long-term pathology on these findings.