An implication for post-transcriptional control: reciprocal changes of melanocortin receptor type 2 mRNA and protein expression in alopecia areata

Role of neurogenic inflammation in the pathogenesis of alopecia areata

Alopecia areata refers to an autoimmune illness indicated by persistent inflammation. The key requirement for alopecia areata occurrence is the disruption of immune-privileged regions within the hair follicles. Recent research has indicated that neuropeptides play a role in the damage to hair follicles by triggering neurogenic inflammation, stimulating mast cells ambient the follicles, and promoting apoptotic processes in keratinocytes. However, the exact pathogenesis of alopecia areata requires further investigation. Recently, there has been an increasing focus on understanding the mechanisms of immune diseases resulting from the interplay between the nervous and the immune system. Neurogenic inflammation due to neuroimmune disorders of the skin system may disrupt the inflammatory microenvironment of the hair follicle, which plays a crucial part in the progression of alopecia areata.

Effects of hydrogen peroxide on biological characteristics and osteoinductivity of decellularized and demineralized bone matrices

Due to the similar collagen composition and closely physiological relationship with soft connective tissues, demineralized bone matrices (DBMs) were used to repair the injured tendon or ligament. However, the osteoinductivity of DBMs would be a huge barrier of these applications. Hydrogen peroxide (H₂ O₂ ) has been proved to reduce the osteoinductivity of DBMs. Nevertheless, the biological properties of H₂ O₂ -treated DBMs have not been evaluated completely, while the potential mechanism of H₂ O₂ compromising osteoinductivity is also unclear. Hence, the purpose of this study was to characterize the biological properties of H₂ O₂ -treated DBMs and search for the proof that H₂ O₂ could compromise osteoinductivity of DBMs. Decellularized and demineralized bone matrices (DCDBMs) were washed by 3% H₂ O₂ for 12 h to fabricate the H₂ O₂ -treated DCDBMs (HPTBMs). Similar biological properties including collagen, biomechanics, and biocompatibility were observed between DCDBMs and HPTBMs. The immunohistochemistry staining of bone morphogenetic protein 2 (BMP-2) was negative in HPTBMs. Furthermore, HPTBMs exhibited significantly reduced osteoinductivity both in vitro and in vivo. Taken together, these findings suggest that the BMP-2 in DCDBMs could be the target of H₂ O₂ . HPTBMs could be expected to be used as a promising scaffold for tissue engineering. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Cigarette Smoke During Breastfeeding in Rats Changes Glucocorticoid and Vitamin D Status in Obese Adult Offspring

Maternal smoking increases obesogenesis in the progeny. Obesity is associated with several hormonal dysfunctions. In a rat model of postnatal tobacco smoke exposure, we previously reported increased central fat depot and disruption of some hormonal systems in the adult offspring. As both glucocorticoids and vitamin D alter lipogenesis and adipogenesis, here we evaluated the metabolism of these two hormones in visceral adipose tissue (VAT) and liver by Western blotting, and possible associations with lipogenesis biomarkers in adult rats that were exposed to tobacco smoke during their suckling period. At postnatal day (PN) 3, dams and offspring of both sexes were exposed (S group) or not (C group) to tobacco smoke, 4 × 1 h/day. At PN180, corticosteronemia was lower in S male and higher in S female offspring, without alterations in peripheral glucocorticoid metabolism and receptor. Adrenal ACTH receptor (MC2R) was higher in both sexes of S group. Despite unchanged serum vitamin D, liver 25-hydroxylase was higher in both sexes of S group. Male S offspring had higher 1α-hydroxylase, acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) in VAT. Both sexes showed increased ACC protein content and reduced sirtuin mRNA in liver. Male S offspring had lower liver peroxisome proliferator-activated receptor-α. Tobacco exposure during lactation induced abdominal obesity in both sexes via distinct mechanisms. Males and females seem to develop HPA-axis dysfunction instead of changes in glucocorticoid metabolism and action. Lipogenesis in VAT and liver, as well as vitamin D status, are more influenced by postnatal smoke exposure in male than in female adult rat offspring.

Development of autoimmune hair loss disease alopecia areata is associated with cardiac dysfunction in C3H/HeJ mice

Alopecia areata (AA) is a chronic autoimmune hair loss disease that affects several million men, women and children worldwide. Previous studies have suggested a link between autoimmunity, stress hormones, and increased cardiovascular disease risk. In the current study, histology, immunohistology, quantitative PCR (qPCR) and ELISAs were used to assess heart health in the C3H/HeJ mouse model for AA and heart tissue response to adrenocorticotropic hormone (ACTH) exposure. Mice with AA exhibited both atrial and ventricular hypertrophy, and increased collagen deposition compared to normal-haired littermates. QPCR revealed significant increases in Il18 (4.6-fold), IL18 receptor-1 (Il18r1; 2.8-fold) and IL18 binding protein (Il18bp; 5.2-fold) in AA hearts. Time course studies revealed a trend towards decreased Il18 in acute AA compared to controls while Il18r1, Il18bp and Casp1 showed similar trends to those of chronic AA affected mice. Immunohistochemistry showed localization of IL18 in chronic AA mouse atria. ELISA indicated cardiac troponin-I (cTnI) was elevated in the serum and significantly increased in AA heart tissue. Cultures of heart atria revealed differential gene expression between AA and control mice in response to ACTH. ACTH treatment induced significant increase in cTnI release into the culture medium in a dose-dependent manner for both AA and control mice. In conclusion, murine AA is associated with structural, biochemical, and gene expression changes consistent with cardiac hypertrophy in response to ACTH exposure.