Female pattern hair loss: beyond an androgenic aetiology?

Intermediate Hair Follicles from Patients with Female Pattern Hair Loss Are Associated with Nutrient Insufficiency and a Quiescent Metabolic Phenotype

Female pattern hair loss (FPHL) is a non-scarring alopecia resulting from the progressive conversion of the terminal (t) scalp hair follicles (HFs) into intermediate/miniaturized (i/m) HFs. Although data supporting nutrient deficiency in FPHL HFs are lacking, therapeutic strategies are often associated with nutritional supplementation. Here, we show by metabolic analysis that selected nutrients important for hair growth such as essential amino acids and vitamins are indeed decreased in affected iHFs compared to tHFs in FPHL scalp skin, confirming nutrient insufficiency. iHFs also displayed a more quiescent metabolic phenotype, as indicated by altered metabolite abundance in freshly collected HFs and release/consumption during organ culture of products/substrates of TCA cycle, aerobic glycolysis, and glutaminolysis. Yet, as assessed by exogenous nutrient supplementation ex vivo, nutrient uptake mechanisms are not impaired in affected FPHL iHFs. Moreover, blood vessel density is not diminished in iHFs versus tHFs, despite differences in tHFs from different FPHL scalp locations or versus healthy scalp or changes in the expression of angiogenesis-associated growth factors. Thus, our data reveal that affected iHFs in FPHL display a relative nutrient insufficiency and dormant metabolism, but are still capable of absorbing nutrients, supporting the potential of nutritional supplementation as an adjunct therapy for FPHL.

Integral Roles of Specific Proteoglycans in Hair Growth and Hair Loss: Mechanisms behind the Bioactivity of Proteoglycan Replacement Therapy with Nourkrin® with Marilex® in Pattern Hair Loss and Telogen Effluvium

Follicular proteoglycans are key players with structural, functional, and regulatory roles in the growth and cycling behaviour of the hair follicles. The expression pattern of specific proteoglycans is strongly correlated with follicular phase transitions, which further affirms their functional involvement. Research shows that bioactive proteoglycans, e.g., versican and decorin, can actively trigger follicular phase shift by their anagen-inducing, anagen-maintaining, and immunoregulatory properties. This emerging insight has led to the recognition of “dysregulated proteoglycan metabolism” as a plausible causal or mediating pathology in hair growth disorders in both men and women. In support of this, declined expression of proteoglycans has been reported in cases of anagen shortening and follicular miniaturisation. To facilitate scientific communication, we propose designating this pathology “follicular hypoglycania (FHG),” which results from an impaired ability of follicular cells to replenish and maintain a minimum relative concentration of key proteoglycans during anagen. Lasting FHG may advance to structural decay, called proteoglycan follicular atrophy (PFA). This process is suggested to be an integral pathogenetic factor in pattern hair loss (PHL) and telogen effluvium (TE). To address FHG and PFA, a proteoglycan replacement therapy (PRT) program using oral administration of a marine-derived extract (Nourkrin® with Marilex®, produced by Pharma Medico Aps, Aarhus, Denmark) containing specific proteoglycans has been developed. In clinical studies, this treatment significantly reduced hair fall, promoted hair growth, and improved quality of life in patients with male- and female-pattern hair loss. Accordingly, PRT (using Nourkrin® with Marilex®) can be recommended as an add-on treatment or monotherapy in patients with PHL and TE.

Safety of 5α-reductase inhibitors and spironolactone in breast cancer patients receiving endocrine therapies

PURPOSE

To provide dermatologists and oncologists with a foundation for practical understanding and uses of 5α-reductase inhibitors and spironolactone for breast cancer patients and survivors receiving endocrine therapies (ETs), including the effect of these treatments on sex hormone levels, any reported drug interactions, and any risk of malignancy.

METHODS

All published studies from January 1978 through April 2018 were considered, using databases such as PubMed, Google Scholar, and Science Direct. Forty-seven studies were included in this review.

RESULTS

There is no evidence of interactions between 5α-reductase inhibitors and spironolactone with ETs used in breast cancer. Sex hormone alteration with 5α-reductase inhibitor or spironolactone use is variable. Three randomized controlled trials, 1 case-control study, and 6 retrospective cohort studies, including 284 female patients, studied the effects of 5α-reductase inhibitors on serum estrogen levels. Levels were increased in 97 of 284 (34%) patients, decreased in 15 of 284 (5.3%) patients, and unchanged in 162 of 284 (57%) patients. Four retrospective cohort studies, 1 case study, and 1 double-blinded crossover study, including 95 female patients, assessed the effect of spironolactone on estrogen levels. Levels were increased in 25 of 95 (26%) patients, decreased in 6 of 95 (6.3%) patients, and unchanged in 64 of 95 (67%) patients. Ultimately, most patients did not have a significant alteration in the level of estrogen when using 5α-reductase inhibitors or spironolactone. No consistent evidence of increased risk of female breast cancer while on spironolactone was reported in 3 studies including 49,298 patients; the risk of breast cancer with the use of 5α-reductase inhibitors has not been studied.

CONCLUSIONS

Most patients did not show increased estrogen levels with spironolactone and there were no data suggesting increased risk of breast cancer. Based on hormonal and pharmacological activity, spironolactone may be considered for further research on alopecia and hirsutism in breast cancer patients.

Hair disorders in cancer survivors

With increasing survival rates across all cancers, survivors represent a growing population that is frequently affected by persistent or permanent hair growth disorders as a result of systemic therapies, radiotherapy, surgical procedures, and therapeutic transplants. These hair disorders include persistent chemotherapy-induced alopecia, persistent radiotherapy-induced alopecia, endocrine therapy-induced alopecia and hirsutism, postsurgery alopecia and localized hypertrichosis, and persistent stem cell transplantation and targeted therapy-induced alopecia. The information contained in this continuing medical education series should facilitate a better understanding on hair disorders in cancer survivors so that adequate support and therapies may be provided.

Tumour necrosis factor alpha, interferon gamma and substance P are novel modulators of extrapituitary prolactin expression in human skin

Human scalp skin and hair follicles (HFs) are extra-pituitary sources of prolactin (PRL). However, the intracutaneous regulation of PRL remains poorly understood. Therefore we investigated whether well-recognized regulators of pituitary PRL expression, which also impact on human skin physiology and pathology, regulate expression of PRL and its receptor (PRLR) in situ. This was studied in serum-free organ cultures of microdissected human scalp HFs and skin, i.e. excluding pituitary, neural and vascular inputs. Prolactin expression was confirmed at the gene and protein level in human truncal skin, where its expression significantly increased (p = 0.049) during organ culture. There was, however, no evidence of PRL secretion into the culture medium as measured by ELISA. PRL immunoreactivity (IR) in female human epidermis was decreased by substance P (p = 0.009), while neither the classical pituitary PRL inhibitor, dopamine, nor corticotropin-releasing hormone significantly modulated PRL IR in HFs or skin respectively. Interferon (IFN) γ increased PRL IR in the epithelium of human HFs (p = 0.044) while tumour necrosis factor (TNF) α decreased both PRL and PRLR IR. This study identifies substance P, TNFα and IFNγ as novel modulators of PRL and PRLR expression in human skin, and suggests that intracutaneous PRL expression is not under dopaminergic control. Given the importance of PRL in human hair growth regulation and its possible role in the pathogenesis of several common skin diseases, targeting intracutaneous PRL production via these newly identified regulatory pathways may point towards novel therapeutic options for inflammatory dermatoses.

Problems in pattern alopecia

Female pattern hair loss (FPHL) was originally described as synonymous with androgenetic alopecia. However, the role of androgens in FPHL has not been proven, and the etiology is not yet defined. Several patterns of hair loss in women have been described, in addition to descriptions of scarring alopecias mimicking FPHL. In this paper, we discuss FPHL as an entity other than androgenetic alopecia and suggest that de-emphasizing the physicians reliance on pattern in the diagnosis of hair loss in women, and instead utilizing other tools including dermoscopy and histopathology, would benefit clinician's efforts in treating alopecias.

Androgen actions on the human hair follicle: perspectives

Androgens stimulate beard growth but suppress hair growth in androgenetic alopecia (AGA). This condition is known as 'androgen paradox'. Human pilosebaceous units possess enough enzymes to form the active androgens testosterone and dihydrotestosterone. In hair follicles, 5α-reductase type 1 and 2, androgen receptors (AR) and AR coactivators can regulate androgen sensitivity of dermal papillae (DP). To regulate hair growth, androgens stimulate production of IGF-1 as positive mediators from beard DP cells and of TGF-β1, TGF-β2, dickkopf1 and IL-6 as negative mediators from balding DP cells. In addition, androgens enhance inducible nitric oxide synthase from occipital DP cells and stem cell factor for positive regulation of hair growth in beard and negative regulation of balding DP cells. Moreover, AGA involves crosstalk between androgen and Wnt/β-catenin signalling. Finally, recent data on susceptibility genes have provided us with the impetus to investigate the molecular pathogenesis of AGA.