Proteomic analysis of balding and non-balding mesenchyme-derived dermal papilla cells from androgenetic alopecia patients using on-line two-dimensional reversed phase-reversed phase LC–MS/MS

PAICS as a potential target for cancer therapy linking purine biosynthesis to cancer progression

Tumor cells are required to undergo metabolic reprogramming for rapid development and progression, and one of the metabolic characteristics of cancer cells is the excessive synthesis and utilization of nucleotides. Abnormally increased nucleotides and their metabolites not only directly accelerate tumor cell progression but also indirectly act on stromal cells in the tumor microenvironment (TME) via a paracrine manner to regulate tumor progression. Purine nucleotides are mainly produced via de novo nucleotide synthesis in tumor cells; therefore, intervening in their synthesis has emerged as a promising strategy in anti-tumor therapy. De novo purine synthesis is a 10-step reaction catalyzed by six enzymes to synthesize inosine 5-monophosphate (IMP) and subsequently synthesize AMP and GMP. Phosphoribosylaminoimidazole carboxylase/phosphori-bosylaminoimidazole succinocarboxamide synthetase (PAICS) is a bifunctional enzyme that catalyzes de novo purine synthesis. Aberrantly elevated PAICS expression in various tumors is associated with poor prognosis. Evidence suggests that PAICS and its catalytic product, N-succinylcarboxamide-5-aminoimidazole ribonucleotide (SAICAR), could inhibit tumor cell apoptosis and promote the growth, epithelial-mesenchymal transition (EMT), invasion, and metastasis by regulating signaling pathways such as pyruvate kinase M2 (PKM2), extracellular signal-related kinases 1 and 2 (ERK1/2), focal adhesion kinase (FAK) and so on. This review summarizes the structure, biological functions and the molecular mechanisms of PAICS in cancer development and discusses its potential to be a target for tumor therapy.

Overexpression of miR-122 promotes apoptosis of dermal papilla cells by directly targeting IGF1R in androgenetic alopecia

Androgenetic alopecia (AGA) is the most common pattern of hair loss resulting from the effects of androgen on hair follicle. MicroRNAs (miRs) serve imperative roles in the regulation of many biological processes of hair follicle. However, the exact molecular mechanism of AGA remains to be elucidated. In the present study, we found miR-122, which is mainly recognized as a tumor suppressor, was highly overexpressed in the bulb of balding HFs in comparison with non-balding ones in AGA. Moreover, miR-122 induces apoptosis of human dermal papilla cells (hDPCs) with miR-122 mimics in vitro, and the expression of insulin-like growth factor 1 receptor (IGF1R) in hDPCs was reduced following upregulation of miR-122. Mechanistically, dual luciferase reporter assay confirmed that miR-122 directly targeted the 3'-untranslated region of IGF1R.These findings suggested that upregulation of miR-122 induces apoptosis, potentially via the repression of IGF1R in hDPCs of AGA, providing a novel insight into the potential pathological mechanism of miR-122 in AGA DPCs. This article is protected by copyright. All rights reserved.

An appraisal of laboratory models of androgenetic alopecia: A systematic review

Background

Androgenetic alopecia (AGA) is the most common form of non‐scarring alopecia in humans. Several studies have used different laboratory models to study the pathogenesis and interventions for AGA. These study models have proved beneficial and have led to the approval of two drugs. However, the need to build on existing knowledge remains by examining the relevance of study models to the disease.

Objective

We sought to appraise laboratory or pre‐clinical models of AGA.

Method

We searched through databases (PubMed, ScienceDirect, Web of Science, World CAT, Scopus and Google Scholar) for articles on AGA‐related studies from 1942 to March 2019 with a focus on study models.

Results

The search rendered 101 studies after screening and deduplication. Several studies (70) used in vitro models, mostly consisting of two‐dimensional monolayer cells for experiments involving the characterization of androgen and 5‐alpha reductase (5AR) and inhibition thereof, the effects of dihydrotestosterone (DHT) and biomarker(s) of AGA. Twenty‐seven studies used in vivo models of mice and monkeys to investigate DHT synthesis, the expression and inhibition of 5AR and hair growth. Only four studies used AGA‐related or healthy excisional/punch biopsy explants as ex vivo models to study the action of 5AR inhibitors and AGA‐associated genes. No study used three‐dimensional [3‐D] organoids or organotypic human skin culture models.

Conclusion

We recommend clinically relevant laboratory models like human or patient‐derived 3‐D organoids or organotypic skin in AGA‐related studies. These models are closer to human scalp tissue and minimize the use of laboratory animals and could ultimately facilitate novel therapeutics.

Increased Expression of Zyxin and Its Potential Function in Androgenetic Alopecia

Androgenetic alopecia (AGA) is the most common progressive form of hair loss, occurring in more than half of men aged > 50 years. Hair follicle (HF) miniaturization is a feature of AGA, and dermal papillae (DP) play key roles in hair growth and regeneration by regulating follicular cell activity. Previous studies have revealed that adhesion signals are important factors in AGA development. Zyxin (ZYX) is an actin-interacting protein that is essential for cell adhesion and migration. The aim of this research was to investigate the expression and potential role of ZYX in AGA. Real-time polymerase chain reaction (RT-PCR) analysis revealed that ZYX expression was elevated in the affected frontal HF of individuals with AGA compared to unaffected occipital HF. Moreover, increased ZYX expression was also observed within DP using immunofluorescence staining. Our in vivo results revealed that ZYX knockout mice showed enhanced hair growth and anagen entry compared to wild-type mice. Reducing ZYX expression in ex vivo cultured HFs by siRNA resulted in the enhanced hair shaft production, delayed hair follicle catagen entry, increased the proliferation of dermal papilla cells (DPCs), and upregulated expression of stem cell-related proteins. These results were further validated in cultured DPCs in vitro. To further reveal the mechanism by which ZYX contributes to AGA, RNA-seq analysis was conducted to identify gene signatures upon ZYX siRNA treatment in cultured hair follicles. Multiple pathways, including focal adhesion and HIF-1 signaling pathways, were found to be involved. Collectively, we discovered the elevated expression of ZYX in the affected frontal hair follicles of AGA patients and revealed the effects of ZYX downregulation on in vivo mice, ex vivo hair follicles, and in vitro DPC. These findings suggest that ZYX plays important roles in the pathogenesis of AGA and stem cell properties of DPC and may potentially be used as a therapeutic target in AGA.

Outcome of Intra-operative Injected Platelet-rich Plasma Therapy During Follicular Unit Extraction Hair Transplant: A Prospective Randomised Study in Forty Patients

Context:

Platelet-rich plasma (PRP) therapy is finding importance in aesthetic medicine.

Aim:

The objective of this study was to study efficacy of PRP therapy in follicular unit extraction (FUE) hair transplant.

Materials and Methods:

It is a single-blind, prospective randomised study on 40 FUE hair transplant subjects, allocated in two groups (PRP and non-PRP) alternately. PRP was injected intra-operatively immediately after creating slits over the recipient area in PRP group; and normal saline in non-PRP group. Two groups were evaluated at 2, 4 and 8 weeks, 3 and 6 months of the procedure.

Statistical Analysis:

It was done using Chi-square test and test of significance was set as P < 0.05.

Results:

In PRP group, all subjects had >75% hair regrowth at 6 months, density of >75% grafts was noticed in 12 patients at 4 weeks meaning reduced fall of transplanted hair during catagen phase. New hair growth started at 8 weeks in 16 patients and redness over recipient area completely disappeared in 19 patients at 3 months of surgery and activity in dormant follicles as fine thread like hair was noticed besides the thick transplanted hair in all subjects. In non-PRP group, four patients had >75% hair regrowth at 6 months; none showed >75% graft density at 4 weeks, and 13 subjects showed dormant follicle activity at 4 months. The number of patients having lengthier hairs was significantly more in PRP group.

Conclusion:

Intra-operative PRP therapy is beneficial in giving faster density, reducing the catagen loss of transplanted hair, recovering the skin faster and activating dormant follicles in FUE transplant subjects.

Fibroblast heterogeneity and its implications for engineering organotypic skin models in vitro

Advances in cell culture methods, multidisciplinary research, clinical need to replace lost skin tissues and regulatory need to replace animal models with alternative test methods has led to development of three dimensional models of human skin. In general, these in vitro models of skin consist of keratinocytes cultured over fibroblast-populated dermal matrices. Accumulating evidences indicate that mesenchyme-derived signals are essential for epidermal morphogenesis, homeostasis and differentiation. Various studies show that fibroblasts isolated from different tissues in the body are dynamic in nature and are morphologically and functionally heterogeneous subpopulations. Further, these differences seem to be dictated by the local biological and physical microenvironment the fibroblasts reside resulting in "positional identity or memory". Furthermore, the heterogeneity among the fibroblasts play a critical role in scarless wound healing and complete restoration of native tissue architecture in fetus and oral mucosa; and excessive scar formation in diseased states like keloids and hypertrophic scars. In this review, we summarize current concepts about the heterogeneity among fibroblasts and their role in various wound healing environments. Further, we contemplate how the insights on fibroblast heterogeneity could be applied for the development of next generation organotypic skin models.

Quantitative proteomics approach to screening of potential diagnostic and therapeutic targets for laryngeal carcinoma

To discover candidate biomarkers for diagnosis and detection of human laryngeal carcinoma and explore possible mechanisms of this cancer carcinogenesis, two-dimensional strong cation-exchange/reversed-phase nano-scale liquid chromatography/mass spectrometry analysis was used to identify differentially expressed proteins between the laryngeal carcinoma tissue and the adjacent normal tissue. As a result, 281 proteins with significant difference in expression were identified, and four differential proteins, Profilin-1 (PFN1), Nucleolin (NCL), Cytosolic non-specific dipeptidase (CNDP2) and Mimecan (OGN) with different subcellular localization were selectively validated. Semiquantitative RT-PCR and Western blotting were performed to detect the expression of the four proteins employing a large collection of human laryngeal carcinoma tissues, and the results validated the differentially expressed proteins identified by the proteomics. Furthermore, we knocked down PFN1 in immortalized human laryngeal squamous cell line Hep-2 cells and then the proliferation and metastasis of these transfected cells were measured. The results showed that PFN1 silencing inhibited the proliferation and affected the migration ability of Hep-2 cells, providing some new insights into the pathogenesis of PFN1 in laryngeal carcinoma. Altogether, our present data first time show that PFN1, NCL, CNDP2 and OGN are novel potential biomarkers for diagnosis and therapeutic targets for laryngeal carcinoma, and PFN1 is involved in the metastasis of laryngeal carcinoma.