How good is artificial intelligence (AI) at solving hairy problems? A review of AI applications in hair restoration and hair disorders.

Artificial intelligence (AI) applications in medicine are rapidly evolving. Deep learning diagnostic models that can accurately classify skin lesions have been developed. New AI applications are also starting to emerge in the hair restoration field. The objective was to review the current and future clinical applications of AI in hair restoration and hair disorder diagnosis. Current AI applications in hair restoration include fully automated systems for hair detection and hair growth measurement. New deep learning-based systems have been proposed for scalp diagnosis and automated hair loss measurements, including devices that can be used for self-diagnosis. Hair restoration experts should recognize the potential benefits and limitations of these emerging technologies as they become more readily available to both clinicians and patients.

Hair loss treatment information on Facebook: Content analysis and comparison with other online sources.

BACKGROUND: Facebook is the biggest online social networking platform, and it is being utilized by patients for peer support as well as to explore treatment options. Hair loss patients can experience negative psychological effects and are likely to turn to social networking platforms for support and treatment information. AIMS: To evaluate the type and quality of Facebook hair loss treatment information that can be accessed by hair loss patients. METHODS: In August 2020, we searched Google for publicly accessible Facebook hair loss treatment content using the terms hair loss, alopecia, hair loss treatment, hair restoration, and hair transplant. We retrieved 133 Facebook pages and ranked them based on the number of visitors who received regular content updates. Content posted on the Top 5 most popular pages was analyzed based on type (advertising vs informational) and information quality (unsupported or supported by medical evidence). RESULTS: Most Facebook hair loss pages advertised products or hair restoration clinics, or were aimed at fundraising for alopecia organizations. There was high interest in natural hair loss treatments and follicular unit excision (FUE) procedures, consistent with global online search trends. Some products advertised as "natural" contained minoxidil. "Before & after" images of FUE procedures were popular with users. Only 3%-13% of hair loss treatment posts were supported by medical evidence and user engagement with this content was low. CONCLUSION: There is high user interest in hair loss treatment content on Facebook. Hair restoration specialists should discuss online sources of treatment information with potential patients.

Analysis of YouTube hair loss treatment information: What makes for engaging content?

Patients are increasingly seeking effective hair loss treatments. The internet and social media are popular sources of health information, but the quality and reliability of the content available to patients is highly variable. More than two thirds of American adults reported using YouTube in 2019. We investigated public interest in hair loss treatment information on YouTube and evaluated the quality of health information in videos with high viewer engagement. In July 2020, we used Google Trends, limited to YouTube searches, to analyze relative interest in hair loss treatments worldwide. We searched YouTube using nonsurgical and surgical hair loss treatment terms and we analyzed the retrieved video content. The DISCERN tool was used to evaluate the quality of health information in the hair loss treatment videos with highest viewer engagement. There is increasing public interest in YouTube searches for hair loss treatments. A large number of hair loss treatment videos are available on YouTube, but potential patients are likely to access mostly new content created by well-subscribed channels. Videos with high viewer engagement contain information that can be useful in guiding treatment decisions, but tend to be biased because they are intended to promote dermatology and hair restoration clinics. Patients are using YouTube as a source of hair loss treatment information. Videos created by hair restoration experts contain reliable information, but their quality can be improved by providing links to other sources.

DRM02, a novel phosphodiesterase-4 inhibitor with cutaneous anti-inflammatory activity.

Chronic inflammatory skin disorders are frequently associated with impaired skin barrier function. Selective phosphodiesterase-4 (PDE4) inhibition constitutes an effective therapeutic strategy for the treatment of inflammatory skin diseases. We now report the pharmacological anti-inflammatory profile of DRM02, a novel pyrazolylbenzothiazole derivative with selective in vitro inhibitory activity toward PDE4 isoforms A, B and D. DRM02 treatment of cultured primary human and mouse epidermal keratinocytes interfered with pro-inflammatory cytokine production elicited by interleukin-1α and tumor necrosis factor-α. Similarly, DRM02 inhibited the production of pro-inflammatory cytokines by human peripheral blood mononuclear cells ex vivo and cultured THP-1 monocyte-like cells, with IC50 values of 0.6-14 µM. These anti-inflammatory properties of DRM02 were associated with dose-dependent repression of nuclear factor-κB (NF-κB) transcriptional activity. In skin inflammation in vivo mouse models, topically applied DRM02 inhibited the acute response to phorbol ester and induced Th2-type contact hypersensitivity reactivity. Further, DRM02 also decreased cutaneous clinical changes and expression of Th17 immune pathway cytokines in a mouse model of psoriasis evoked by repeated topical imiquimod application. Thus, the overall pharmacological profiling of the PDE4 inhibitor DRM02 has revealed its potential as a topical therapy for inflammatory skin disorders and restoration of skin homeostasis.

Targeting FER Kinase Inhibits Melanoma Growth and Metastasis.

Melanoma is one of the most aggressive types of tumors and exhibits high metastatic potential. Fes-related (FER) kinase is a non-receptor tyrosine kinase that has been implicated in growth and metastasis of various epithelial tumors. In this study, we have examined the role that FER kinase plays in melanoma at the molecular level. FER-depleted melanoma cells exhibit impaired Wnt/ß-catenin pathway activity, as well as multiple proteomic changes, which include decreased abundance of L1-cell adhesion molecule (L1-CAM). Consistent with the pro-metastatic functions of these pathways, we demonstrate that depletion of FER kinase decreases melanoma growth and formation of distant metastases in a xenograft model. These findings indicate that FER is an important positive regulator of melanoma metastasis and a potential target for innovative therapies.

Integrin-linked kinase and ELMO2 modulate recycling endosomes in keratinocytes.

The formation of tight cell-cell junctions is essential in the epidermis for its barrier properties. In this tissue, keratinocytes follow a differentiation program tightly associated with their movement from the innermost basal to the outer suprabasal layers, and with changes in their cell-cell adhesion profile. Intercellular adhesion in keratinocytes is mediated through cell-cell contacts, including E-cadherin-based adherens junctions. Although the mechanisms that mediate E-cadherin delivery to the plasma membrane have been widely studied in simple epithelia, this process is less well understood in the stratified epidermis. In this study, we have investigated the role of Engulfment and Cell Motility 2 (ELMO2) and integrin-linked kinase (ILK) in the positioning of E-cadherin-containing recycling endosomes during establishment of cell-cell contacts in differentiating keratinocytes. We now show that induction of keratinocyte differentiation by Ca2+ is accompanied by localization of ELMO2 and ILK to Rab4- and Rab11a-containing recycling endosomes. The positioning of long-loop Rab11a-positive endosomes at areas adjacent to cell-cell contacts is disrupted in ELMO2- or ILK-deficient keratinocytes, and is associated with impaired localization of E-cadherin to cell borders. Our studies show a previously unrecognized role for ELMO2 and ILK in modulation of endosomal positioning, which may play key roles in epidermal sheet maintenance and permeability barrier function.

An ELMO2-RhoG-ILK network modulates microtubule dynamics.

ELMO2 belongs to a family of scaffold proteins involved in phagocytosis and cell motility. ELMO2 can simultaneously bind integrin-linked kinase (ILK) and RhoG, forming tripartite ERI complexes. These complexes are involved in promoting ß1 integrin-dependent directional migration in undifferentiated epidermal keratinocytes. ELMO2 and ILK have also separately been implicated in microtubule regulation at integrin-containing focal adhesions. During differentiation, epidermal keratinocytes cease to express integrins, but ERI complexes persist. Here we show an integrin-independent role of ERI complexes in modulation of microtubule dynamics in differentiated keratinocytes. Depletion of ERI complexes by inactivating the Ilk gene in these cells reduces microtubule growth and increases the frequency of catastrophe. Reciprocally, exogenous expression of ELMO2 or RhoG stabilizes microtubules, but only if ILK is also present. Mechanistically, activation of Rac1 downstream from ERI complexes mediates their effects on microtubule stability. In this pathway, Rac1 serves as a hub to modulate microtubule dynamics through two different routes: 1) phosphorylation and inactivation of the microtubule-destabilizing protein stathmin and 2) phosphorylation and inactivation of GSK-3ß, which leads to the activation of CRMP2, promoting microtubule growth. At the cellular level, the absence of ERI species impairs Ca(2+)-mediated formation of adherens junctions, critical to maintaining mechanical integrity in the epidermis. Our findings support a key role for ERI species in integrin-independent stabilization of the microtubule network in differentiated keratinocytes.

Analysis of nuclear export using photoactivatable GFP fusion proteins and interspecies heterokaryons.

In this chapter, we review protocols for the analysis of nucleocytoplasmic shuttling of transcription factors and nuclear proteins, using two different approaches. The first involves the use of photoactivatable forms of the protein of interest by fusion to photoactivatable green fluorescent protein to follow its movement out of the nucleus by live-cell confocal microscopy. This methodology allows for the kinetic characterization of protein movements as well as measurement of steady-state levels. In a second procedure to assess the ability of a nuclear protein to move into and out of the nucleus, we describe the use of interspecies heterokaryon assays, which provide a measurement of steady-state distribution. These technologies are directly applicable to the analysis of nucleocytoplasmic movements not only of transcription factors, but also other nuclear proteins.

A novel mechanism of E2F1 regulation via nucleocytoplasmic shuttling: determinants of nuclear import and export.

E2F1 is a transcription factor central for cell survival, proliferation, and repair following genomic insult. Depending on the cell type and conditions, E2F1 can induce apoptosis in transformed cells, behaving as a tumour suppressor, or impart growth advantages favouring tumour formation. The pleiotropic functions of E2F1 are a likely consequence of its ability to transcriptionally control a wide variety of target genes, and require tight regulation of its activity at multiple levels. Although sequestration of proteins to particular cellular compartments is a well-established regulatory mechanism, virtually nothing is known about its contribution to modulation of E2F1 target gene expression. We have examined the subcellular trafficking of E2F1 and, contrary to the widely held notion that this factor is constitutively nuclear, we now demonstrate that it is subjected to continuous nucleocytoplasmic shuttling. We have also defined two nuclear localization domains and a nuclear export region, which mediates CRM1-dependent transit out of the nucleus. The predominant subcellular location of E2F1 is likely determined by the balance between the activity of nuclear import and export domains, and can be modulated by differentiation stimuli in epidermal cells. Thus, we have identified a hitherto unrecognized mechanism to control E2F1 function through modulation of its subcellular localization.

Signalling in the epidermis: the E2F cell cycle regulatory pathway in epidermal morphogenesis, regeneration and transformation.

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis.

Serp-1, a viral anti-inflammatory serpin, regulates cellular serine proteinase and serpin responses to vascular injury.

Complex DNA viruses have tapped into cellular serpin responses that act as key regulatory steps in coagulation and inflammatory cascades. Serp-1 is one such viral serpin that effectively protects virus-infected tissues from host inflammatory responses. When given as purified protein, Serp-1 markedly inhibits vascular monocyte invasion and plaque growth in animal models. We have investigated mechanisms of viral serpin inhibition of vascular inflammatory responses. In vascular injury models, Serp-1 altered early cellular plasminogen activator (tissue plasminogen activator), inhibitor (PAI-1), and receptor (urokinase-type plasminogen activator) expression (p < 0.01). Serp-1, but not a reactive center loop mutant, up-regulated PAI-1 serpin expression in human endothelial cells. Treatment of endothelial cells with antibody to urokinase-type plasminogen activator and vitronectin blocked Serp-1-induced changes. Significantly, Serp-1 blocked intimal hyperplasia (p < 0.0001) after aortic allograft transplant (p < 0.0001) in PAI-1-deficient mice. Serp-1 also blocked plaque growth after aortic isograft transplant and after wire-induced injury (p < 0.05) in PAI-1-deficient mice indicating that increase in PAI-1 expression is not required for Serp-1 to block vasculopathy development. Serp-1 did not inhibit plaque growth in uPAR-deficient mice after aortic allograft transplant. We conclude that the poxviral serpin, Serp-1, attenuates vascular inflammatory responses to injury through a pathway mediated by native uPA receptors and vitronectin.

Active nuclear import and export pathways regulate E2F-5 subcellular localization.

Epidermal keratinocyte differentiation is accompanied by differential regulation of E2F genes, including up-regulation of E2F-5 and its concomitant association with the retinoblastoma family protein p130. This complex appears to play a role in irreversible withdrawal from the cell cycle in differentiating keratinocytes. We now report that keratinocyte differentiation is also accompanied by changes in E2F-5 subcellular localization, from the cytoplasm to the nucleus. To define the molecular determinants of E2F-5 nuclear import, we tested its ability to enter the nucleus in import assays in vitro using digitonin-permeabilized cells. We found that E2F-5 enters the nucleus through mediated transport processes that involve formation of nuclear pore complexes. It has been proposed that E2F-4 and E2F-5, which lack defined nuclear localization signal (NLS) consensus sequences, enter the nucleus in association with NLS-containing DP-2 or pRB family proteins. However, we show that nuclear import of E2F-5 only requires the first N-terminal 56 amino acid residues and is not dependent on interaction with DP or pRB family proteins. Because E2F-5 is predominantly cytoplasmic in undifferentiated keratinocytes and in other intact cells, we also examined whether this protein is subjected to active nuclear export. Indeed, E2F-5 is exported from the nucleus through leptomycin B-sensitive, CRM1-mediated transport, through a region corresponding to amino acid residues 130-154. This region excludes the DNA- and the p130-binding domains. Thus, the subcellular distribution of E2F-5 is tightly regulated in intact cells, through multiple functional domains that direct nucleocytoplasmic shuttling of this protein.