Funded Research

In alopecia areata (AA), thousands of actively growing (anagen) scalp hair follicles transition into a dormant (telogen) state. When AA resolves, either spontaneously or in response to JAK inhibitor treatment, the newly formed anagen follicles re-emerge rapidly in what grossly appear to be spreading waves. This growth pattern is commonly seen in rodents, where spreading waves are the outcome of a collective behavior, when anagen follicles signal to activate neighboring telogen follicles to also enter anagen in a chain-like reaction. This mechanism leads to a highly efficient anagen activation across large regions of skin. Inspired by our preliminary data on hair regrowth patterns in JAK inhibitor-treated AA patients, in this pilot application we propose to definitively establish the existence of a wave-like mechanism for anagen activation in human scalp, using optical coherence tomography imaging coupled with histological analysis of re-growing wave-front in AA. We will also collect single-cell RNA-sequencing data from wave-front hair-bearing skin and compare its cellular composition and key molecular changes to those of adjacent alopecic areas. High throughput single-cell data will be used to develop hypotheses on cellular and signaling changes that accompany collective AA hair regrowth, previously undescribed in human hair. We will be able to identify hair regeneration-associated changes in intra- and peri-follicular cell types, including immune cells, and key inhibitory and activating signaling factor changes. The hypothesis proposed herein is novel for the AA field, and its results will significantly advance the understanding of AA resolution mechanisms and open new lines of AA research.

Although novel treatments for alopecia areata (AA) such as JAK inhibitors can be efficacious, they are extremely expensive, may have long-term adverse effects, and don’t prevent AA relapse after therapy is discontinued. Therefore, new supportive AA therapies remain to be developed that also aid more permanent hair regrowth. Autophagy is a organelle and protein recycling process used by cells to facilitate growth and survival during stress. Recently, we have demonstrated that human scalp hair follicles (HFs) recruit autophagy to sustain their growth, while blocking HF autophagy inhibits human hair growth, Therefore, we propose to explore whether AA HFs display malfunctions in autophagy, which may make them more susceptible to immune-mediated HF damage, and whether promoting HF autophagy with nutraceuticals enhances human HF growth and stress-resistance. Specifically, we will investigate whether the expression of autophagy marker proteins and autophagolysosomes differ between healthy, non-lesional and lesional AA HFs. Next, we study whether interferon- the key cytokine in AA pathogenesis, modulates autophagy (i.e. LC3B and SQSTM1 expression and autophagolysosome generation) and whether inhibiting autophagy by LC3B gene-silencing prevents or promotes interferon-induced damage in organ-cultured human HFs. Finally, we will investigate whether enhancing autophagy by recognized enhancers of autophagic flux, i.e. the nutritional supplements caffeine and/or methylspermidine, makes cultured human HFs more resistant to interferon-induced HF damage and growth inhibition. These important pilot data will systematically introduce autophagy into translational AA research and is expected to identify a novel supportive therapeutic strategy in future AA management by nutraceuticals/cosmetics that targets autophagy.

Regulatory T cells (Tregs) play a major role in establishing and maintaining immune homeostasis. We have discovered that both murine and human skin contain a unique population of Tregs that preferentially localize to hair follicles (HFs) and that these cells are required for HF regeneration as well as proper HF cycling. In addition, we have found that Tregs mediate these effects by promoting the activation and differentiation of hair follicle stem cells (HFSCs). The underlying theme of this proposal is to provide the cellular and molecular foundation for Treg augmentation therapy to treat patients with alopecia areata (AA). To achieve this goal, we will assess whether augmenting Tregs in mice results in enhanced HFSC function and HF cycling/regeneration. In addition, using cutting-edge CyTOF technology, we will comprehensively quantify the immune cell subsets infiltrating AA skin. In final experiments, we will attempt to augment Tregs in single cell suspensions derived from lesional AA skin and Treg activation quantified relative to other immune cell subsets. Given that AA is defined by both a dysfunction in HF regeneration and a defect in Tregs, our results may have direct implications for patients suffering from this disease.

Alopecia Areata (AA) is an organ-restricted autoimmune disease that specifically attacks the hair follicles, resulting in well-demarcated (AA Patchy) or diffuse non-scarring hair loss of the scalp (AA Totalis) or the entire body (AA Universalis). AA is a highly prevalent disease with a lifetime risk of 2.1%, however, the underlying disease mechanisms remain incompletely defined and under-studied. Histologically, AA presents as a “swarm of bees” in which inflammatory T lymphocytes attack the pigmented actively growing hair follicles. The prevalent notion for disease is thought to be the loss of immune privilege of hair follicles causing abnormal activation of pathogenic T cells. Genetic association studies previously conducted in our lab found several autophagy related genes associated with AA. In addition, our gene expression analysis revealed altered expression of autophagy related genes, prompting us to hypothesize that dysregulation of autophagy plays a critical role in AA pathogenesis. Autophagy is a survivalpromoting mechanism that involves capturing, degradation, and recycling of intracellular proteins and organelles in lysosomes. However, the contribution of autophagy in loss of hair follicle immune privilege and development of AA is not characterized. This project aims to understand the role of autophagy in normal hair cycling and its contribution to the development of alopecia in grafted C3H/HeJ mouse model.