Biology subjects

Kim, E. A.

Publications and source records attributed to Kim, E. A..

3 recordsLinked to original sources

bioRxiv2026

Single cell RNA-sequencing reveals an association between testosterone treatment and reduced hormone signaling in the human mammary gland

Testosterone is the most studied androgen in hormone replacement therapy in postmenopausal women. Many transgender men also receive long-term testosterone replacement therapy (TRT) and have high serum testosterone levels compared to the low levels seen in cisgender women. Compared to other sex hormones such as estrogen and progesterone, the effects of testosterone on the mammary gland have been relatively understudied and there is little data regarding the long term safety of this treatment. Comparison of mammary glands from transgender men on TRT and cisgender women can reveal the effects of testosterone treatment on mammary gland biology and provide critical information regarding the long-term effects of TRT on patient health and disease outcomes. In this study, we performed single-cell RNA sequencing of breast tissues from a demographics-matched cohort of cisgender women and transgender men on TRT. Surprisingly, participants on TRT had unchanged serum levels of estradiol compared to controls. Among the observed transcriptional differences for participants on TRT were a dramatically reduced expression of genes downstream of estrogen signaling pathways in hormone receptor positive (HR+) luminal epithelial cells, as well as a decreased overall menstrual cycle-related hormone signaling. We confirmed this finding experimentally by showing reduced expression of progesterone receptor a/b, a prominent marker of estrogen signaling, in donors on TRT. Our results support the hypothesis that high levels of testosterone in transgender men on TRT suppress sex hormone signaling in the breast as seen on their impact on HR+ mammary epithelial cells, with implications for TRT as an antagonist of estrogen signaling and protection against breast cancer.

cell biology↗

bioRxiv2024

A Novel Whole Tissue Explant Model of Hidradenitis Suppurativa

Hidradenitis Suppurativa (HS) is a relatively common and highly morbid inflammatory skin disease. Due to our relatively limited understanding of HSs pathogenesis, there are currently insufficient treatment options available, and many patients medical needs are not being met. This is partly due to a scarcity of ex vivo human assays and animal models that accurately recapitulate the disease. To address this deficit, we have developed a whole-tissue explant model of HS to examine its pathogenic mechanisms and the efficacy of potential treatments within intact human tissue. We measured cytokine protein and RNA within whole tissue maintained in an agar-media solution, finding that IL-6 and IL-8 concentrations trended upwards in both HS explants and healthy controls, while IL-17A, IL-1{beta}, and TNF- exhibited increases in HS tissue alone. We also show that the explants were responsive to treatment with both dexamethasone and IL-2. Not only do our results show that this model effectively delivers treatments throughout the explants, but they also elucidate which cytokines are related to the explant process regardless of tissue state and which are related to HS tissue specifically, laying the groundwork for future implementations of this model.

immunology↗

bioRxiv2022

Microfluidics-free single-cell genomics with templated emulsification

Single-cell RNA sequencing is now a standard method used to reveal the molecular details of cellular heterogeneity, but current approaches have limitations on speed, scale, and ease of use that stem from the complex microfluidic devices or fluid handling steps required for sample processing. We, therefore, developed a method that does not require specialized microfluidic devices, expertise, or hardware. Our approach is based on particle-templated emulsification, which allows single-cell encapsulation and barcoding of cDNA in uniform droplet emulsions with only a vortexer. PIP-seq accommodates a wide range of emulsification formats, including microwell plates and large-volume conical tubes, enabling thousands of samples or millions of cells to be processed in minutes. We demonstrate that PIP-seq produces high-purity transcriptomes in mouse-human mixing studies, is compatible with multi-omics measurements, and can accurately characterize cell types in human breast tissue when compared to a commercial microfluidic platform. Single-cell transcriptional profiling of mixed phenotype acute leukemia using PIP-seq revealed the emergence of heterogeneity within chemotherapy-resistant cell subsets that were hidden by standard immunophenotyping. PIP-seq is a simple, flexible, and scalable next-generation workflow that extends single-cell sequencing to new applications, including screening, diagnostics, and disease monitoring.

genomics↗