Faculty Bibliography

Chronic wounds, especially in diabetic patients, pose a significant clinical challenge due to impaired microvasculature and delayed healing. This study presents Exo-Q, a novel thermoresponsive hydrogel formed by co-gelation of engineered Q protein nanofibers with exosomes, a class of vesicular intercellular communication mediators. Exo-Q transitions from a gel to a viscoelastic solution at physiological temperature, enabling localized, topical delivery of exosomes with an initial burst release followed by sustained release. In a diabetic mouse wound model, Exo-Q effectively delivered human bone marrow multipotent stromal cell-derived exosomes directly to the wound bed, where they accumulated in endothelial cells of granulation tissue without detectable systemic distribution. Exosomes produced under stringent and replicable cell culture conditions consistently carried biomacromolecular cargo enriched for miRNAs with validated targets in angiogenesis-associated genes, indicative of their therapeutic potential. Topical application of Exo-Q resulted in extensive neovascularized granulation tissue, significantly accelerating wound closure to levels comparable to non-diabetic wounds. Importantly, the hydrogel's modular design maintained the functional integrity of Q protein nanofibers and exosomes, demonstrating compatibility with full-thickness human wounds. This platform allows for tailored customization to address critical stages of diabetic wound healing while ensuring efficacy at low dosages, potentially enabling patient-administered treatment. By leveraging advanced biomaterials, Exo-Q advances the therapeutic efficacy of exosome-based interventions for diabetic wounds, offering a localized, non-invasive solution to chronic, non-healing wounds. This innovative hydrogel platform represents a modular therapeutic strategy with significant potential for clinical applications in regenerative medicine.

Chronic wounds, especially in diabetic patients, pose a significant clinical challenge due to impaired microvasculature and delayed healing. This study presents Exo-Q, a novel thermoresponsive hydrogel formed by co-gelation of engineered Q protein nanofibers with exosomes, a class of vesicular intercellular communication mediators. Exo-Q transitions from a gel to a viscoelastic solution at physiological temperature, enabling localized, topical delivery of exosomes with an initial burst release followed by sustained release. In a diabetic mouse wound model, Exo-Q effectively delivered human bone marrow multipotent stromal cell-derived exosomes directly to the wound bed, where they accumulated in endothelial cells of granulation tissue without detectable systemic distribution. Exosomes produced under stringent and replicable cell culture conditions consistently carried biomacromolecular cargo enriched for miRNAs with validated targets in angiogenesis-associated genes, indicative of their therapeutic potential. Topical application of Exo-Q resulted in extensive neovascularized granulation tissue, significantly accelerating wound closure to levels comparable to non-diabetic wounds. Importantly, the hydrogel's modular design maintained the functional integrity of Q protein nanofibers and exosomes, demonstrating compatibility with full-thickness human wounds. This platform allows for tailored customization to address critical stages of diabetic wound healing while ensuring efficacy at low dosages, potentially enabling patient-administered treatment. By leveraging advanced biomaterials, Exo-Q advances the therapeutic efficacy of exosome-based interventions for diabetic wounds, offering a localized, non-invasive solution to chronic, non-healing wounds. This innovative hydrogel platform represents a modular therapeutic strategy with significant potential for clinical applications in regenerative medicine.

Hair traits are nonpathogenic features that vary among individuals. Unlike hair follicle (HF) diseases, which are rare in the population, hair traits can be measured in everyone. This facilitates the construction of large cohorts that are well-powered for gene discovery. GWASs identify genetic variants that are widely shared among people globally, providing knowledge with broad population relevance. We compile findings from hair trait GWASs to deepen our understanding of HF biology. In reviewing genetic factors that influence hair traits, we demonstrate overlap with disease genes, underscoring that genetic studies of traits improve our knowledge about health and disease.

Gynecologic neuroectodermal tumors either exhibit central nervous system (CNS) differentiation (CNS-like) or represent Ewing sarcoma (EWS) which lacks CNS features and harbors FET-ETS gene fusions. DNA methylation profiling reclassified CNS primitive neuroectodermal tumors into common CNS neoplasms or embryonal tumors with specific epigenetic/ genetic characteristics. Its utility in classifying gynecologic neuroectodermal tumors is unknown. Whole genome DNA methylation profiling was performed on 26 gynecologic neuroectodermal tumors (22 CNS-like tumors, 4 EWS) arising in the ovary, paratubal soft tissue, uterus, and vulva, which were classified by using sarcoma and CNS tumor DNA methylation classifiers. Sarcoma-related gene fusions were confirmed by fluorescence in situ hybridization (FISH) or targeted RNA next generation sequencing (NGS). Tumor only whole exome sequencing (WES) was performed in 13 cases. Copy number alterations and zygosity were inferred from DNA methylation array and WES data. Methylation abnormalities associated with imprinting were examined. The sarcoma methylation classifier identified EWS (n=3) and high-grade endometrial stromal sarcoma (n=1), confirmed by FISH or NGS detection of EWSR1 and YWHAE rearrangements, respectively. The remaining CNS-like tumors were classified by DNA methylation with positive/valid (n=4), indeterminate (n=9), and negative (n=9) scores at family level. Methylation subclasses included teratoma; embryonal tumor with multilayered rosettes, atypical; medulloblastoma, SHH-activated, subtype 3; medulloblastoma, group 3; intraocular medulloepithelioma; supratentorial ependymoma, ZFTA::RELA fused, subclass A; and diffuse pediatric-type high-grade glioma, MYCN subtype. Male gender was predicted in 54% of methylation-confirmed CNS-like tumors and none of the sarcomas. Among CNS-like tumors, copy number analyses identified genome-wide chromosomal gains and losses, and WES revealed genome-wide allelic imbalance suggestive of genome wide duplications. Epigenetic imprinting analyses showed increased paternal or maternal imprinting signal across multiple chromosomes suggesting uniparental duplication. DNA methylation profiling successfully classified gynecologic neuroectodermal tumors as known CNS tumor or sarcoma entities. Epigenetic and exomic studies suggest a male genome and increased maternal allelic contribution in CNS-like tumors, suggesting development via conception or chimerism.

The impact of Dicer/miRNAs during postnatal retinogenesis is unknown. This study aimed to deplete Dicer in postnatal retinal progenitor/precursor cells (RPCs/PCs) and to evaluate the structure and function of the adult Dicer-cKO retina using optical coherence tomography (OCT), electroretinography (ERG), and histology. We found impaired rod function, a significantly reduced number of rod bipolar cells and their associated functions, a decreased Müller glia population, and an increased population of HuC/D + Pax6/+ amacrine cells in the adult Dicer-cKO retina. Transcriptional analyses conducted in one-week-old mice showed early alterations in mRNA and miRNA levels. Single-cell RNA sequencing and initial histological analysis in young mice revealed a delay in differentiation/incomplete maturation, as indicated by an enlarged progenitor/precursor population at young ages that persists into adulthood. This suggests that Dicer/miRNAs in late RPC/PCs are essential for the proper formation and maturation of late RPC progenies and may also play a role in regulating cell state.

Plasmacytoid dendritic cells (pDCs) mount powerful antiviral type I interferon (IFN-I) responses, yet only a fraction of pDCs produces high levels of IFN-I. Here we report that peripheral pDCs in naive mice comprise three subsets (termed A, B and C) that represent progressive differentiation stages. This heterogeneity was generated by tonic IFN-I signaling elicited in part by the cGAS/STING and TLR9 DNA-sensing pathways. A small 'IFN-I-naive' subset (pDC-A) could give rise to other subsets; it was expanded in STING deficiency or after the IFN-I receptor blockade, but was abolished by exogenous IFN-I. In response to RNA viruses, pDC-A showed increased Bcl2-dependent survival and superior IFN-I responses, but was susceptible to virus infection. Conversely, the majority of pDCs comprised the 'IFN-I-primed' subsets (pDC-B/C) that showed lower IFN-I responses and poor survival, but did not support virus replication. Thus, tonic IFN-I signaling decreases the cytokine-producing capacity and survival of pDCs but increases their virus resistance, facilitating optimal antiviral responses.

Phenotype switching is a form of cellular plasticity in which cancer cells reversibly move between two opposite extremes: proliferative versus invasive states^1,2. Although it has long been hypothesized that such switching is triggered by external cues, the identity of these cues remains unclear. Here we demonstrate that mechanical confinement mediates phenotype switching through chromatin remodelling. Using a zebrafish model of melanoma coupled with human samples, we profiled tumour cells at the interface between the tumour and surrounding microenvironment. Morphological analysis of interface cells showed elliptical nuclei, suggestive of mechanical confinement by the adjacent tissue. Spatial and single-cell transcriptomics demonstrated that interface cells adopted a gene program of neuronal invasion, including the acquisition of an acetylated tubulin cage that protects the nucleus during migration. We identified the DNA-bending protein HMGB2 as a confinement-induced mediator of the neuronal state. HMGB2 is upregulated in confined cells, and quantitative modelling revealed that confinement prolongs the contact time between HMGB2 and chromatin, leading to changes in chromatin configuration that favour the neuronal phenotype. Genetic disruption of HMGB2 showed that it regulates the trade-off between proliferative and invasive states, in which confined HMGB2^high tumour cells are less proliferative but more drug-resistant. Our results implicate the mechanical microenvironment as a mechanism that drives phenotype switching in melanoma.

The understanding of the mechanisms that control key features of immune cells in various disease contexts remains limited, and few techniques are available for manipulating immune cells. Thus, discovering novel strategies for regulating immune cells is essential for gaining insight into their roles in health and disease. In this study, we investigated the potential of the recently described Universal Receptive System to regulate human immune cell functions. This was achieved for the first time by specifically targeting newly discovered surface-bound DNA- and RNA-based receptors on leukocytes using endonucleases and generating "Leukocyte-Tells." Using this approach, 1,496 genes were upregulated, many of which are related to immune cell signaling, migration, endocytosis, and phagocytosis pathways. The antimicrobial and anticancer activities of Leukocyte-Tells exceeded those of control leukocytes in vitro. Under some conditions, such as in antibiofilm experiments against biofilms of Staphylococcus spp., Pseudomonas spp, Candida spp., and other microorganisms, Leukocyte-Tells showed up to 1,000,000-fold higher activities than did control leukocytes. Additionally, Leukocyte-Tells exhibited significantly higher levels of TNF, IL-1β, IFN-γ, IL-6, and IL-10 production. Our findings reveal, for the first time, that the Universal Receptive System can orchestrate fundamental properties of immune cells, including enhanced antimicrobial and anti-tumor activities. This novel approach offers a new avenue for understanding the biology and regulation of white blood cells. Regulation of leucocyte activity is crucial for a properly functioning immune response and developing novel cell-based therapies. Our previous findings demonstrated the existence of nucleic acid-based receptors (Teazeled receptors, TezRs) that govern the responses of various cell types to a diverse array of environmental factors. Here, we discovered that by modulating these TezRs, we could upregulate immune cell signaling, migration, endocytosis, and phagocytosis pathways in leukocytes. By leveraging TezRs, we generated Leukocyte-Tells, which exhibited significantly higher antimicrobial and anticancer activities than the original immune cells.

Disorders affecting the hair follicle (HF) and pilosebaceous unit impose psychosocial and financial burdens on patients and may signal risk for other medical conditions. Human genetic studies help to identify key physiological mechanisms that govern health and are increasingly used to improve drug development. GWASs identify genetic variants that are common in the population and implicate disease mechanisms that are widely shared among patients. In this study, we synthesize knowledge about the biology of the pilosebaceous unit that has been derived from GWASs of hair-related diseases. We identify the key genetic drivers and reveal fundamental biological themes that cut across diseases to identify crucial regulators of HF health.