Biology subjects

Sherrill, J. D.

Publications and source records attributed to Sherrill, J. D..

6 recordsLinked to original sources

bioRxiv2025

Distinct roles for thymic stromal lymphopoietin (TSLP) and IL-33 in experimental eosinophilic esophagitis

RationaleThymic stromal lymphopoietin (TSLP) and IL-33 are alarmins implicated in EoE pathogenesis by activating multiple cells including mast cells (MCs). Whether TSLP or IL-33 have a role in EoE and whether their activities are distinct requires further investigation. MethodsExperimental EoE was induced in wild type (WT) Il33-/-and Crlf2-/- mice. TSLP or IL-5 were neutralized using antibodies. Esophageal histopathology was determined by H&E, anti-Ki67, anti-CD31 and anti-MBP staining. Esophageal RNA was subjected to RNA sequencing. Bone marrow-derived MCs were activated with TSLP and IL-13 was determined (ELISA) ResultsTSLP and IL-33 were overexpressed in human and experimental EoE. Human and mouse esophageal MCs displayed the highest level of Crlf2 (TSLPR) compared to other immune cells. Crlf2-/- mice were nearly-completely protected from EoE, and TSLP neutralization resulted in decreased basal cell proliferation, eosinophilia, lamina propria thickening and vascularization. Induction of experimental EoE in Il33-/- mice resulted in reduced eosinophilia but no alterations in tissue remodeling were observed compared to WT mice. RNA sequencing revealed that TSLP regulates the expression of key genes associated with human EoE (e.g. eotaxins, Il19, Klk5, Flg, Il36rn, Il1r2) and suggest a role for TSLP in regulating IL-1 signaling, barrier integrity and epithelial cell differentiation. Experimental EoE was characterized by a MC-associated gene signature and elevated MCs. Activation of MCs with TSLP resulted in secretion of IL-13. ConclusionTSLP and IL-33 have non-redundant functions in experimental EoE. This study highlights TSLP as an upstream regulator of IL-13 and a potential therapeutic target for EoE.

immunology↗

bioRxiv2021

Transcriptomic Analysis of Human Skin Wound Healing and Rejuvenation Following Ablative Fractional Laser Treatment

Ablative fractional laser treatment is considered the gold standard for skin rejuvenation. In order to understand how fractional laser works to rejuvenate skin, we performed microarray profiling on skin biopsies to identify temporal and dose-response changes in gene expression following fractional laser treatment. The backs of 14 women were treated with ablative fractional laser (Fraxel(R)) and 4 mm punch biopsies were collected from an untreated site and at the treated sites 1, 3, 7, 14, 21 and 28 days after the single treatment. In addition, in order to understand the effect that multiple fractional laser treatments have on skin rejuvenation, several sites were treated sequentially with either 1, 2, 3, or 4 treatments (with 28 days between treatments) followed by the collection of 4 mm punch biopsies. RNA was extracted from the biopsies, analyzed using Affymetrix U219 chips and gene expression was compared between untreated and treated sites. We observed dramatic changes in gene expression as early as 1 day after fractional laser treatment with changes remaining elevated even after 1 month. Analysis of individual genes demonstrated significant and time related changes in inflammatory, epidermal, and dermal genes, with dermal genes linked to extracellular matrix formation changing at later time points following fractional laser treatment. When comparing the age-related changes in skin gene expression to those induced by fractional laser, it was observed that fractional laser treatment reverses many of the changes in the aging gene expression. Finally, multiple fractional laser treatments resulted in continued changes in gene expression, with many genes either differentially regulated or continuously upregulated with increasing number of treatments, indicating that maximal skin rejuvenation requires multiple fractional laser treatments. In conclusion, fractional laser treatment of skin activates several biological processes involved in wound healing and tissue regeneration, all of which significantly contribute to the rejuvenating effect of fractional laser treatment on aged skin.

bioinformatics↗

bioRxiv2021

Combinations of Peptides Synergistically Activate the Regenerative Capacity of Skin Cells In Vitro

OBJECTIVETo explore synergistic effects related to skin regeneration, peptides with distinct biological mechanisms of action were evaluated in combination in different skin cell lines in the presence or absence of niacinamide (Nam). Furthermore, the synergistic responses of peptide combinations on global gene expression were compared to the changes that occur with fractional laser resurfacing treatment, a gold standard approach for skin rejuvenation, to further define optimal peptide combinations. METHODSMicroarray profiling was used to characterize the biological responses of peptide combinations (+/- Nam) relative to the individual components in epidermal keratinocyte and dermal fibroblast cell lines. Cellular functional assays were utilized to confirm the synergistic effects of peptide combinations. Bioinformatics approaches were used to link the synergistic effects of peptide combinations on gene expression to the transcriptomics of the skin rejuvenation response from fractional laser treatment. RESULTSMicroarray analysis of skin cells treated with peptide combinations revealed synergistic changes in gene expression compared to individual peptide controls. Bioinformatic analysis of synergy genes in keratinocytes revealed activation of NRF2-mediated oxidative stress responses by a combination of Ac-PPYL, Pal-KTTKS, and Nam. Additional analysis revealed direct downstream transcriptional targets of NRF2/ARE exhibiting synergistic regulation by this combination of materials, which was corroborated by a cellular reporter assay. NRF2-mediated oxidative stress response pathways were also found to be activated in the transcriptomics of the early skin rejuvenation response to fractional laser treatment, suggesting the importance of this biology in the early stages of tissue repair. Additionally, a second combination of peptides (pal-KT and Ac-PPYL) was found to synergistically restore cellular ATP levels that had been depleted due to the presence of ROS, indicating an additional mechanism whereby peptide synergies may accelerate skin repair. CONCLUSIONThrough combinatorial synergy studies, we have identified additional in vitro skin repair mechanisms beyond the previously described functions of individual peptides and correlated these to the transcriptomics of the skin rejuvenation response of fractional laser treatment. These findings suggest that specific peptides can act together, via complementary and synergistic mechanisms, to holistically enhance the regenerative capacity of in vitro skin cells.

molecular biology↗

bioRxiv2020

Enhanced retinoid response by a combination of the vitamin A ester retinyl propionate with niacinamide and a flavonoid containing Ceratonia siliqua extract in retinoid responsive in vitro models.

OBJECTIVESRetinoids have been used for decades as efficacious topical agents to treat photoaged skin. The purpose of our present research is to evaluate whether the activity of the Vitamin A ester retinyl propionate (RP) can be enhanced by niacinamide (Nam) and a flavonoid containing Ceratonia siliqua (CS) fruit extract in retinoid responsive in vitro models. METHODSRP was tested alone and in combination with Nam and CS in an RAR reporter cell line for promoter activation and compared to trans-retinoic acid (tRA) activation. These treatments were also tested in keratinocytes for gene expression profiling by qPCR using a panel of 40 retinoid responsive genes. RESULTStRA or RP elicited RAR reporter activation in a dose dependent manner. The combination of 0.5 M or 2 M RP with 10 mM Nam had a 56% and 95% signal increase compared to RP, respectively. The addition of 1% CS to 0.5 M or 2 M RP with 10 mM Nam elicited a further increase of 114% and 156%, respectively, over RP and Nam combinations. All retinoids elicited an increase in expression of 40 retinoid sensitive genes over control levels. Of the 40 genes 27 were enhanced by either 0.5 M RP or 2 M RP with 10 mM Nam and 1% CS. Nam or CS had very modest activity in both models. CONCLUSIONThe combination of RP with Nam and CS showed a higher retinoid response than RP in two separate retinoid responsive in vitro models. We hypothesize Nam and CS enhances RP activity by modulating metabolism to tRA via increasing NAD+ pools and inhibiting reduction of retinal (RAL) back to retinol, respectively. The findings provide evidence that this combination may have enhanced efficacy for treating the appearance of photoaged skin.

biochemistry↗

bioRxiv2020

The vitamin A ester retinyl propionate has a unique metabolic profile and higher retinoid-related bioactivity over retinol and retinyl palmitate in human skin models.

Human skin is exposed daily to environmental stressors, which cause acute damage and inflammation. Over time this leads to morphological and visual appearance changes associated with premature aging. Topical vitamin A derivatives such as retinol (ROL), retinyl palmitate (RPalm), and retinyl propionate (RP) have been used to reverse these changes and improve the appearance of skin. This study investigated a stoichiometric comparison of these retinoids using in vitro and ex vivo skin models. Skin biopsies were treated topically to compare skin penetration and metabolism. Treated keratinocytes were evaluated for transcriptomics profiling and hyaluronic acid (HA) synthesis and treated 3D epidermal skin equivalents were stained for epidermal thickness, Ki67, and filaggrin. A retinoic acid receptor-alpha (RAR) reporter cell line was used to compare retinoid activation levels. Results from ex vivo skin found that RP and ROL have higher penetration levels compared to RPalm. RP is metabolized primarily into ROL in the viable epidermis and dermis whereas ROL is esterified into RPalm and metabolized into the inactive retinoid 14-hydroxy-4,14-retro-retinol (14-HRR). RP treatment yielded higher RAR activation and HA synthesis levels than ROL whereas RPalm had a null effect. In keratinocytes, RP and ROL stimulated similar gene expression patterns and pathway theme profiles. In conclusion, RP and ROL show a similar response directionality whereas RPalm response was inconsistent. Additionally, RP has a consistently higher magnitude of response compared with ROL or RPalm.

biochemistry↗

bioRxiv2019

A single-sample circadian biomarker that performs across populations and platforms

BackgroundFor circadian medicine to influence health, such as when to take a drug or undergo a procedure, a practical way to measure body time is needed. Recent machine learning algorithms show that gene expression data from blood and skin can provide reliable estimates of body time. However, for clinical viability, a biomarker must be easily measured and generalizable to a broad population. It is not clear that any circadian biomarker yet satisfies these criteria.\n\nResultsWe analyzed 24 h molecular rhythms in human dermis and epidermis at three distinct body sites, leveraging both longitudinal and population data. Circadian clock function was strongest in the epidermis, regardless of body site. We identified a 12-gene biomarker set that reported circadian phase to within 3 hours from a single sample of epidermis--the skins most superficial layer. This set performed well across body sites, ages, sexes, and detection platforms.\n\nConclusionsThis research shows that the clock in epidermis is more robust than dermis regardless of body site. To encourage ongoing validation of this biomarker in diverse populations, diseases, and experimental designs, we developed SkinPhaser--a user-friendly app to test biomarker performance in datasets (https://github.com/gangwug/SkinPhaser).

systems biology↗