Project description:Aging is characterized by a gradual decline in function, partly due to molecular damage that accumulates over time. Human skin is highly susceptible to both chronological aging and environmental damage in the form of UV photoaging. This results in detrimental structural and physiological changes with age. In this study we sought to comprehensively address both chronological and photoaging at the single-cell level, and to explore genetic and environmental factors, revealing their influences on the aging process. We included samples from young, middle-aged, and old individuals, and with these samples, we compared chronological aging and photoaging. Utilizing single-cell RNA sequencing, we created a comprehensive human skin cell atlas, that offers insights into the cellular composition and functions. We investigated the renewal ability of epidermis stem cells as they age and extended the study to fibroblasts, hair follicles, and endothelial cells. Examining the genetic landscape of aging in keratinocytes, we identified two distinct "gene modules" with altered gene expression during aging. Furthermore, we uncovered that skin aging involves interactions between epidermal keratinocytes and dermal fibroblasts, as well as extensive communication of keratinocytes with various other skin cell types as revealed through ligand-receptor pairs. Interactions, such as COL17A1-A1b1complex, highlighted a direct link between keratinocytes and fibroblast stimulation for collagen production. Most importantly, A key gene, MYO1, associated with skin aging was identified, leading to the development of an innovative mRNA treatment aimed at promoting skin rejuvenation by targeting this gene. Experimental results demonstrated that the mRNA treatment reduces basal stem cell senescence, increases basal stem cell proliferation, and enhances collagen production in fibroblasts via keratinocyte-fibroblast communication. The MYO1-targeted treatment is validated as an effective strategy for reversing skin aging by targeting cellular mechanisms.
Project description: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.
Project description:Studies in model organisms suggest that aged cells can be functionally rejuvenated, but whether this concept applies to human skin is unclear. Here we apply deep sequencing of RNA 3' ends ("3-seq") to discover the gene expression program associated with human photoaging and intrinsic skin aging (collectively termed "skin aging") and the impact of broadband light (BBL) treatment. We find that skin aging was associated with the significantly altered expression level of 2,265 coding and noncoding RNAs, of which 1,293 became "rejuvenated" after BBL treatment, i.e. more similar in expression level of youthful skin. Rejuvenated genes (RGs) included several known key regulators of organismal longevity and their proximal long non-coding RNAs. Skin aging is not associated with systematic changes in 3' end mRNA processing. Hence, BBL treatment can restore the gene expression pattern of photoaged and intrinsically aged human skin to resemble young skin. In addition, our data reveals a novel set of targets that may lead to new insights into the human skin aging process. Examination of broadband light treated and untreated human skin transcriptomes of 5 women aged 50 years or more. They were compared to the skin transcriptomes of 5 young women aged 30 years or less.
Project description:Studies in model organisms suggest that aged cells can be functionally rejuvenated, but whether this concept applies to human skin is unclear. Here we apply deep sequencing of RNA 3' ends ("3-seq") to discover the gene expression program associated with human photoaging and intrinsic skin aging (collectively termed "skin aging") and the impact of broadband light (BBL) treatment. We find that skin aging was associated with the significantly altered expression level of 2,265 coding and noncoding RNAs, of which 1,293 became "rejuvenated" after BBL treatment, i.e. more similar in expression level of youthful skin. Rejuvenated genes (RGs) included several known key regulators of organismal longevity and their proximal long non-coding RNAs. Skin aging is not associated with systematic changes in 3' end mRNA processing. Hence, BBL treatment can restore the gene expression pattern of photoaged and intrinsically aged human skin to resemble young skin. In addition, our data reveals a novel set of targets that may lead to new insights into the human skin aging process.
Project description:Actinic keratoses (AK) are proliferations of pre-neoplastic keratinocytes in the epidermis that are the result of cumulative ultraviolet (UV) radiations from sun exposure. Lesions are commonly found on sites of sun-exposed skin such as the face, balding scalp, and back of the hand. AKs may present on a patient as a few detectable lesions and 5-10% of them are susceptible to transform into SCC. In contrast, Organ Transplant Recipients (OTR) are of increasing risk at developing cancers as a consequence of long-term immunosuppressive therapy. The molecular changes that occur in lesional and perilesional skin of OTR patients 18 weeks following of PDT with topical MAL treatment were investigated to better understand the effect of the therapeutic intervention on the AK lesions. Our data show the complete normalization of the skin biology in the treated areas, i. e restoration of normal proliferation related gene profiles, and correction of aberrantly expressed cancer associated genes. We were also able to uncover a transcriptional signature of a rejuvenation effect induced by MAL-PDT in photodamaged skin opening new avenues in the use of PTD for treating photodamaged skin and field cancerized areas.
Project description:How developmental programs reactivate in regeneration is a fundamental question in biology. We addressed this question through the study of Wound Induced Hair follicle Neogenesis (WIHN), an adult organogenesis model where stem cells regenerate entirely new hair follicles de novo following deep wounding. The exact mechanism is uncertain. Here we show that self-noncoding dsRNA activates the anti-viral receptor TLR3 to induce intrinsic retinoic acid (RA) synthesis in a gradient that predicts new hair follicle formation after wounding in mice. Additionally, in humans, rejuvenation lasers induce gene expression signatures for dsRNA and RA, with measurable increases in intrinsic RA synthesis. These results demonstrate a novel stimulus for retinoic acid synthesis by non-coding dsRNA, relevant to their broad functions in development and immunity. The goal of this study is to investigate whole genome analysis in human skin with CO2 laser treatment, which leads to enhanced skin rejuvenation. Under Hopkins IRB (IRB00028768), 17 Caucasian women Fitzpatrick types I-III with average age of 55 and moderate to severe baseline photoaging were enrolled. Laser treatments and biopsy schedule were as listed, with treatments occurring both to the arm, and arm biopsies used for gene expression data listed.
Project description:We sequenced mRNA of G. biloba leaves from truncation treatment and control using the Illumina HiSeq4000 platform. We identified the transcriptome changes in leaves between truncation group and control group, which provided valuable information for uncovering the molecular mechanisms of flavonoid accumulation in G. biloba under rejuvenation.
Project description:Proliferative and replicative senescent fibroblasts from aged human donors were reprogrammed towards pluripotency and re-differentiated in fibroblasts and then further analyzed for rejuvenation assessment. Comparison of microarrays were performed by non hierarchical clustering visualized in with Treeview software