MiR-30a-5p Alters Epidermal Terminal Differentiation during Aging by Regulating BNIP3L/NIX-Dependent Mitophagy

Aging is associated with impaired triggering of TRPV3-mediated cutaneous vasodilation: a crucial process for local heat exposure

Sensing temperature is vitally important to adapt our body to environmental changes. Local warm detection is required to initiate regulation of cutaneous blood flow, which is part of the peripheral thermoregulatory mechanisms, and thus avoid damage to surrounding tissues. The mechanisms mediating cutaneous vasodilation during local heat stress are impaired with aging. However, the impact of aging on the ability of the skin to detect subtle thermal changes is unknown. Among heat-activated cation channels, transient receptor potential vanilloid 3 (TRPV3) is a thermo-sensor predominantly expressed on keratinocytes and involved in local vascular thermoregulatory mechanisms of the skin in young mice. In the present study, using a murine in vivo model of local heat exposure of the skin, we showed that heat-induced vasodilation was reduced in old mice associated with reduced expression of TRPV3 channels. We also found a decrease in expression and activity of TRPV3 channel, as well as reduced TRPV3-dependent adenosine tri-phosphate release in human primary keratinocytes from old donors. This study shows that aging alters the epidermal TRPV3 channels, which might delay the detection of changes in skin temperature, thereby limiting the mechanisms triggered for local vascular thermoregulation in the old skin.

Identification and validation of senescence-related genes in polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is an exceedingly intractable issue affecting female endocrine and reproductive health. However, the etiology and intricate pathological mechanisms of PCOS remain unclear. Nowadays, aging was found to share multiple common pathological mechanisms with PCOS, which causes probing into the pathogenesis of PCOS from senescence. However, no bioinformatics analyses have specifically focused on connection between PCOS and ovarian aging.

METHODS

Differentially expressed aging-related genes in PCOS were identified and then analyzed using function enrichment method. Hub genes were determined based on multiple algorithms, and expression validation of hub genes was performed in both datasets and experiments (human granulosa-like tumor cell line, KGN; human Granulosa Cell, hGCs). Finally, a transcription factor-miRNA-gene network of hub genes was constructed.

RESULTS

Here, we identified 73 aging-related differential expression genes (ARDEGs) by intersecting DEGs in PCOS and senescence-related gene set. Furthermore, we performed biological functions and potential pathways of ARDEGs and potential hub genes were also screened by multiple algorithms. From the perspective of immune dysfunction, we analyzed the correlation between PCOS and immune cells. Finally, TF-miRNA-gene networks were constructed. Finally, TF-miRNA-gene networks were constructed.

CONCLUSIONS

Our work aimed to elucidate the relation between PCOS and cellular senescence based on bioinformatics strategy, deepening the understanding of mechanisms and to seek for novel therapy strategies for improving reproductive lifespan and female health. Exploring the potential molecular mechanism of cell aging in PCOS is expected to bring a new breakthrough for PCOS diagnosis and therapy strategies. And this, might deepen our understanding about intricate mechanisms of ovarian aging.

A Systematic Review of Stem Cell Differentiation into Keratinocytes for Regenerative Applications

To improve wound healing or treatment of other skin diseases, and provide model cells for skin biology studies, in vitro differentiation of stem cells into keratinocyte-like cells (KLCs) is very desirable in regenerative medicine. This study examined the most recent advancements in in vitro differentiation of stem cells into KLCs, the effect of biofactors, procedures, and preparation for upcoming clinical cases. A range of stem cells with different origins could be differentiated into KLCs under appropriate conditions. The most effective ways of stem cell differentiation into keratinocytes were found to include the co-culture with primary epithelial cells and keratinocytes, and a cocktail of growth factors, cytokines, and small molecules. KLCs should also be supported by biomaterials for the extracellular matrix (ECM), which replicate the composition and functionality of the in vivo extracellular matrix (ECM) and, thus, support their phenotypic and functional characteristics. The detailed efficient characterization of different factors, and their combinations, could make it possible to find the significant inducers for stem cell differentiation into epidermal lineage. Moreover, it allows the development of chemically known media for directing multi-step differentiation procedures.In conclusion, the differentiation of stem cells to KLCs is feasible and KLCs were used in experimental, preclinical, and clinical trials. However, the translation of KLCs from in vitro investigational system to clinically valuable cells is challenging and extremely slow.

Chronological aging impacts abundance, function and microRNA content of extracellular vesicles produced by human epidermal keratinocytes

The disturbance of intercellular communication is one of the hallmarks of aging. The goal of this study is to clarify the impact of chronological aging on extracellular vesicles (EVs), a key mode of communication in mammalian tissues. We focused on epidermal keratinocytes, the main cells of the outer protective layer of the skin which is strongly impaired in the skin of elderly. EVs were purified from conditioned medium of primary keratinocytes isolated from infant or aged adult skin. A significant increase of the relative number of EVs released from aged keratinocytes was observed whereas their size distribution was not modified. By small RNA sequencing, we described a specific microRNA (miRNA) signature of aged EVs with an increase abundance of miR-30a, a key regulator of barrier function in human epidermis. EVs from aged keratinocytes were found to be able to reduce the proliferation of young keratinocytes, to impact their organogenesis properties in a reconstructed epidermis model and to slow down the early steps of skin wound healing in mice, three features observed in aged epidermis. This work reveals that intercellular communication mediated by EVs is modulated during aging process in keratinocytes and might be involved in the functional defects observed in aged skin.

Mitochondrial dynamics and metabolism across skin cells: implications for skin homeostasis and aging

Aging of human skin is a complex process leading to a decline in homeostasis and regenerative potential of this tissue. Mitochondria are important cell organelles that have a crucial role in several cellular mechanisms such as energy production and free radical maintenance. However, mitochondrial metabolism as well as processes of mitochondrial dynamics, biogenesis, and degradation varies considerably among the different types of cells that populate the skin. Disturbed mitochondrial function is known to promote aging and inflammation of the skin, leading to impairment of physiological skin function and the onset of skin pathologies. In this review, we discuss the essential role of mitochondria in different skin cell types and how impairment of mitochondrial morphology, physiology, and metabolism in each of these cellular compartments of the skin contributes to the process of skin aging.