Adipose tissue, which is the crucial energy reservoir and endocrine organ for the maintenance of systemic glucose, lipid, and energy homeostasis, undergoes significant changes during aging. These changes cause physiological declines and age-related disease in the elderly population. Here, we review the age-related changes in adipose tissue at multiple levels and highlight the underlying mechanisms regulating the aging process. We also discuss the pathogenic pathways of age-related fat dysfunctions and their systemic negative consequences, such as dyslipidemia, chronic general inflammation, insulin resistance, and type 2 diabetes (T2D). Age-related changes in adipose tissue involve redistribution of deposits and composition, in parallel with the functional decline of adipocyte progenitors and accumulation of senescent cells. Multiple pathogenic pathways induce defective adipogenesis, inflammation, aberrant adipocytokine production, and insulin resistance, leading to adipose tissue dysfunction. Changes in gene expression and extracellular signaling molecules regulate the aging process of adipose tissue through various pathways. In addition, adipose tissue aging impacts other organs that are infiltrated by lipids, which leads to systemic inflammation, metabolic system disruption, and aging process acceleration. Moreover, studies have indicated that adipose aging is an early onset event in aging and a potential target to extend lifespan. Together, we suggest that adipose tissue plays a key role in the aging process and is a therapeutic target for the treatment of age-related disease, which deserves further study to advance relevant knowledge.

IMPORTANCE Previous anatomical and clinical studies have suggested that targeted restoration of the volume and distribution of fat compartments using appropriate cannula entry sites and injection planes is an excellent fat-grafting technique for facial contouring and hand rejuvenation. OBJECTIVE To perform subjective and objective evaluations of the safe and effective profile of the targeted fat-grafting technique for temporal hollowing augmentation. DESIGN, SETTING, AND PARTICIPANTS In a retrospective cohort study, a total of 96 consecutive patients with temporal hollowing were treated at the

Background Adipose-derived stem cells (ADSCs) promote tissue regeneration and repair. Cryoprotective agents (CPAs) protect cells from cryodamage during cryopreservation. Safe and efficient cryopreservation of ADSCs is critical for cell-based therapy in clinical applications. However, most CPAs are used at toxic concentrations, limiting their clinical application. Objective The aim of this study is to develop a non-toxic xeno-free novel CPA aiming at achieving high-efficiency and low-risk ADSC cryopreservation. Methods We explored different concentrations of trehalose (0.3 M, 0.6 M, 1.0 M, and 1.25 M) and glycerol (10%, 20%, and 30% v/v) for optimization and evaluated and compared the outcomes of ADSCs cryopreservation between a combination of trehalose and glycerol and the commonly used CPA DMSO (10%) + FBS (90%). All samples were slowly frozen and stored in liquid nitrogen for 30 days. The effectiveness was evaluated by the viability, proliferation, migration, and multi-potential differentiation of the ADSCs after thawing. Results Compared with the groups treated with individual reagents, the 1.0 M trehalose (Tre) + 20% glycerol (Gly) group showed significantly higher efficiency in preserving ADSC activities after thawing, with better outcomes in both cell viability and proliferation capacity. Compared with the 10% DMSO + 90% FBS treatment, the ADSCs preserved in 1.0 M Tre + 20% Gly showed similar cell viability, surface markers, and multi-potential differentiation but a significantly higher migration capability. The results indicated that cell function preservation can be improved by 1.0 M Tre + 20% Gly. Conclusions The 1.0 M Tre + 20% Gly treatment preserved ADSCs with a higher migration capability than 10% DMSO + 90% FBS and with viability higher than that with trehalose or glycerol alone but similar to that with 10% DMSO + 90% FBS and fresh cells. Moreover, the new CPA achieves stemness and multi-potential differentiation similar to those in fresh cells. Our results demonstrate that 1.0 M Tre + 20% Gly can more efficiently cryopreserve ADSCs and is a non-toxic CPA that may be suitable for clinical applications.