Associations between genetically predicted sex and growth hormones and facial aging in the UK Biobank: a two-sample Mendelian randomization study.

Background: Aging is an inescapable process, but it can be slowed down, particularly facial aging. Sex and growth hormones have been shown to play an important role in the process of facial aging. We investigated this association further, using a two-sample Mendelian randomization study. Methods: We analyzed genome-wide association study (GWAS) data from the UK Biobank database comprising facial aging data from 432,999 samples, using two-sample Mendelian randomization. In addition, single-nucleotide polymorphism (SNP) data on sex hormone-binding globulin (SHBG) and sex steroid hormones were obtained from a GWAS in the UK Biobank [SHBG, N = 189,473; total testosterone (TT), N = 230,454; bioavailable testosterone (BT), N = 188,507; and estradiol (E2), N = 2,607)]. The inverse-variance weighted (IVW) method was the major algorithm used in this study, and random-effects models were used in cases of heterogeneity. To avoid errors caused by a single algorithm, we selected MR-Egger, weighted median, and weighted mode as supplementary algorithms. Horizontal pleiotropy was detected based on the intercept in the MR-Egger regression. The leave-one-out method was used for sensitivity analysis. Results: SHBG plays a promoting role, whereas sex steroid hormones (TT, BT, and E2) play an inhibitory role in facial aging. Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels had no significant effect on facial aging, which is inconsistent with previous findings in vitro. Conclusion: Regulating the levels of SHBG, BT, TT, and E2 may be an important means to delay facial aging.

Osteogenically-induced exosomes stimulate osteogenesis of human adipose-derived stem cells.

Exosomes exhibit great therapeutic potential in bone tissue engineering. The study aimed to investigate whether the exosomes derived from human adipose-derived stem cells (hADSCs-Exos) during different time-span of osteogenic differentiation could promote osteogenesis. The appropriate concentrations of hADSCs-Exos to enhance the proliferation, migration and osteogenesis of hADSCs-Exos were also examined. PKH67 labelled hADSCs-Exos was used to detect the internalization ability of hADSCs. The osteogenic differentiation abilities of hADSCs after treatment with hADSCs-Exos was evaluated by Alizarin red staining (ARS). The proliferation and migration of hADSCs was examined by cell counting kit-8 and wound healing assay, respectively. The expression of exosomal surface markers and osteoblast-related protein of hADSCs was assessed by Western blot. PKH67-labelled exosomes were internalized by hADSCs after 4 h incubation. ARS showed that the amount of mineralized nodules in Exo1-14d group was significantly higher than that in Exo15-28d group. hADSCs-Exos could promote the proliferation and migration capacity of hADSCs. Western blot analysis showed that after hADSCs-Exos treatment, ALP and RUNX2 were significantly enhanced. Specially, the Exo1-14d group of 15 µg/mL significantly upregulated the expression of RUNX2 than the other exosomes treated groups. Our findings suggest that exosomes secreted by hADSCs during osteogenic induction for 1-14 days could be efficiently internalized by hADSCs and could induce osteogenic differentiation of hADSCs. Moreover, administration of Exo1-14d at 15 µg/mL promoted the proliferation and migration of hADSCs. In conclusion, our research confirmed that comprised of hADSCs-Exos and hADSCs may provide a new therapeutic paradigm for bone tissue engineering.

Investigation of retro-orbicularis oculi fat and associated orbital septum connective tissues in upper eyelid surgery.

BACKGROUND: To study the anatomical characteristics of retro-orbicularis oculi fat (ROOF) in the upper eyelid and to investigate its relevance in upper eyelid surgery. METHODS: Thirty-eight Chinese hemifacial cadaver specimens were used. Several sagittal plane section planes were recorded from the medial canthus to the lateral canthus of the eyelid after P45 sheet plastination. ROOF and the associated orbital septum connective tissues in the 38 hemifaces were studied. According to the anatomic results, the lowest point of the junction of the orbital septum and the ROOF (SRJ) was raised for surgical dissection. We improved the intraoperative management of patients who underwent upper eyelid surgery in the plastic surgery department of the First Affiliated Hospital of Dalian Medical University in 2019. Patients were evaluated by observation and self-assessment. RESULTS: ROOF is fascia adipose tissue. In the upper portion of upper eyelid, ROOF fibers were observed to be extremely dense and continuous with the fascia on the surfaces of orbicularis oculi muscle, the periosteum of the orbital margin, and the orbital septum. In the middle portion, positional relationships were identified between the lowest point of the SRJ and the lowest point of the junction of the orbital septum and the levator palpebrae superioris (SAJ). Lifting the SRJ significantly increased the upper eyelid reflex distance in all 57 patients. CONCLUSIONS: ROOF is an important factor in upper eyelid surgery. Lifting the SRJ effectively improves the retraction force of the levator palpebrae superioris muscle (LPS).

[Anthropometric analysis of facial aging in 1200 Han adult people in Dalian].

OBJECTIVE: To investigate the facial aging analysis of 1200 Han adult people in Dalian with iris diameter, so as to provide reference for facial rejuvenation in Han people. METHODS: 1200 facial digital photographs from the second-generation ID card of China were stratified randomly selected as the research sample, excluding facial deformity, tattooing eyebrow, tattooing lid margin, ptosis, lip grain and eyebrow deformity cases, as well as the cases whose join point of upper eyelid and lower eyelid not exposed at the nasal side. These photos were divided into six cohorts: female aged 18, 38, and 68 years old; and male aged 18, 38, and 68 years old, with 200 cases in each cohort. The individual iris diameter was divided into 20 equal parts in each photograph, with each part marked one unit as individual iris diameter ruler. Ten values were made from a horizontal plane between the medial canthus to ten points at one face ( the line between two medial canthus is used as the horizontal line, circumocular and facial soft tissue were measured with individual iris diameter ruler on the photographs), then the results were analyzed with Adobe Photoshop software. RESULTS: There are statistically significant differences in eyebrow height (36.42 ± 4.22 unit in 18 years old male group, 40.22 ± 6.90 unit in 38 years old male group, 34.83 ± 9.39 unit in 68 years old male group; 37.59 ± 6.72 unit in 18 years old female group, 41.09 ± 5.15 unit in 38 years old female group, 36.84 ± 9.45 unit in 68 years old female group), palpebral fissure height, physiognomic external canthus height, palpebral fissure width, pupil height and other items (P < 0.05). CONCLUSIONS: (1) The brow position rises to the peak level at middle age (38 years old group), then drops down gradually with aging. (2) The physiognomic external canthus moves towards the nasal side and caudal side with aging. (3) Eyeball moves towards caudal side with aging. (4) The soft tissue around bilateral angle of mouth, nasal tip and submaxilla moves towards caudal side with aging. (5) The measurement of individual iris diameter ruler can apply to analyze the aging changes of facial soft tissue, and is more suitable for the case when facial photographs are taken at different distances.

The Use of P45 Plastination Technique to Study the Distribution of Preseptal and Preaponeurotic Fat Tissues in Asian Eyelids.

This study evaluated the anatomical features of preseptal and preaponeurotic fat tissues in the upper eyelids of individuals of Asian heritage. Specifically, we attempted to elucidate the role of these tissues in the formation of sunken upper eyelids and devise an easy and feasible approach to rectify this. Sixteen heads (32 facial halves) from fresh adult cadavers were processed using the P45 plastination techniques. The polymer resulted in transparent plastination, and the sagittal median section of the eyeballs was dissected. Gross anatomy results of 12 adult cadaveric heads (24 facial halves) were included as supplementary data. The orbital septum was observed on sagittal section slides prepared with P45 sheet plastination. Based on the amount of fat distribution, the upper eyelid was classified into three groups: preseptal fat predominant type, preaponeurotic fat predominant type, and orbital septum equilibrium type (relative distribution of 31.3, 12.5, and 56.3 % in plastinated slices, and 29.2, 16.7, and 54.2 % in gross anatomical studies). Major tissues on P45 sheet plastination slices in the supraorbital region were preseptal fat, preaponeurotic fat, frontalis muscle and frontalis muscle aponeurosis, and partial orbicularis oculi muscle. The muscle fibers of the frontalis muscle and orbicularis oculi were interconnected and extended backward to connect with the orbital septum through preseptal fat. In conclusion, the morphology and external appearance of the upper eyelids depend on the relative relationship between preseptal and preaponeurotic fat tissues. Mildly or moderately sunken upper eyelids can be corrected by modifying the soft tissue in the supraorbital margin.

Are There Differences Between the Upper and Lower Parts of the Superficial Musculoaponeurotic System? A Preliminary Biomechanical Study.

BACKGROUND: The superficial musculoaponeurotic system (SMAS) becomes thinner and gradually disappears from the midface. In rhytidectomy, manipulation of the SMAS occurs in the lateral area, and previous research has focused primarily on the SMAS region as a whole. OBJECTIVES: In this preliminary study, the authors compared the viscoelasticity of the upper and lower regions of the SMAS using biomechanical techniques. METHODS: Two adjacent projection regions of the SMAS were designated: region 1 and region 2, representing the upper and lower parts, respectively. The SMAS tissues from 8 fresh-frozen cadaver heads were cut into 64 samples before biomechanical testing, and the following variables were recorded for subsequent analysis: stress-strain curve, elastic modulus, ultimate strength, and elongation at break. RESULTS: The stiffness of region 1 was markedly greater than that of region 2. Energy dissipation was greater in region 2. Elastic modulus and ultimate strength were significantly higher for region 1, and elongation at break was longer in region 2. The fit curve of the 2 regions deviated markedly. CONCLUSIONS: The biomechanical properties of the upper and lower regions of the lateral SMAS are functionally different. Such knowledge will help refine the planning and design of facial surgery and improve outcomes for patients who undergo rhytidectomy.