Arachidonic acid in aging: New roles for old players.

BACKGROUND: Arachidonic acid (AA), one of the most ubiquitous polyunsaturated fatty acids (PUFAs), provides fluidity to mammalian cell membranes. It is derived from linoleic acid (LA) and can be transformed into various bioactive metabolites, including prostaglandins (PGs), thromboxanes (TXs), lipoxins (LXs), hydroxy-eicosatetraenoic acids (HETEs), leukotrienes (LTs), and epoxyeicosatrienoic acids (EETs), by different pathways. All these processes are involved in AA metabolism. Currently, in the context of an increasingly visible aging world population, several scholars have revealed the essential role of AA metabolism in osteoporosis, chronic obstructive pulmonary disease, and many other aging diseases. AIM OF REVIEW: Although there are some reviews describing the role of AA in some specific diseases, there seems to be no or little information on the role of AA metabolism in aging tissues or organs. This review scrutinizes and highlights the role of AA metabolism in aging and provides a new idea for strategies for treating aging-related diseases. KEY SCIENTIFIC CONCEPTS OF REVIEW: As a member of lipid metabolism, AA metabolism regulates the important lipids that interfere with the aging in several ways. We present a comprehensivereviewofthe role ofAA metabolism in aging, with the aim of relieving the extreme suffering of families and the heavy economic burden on society caused by age-related diseases. We also collected and summarized data on anti-aging therapies associated with AA metabolism, with the expectation of identifying a novel and efficient way to protect against aging.

REPIN1 regulates iron metabolism and osteoblast apoptosis in osteoporosis.

Osteoporosis is not well treated due to the difficulty of finding commonalities between the various types of it. Iron homeostasis is a vital component in supporting biochemical functions, and iron overload is recognized as a common risk factor for osteoporosis. In this research, we found that there is indeed evidence of iron accumulation in the bone tissue of patients with osteoporosis and REPIN1, as an origin specific DNA binding protein, may play a key role in this process. We revealed that sh-Repin1 therapy can rescue bone loss in an iron-overload-induced osteoporosis mouse model. Knockdown of Repin1 can inhibit apoptosis and enhance the resistance of osteoblasts to iron overload toxicity. REPIN1 promoted apoptosis by regulating iron metabolism in osteoblasts. Mechanistically, knockdown of Repin1 decreased the expression of Lcn2, which ameliorated the toxic effects of intracellular iron overload. The anti-iron effect of lentivirus sh-Repin1 was partially reversed or replicated by changing LCN2 expression level via si-RNA or plasmid, which indirectly verified the key regulatory role of LCN2 as a downstream target. Furthermore, the levels of BCL2 and BAX, which play a key role in the mitochondrial apoptosis pathway, were affected. In summary, based on the results of clinical specimens, animal models and in vitro experiments, for the first time, we proved the key role of REPIN1 in iron metabolism-related osteoporosis.

Short-term changes in and preoperative factors affecting vaulting after posterior chamber phakic Implantable Collamer Lens implantation.

BACKGROUND: To describe the very early vault changes in the first month after Implantable Collamer Lens (ICL) implantation and to evaluate the effect of preoperative biometric factors on vault. METHODS: Eighty-three eyes from eighty-three subjects with complete data who met follow-up requirements were recruited in this retrospective study between May 2019 and March 2020. We quantitatively assessed the postoperative vault at 2 h, 1 day, 1 week, and 1 month following implantation. Associations between the postoperative vault and age, ICL size, spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), flat keratometry (K), steep K, mean K, anterior chamber depth (ACD), crystalline lens thickness (LT), white-to-white (WTW) diameter obtained by three devices, horizontal and vertical sulcus-to-sulcus (STS) diameter, bright and dark pupil sizes (BPS and DPS) and DPS-BPS were investigated using Spearman's correlation analysis and stepwise multiple regression analysis. RESULTS: The mean vault values at 2 h, 1 day, 1 week, and 1 month after ICL implantation were 672.05 ± 30.72, 389.15 ± 28.33, 517.23 ± 30.76 and 530.12 ± 30.22 µm, respectively. Significant differences were found in the vault values at 2 h, 1 day and 1 week after the operation. The ICL size (ß = 0.942; p < 0.001), followed by horizontal STS (ß = -0.517; p < 0.001), crystalline LT (ß = -0.376; p < 0.001) and vertical STS (ß = -0.257; p = 0.017), significantly influenced the vault at 1 month after the operation. The multiple regression equation was expressed as follows: central vault (µm) = -1369.05 + 657.121 × ICL size- 287.408 × horizontal STS - 432.497 × crystalline LT - 137.33 × vertical STS (adjusted R2 = 0.643). CONCLUSIONS: After ICL implantation, the vault decreased and then increased, but it did not return to the vault value 2 h after surgery. The ICL size, horizontal and vertical STS and crystalline LT are key factors for predicting postoperative vaulting.

Analysis of macular microvasculature and thickness after ICL implantation in patients with myopia using optical coherence tomography.

AIM: To investigate changes in macular vessels and thickness in myopic eyes after intraocular collamer lens (ICL) implantation using quantitative optical coherence tomography angiography (OCTA). METHODS: This retrospective included 73 myopic eyes of 73 patients (average age, 27.53±6.16y) who underwent ICL implantation (28 eyes were Toric ICL). Axial length (AL), uncorrected visual acuity (UCVA), refractive dioptre (RD), intraocular pressure (IOP) and OCTA were measured and compared with before and 1wk, 1, and 3mo after surgery. OCTA was used to image vessel density (VD) and skeleton density (SD) in both the superficial (SCP) and deep capillary plexus (DCP). Central retinal thickness (CRT) and ganglion cell-inner plexiform layer thickness (GCT) were also measured. Changes between pre- and postoperative measurements were analysed by repeated measures analysis of variance. RESULTS: Compared with preoperative data, postoperative data on UCVA revealed significant improvements in all patients (P<0.05). However, there was no significant difference in IOP. After the operation, CRT and GCT exhibited significant changes (P<0.05). Among these measures, CRT was significantly higher at one and three months postoperative (all P<0.01). GCT was significantly higher at 1wk, 1, and 3mo postoperative (all P<0.01). Changes in VD and SD were nonsignificant in both the SCP and DCP. There was no difference in postoperative changes between the ICL and Toric ICL groups. CONCLUSION: ICL and Toric ICL implantation both have good efficacy and safety for myopic eyes, but macular area changes that occur after surgery need attention.

Association between breastfeeding and osteoporotic hip fracture in women: a dose-response meta-analysis.

OBJECTIVE: Approximately 300 mg of calcium a day is provided into infants to maintain the physical development of infants, and 5 to 10% bone loss occurs in women during breastfeeding. Hip fractures are considered the most serious type of osteoporotic fracture. We performed this meta-analysis to investigate the association between breastfeeding and osteoporotic hip fractures. MATERIAL AND METHODS: PubMed and Embase were searched until May 1, 2019, for studies evaluating the relationship between breastfeeding and osteoporotic hip fracture in women. The quality of the included studies was evaluated by the methodological index for non-randomized studies (MINORS). For the dose-response meta-analysis, we used the "generalized least squares for trend estimation" method proposed by Greenland and Longnecker to take into account the correlation with the log RR estimates across the duration of breastfeeding. RESULTS: Seven studies were moderate or high quality, enrolling a total of 103,898 subjects. The pooled outcomes suggested that breastfeeding can decrease the incidence of osteoporotic hip fracture (RR = 0.64 (95% CI 0.43, 0.95), P = 0.027). Dose-response analysis demonstrated that the incidence of osteoporotic hip fracture decreased with the increase of breastfeeding time. The RR and 95% CI for 3 months, 6 months, 12 months, and 24 months were RR = 0.93, 95% CI 0.88, 0.98; RR = 0.87, 95% CI 0.79, 0.96; RR = 0.79, 95% CI 0.67, 0.92; and RR = 0.76, 95% CI 0.59, 0.98, respectively, whereas no significant relationship was found between them when the duration of breastfeeding time was more than 25 months. CONCLUSIONS: Our meta-analysis demonstrated that the incidence of osteoporotic hip fracture decreased with the extension of breastfeeding time. However, there is no significant relationship between them when the duration of breastfeeding time was more than 25 months.

A New Approach for the Segmentation of Three Distinct Retinal Capillary Plexuses Using Optical Coherence Tomography Angiography.

PURPOSE: To segment three distinct retinal capillary plexuses by using optical coherence tomography angiography (OCTA). METHODS: This prospective study included 30 eyes of 15 healthy subjects. En face OCTA images generated by the AngioPlex platform were manually segmented by the "progressive matching" method to the superficial, middle, and deep capillary plexuses (SCP, MCP, and DCP, respectively). The estimated position of each plexus relative to the reference line was calculated. Vascular density (VD) and skeleton density (SD) analyses, as well as the interclass correlation coefficient and relative standard deviation, were performed on each capillary plexus. We also measured central retinal thickness (CRT) and ganglion cell layer thickness (GCT). RESULTS: Thirty eyes of 15 healthy subjects (9 females; average age of 28.33 ± 3.07 years) were included in the analysis. We defined the relative estimated positions of the outer boundary MCP to the RPEfit as MCP = 14.491 - 0.307 CRT - 1.443 GCT, while the outer boundary of DCP was 37.63 ± 7.04 µm below the IPL. The VDs of SCP, MCP, and DCP were 32.97% ± 3.90%, 45.05% ± 5.34%, and 37.34% ± 4.96%, respectively, while the SDs of SCP, MCP, and DCP were 14.45 ± 1.51 mm-1, 19.80 ± 1.92 mm-1, and 17.38 ± 1.97 mm-1, respectively. CONCLUSIONS: With the progressive matching method, we segmented three capillary plexuses and defined the relative estimated positions of each capillary plexus to the reference line and calculated the VD and SD of three capillary plexuses in healthy subjects, providing controls for future studies. TRANSLATIONAL RELEVANCE: Our study provides a visual method for OCTA image vascular segmentation and provides reference and control for future studies on retinal three capillary plexuses.

Comparing complications of vertebroplasty and kyphoplasty for treating osteoporotic vertebral compression fractures: a meta-analysis of the randomized and non-randomized controlled studies.

PURPOSE: To compare complications of percutaneous vertebroplasty (PVP) and balloon kyphoplasty (BKP) for the treatment of osteoporotic vertebral compression fractures (OVCFs). BACKGROUND: PVP and BKP are two minimally invasive procedures for treating OVCFs, while few studies emphases attention to intra- and post-operative complications about the two procedures. METHODS: Online databases were searched for studies comparing complications of PVP and BKP for OVCFs, the randomized controlled trials, clinical controlled trials and cohort studies that provided related data were identified. Demographic characteristics and complications related to procedures were extracted and analysed from all of the included studies. RESULTS: Nineteen studies encompassing 1,787 patients in total, of whom 887 received PVP and 900 received BKP, met the inclusion criteria. For subsequent fractures, our meta-analysis detected no significant difference between the two procedures, both for adjacent fractures (p = 0.29) and non-adjacent fractures (p = 0.37). For cement extravasations, there was no significant difference between the two interventions if considering disc spaces extravasations only (p = 0.24), while considering total extravasations and paravertebral extravasations, the cement leakage rate in the PVP group was significantly higher than the BKP group (total: p < 0.01; paravertebral: p < 0.01). CONCLUSIONS: The two procedures suffer from equal risk of subsequent spinal fractures; PVP has a significant higher cement leakage rate compared to BKP, mainly caused by a higher paravertebral leakage, patients with extremely poor pulmonary function or unstable haemodynamic are better candidates for BKP.

The optimal concentration of topical hydroxycamptothecin in preventing intraarticular scar adhesion.

10-Hydroxycamptothecin could reduce intraarticular adhesion by inhibiting fibroblasts proliferation after knee surgery. However, the ideal concentration of hydroxycamptothecin have not been defined. This study was tried to verify the optimal concentration of 10-hydroxycamptothecin in preventing knee intraarticular adhesion. Sixty rabbits were randomly divided into five groups. Approximately 10 mm × 10 mm of the cortical bone was removed from both sides of the femoral condyle and the underneath cancellous bone was exposed. Various concentrations of hydroxycamptothecin (0.1 mg/ml, 0.5 mg/ml, 1.0 mg/ml, 2.0 mg/ml) or saline were applied to the decorticated areas for 10 minutes. After four weeks, the degree of inraarticular adhesion was assessed by macroscopic evaluation, biochemical analysis of hydroxyproline content and histological evaluation. The results demonstrated that the extent of knee inraarticular adhesion in 1.0 mg/ml group and 2.0 mg/ml hydroxycamptothecin group were significantly lower than those of 0.5 mg/ml group, 0.1 mg/ml hydroxycamptothecin group and control group. Moreover, there was no significant difference between 1.0 mg/ml group and 2.0 mg/ml hydroxycamptothecin group. In conclusion, topical application of 1.0 mg/ml hydroxycamptothecin may be the optimal concentration in reducing intraarticular adhesion after knee surgery in rabbits.

The isolation and cultivation of bone marrow stem cells and evaluation of differences for neural-like cells differentiation under the induction with neurotrophic factors.

The bone marrow represents the most common source from which to isolate mesenchymal stem cells (MSCs). They can be obtained directly from patients and successfully induced to form various differentiated cell types. In addition, cell-based transplantation therapies have been proven to be promising strategies for curing disease of the nerve system. Therefore, it was particularly important to establish an easy and feasible method for the isolation, purification, and differentiation of bone marrow stromal cells (BMSCs). The aim of this study was to isolate and characterize putative bone marrow derived MSCs from Sprague-Dawley (SD) rats. Furthermore, differentiation effects were compared between the GDNF-induction group and the BDNF-induction group. Of these, BMSCs were isolated from the SD rats in a traditional manner, and identified based on plastic adherence, morphology, and surface phenotype assays. After induction with GDNF and BDNF, viability of BMSCs was detected by MTT assay and neuronal differentiation of BMSCs was confirmed by using immunofluorescence and Western blotting. Besides, the number of BMSCs that obviously exhibited neuronal morphology was counted and the results were compared between the GDNF-induction group and BDNF-induction groups. Our results indicate that direct adherence was a simple and convenient method for isolation and cultivation of BMSCs. Furthermore, BMSCs can be induced in vitro to differentiate into neuronal cells by using GDNF, which could achieve a more persistent and stable inducing effect than when using BDNF.