Bone Metabolic Markers in Patients with Obstructive Sleep Apnea Syndrome

PRKAA2 Promotes Tumor Growth and Inhibits Ferroptosis through SLC7A11/GSH/GPX4 Pathway in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most pervasive sort of lung cancer with deadly outcome. According to recent studies, a number of neoplastic disorders and ferroptosis are intimately connected. This study aims to identify the role of key ferroptosis-related gene (protein kinase AMP-activated catalytic subunit alpha 2, PRKAA2) and explore new directions for the diagnosis and treatment of NSCLC. The PRKAA2 expression and its influence on survival were analyzed in multiple public databases (TCGA, TIMER2.0, and GEPIA). And PRKAA2 mRNA level in NSCLC cells were examined by qRT-PCR. Silencing of PRKAA2 (sh-PRKAA2) were used to cell transfection. CCK-8, EdU, and flow cytometry assays were used to measure cell proliferation and apoptosis. The protein levels of ferroptosis markers (SLC7A11, GPX4, and NRF2) were determined by western blotting. Meanwhile, the related ferroptosis analysis, such as malondialdehyde (MDA) and glutathione (GSH), reactive oxygen species (ROS), iron, and Fe2+ levels were also detected in the transfected cells. Moreover, the relationship between PRKAA2 expression and SLC7A11 was analyzed. NSCLC xenograft mouse models were used for in vivo verification of the PRKAA2 function. Here, our data revealed that PRKAA2 was upregulated in NSCLC cells. Additionally, PRKAA2 strengthened cell proliferation and attenuated apoptosis and ferroptosis of NSCLC cells. The depletion of PRKAA2 enhanced the erastin-induced inhibition effect on cell growth, and notably increased the levels of MDA, ROS, iron, and Fe2+, while decreased GSH level in NSCLC cells. In the mechanism exploration, we discovered that PRKAA2 could activate the SLC7A11/GSH/GPx4 antioxidant pathway. The rescue experiments showed that SLC7A11 abrogated the inhibitive impacts of PRKAA2 repression on cellular proliferation, cell apoptosis, and ferroptosis in NSCLC. Besides, animal experiments proved that PRKAA2 enhanced NSCLC tumor growth in vivo. The results discovered that PRKAA2 accelerated the malignant progression, diminished apoptosis and ferroptosis in NSCLC through SLC7A11/GSH/GPX4 pathway. This study provide a novel target in the application of PRKAA2 for NSCLC treatment.

Serum 25(OH)D levels and obstructive sleep apnea syndrome severity in patients without comorbidities: a systematic review and meta-analysis

PURPOSE

The aim of the present systematic review was to corroborate existing evidence on how serum25(OH)D levels affect obstructive sleep apnea syndrome (OSAS) severity in the absence of comorbidities.

METHODS

From inception to May 2024, PubMed, Scopus, and Embase electronic databases were systematically screened to identify randomized controlled trials (RCTs), quasi-RCTs, prospective, and retrospective studies. A strict search protocol was applied following the application of PROSPERO, under the registration number CRD42023468744. The formulated question based on PICO process was: "how do serum25(OH)D levels affect the severity of OSAS or result in enhanced sleep function?". Collected results were finally reviewed for meta-analysis and quality assessment according to the ROBINS-I tool.

RESULTS

Data from 24 studies were pooled and divided into 15 case-control studies and 9 cross-sectional studies. All studies involved a total of 2640 OSAS subjects and 933 healthy subjects. All studies underwent qualitative analysis whereas only 20 were collected for meta-analysis. Mild OSAS showed 25(OH)D levels non-statistically significant (P = 0.12) than the healthy patients whereas moderate OSAS (P = 0.004) and severe OSAS (P < 0.001) differed significantly from control groups. Meta-regression suggested that OSAS severity correlated inversely to the deficiency of 25(OH)D serum levels. Qualitative assessment and Egger's test revealed an elevated risk of bias but low presence of publication bias, respectively.

CONCLUSION

Serum levels of 25(OH)D were observed to be inversely proportional to OSAS severity in patients without coexisting morbidities. 25(OH)D levels in mild OSAS patients were not significantly different from non-OSAS patients, suggesting vitamin supplementation to improve potential sleep disorders.

The association between obstructive sleep apnea and osteoporosis: A systematic review and meta-analysis

Obstructive sleep apnea (OSA) is a sleep disorder with well-known metabolic consequences. The relationship between OSA and bone health, especially osteoporosis, remains poorly understood. Given that both OSA and osteoporosis are highly prevalent chronic conditions with significant public health implications, this study aims to investigate the association of OSA with bone health and osteoporosis. A systematic search of PubMed, Embase and Cochrane Library was conducted from inception to November 22, 2022. Fifteen studies comprising 158,273 individuals were included. The presence of OSA correlated negatively with bone mineral density on meta-analysis (pooled correlation = -0.30; 95 % CI, -0.42 to -0.17; N = 8). Individuals with OSA had poorer bone mineral density scores (mean difference = -0.58, 95 % CI, -1.15 to -0.01; N = 8), and significantly higher risk of developing osteoporosis (adjusted odds ratio = 2.18; 95 % CI, 1.14 to 4.16; N = 4). Notably, both body mass index (BMI) and age were not significant effect modulators in the correlation of OSA and bone density. These findings suggest that OSA is associated with diminished bone health, and it is severity-dependent. Further studies are required to determine if treatment of OSA may have the potential to mitigate these risks.

Vitamin D deficiency: A forgotten aspect in sleep disorders? A critical update

Over the past few years, there has been a surge in interest regarding the connection between sleep duration and quality, sleep disorders, mainly Obstructive sleep apnoea (OSA) and Vitamin D. There is growing evidence to support a new role of Vitamin D in the maintenance and regulation of optimal sleep. Furthermore, a notable link has been identified between OSA and a decrease in serum Vitamin D levels, which appears to intensify as the severity of sleep apnea worsens. Vitamin D status could also potentially serve as a mediator or provide an explanation for the association between OSA and cardiometabolic morbidity, but the current state of research in this area is inadequate. Studies have indicated that the supplementation of Vitamin D can optimize sleep quality, presenting more proof of the connection between insufficient vitamin D levels and sleep disorders. However, it is unclear whether low serum Vitamin D levels are a contributing factor to OSA development or if OSA predisposes individuals to Vitamin D deficiency. As a result, various studies have endeavored to examine the complex relationship between OSA and Vitamin D deficiency. In children and adolescents, while data is limited, there seems also to be a link between sleep disorders and Vitamin D levels. Therefore, the objective of this review is to provide a comprehensive overview of the current evidence on the association between Vitamin D and sleep disorders in both adults and children.

Mining Candidate Genes and Identifying Risk Factors for Leg Disease in Broilers: A Mendelian Randomization Study

Clinical investigations have highlighted disruptions in bone metabolic processes and abnormal fluctuations in serum indicator levels during the onset of leg disease (LD) in broilers. However, the presence of a genetic causal relationship for this association remains undetermined. Therefore, the aim of this study is to discern the risk factors underlying LD development using 1235 sequenced white-feathered broilers. We employed Mendelian randomization (MR) analysis to assess the associations of bone strength (BS), bone mineral density (BMD), tibial bone weight (TBW), tibial bone length (TBL), tibial bone diameter (TBD), bone ash (BA), ash calcium (Ash Ca), ash phosphorus (Ash P), serum calcium (Ca), serum phosphorus (P), serum alkaline phosphatase (ALP), and serum osteoprotegerin (OPG) with the incidence of LD. Compelling evidence underscores a causal link between the risk of developing LD and decreased BMD (odds ratio (OR) = 0.998; 95% CI: 0.983, 0.993; P < 0.001) and narrower TBD (OR = 0.985, 95% CI: 0.975, 0.994, P = 0.002). Additionally, serum OPG concentrations (OR: 0.995, 95% CI: 0.992, 0.999, P = 0.008) were associated with BMD (OR = 0.0078, 95% CI = 0.0043 to 0.0140, P < 0.001), indicating a robust genetic relationship between ALP concentrations (OR: 0.988, 95% CI: 0.984, 0.993, P < 0.001) and TBD (OR = 0.0046, 95% CI = 0.0026, 0.0083, P < 0.001). Moreover, elevated serum Ca (OR: 0.564, 95% CI: 0.487, 0.655, P < 0.001) and P (OR: 0.614, 95% CI: 0.539, 0.699, P < 0.001) levels were associated with a narrower TBD. Elevated serum levels of Ca, P, ALP, and OPG contribute to disturbances in bone metabolism, while decreased BMD and narrower TBD are associated with a greater risk of developing LD in broilers. This discovery elucidates the metabolic risk factors for LD in broilers and could provide information on LDs, such as osteoporosis, in humans.

Association between obstructive sleep apnea and low bone mass in adults: a systematic review and meta-analysis

Introduction

This study aimed to synthesize existing evidence on the potential association between obstructive sleep apnea (OSA) and low bone mass in adults.

Methods

Electronic searches of four main databases were performed. The inclusion criteria consisted of observational studies investigating the relationship between OSA and bone mass, osteoporosis, fractures, or bone metabolism markers in adult population. Bone mineral density (BMD) and T score of lumbar and femur neck, incidence of osteoporosis and fractures, bone metabolism marker levels were extracted as primary outcomes.

Results

Among the 693 relevant publications, 10 studies consisting of 158,427 participants met with the inclusion and exclusion criteria. Meta-analysis showed a significant lower BMD of lumbar (mean difference (MD) = - 0.03; 95% CI - 0.05, - 0.01; I2 = 46%), femur neck (MD = - 0.06; 95% CI - 0.12, 0.00; I2 = 71%), and a significant lower T score of lumbar (MD = - 0.42; 95% CI - 0.79, - 0.05; I2 = 63%) in the OSA group. The results suggested that both male (odds ratio (OR) = 2.03; 95% CI 1.23, 3.35; I2 = 38%) and female (OR = 2.56; 95% CI 1.96, 3.34; I2 = 0%) had higher risk of osteoporosis in the OSA group. Besides, meta-analysis also showed that bone-specific alkaline phosphatase was significantly lower in OSA patients (MD = - 1.90; 95% CI - 3.48, - 0.32; I2 = 48%).

Conclusions

A potential association between OSA and lower bone mass in adults is preliminarily proved. It also seems plausible that both male and female with OSA have a higher risk of osteoporosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00481-1.

Obstructive sleep apnea and vitamin D: an updated systematic review and meta-analysis

PURPOSE  : Obstructive sleep apnea (OSA) is a chronic, sleep-related breathing disorder which leads to increased cardiovascular risks. Vitamin D deficiency is associated with various cardiometabolic complications, including increased cardiovascular morbidity and mortality. We aimed to analyze the difference in serum 25-hydroxyvitamin D (25-OHD) level, prevalence of vitamin D insufficiency and deficiency, and the effect of CPAP treatment on serum 25-OHD levels among adult patients with OSA.

METHODS

We pooled data from 18 observational studies involving 5592 individuals. Baseline parameters that might have contributed to the significant differences observed were also analyzed.

RESULTS

Patients with OSA had significantly lower serum 25-OHD levels (pooled d +  - 0.74 [95% CI: - 1.19 to - 0.28], p < 0.01) and higher prevalence of vitamin D deficiency (pooled log (odds ratio) 0.98 [95% CI: 0.30 to 1.67], p < 0.01) compared to those without OSA. Subgroup analysis demonstrated that these differences were significant only in moderate OSA and severe OSA. Neither age nor BMI nor geographical latitude contributed significantly to the differences observed in serum 25-OHD levels. The use of CPAP did not lead to significant changes in serum 25-OHD levels.

CONCLUSION

Patients with OSA have lower serum 25-OHD levels with a higher prevalence of vitamin D deficiency, regardless of age or BMI, pointing to an independent association between vitamin D and OSA.

Night shift work and serum markers of bone turnover in male shift workers

Night shift work is related to sleep disorders, disruption of circadian rhythm and low serum levels of vitamin D. It is known that all these conditions can adversely affect bone mass. The rate of bone turnover can be assessed through the measurement of molecules called bone turnover markers, including C-terminal telopeptide fragment of type I collagen (CTX) and procollagen type I N-terminal propeptide (P1NP). In this study, we evaluated the serum levels of CTX, P1NP and 25-Hydroxy Vitamin D in 82 male subjects (42 daytime workers and 40 night shift workers) to assess the possible risk of osteoporosis in male shift workers. Serum levels of CTX and P1NP were found to be higher in night shift workers than in daytime workers. No significant difference was found in vitamin D levels between night shift and daytime workers. The increased CTX and P1NP levels reveal a higher rate of bone turnover in night shift workers and thus a possible increased risk of osteoporosis in this category of workers compared with daytime workers. In view of this, our results highlight the importance of further studies investigating the bone health in male night shift workers.

MGST1 Expression Is Associated with Poor Prognosis, Enhancing the Wnt/β-Catenin Pathway via Regulating AKT and Inhibiting Ferroptosis in Gastric Cancer

BACKGROUND

The role of microsomal glutathione S-transferase 1 (MGST1) underlying gastric cancer (GC) is unclear. The purpose of this research was to study the expression level and biological functions of MGST1 in GC cells.

METHODS

Expression of MGST1 was detected by RT-qPCR, Western blot (WB), and immunohistochemical staining. MGST1 was knockdown and overexpression by short hairpin RNA lentivirus in GC cells. Cell proliferation was evaluated by the CCK-8 assay and EDU assay. The cell cycle was detected by flow cytometry. The TOP-Flash reporter assay was used to examine the activity of T-cell factor/lymphoid enhancer factor transcription based on β-catenin. WB was performed to assess the protein levels involved in the cell signaling pathway and ferroptosis. The MAD assay and C11 BODIPY 581/591 lipid peroxidation probe assay were performed to determine the reactive oxygen species lipid level in GC cells.

RESULTS

MGST1 expression was upregulated in GC and it was correlated with poor overall survival of GC patients. MGST1 knockdown significantly inhibited GC cell proliferation and cell cycle by regulating the AKT/GSK-3β/β-catenin axis. In addition, we found that MGST1 inhibits ferroptosis in GC cells.

CONCLUSION

These findings suggested that MGST1 played a confirmed role in promoting GC development and serving as a possible independent prognostic factor for GC.

Relationship between obstructive sleep apnea-hypopnea syndrome and osteoporosis adults: A systematic review and meta-analysis

OBJECTIVE

This study is undertaken to explore the relationship between obstructive sleep apnea-hypopnea syndrome (OSAHS) and osteoporosis, including the relationship between OSAHS and osteoporosis incidence, lumbar spine bone mineral density (BMD), and lumbar spine T-score.

METHOD

Cochrane Library, PubMed, Embase, Web of Science, and other databases are searched from their establishment to April 2022. Literature published in 4 databases on the correlation between OSAHS and osteoporosis,lumbar spine BMD,lumbar spine T-score is collected. Review Manager 5.4 software is used for meta-analysis.

RESULTS

A total of 15 articles are selected, including 113082 subjects. Compared with the control group, the OSAHS group has a higher incidence of osteoporosis (OR = 2.03, 95% CI: 1.26~3.27, Z = 2.90, P = 0.004), the lumbar spine BMD is significantly lower (MD = -0.05, 95% CI: -0.08~-0.02, Z = 3.07, P = 0.002), and the lumbar spine T-score is significantly decreased (MD = -0.47, 95% CI: -0.79~-0.14, Z = 2.83, P = 0. 005).

CONCLUSION

Compared with the control group, the OSAHS group has a higher incidence of osteoporosis and decreased lumbar spine BMD and T-score. In order to reduce the risk of osteoporosis, attention should be paid to the treatment and management of adult OSAHS, and active sleep intervention should be carried out.

MiR-27a-3p Promotes Non-Small Cell Lung Cancer Through SLC7A11-Mediated-Ferroptosis

Background

Ferroptosis is a newly generated regulatory cell death promoted by the accumulated lipid-based reactive oxygen species (ROS). Solute carrier family 7 member 11 (SLC7A11), the cystine/glutamate antiporter, is known as a ferroptosis executor that exhibits a positive correlation with carcinoma progression because of antioxidant function. Nonetheless, it is yet unclear on the understanding of ferroptosis regulation in lung cancer.

Methods

Database, qRT-PCR, Western-blot (WB), and immunohistochemistry were utilized to determine SLC7A11 expression and function, as well as gene iron related to necrosis in clinical tissue specimens and cells; a ferroptosis inducer, inhibitors, and SLC7A11 lentivirus were used to confirm SLC7A11's biological activity in cell viability, oxidative stress, lipid peroxidation, and iron ion enrichment in non-small cell lung cancer (NSCLC) in different cells; lentivirus was used to infect lung adenocarcinoma cell lines to acquire miR-27a-3p overexpression and knockdown cell lines, and to detect SLC7A11 level through qRT-PCR and WB. The influence of upregulated/downregulated miR-27a-3p on ferroptosis and other related biological characteristics of lung adenocarcinoma cell lines was detected.

Results

Upregulated SLC7A11 was shown in NSCLC patients and cells, and increased SLC7A11 had a relation to the poorly prognostic status of NSCLC patients. Besides, a novel miRNA, miR-27a-3p, was an essential modulator of ferroptosis via directly targeting SLC7A11 in NSCLC cells. Overexpressing miR-27a-3p led to SLC7A11 suppression via directly binding to its 3'-UTR, followed by the reduction of erastin-caused ferroptosis. In contrast, inhibited miR-27a-3p resulted in an increase in NSCLC cells' sensitivity to erastin. Of importance, the accumulated lipid ROS and cell death of iron peptide mediated by anti-miR-27a-3p can be eliminated by impeding the glutamylation process. Our literature collectively uncovered that miR-27a-3p modulated ferroptosis by targeting SLC7A11 in NSCLC cells, illustrating the important role of miRNA in ferroptosis.

Conclusion

MiR-27a-3p modulates ferroptosis via targeting SLC7A11 in NSCLC cells, implying the significant role of miR-27a-3p/SLC7A11 in ferroptosis.

Chronic intermittent hypoxia aggravates skeletal muscle aging by down-regulating Klc1/grx1 expression via Wnt/β-catenin pathway

OBJECTIVE

Sleep breathing disorder may affect skeletal muscle decline in the elderly, but the mechanism is not clear. Therefore, this study explores the mechanism of skeletal muscle aging in chronic intermittent hypoxia (CIH) rats.

METHODS

In vitro and in vivo CIH models were constructed in L6 cells and SD rats by treating chronic intermittent hypoxia. Pathological changes of skeletal muscle in vivo were measured by hematoxylin-eosin (HE) staining. Cell proliferation and apoptosis were detected by CCK-8 and Flow cytometer, respectively. The expression of KLC1/GRX1 and the proteins related to the Wnt/β-catenin pathway were measured by qRT-PCR and western blot.

RESULTS

CIH model was successfully established induced by chronic intermittent hypoxia with lower skeletal muscle index (SMI), increased inward migration of muscle fiber cell nucleus, and muscle cells' distance. The results showed that Wnt/β-catenin signalling was activatedin both L6 cells and CIH rats' model. KLC1 and GRX1 were significantly downregulated in the CIH model. Loss of function showed that downregulation of KLC1 promoted L6 cell and skeletal muscle aging in vitro and in vivo, respectively.

CONCLUSION

Our results demonstrated that CIH aggravated skeletal muscle aging by down-regulating KLC1/GRX1 expression via the Wnt/β-catenin pathway.

A meta-analysis: Does vitamin D play a promising role in sleep disorders?

BACKGROUND

Sleep disorders, one of the most common problems in the general population, have been related to a series of harmful health consequences. Vitamin D appears to be associated with sleep disorders. However, the difference in vitamin D levels between sleep disorder subjects and people without a sleep disorder is unclear. Simultaneously, the influence of vitamin D replenishment on sleep disorders remains controversial.

METHODS

PubMed, MEDLINE, Web of Science, and Cochrane Library were searched for literatures published until October 2019. Using a random effects model, a meta-analysis was conducted to calculate the standard mean difference to evaluate the difference in vitamin D concentrations between sleep disorder subjects and normal people and the efficacy of vitamin D supplementation on sleep disorders.

RESULTS

Our study found that the serum vitamin D levels in the sleep disorder subjects were lower than that in the normal people (SMD = -0.75 ng/ml, 95% CI = -0.93, -0.57 ng/ml). Moreover, the Pittsburgh Sleep Quality Index (PSQI)in the subjects with vitamin D supplementation was lower than that in the controls (SMD = -0.45, 95% CI = -0.76, -0.13).

CONCLUSIONS

Vitamin D could play a promising role in sleep disorders. More data are required to confirm the efficacy of vitamin D supplementation for improving sleep disorders.

Bone metabolism parameters and inactive matrix Gla protein in patients with obstructive sleep apnea†

STUDY OBJECTIVES

The aim of this study was to investigate differences in dual-energy X-ray absorptiometry (DXA) parameters, trabecular bone score (TBS), bone turnover markers and inactive matrix Gla protein (dp-ucMGP) between patients with obstructive sleep apnea (OSA) and healthy controls.

METHODS

This study enrolled 53 male patients diagnosed with OSA, and 50 age- and body mass index (BMI)-matched control subjects. All participants underwent DXA imaging, TBS assessment and blood sampling for biochemical analysis of bone metabolism markers.

RESULTS

Mean apnea-hypopnea index (AHI) score of OSA patients was 43.8 ± 18.8 events/h. OSA patients had significantly higher plasma dp-ucMGP levels in comparison to controls (512.7 ± 71.9 vs. 465.8 ± 50.9 pmol/L, p < 0.001). OSA and control group did not significantly differ regarding standard DXA results, while TBS values were significantly lower in the OSA group (1.24 ± 0.17 vs. 1.36 ± 0.15, p < 0.001). AHI score was a significant independent correlate of plasma dp-ucMGP levels (β ± SE, 1.461 ± 0.45, p = 0.002). In addition, TBS retained a significant relationship with dp-ucMGP values (β ± SE, -93.77 ± 38.1, p = 0.001).

CONCLUSIONS

dp-ucMGP levels are significantly higher in patients with OSA and correlate with disease severity. In addition, TBS values in OSA patients are lower in comparison with the control group and decrease with disease severity.