Genomic analysis reveals phylogeny of Zygophyllales and mechanism for water retention of a succulent xerophyte.

Revealing the genetic basis for stress-resistant traits in extremophile plants will yield important information for crop improvement. Zygophyllum xanthoxylum, an extant species of the ancient Mediterranean, is a succulent xerophyte that can maintain a favorable water status under desert habitats; however, the genetic basis of this adaptive trait is poorly understood. Furthermore, the phylogenetic position of Zygophyllales, to which Z. xanthoxylum belongs, remains controversial. In this study, we sequenced and assembled the chromosome-level genome of Z. xanthoxylum. Phylogenetic analysis showed that Zygophyllales and Myrtales form a separated taxon as a sister to the clade comprising fabids and malvids, clarifying the phylogenetic position of Zygophyllales at whole-genome scale. Analysis of genomic and transcriptomic data revealed multiple critical mechanisms underlying the efficient osmotic adjustment using Na+ and K+ as "cheap" osmolytes that Z. xanthoxylum has evolved through the expansion and synchronized expression of genes encoding key transporters/channels and their regulators involved in Na+/K+ uptake, transport, and compartmentation. It is worth noting that ZxCNGC1;1 (cyclic nucleotide-gated channels) and ZxCNGC1;2 constituted a previously undiscovered energy-saving pathway for Na+ uptake. Meanwhile, the core genes involved in biosynthesis of cuticular wax also featured an expansion and upregulated expression, contributing to the water retention capacity of Z. xanthoxylum under desert environments. Overall, these findings boost the understanding of evolutionary relationships of eudicots, illustrate the unique water retention mechanism in the succulent xerophyte that is distinct from glycophyte, and thus provide valuable genetic resources for the improvement of stress tolerance in crops and insights into the remediation of sodic lands.

The mitochondrial UPR induced by ATF5 attenuates intervertebral disc degeneration via cooperating with mitophagy.

Intervertebral disc degeneration (IVDD) is an aging disease that results in a low quality of life and heavy socioeconomic burden. The mitochondrial unfolded protein response (UPRmt) take part in various aging-related diseases. Our research intents to explore the role and underlying mechanism of UPRmt in IVDD. Nucleus pulposus (NP) cells were exposed to IL-1ß and nicotinamide riboside (NR) served as UPRmt inducer to treat NP cells. Detection of ATP, NAD + and NADH were used to determine the function of mitochondria. MRI, Safranin O-fast green and Immunohistochemical examination were used to determine the degree of IVDD in vivo. In this study, we discovered that UPRmt was increased markedly in the NP cells of human IVDD tissues than in healthy controls. In vitro, UPRmt and mitophagy levels were promoted in NP cells treated with IL-1ß. Upregulation of UPRmt by NR and Atf5 overexpression inhibited NP cell apoptosis and further improved mitophagy. Silencing of Pink1 reversed the protective effects of NR and inhibited mitophagy induced by the UPRmt. In vivo, NR might attenuate the degree of IDD by activating the UPRmt in rats. In summary, the UPRmt was involved in IVDD by regulating Pink1-induced mitophagy. Mitophagy induced by the UPRmt might be a latent treated target for IVDD.

Effectiveness of Physiotherapeutic Scoliosis-Specific Exercises on 3-Dimensional Spinal Deformities in Patients With Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-analysis.

OBJECTIVE: To investigate the effects of physiotherapeutic scoliosis-specific exercises (PSSE) on coronal, horizontal, and sagittal deformities of the spine in adolescent idiopathic scoliosis (AIS) as well as how curve severity, intervention duration, and intervention type could modify these effects. DATA SOURCES: Data sources included PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases, which were searched from their inception to September 5, 2023. STUDY SELECTION: Clinical controlled trials reporting the effects of PSSE on the Cobb angle, angle of trunk rotation (ATR), thoracic kyphosis (TK), or lumbar lordosis in patients with AIS aged 10-18 years. The experimental groups received PSSE; the control groups received standard care (observation or bracing) or conventional exercise such as core stabilization exercise, Pilates, proprioceptive neuromuscular facilitation, and other nonspecific exercises. DATA EXTRACTION: Two researchers independently extracted key information from eligible studies. The quality of the studies was assessed using the Cochrane Handbook version 5.1.0 risk of bias assessment and the JBI Center for Evidence-Based Health Care (2016) of quasi-experimental research authenticity assessment tool. The level and certainty of evidence were rated according to the Grading of Recommendations, Assessment, Development, and Evaluation framework. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The protocol for this study was registered in PROSPERO (CRD42023404996). DATA SYNTHESIS: Twelve randomized controlled trials (RCTs) and 5 non-RCTs were meta-analyzed separately. The results indicated that compared with other nonsurgical management, PSSE significantly improved the Cobb angle, ATR, and TK, whereas the lumbar lordosis improvement was not statistically significant. Additionally, the efficacy of PSSE on Cobb angle was not significant in patients with curve severity ≥30° compared with controls. Nevertheless, the pooled effect of PSSE on Cobb angle was not significantly modified by intervention duration and intervention type and that on ATR was not significantly modified by intervention duration. The overall quality of evidence according to Grading of Recommendations, Assessment, Development, and Evaluation was moderate to low for RCT and very low for non-RCT. CONCLUSIONS: PSSE exhibited positive benefits on the Cobb angle, ATR, and TK in patients with AIS compared with other nonsurgical therapies. In addition, the effectiveness of PSSE may be independent of intervention duration and intervention type but may be influenced by the initial Cobb angle. However, more RCTs are needed in the future to validate the efficacy of PSSE in moderate AIS with a mean Cobb angle ≥30°. Current evidence is limited by inconsistent control group interventions and small sample size of the studies.

Insulin resistance is associated with the presence and severity of retinopathy in patients with type 2 diabetes.

BACKGROUND: To assess the relationship between novel insulin resistance (IR) indices and the presence and severity of diabetic retinopathy (DR) in patients with type 2 diabetes. METHODS: This is a cross-sectional study involving 2211 patients. The study outcomes were DR events. The study exposures were IR indices including estimated glucose disposal rate (eGDR), natural logarithm of glucose disposal rate (lnGDR), metabolic insulin resistance score (METS-IR), triglyceride glucose index-body mass index (TyG-BMI), triglyceride glucose index-waist-to-hip ratio (TyG-WHR), and triglyceride/high-density lipoprotein cholesterol(TG/HDL-c ratio). We used binary and multivariate ordered logistic regression models to estimate the association between different IR indices and the presence and severity of DR. Subject work characteristic curves were used to assess the predictive power of different IR indices for DR. RESULTS: DR was present in 25.4% of participants. After adjusting for all covariates, per standard deviation (SD) increases in eGDR (ratio [OR] 0.38 [95% CI 0.32-0.44]), lnGDR (0.34 [0.27-0.42]) were negatively associated with the presence of DR. In contrast, per SD increases in METS-IR (1.97 [1.70-2.28]), TyG-BMI (1.94 [1.68-2.25]), TyG-WHR (2.34 [2.01-2.72]) and TG/HDL-c ratio (1.21 [1.08-1.36]) were positively associated with the presence of DR. eGDR was strongly associated with severity of DR. Of all variables, eGDR had the strongest diagnostic value for DR (AUC = 0.757). CONCLUSIONS: Of the six IR indices, eGDR was significantly associated with the presence and severity of DR in patients with type 2 diabetes. eGDR has a good predictive value for DR. Thus, eGDR maybe a stronger marker of DR.

Regulatory mechanism of miR-20a-5p in neuronal damage and inflammation in lipopolysaccharide-induced BV2 cells and MPTP-HCl-induced Parkinson's disease mice.

BACKGROUND: Parkinson's disease (PD) is a prevailing neurodegenerative disorder increasingly affecting the elderly population. The involvement of microRNAs (miRNAs) in PD has been confirmed. We sought to explore the molecular mechanism of miR-20a-5p in PD. METHODS: Lipopolysaccharide (LPS)-induced BV2 cell model and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP-HCl)-induced PD mouse model were established. miR-20a-5p, inducible nitric oxide synthase (iNOS), interleukin (IL)-6, tumour necrosis factor (TNF)-α, transforming growth factor (TGF)-ß1, and IL-10 expression in BV2 cells was examined by reverse transcription - quantitative polymerase chain reaction. Cell viability was assessed by MTT assay. The apoptotic rate and levels of Bcl-2, Bax, cleaved caspase-3, and signal transducer and activator of transmission (STAT)3 were examined by flow cytometry and Western blot. Bioinformatics software predicted the potential binding sites of miR-20a-5p and STAT3. Dual-luciferase experiment verified the binding relationship. Iba1-positive and tyrosine hydroxylase (TH)-positive cell numbers in substantia nigra pars compacta were detected by immunohistochemistry. The effect of miR-20a-5p on motor function in MPTP-induced PD mice was detected by Rota-rod test, Pole test, Traction test and Beam-crossing task. RESULTS: miR-20a-5p was under-expressed in LPS-induced BV2 cells. Overexpression of miR-20a-5p increased the viability of LPS-induced BV2 cells and reduced apoptosis rates. Moreover, overexpression of miR-20a-5p reduced cleaved caspase-3, Bax, iNOS, IL-6, and TNF-α and increased Bcl-2 and TGF-ß1, and IL-10. miR-20a-5p targeted STAT3. STAT3 overexpression partially reversed miR-20a-5p overexpression-mediated effects on LPS-induced BV2 cell viability, apoptosis, and inflammatory responses. miR-20a-5p overexpression inhibited MPTP-induced STAT3 and α-synuclein levels, microglia activation, and inflammatory response, and reduced the loss of TH-positive cells in mice. miR-20a-5p overexpression ameliorated MPTP-induced dyskinesia in PD model mice. CONCLUSION: miR-20a-5p alleviates neuronal damage and suppresses inflammation by targeting STAT3 in PD.

Aberrant global and local dynamic properties in schizophrenia with instantaneous phase method based on Hilbert transform.

BACKGROUND: Emerging functional imaging studies suggest that schizophrenia is associated with aberrant spatiotemporal interaction which may result in aberrant global and local dynamic properties. METHODS: We investigated the dynamic functional connectivity (FC) by using instantaneous phase method based on Hilbert transform to detect abnormal spatiotemporal interaction in schizophrenia. Based on resting-state functional magnetic resonance imaging, two independent datasets were included, with 114 subjects from COBRE [51 schizophrenia patients (SZ) and 63 healthy controls (HCs)] and 96 from OpenfMRI (36 SZ and 60 HCs). Phase differences and instantaneous coupling matrices were firstly calculated at all time points by extracting instantaneous parameters. Global [global synchrony and intertemporal closeness (ITC)] and local dynamic features [strength of FC (sFC) and variability of FC (vFC)] were compared between two groups. Support vector machine (SVM) was used to estimate the ability to discriminate two groups by using all aberrant features. RESULTS: We found SZ had lower global synchrony and ITC than HCs on both datasets. Furthermore, SZ had a significant decrease in sFC but an increase in vFC, which were mainly located at prefrontal cortex, anterior cingulate cortex, temporal cortex and visual cortex or temporal cortex and hippocampus, forming significant dynamic subnetworks. SVM analysis revealed a high degree of balanced accuracy (85.75%) on the basis of all aberrant dynamic features. CONCLUSIONS: SZ has worse overall spatiotemporal stability and extensive FC subnetwork lesions compared to HCs, which to some extent elucidates the pathophysiological mechanism of schizophrenia, providing insight into time-variation properties of patients with other mental illnesses.

Safety and Efficacy of Polyetheretherketone (PEEK) Cages and Cadaveric Allografts in Transforaminal Lumbar Interbody Fusion (TLIF) for Treating Lumbar Pyogenic Spondylodiscitis.

Purpose: There have been many studies in the operative management of pyogenic spondylodiscitis with foreign materials. However, it still remains an issue of debate on whether the allografts may be used in pyogenic spondylodiscitis. This study sought to evaluate the safety and effectiveness of PEEK cages and the cadaveric allograft in transforaminal lumbar interbody fusion (TLIF) for treating lumbar pyogenic spondylodiscitis. Methods: From January 2012 to December 2019, 56 patients underwent surgery for lumbar pyogenic spondylodiscitis. The posterior debridement of all patients and their fusion with allografts, local bone grafts, and bone chip cages were performed before posterior pedicle screw fusion. An assessment of the residual pain, the grade of neurological injury, and the resolution of infection was conducted on 39 patients. The clinical outcome was evaluated using a visual analog scale (VAS) and the Oswestry Disability Index (ODI), and neurological outcomes were appraised based on Frankel grades. The radiological outcomes were evaluated via focal lordosis, lumbar lordosis, and the state of the fusion. Results: Staphylococcus aureus and Staphylococcus epidermidis were the most common causative organisms. The mean preoperative focal lordosis was -1.2° (-11.4° to 5.7°), and the mean postoperative focal lordosis increased to 10.3° (4.3°-17.2°). At the final follow-up, there were five cases with subsidence of the cage, no case of recurrence, and no case with cage and screw loosening or migration. The mean preoperative VAS and ODI scores were 8.9 and 74.6%, respectively, and improvements in VAS and ODI were 6.6 ± 2.2 and 50.4 ± 21.3%, respectively. The Frankel grade D was found in 10 patients and grade C in 7. Following the final follow-up, only one patient improved from Frankel grade C to grade D while the others recovered completely. Conclusion: The PEEK cage and cadaveric allograft combined with local bone grafts is a safe and effective choice for intervertebral fusion and restoring sagittal alignment without increased incidence of relapse for treating lumbar pyogenic spondylodiscitis.

Cascading Robustness Analysis of Wireless Sensor Networks with Varying Multisink Placement.

In practical wireless sensor networks (WSNs), cascading failures are closely related to network load distribution, which in turn strongly relies on the locations of multiple sink nodes. For such a network, understanding how the multisink placement affects its cascading robustness is essential but still largely missing in the field of complex networks. To this end, this paper puts forward an actual cascading model for WSNs based on the multisink-oriented load distribution characteristics, in which two load redistribution mechanisms (i.e., global routing and local routing) are designed to imitate the most commonly used routing schemes. On this basis, a number of topological parameters are considered to quantify the sinks' locations, and then, the relationship between these quantities with network robustness is investigated on two typical WSN topologies. Moreover, by employing the simulated annealing approach, we find the optimal multisink placement for maximizing network robustness and compare the topological quantities before and after the optimization to validate our findings. The results indicate that for the sake of enhancing the cascading robustness of a WSN, it is better to place its sinks as hubs and decentralize these sinks, which is independent of network structure and routing scheme.

Exosomal ncRNAs: Novel therapeutic target and biomarker for diabetic complications.

Exosomes are discoid vesicles with a diameter of 40-160 nm. They are mainly derived from the multivesicular body formed by the invagination of lysosomal particles in the cell, which are released into the extracellular matrix after the fusion of the outer membrane. Exosomes are widespread and distributed in various body fluids, they are rich in nucleic acids (microRNA, lncRNA, circRNA, mRNA, tRNA, etc.), proteins, lipids, etc. As an important mediator of cellular communication, exosomes carry and transmit important signaling molecules and are widely involved in intercellular material transport and information transfer, they regulate cellular physiological activities and are closely related to the occurrence and course of various diseases. In recent years, with the deepening of exosome-related research, we discovered that exosomal non-coding RNAs are associated with diabetic complications such as diabetic retinopathy, diabetic nephropathy, diabetic foot ulcer. This article reviews the new findings of exosomal non-coding RNAs (mainly microRNAs, lncRNAs, circRNAs) in diabetic complications, and analyzes the potential of exosomal ncRNA as new biomarkers and new cell-free therapies in the diagnosis and treatment of diabetic complications, hoping to provide new ideas for the prevention, diagnosis, and treatment of diabetic complications.

Survival outcome assessment for triple-negative breast cancer: a nomogram analysis based on integrated clinicopathological, sonographic, and mammographic characteristics.

OBJECTIVE: This study aimed to incorporate clinicopathological, sonographic, and mammographic characteristics to construct and validate a nomogram model for predicting disease-free survival (DFS) in patients with triple-negative breast cancer (TNBC). METHODS: Patients diagnosed with TNBC at our institution between 2011 and 2015 were retrospectively evaluated. A nomogram model was generated based on clinicopathological, sonographic, and mammographic variables that were associated with 1-, 3-, and 5-year DFS determined by multivariate logistic regression analysis in the training set. The nomogram model was validated according to the concordance index (C-index) and calibration curves in the validation set. RESULTS: A total of 636 TNBC patients were enrolled and divided into training cohort (n = 446) and validation cohort (n = 190). Clinical factors including tumor size > 2 cm, axillary dissection, presence of LVI, and sonographic features such as angular/spiculated margins, posterior acoustic shadows, and presence of suspicious lymph nodes on preoperative US showed a tendency towards worse DFS. The multivariate analysis showed that no adjuvant chemotherapy (HR = 6.7, 95% CI: 2.6, 17.5, p < 0.0005), higher axillary tumor burden (HR = 2.7, 95% CI: 1.0, 7.1, p = 0.045), and ≥ 3 malignant features on ultrasound (HR = 2.4, CI: 1.1, 5.0, p = 0.021) were identified as independent prognostic factors associated with poorer DFS outcomes. In the nomogram, the C-index was 0.693 for the training cohort and 0.694 for the validation cohort. The calibration plots also exhibited excellent consistency between the nomogram-predicted and actual survival probabilities in both the training and validation cohorts. CONCLUSIONS: Clinical variables and sonographic features were correlated with the prognosis of TNBCs. The nomogram model based on three variables including no adjuvant chemotherapy, higher axillary tumor load, and more malignant sonographic features showed good predictive performance for poor survival outcomes of TNBC. KEY POINTS: • The absence of adjuvant chemotherapy, heavy axillary tumor load, and malignant-like sonographic features can predict DFS in patients with TNBC. • Mammographic features of TNBC could not predict the survival outcomes of patients with TNBC. • The nomogram integrating clinicopathological and sonographic characteristics is a reliable predictive model for the prognostic outcome of TNBC.

Pathological personality, situations, and their joint influences on daily emotional symptoms.

OBJECTIVE: The present research aims to advance current understanding on how individuals with pathological personality traits construe their day-to-day situational experiences. METHOD: College students (N = 231) completed a measure of personality pathology, followed by six assessments of everyday situations and anxiety/depression symptoms over two weeks. RESULTS: Multilevel analyses indicated that personality pathology was meaningfully associated with situational experiences. Major findings suggested that situations that entailed aggravations and interpersonal confrontations were associated with negative affectivity, antagonism, and psychoticism. Detached individuals were less likely to experience pleasant and social situations. Exploratory analyses suggested an amplification effect where individuals high on personality pathology were more anxious or depressed when they perceived certain situational features, compared to their low trait counterparts. However, such cross-level interactions constituted a small minority; most personality traits and situations exerted additive effects on symptoms. CONCLUSION: Situational experiences appear to be driven in part by personality pathology. The exacerbation of daily negative symptoms can be attributed to the joint (largely additive) influence of the trigger situations and pathological personality traits.

Involvement of oxidative stress-induced annulus fibrosus cell and nucleus pulposus cell ferroptosis in intervertebral disc degeneration pathogenesis.

Ferroptosis is a necrotic form of regulated cell death that was associated with lipid peroxidation and free iron-mediated Fenton reactions. It has been reported that iron deficiency had been implicated in the pathogenesis of intervertebral disc degeneration (IVDD) by activating apoptosis. However, the role of ferroptosis in the process of IVDD has not been illuminated. Here, we demonstrate the involvement of ferroptosis in IVDD pathogenesis. Our in vitro models show the changes in protein levels of ferroptosis marker and enhanced lipid peroxidation level during oxidative stress. Safranin O staining, hematoxylin-eosin staining, and immunohistochemical were used to assess the IVDD after 8 weeks of surgical procedure in vivo. Treatment with ferrostatin-1, deferoxamine, and RSL3 demonstrate the role of ferroptosis in tert-butyl hydroperoxide (TBHP)-treated annulus fibrosus cells (AFCs) and nucleus pulposus cells (NPCs). Ferritinophagy, nuclear receptor coactivator 4 (NCOA4)-mediated ferritin selective autophagy, is originated during the process of ferroptosis in response to TBHP treatment. Knockdown and overexpression NCOA4 further prove TBHP may induce ferroptosis of AFCs and NPCs in an autophagy-dependent way. These findings support a role for oxidative stress-induced ferroptosis in the pathogenesis of IVDD.

Exosomes derived from vascular endothelial cells antagonize glucocorticoid-induced osteoporosis by inhibiting ferritinophagy with resultant limited ferroptosis of osteoblasts.

High dose and long-term steroid treatment can alter antioxidative ability and decrease the viability and function of osteoblasts, leading to osteoporosis and osteonecrosis. Ferroptosis, a new type of cell death characterized by excessive lipid peroxidation due to the downregulation of GPX4 and system Xc- , is involved in glucocorticoid-induced osteoporosis. Endothelial cell-secreted exosomes (EC-Exos) are important mediators of cell-to-cell communication and are involved in many physiological and pathological processes. However, the effect of EC-Exos on osteoblasts exposed to glucocorticoids has not been reported. Here, we explored the role of EC-Exos in glucocorticoid-induced osteoporosis. In vivo and in vitro experiments indicated that EC-Exos reversed the glucocorticoid-induced osteogenic inhibition of osteoblasts by inhibiting ferritinophagy-dependent ferroptosis.

Insights into the historical assembly of global dryland floras: the diversification of Zygophyllaceae.

BACKGROUND: Drylands cover nearly 41% of Earth's land surface and face a high risk of degradation worldwide. However, the actual timeframe during which dryland floras rose on a global scale remains unknown. Zygophyllaceae, an important characteristic component of dryland floras worldwide, offers an ideal model group to investigate the diversification of dryland floras. Here, we used an integration of the phylogenetic, molecular dating, biogeographic, and diversification methods to investigate the timing and patterns of lineage accumulation for Zygophyllaceae overall and regionally. We then incorporated the data from other dominant components of dryland floras in different continents to investigate the historical construction of dryland floras on a global scale. RESULTS: We provide the most comprehensive phylogenetic tree for Zygophyllaceae so far based on four plastid and nuclear markers. Detailed analyses indicate that Zygophyllaceae colonized Africa, Asia, Australia, and the New World at different periods, sometimes multiple times, but Zygophyllaceae lineages in the four regions all experienced a rapid accumulation beginning at the mid-late Miocene (~ 15-10 Ma). Other eleven essential elements of dryland floras become differentiated at the same time. CONCLUSIONS: Our results suggest that the rise of global dryland floras is near-synchronous and began at the mid-late Miocene, possibly resulting from the mid-Miocene global cooling and regional orogenetic and climate changes. The mid-late Miocene is an essential period for the assembly and evolution of global dryland floras.

Evidence of the Role of R-Spondin 1 and Its Receptor Lgr4 in the Transmission of Mechanical Stimuli to Biological Signals for Bone Formation.

The bone can adjust its mass and architecture to mechanical stimuli via a series of molecular cascades, which have been not yet fully elucidated. Emerging evidence indicated that R-spondins (Rspos), a family of secreted agonists of the Wnt/ß-catenin signaling pathway, had important roles in osteoblastic differentiation and bone formation. However, the role of Rspo proteins in mechanical loading-influenced bone metabolism has never been investigated. In this study, we found that Rspo1 was a mechanosensitive protein for bone formation. Continuous cyclic mechanical stretch (CMS) upregulated the expression of Rspo1 in mouse bone marrow mesenchymal stem cells (BMSCs), while the expression of Rspo1 in BMSCs in vivo was downregulated in the bones of a mechanical unloading mouse model (tail suspension (TS)). On the other hand, Rspo1 could promote osteogenesis of BMSCs under CMS through activating the Wnt/ß-catenin signaling pathway and could rescue the bone loss induced by mechanical unloading in the TS mice. Specifically, our results suggested that Rspo1 and its receptor of leucine-rich repeat containing G-protein-coupled receptor 4 (Lgr4) should be a novel molecular signal in the transmission of mechanical stimuli to biological signal in the bone, and this signal should be in the upstream of Wnt/ß-catenin signaling for bone formation. Rspo1/Lgr4 could be a new potential target for the prevention and treatment of disuse osteoporosis in the future.

Significance of hypoxia in the physiological function of intervertebral disc cells.

The intervertebral disc (IVD) is the largest avascular structure in the body, and IVD cells reside in vivo in an environment that is considered to be hypoxic. However, the role of oxygen in IVD cell biology remains an issue of debate. By reviewing the available literature about the effect of oxygen tension on regulating the phenotype, energy metabolism, matrix production, and survival of IVD cells, as well as on the expression and function of hypoxia-inducible factor in IVD cells, we conclude that hypoxia is essential in maintaining the physiological function of IVD cells. Modulating the oxygen tension of the IVD or the activity of hypoxia-inducible factor in IVD cells may be a promising strategy for the prevention and treatment of IVD degeneration.

The responses of autophagy and apoptosis to oxidative stress in nucleus pulposus cells: implications for disc degeneration.

BACKGROUND/AIMS: Apoptosis and autophagy are two patterns of programmed cell death which play important roles in the intervertebral disc degeneration. Oxidative stress is an important factor for the induction of programmed cell death. However, the cellular reactions linking autophagy to apoptosis of disc cells under oxidative stress have never been described. This study investigated the responses of autophagy and apoptosis and their interactions in the nucleus pulposus cells (NP cells) under oxidative stress, with the aim to better understand the mechanism of disc degeneration. METHODS: NP cells isolated from rat lumbar discs were subjected to different concentrations of H2O2 for various time periods. Cell viability was determined by CCK-8 assay, and their apoptosis and autophagy responses were evaluated by fluorescent analysis, flow cytometry and western blotting, et al. The interactions of autophagy and apoptosis and the possible signaling pathways were also investigated by using autophagy modulators. RESULTS: H2O2 increased the lysosomal membrane permeability in the NP cells and induced apoptosis through the mitochondrial pathway subsequently. Meanwhile, H2O2 stimulated an early autophagy response through the ERK/m-TOR signaling pathway. Autophagy inhibition significantly decreased the apoptosis incidence in the cells insulted by H2O2. CONCLUSION: These results suggested that controlling the autophagy response in the NP cells under oxidative stress should be beneficial for the survival of the cells and probably delay the process of disc degeneration.

Decreased activity of osteocyte autophagy with aging may contribute to the bone loss in senile population.

Age-related bone loss is a major cause of osteoporosis and osteoporotic fractures in the elderly. However, the underlying molecular mechanism of age-related bone loss is still poorly understood. The aim of this study was to clarify whether autophagy in osteocytes was involved in age-related bone loss. Male Sprague-Dawley (SD) rats in 3, 9, and 24 month old were used to mimic the age-related bone loss in men. Micro-CT evaluation, histomorphometric analysis, and measurement of bone turnover rate verified age-related bone loss in the male SD rats. Immunofluorescent histochemistry, RT-PCR, and Western blot assessment demonstrated that the expression of LC3-II, LC3-II/I, Beclin-1, and Ulk-1 in the osteocytes decreased with age, while SQSTM1/p62 and apoptosis in the osteocytes increased. A significant correlation between the markers of osteocyte autophagy and bone mineral density in the proximal tibia was revealed. However, osteocyte autophagy was not correlated with osteocyte apoptosis in the process of aging. These results suggested that osteocyte autophagy was possibly involved in the age-related bone loss. Decreased activity of osteocyte autophagy independent of apoptosis might contribute to the age-related bone loss in senile osteoporosis.

The effect of transforming growth factor ß1 on the crosstalk between autophagy and apoptosis in the annulus fibrosus cells under serum deprivation.

Autophagy and apoptosis are important in maintaining the metabolic homeostasis of intervertebral disc cells, and transforming growth factor-ß1 (TGF-ß1) is able to delay intervertebral disc degeneration. This study determined the effect of TGF-ß1 on the crosstalk between autophagy and apoptosis in the disc cells, with the aim to provide molecular mechanism support for the prevention and treatment of disc degeneration. Annulus fibrosus (AF) cells were isolated and cultured under serum starvation. 10 ng/mL TGF-ß1 reduced the apoptosis incidence in the cells under serum starvation for 48 h, down-regulated the autophagy incidence in the cells pretreated with 3-methyladenine (3-MA) or Bafilomycin A (Baf A), partly rescued the increased apoptosis incidence in the cells pretreated with 3-MA, while further reduced the decreased apoptosis incidence in the cells pretreated with Baf A. Meanwhile, TGF-ß1 down-regulated the expressions of autophagic and apoptotic markers in the cells under starvation, partly down-regulated the expressions of Beclin-1, LC3 II/I and cleaved caspase-3 in the cells pretreated with 3-MA or Baf A, while significantly decreased the expression of Bax/Bcl-2 in the cells pretreated with Baf A. 3-MA blocked the phosphorylation of both AKT and mTOR and partly reduced the inhibitory effect of TGF-ß1 on the expression of LC3 II/I and cleaved caspase-3. TGF-ß1 enhanced the expression of p-ERK1/2 and down-regulated the expressions of LC3 II/I and cleaved caspase-3. U0126 partly reversed this inhibitory effect of TGF-ß1. In conclusion, TGF-ß1 protected against apoptosis of AF cells under starvation through down-regulating excessive autophagy. PI3K-AKT-mTOR and MAPK-ERK1/2 were the possible signaling pathways involved in this process.

Intraobserver and interobserver reliability of measures of cervical sagittal rotation.

BACKGROUND: Diagnosis and treatment decisions of cervical instability are made, in part, based on the clinician's assessment of sagittal rotation on flexion and extension radiographs. The objective of this study is to evaluate the intraobserver and interobserver reliability of three measurement techniques in assessing cervical sagittal rotation. METHODS: Fifty lateral radiographs of patients with single-level cervical degenerative disc were selected and measured on two separate occasions by three spine surgeons using three different measurement techniques. Cervical sagittal rotation was measured using three different techniques. RESULTS: Intraclass correlation coefficients were most consistent for Method 2 (ICC 0.93-0.96) followed by Method 1 (ICC 0.88-0.91) and Method 3 (ICC 0.81-0.87). Intraobserver agreement (% of repeated measures within 0.5° of the original measurement) ranged between 76% and 96% for all techniques, with Method 2 showing the best agreement (92%-96%). Paired comparisons between observers varied considerably with interobserver reliability correlation coefficients ranging from 0.54 to 0.89. Method 2 showed the highest interobserver reliability coefficient (0.82, range 0.73-0.88). Method 2 was also more reliable for the classification of "instability". Intraobserver percent agreements ranged from 94 to 98% for Method 2 versus 84% to 90% for Method 1 and 78% to 86% for Method 3, while interobserver percent agreements ranged from 90% to 98% for Method 2 versus 86% to 94% for Method 1 and 74% to 84% for Method 3. CONCLUSIONS: Method 2 (measuring the angle from the inferior endplate of the vertebra above the degenerative disc and the inferior endplate of the vertebra below the degenerative disc) showed the best intraobserver and interobserver reliability overall in assessing cervical sagittal rotation.