SP1/CTR1-mediated oxidative stress-induced cuproptosis in intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is an age-related disease and is responsible for low back pain. Oxidative stress-induced cell death plays a fundamental role in IDD pathogenesis. Cuproptosis is a recently discovered form of programmed cell death dependent on copper availability. Whether cuproptosis is involved in IDD progression remains unknown. Herein, we established in vitro and in vivo models to investigate cuproptosis in IDD and the mechanisms by which oxidative stress interacts with copper sensitivity in nucleus pulposus cells (NPCs). We found that ferredoxin-1 (FDX1) content increased in both rat and human degenerated discs. Sublethal oxidative stress on NPCs led to increased FDX1 expression, tricarboxylic acid (TCA) cycle-related proteins lipoylation and aggregation, and cell death in the presence of Cu2+ at physiological concentrations, while FDX1 knockdown inhibited cell death. Since copper homeostasis is involved in copper-induced cytotoxicity, we investigated the role of copper transport-related proteins, including importer (CTR1) and efflux pumps (ATPase transporter, ATP7A, and ATP7B). CTR1 and ATP7A content increased under oxidative stress, and blocking CTR1 reduced oxidative stress/copper-induced TCA-related protein aggregation and cell death. Moreover, oxidative stress promoted the expression of specific protein 1 (SP1) and SP1-mediated CTR1 transcription. SP1 inhibition decreased cell death rates, preserved disc hydration, and alleviated tissue degeneration. This suggests that oxidative stress upregulates FDX1 expression and copper flux through promoting SP1-mediated CTR1 transcription, leading to increased TCA cycle-related protein aggregation and cuproptosis. This study highlights the importance of cuproptosis in IDD progression and provides a promising therapeutic target for IDD treatment.

Enzymatically Bioactive Nucleus Pulposus Matrix Hydrogel Microspheres for Exogenous Stem Cells Therapy and Endogenous Repair Strategy to Achieve Disc Regeneration

Exogenous stem cell therapy and endogenous repair has shown great potential in intervertebral disc regeneration. However, limited nutrients and accumulation of lactate largely impair the survival and regenerative capacity of implanted stem cells and endogenous nucleus pulposus cells (NPCs). Herein, an injectable hydrogel microsphere (LMGDNPs) have been developed by immersing lactate oxidase (LOX)-manganese dioxide (MnO2 ) nanozyme (LM) into glucose-enriched decellularized nucleus pulposus hydrogel microspheres (GDNPs) through a microfluidic system. LMGDNPs showed a delayed release profile of LOX and satisfactory enzymatic capacity in consuming lactate. Mesenchymal stem cells (MSCs) plated on LMGDNPs exhibited better cell viability than cells on GelMA and decellularized nucleus pulposus microspheres (DNP) and showed a obviously increased NPCs phenotype. LMGDNPs prevented MSCs and NPCs death and promoted extracellular matrix synthesis by exhausting lactate. It is determined that LMGDNPs promoted NPCs autophagy by activating transforming growth factor β2 overlapping transcript 1 (TGFB2-OT1), relying on the nanozyme. MSCs-loaded LMGDNPs largely preserved disc hydration and alleviated matrix degradation in vivo. Summarily, LMGDNPs promoted cell survival and matrix regeneration by providing a nutrient supply, exhausting lactate, and activating autophagy via TGFB2-OT1 and its downstream pathway and may serve as an ideal delivery system for exogenous stem cell therapy and endogenous repair.

Nucleus pulposus cells regulate macrophages in degenerated intervertebral discs via the integrated stress response-mediated CCL2/7-CCR2 signaling pathway

Lower back pain (LBP), which is a primary cause of disability, is largely attributed to intervertebral disc degeneration (IDD). Macrophages (MΦs) in degenerated intervertebral discs (IVDs) form a chronic inflammatory microenvironment, but how MΦs are recruited to degenerative segments and transform into a proinflammatory phenotype remains unclear. We evaluated chemokine expression in degenerated nucleus pulposus cells (NPCs) to clarify the role of NPCs in the establishment of an inflammatory microenvironment in IDD and explored the mechanisms. We found that the production of C-C motif chemokine ligand 2 (CCL2) and C-C motif chemokine ligand 7 (CCL7) was significantly increased in NPCs under inflammatory conditions, and blocking CCL2/7 and their receptor, C-C chemokine receptor type 2(CCR2), inhibited the inductive effects of NPCs on MΦ infiltration and proinflammatory polarization. Moreover, activation of the integrated stress response (ISR) was obvious in IDD, and ISR inhibition reduced the production of CCL2/7 in NPCs. Further investigation revealed that activating Transcription Factor 3 (ATF3) responded to ISR activation, and ChIP-qPCR verified the DNA-binding activity of ATF3 on CCL2/7 promoters. In addition, we found that Toll-like receptor 4 (TLR4) inhibition modulated ISR activation, and TLR4 regulated the accumulation of mitochondrial reactive oxygen species (mtROS) and double-stranded RNA (dsRNA). Downregulating the level of mtROS reduced the amount of dsRNA and ISR activation. Deactivating the ISR or blocking CCL2/7 release alleviated inflammation and the progression of IDD in vivo. Moreover, MΦ infiltration and IDD were inhibited in CCR2-knockout mice. In conclusion, this study highlights the critical role of TLR4/mtROS/dsRNA axis-mediated ISR activation in the production of CCL2/7 and the progression of IDD, which provides promising therapeutic strategies for discogenic LBP.

An Engineered Bionic Nanoparticle Sponge as a Cytokine Trap and Reactive Oxygen Species Scavenger to Relieve Disc Degeneration and Discogenic Pain

The progressive worsening of disc degeneration and related nonspecific back pain are prominent clinical issues that cause a tremendous economic burden. Activation of reactive oxygen species (ROS) related inflammation is a primary pathophysiologic change in degenerative disc lesions. This pathological state is associated with M1 macrophages, apoptosis of nucleus pulposus cells (NPC), and the ingrowth of pain-related sensory nerves. To address the pathological issues of disc degeneration and discogenic pain, we developed MnO2@TMNP, a nanomaterial that encapsulated MnO2 nanoparticles with a TrkA-overexpressed macrophage cell membrane (TMNP). Consequently, this engineered nanomaterial showed high efficiency in binding various inflammatory factors and nerve growth factors, which inhibited inflammation-induced NPC apoptosis, matrix degradation, and nerve ingrowth. Furthermore, the macrophage cell membrane provided specific targeting to macrophages for the delivery of MnO2 nanoparticles. MnO2 nanoparticles in macrophages effectively scavenged intracellular ROS and prevented M1 polarization. Supportively, we found that MnO2@TMNP prevented disc inflammation and promoted matrix regeneration, leading to downregulated disc degenerative grades in the rat injured disc model. Both mechanical and thermal hyperalgesia were alleviated by MnO2@TMNP, which was attributed to the reduced calcitonin gene-related peptide (CGRP) and substance P expression in the dorsal root ganglion and the downregulated Glial Fibrillary Acidic Protein (GFAP) and Fos Proto-Oncogene (c-FOS) signaling in the spinal cord. We confirmed that the MnO2@TMNP nanomaterial alleviated the inflammatory immune microenvironment of intervertebral discs and the progression of disc degeneration, resulting in relieved discogenic pain.

Integrative taxonomy and phylogenetic relationships between representatives of genera within Merliniinae (Nematoda: Merliniidae), with new data on fourteen known and one unknown species

The application of integrative taxonomic approaches is useful to species delineation based on a combination of distinct types of characters, here morphological features and ribosomal DNA sequences. In this study, we surveyed ectoparasitic nematodes of the subfamily Merliniinae in cultivated and natural environments in Iran. Results of morphological and morphometrical studies, light and scanning electron microscopic observations, and molecular analyses allowed us the identification of fourteen known and one unknown species including representatives of the genera Amplimerlinius (five species), Geocenamus (one species), Merlinius (three species), Nagelus (two species), Paramerlinius (one species), Scutylenchus (two species), and Telomerlinius (one species). The unknown species, Scutylenchus sp., characterized by having 35-50 incisures at mid-body; lateral field with 6 longitudinal incisures; lip region slightly offset by a constriction, flattened at front end; bearing 5-7 annuli; cephalic framework not refractive; stylet robust, 18.3-27 μm long; post anal intestinal sac absent; tail elongate conical, dorsally convex, with 24 (19-28) annuli in ventral side, ending to a smooth terminus and males common; spicules 24.5-31 μm long. The phylogenetic analyses were carried out using molecular data from nuclear ribosomal DNA (rDNA) genes viz. D2-D3 expansion segments of the large ribosomal subunit (28S rRNA), partial small ribosomal subunit (18S rRNA), and internal transcribed spacer (ITS). The molecular variability of D2-D3 expansion segments of the 28S rRNA and partial 18S rRNA was low in this family in comparison to the ITS region, which could be a more helpful molecular marker in species and genus identification.

Multifunctional annulus fibrosus matrix prevents disc-related pain via inhibiting neuroinflammation and sensitization

Chronic low back pain mainly attributed to intervertebral disc (IVD) degeneration. Endogenous damage-associated molecular patterns (DAMPs) in the injured IVD, particularly mitochondria-derived nucleic acid molecules (CpG DNA), play a primary role in the inflammatory responses in macrophages. M1-type macrophages form a chronic inflammatory microenvironment by releasing pro-inflammatory factors and nerve growth factor (NGF) that induce nerve growth into the inner annulus fibrosus, resulting in persistent hyperalgesia. We fabricated an amphiphilic polycarbonate that naturally forms cationic nanoparticles (cNP) in aqueous solutions, with the hydrophobic core loaded with TrkA-IN-1, an antagonist against the NGF receptor (TrkA). The drug delivery nanoparticles were denoted as TI-cNP. TrkA-IN-1 and TI-cNP were added to the decellularized annulus fibrosus matrix (DAF) hydrogel to form hybrid hydrogels, denoted as TI-DAF and TI-cNP-DAF, respectively. As a result, TrkA-IN-1 showed a delayed release profile both in TI-DAF and TI-cNP-DAF. Each mole of cNP could bind approximately 3 mol of CpG DNA to inhibit inflammation. cNP-DAF and TI-cNP-DAF significantly inhibited the M1 phenotype induced by CpG DNA. TI-DAF and TI-cNP-DAF reduced neurite branching and axon length, and inhibited the expression of neurogenic mediators (CGRP and substance P) in the presence of NGF. Besides, TI-cNP-DAF relieved mechanical hyperalgesia, reduced CGRP and substance P expression in the dorsal root ganglion, and downregulated GFAP and c-FOS signaling in the spinal cord in the rat disc herniation model. Summarily, TI-cNP-DAF, a novel composite IVD hydrogel, efficiently mediated the inflammatory environment, inhibited nerve ingrowth and sensitization, and could be clinically applied for treating discogenic pain. STATEMENT OF SIGNIFICANCE: Discogenic lower back pain, related to intervertebral disc degeneration (IDD), imposes a tremendous health and economic burden globally. M1-type macrophages release pro-inflammatory factors and nerve growth factor (NGF) that induce nerve growth into the inner annulus fibrosus, resulting in persistent hyperalgesia and discogenic pain. Reconstructing matrix integrity and modulating the inflammatory microenvironment are promising strategies for preventing the ingrowth and activation of neurites. The TI-cNP-DAF hydrogel recovers tissue integrity, alleviates inflammation, and delivers the TrkA antagonist to inhibit the activity of NGF, thus restraining hyperinnervation and nociceptive input. Due to its simple production process, injectability, and acellular strategy, the hydrogel is operable and holds great potential for treating discogenic lower back pain.

Extracellular Vesicle-Conjugated Functional Matrix Hydrogels Prevent Senescence by Exosomal miR-3594-5p-Targeted HIPK2/p53 Pathway for Disc Regeneration

Nucleus pulposus stem cells (NPSCs) senescence plays a critical role in the progression of intervertebral disc degeneration (IDD). Stem cell-derived extracellular vesicles (EV) alleviate cellular senescence. Whereas, the underlying mechanism remains unclear. Low stability largely limited the administration of EV in vivo. RGD, an arginine-glycine-aspartic acid tripeptide, strongly binds integrins expressed on the EV membranes, allowing RGD to anchor EV and prolong their bioavailability. An RGD-complexed nucleus pulposus matrix hydrogel (RGD-DNP) is developed to enhance the therapeutic effects of small EV (sEV). RGD-DNP prolonged sEV retention in vitro and ex vivo. sEV-RGD-DNP promoted NPSCs migration, decreased the number of SA-β-gal-positive cells, alleviated cell cycle arrest, and reduced p16, p21, and p53 activation. Small RNA-seq showed that miR-3594-5p is enriched in sEV, and targets the homeodomain-interacting protein kinase 2 (HIPK2)/p53 pathway. The HIPK2 knockdown rescues the impaired therapeutic effects of sEV with downregulated miR-3594-5p. RGD-DNP conjugate with lower amounts of sEV achieved similar disc regeneration with free sEV of higher concentrations in DNP. In conclusion, sEV-RGD-DNP increases sEV bioavailability and relieves NPSCs senescence by targeting the HIPK2/p53 pathway, thereby alleviating IDD. This work achieves better regenerative effects with fewer sEV and consolidates the theoretical basis for sEV application for IDD treatment.

Transcriptomics of Cruznema velatum (Nematoda: Rhabditidae) with a redescription of the species

Cruznema velatum isolated from soil in a chestnut orchard located at Guangdong province, China, is redescribed with morphology, molecular barcoding sequences, and transcriptome data. The morphological comparison for C. velatum and six other valid species is provided. Phylogeny analysis suggests genus Cruznema is monophyletic. The species is amphimix, can be cultured with Escherichia coli in 7-9 days from egg to egg-laying adult, and has a lifespan of 11 to 14 days at 20°C. The transcription data generated 45,366 unigenes; 29.9%, 31.3%, 24.8%, and 18.6% of unigenes were annotated in KOG, SwissProt, GO, and KEGG, respectively. Further gene function analysis demonstrated that C. velatum share the same riboflavin, lipoic acid, and vitamin B6 metabolic pathways with Caenorhabditis elegans and Pristionchus pacificus.

A predictive model with a risk-classification system for cancer-specific survival in patients with primary osteosarcoma of long bone

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Seven clinical factors were significantly related to the prognosis of patients with long bone osteosarcoma.

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The established nomogram can help surgeons evaluate the prognosis of osteosarcoma patients in the most common sites.

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High-risk individuals can be identified through risk-stratification system.

Background

Osteosarcoma (OS), most commonly occurring in long bone, is a group of malignant tumors with high incidence in adolescents. No individualized model has been developed to predict the prognosis of primary long bone osteosarcoma (PLBOS) and the current AJCC TNM staging system lacks accuracy in prognosis prediction. We aimed to develop a nomogram based on the clinicopathological factors affecting the prognosis of PLBOS patients to help clinicians predict the cancer-specific survival (CSS) of PLBOS patients.

Method

We studied 1199 PLBOS patients from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015 and randomly divided the dataset into training and validation cohorts at a proportion of 7:3. Independent prognostic factors determined by stepwise multivariate Cox analysis were included in the nomogram and risk-stratification system. C-index, calibration curve, and decision curve analysis (DCA) were used to verify the performance of the nomogram.

Results

Age, Histological type, Surgery of primary site, Tumor size, Local extension, Regional lymph node (LN) invasion, and Distant metastasis were identified as independent prognostic factors. C-indexes, calibration curves and DCAs of the nomogram indicating that the nomogram had good discrimination and validity. The risk-stratification system based on the nomogram showed significant differences (P < 0.05) in CSS among different risk groups.

Conclusion

We established a nomogram with risk-stratification system to predict CSS in PLBOS patients and demonstrated that the nomogram had good performance. This model can help clinicians evaluate prognoses, identify high-risk individuals, and give individualized treatment recommendation of PLBOS patients.

IGF Signaling in Intervertebral Disc Health and Disease

Low back pain (LBP) is a common musculoskeletal symptom, which brings a lot of pain and economic loss to patients. One of the most common causes of LBP is intervertebral disc degeneration (IVDD). However, pathogenesis is still debated, and therapeutic options are limited. Insulin-like growth factor (IGF) signaling pathways play an important role in regulating different cell processes, including proliferation, differentiation, migration, or cell death, which are critical to the homeostasis of tissues and organs. The IGF signaling is crucial in the occurrence and progression of IVDD. The activation of IGF signaling retards IVDD by increasing cell proliferation, promoting extracellular matrix (ECM) synthesis, inhibiting ECM decomposition, and preventing apoptosis and senescence of disc cells. However, abnormal activation of IGF signaling may promote the process of IVDD. IGF signaling is currently considered to have a promising treatment prospect for IVDD. An in-depth understanding of the role of IGF signaling in IVDD may help find a novel approach for IVDD treatment.

Endogenous repair theory enriches construction strategies for orthopaedic biomaterials: a narrative review

The development of tissue engineering has led to new strategies for mitigating clinical problems; however, the design of the tissue engineering materials remains a challenge. The limited sources and inadequate function, potential risk of microbial or pathogen contamination, and high cost of cell expansion impair the efficacy and limit the application of exogenous cells in tissue engineering. However, endogenous cells in native tissues have been reported to be capable of spontaneous repair of the damaged tissue. These cells exhibit remarkable plasticity, and thus can differentiate or be reprogrammed to alter their phenotype and function after stimulation. After a comprehensive review, we found that the plasticity of these cells plays a major role in establishing the cell source in the mechanism involved in tissue regeneration. Tissue engineering materials that focus on assisting and promoting the natural self-repair function of endogenous cells may break through the limitations of exogenous seed cells and further expand the applications of tissue engineering materials in tissue repair. This review discusses the effects of endogenous cells, especially stem cells, on injured tissue repairing, and highlights the potential utilisation of endogenous repair in orthopaedic biomaterial constructions for bone, cartilage, and intervertebral disc regeneration.

Glucagon-like peptide-1 receptor activation maintains extracellular matrix integrity by inhibiting the activity of mitogen-activated protein kinases and activator protein-1

Disruption of the intervertebral disc extracellular matrix (ECM) is a hallmark of intervertebral disc degeneration (IDD), which is largely attributed to excessive oxidative stress. However, there is a lack of clinically feasible approaches to promote the reconstruction of the disc ECM. Glucagon-like peptide-1 (GLP-1), a safe polypeptide hormone adopted to treat type 2 diabetes mellitus, has shown great potential for relieving oxidative stress-related damage. To our knowledge, this is the first study to reveal that exenatide, a GLP-1 receptor (GLP-1R) agonist, can upregulate disc ECM synthesis and attenuate oxidative stress-induced ECM degradation and IDD. Mechanistically, we found that exenatide inhibited the activation of mitogen-activated protein kinases (MAPK) signaling pathway and the formation of BATF/JUNs heterodimers (an index of activator protein-1 (AP-1) activity). The restoration of MAPK signaling activation reversed the protective effects of exenatide and enhanced downstream BATF/JUNs binding. BATF overexpression was also found to aggravate disc ECM damage, even in the presence of exenatide. In summary, exenatide is an effective agent that regulates ECM anabolic balance and restores disc degeneration by inhibiting MAPK activation and its downstream AP-1 activity. The present study provides a therapeutic rationale for activating the GLP-1 receptor against IDD and establishes the important role of AP-1 activity in the pathogenesis of IDD.

Corrigendum to 'Decellularized disc hydrogels for hBMSC tissue-specific differentiation and tissue regeneration' [Bioactive Materials 6 (2021) 3541-3556]

[This corrects the article DOI: 10.1016/j.bioactmat.2021.03.014.].

Proper animal experimental designs for preclinical research of biomaterials for intervertebral disc regeneration

Low back pain is a vital musculoskeletal disease that impairs life quality, leads to disability and imposes heavy economic burden on the society, while it is greatly attributed to intervertebral disc degeneration (IDD). However, the existing treatments, such as medicines, chiropractic adjustments and surgery, cannot achieve ideal disc regeneration. Therefore, advanced bioactive therapies are implemented, including stem cells delivery, bioreagents administration, and implantation of biomaterials etc. Among these researches, few reported unsatisfying regenerative outcomes. However, these advanced therapies have barely achieved successful clinical translation. The main reason for the inconsistency between satisfying preclinical results and poor clinical translation may largely rely on the animal models that cannot actually simulate the human disc degeneration. The inappropriate animal model also leads to difficulties in comparing the efficacies among biomaterials in different reaches. Therefore, animal models that better simulate the clinical charateristics of human IDD should be acknowledged. In addition, in vivo regenerative outcomes should be carefully evaluated to obtain robust results. Nevertheless, many researches neglect certain critical characteristics, such as adhesive properties for biomaterials blocking annulus fibrosus defects and hyperalgesia that is closely related to the clinical manifestations, e.g., low back pain. Herein, in this review, we summarized the animal models established for IDD, and highlighted the proper models and parameters that may result in acknowledged IDD models. Then, we discussed the existing biomaterials for disc regeneration and the characteristics that should be considered for regenerating different parts of discs. Finally, well-established assays and parameters for in vivo disc regeneration are explored.

Decellularized Disc Hydrogels for hBMSCs tissue-specific differentiation and tissue regeneration

Tissue specificity, a key factor in the decellularized tissue matrix (DTM), has shown bioactive functionalities in tuning cell fate-e.g., the differentiation of mesenchymal stem cells. Notably, cell fate is also determined by the living microenvironment, including material composition and spatial characteristics. Herein, two neighboring tissues within intervertebral discs, the nucleus pulposus (NP) and annulus fibrosus (AF), were carefully processed into DTM hydrogels (abbreviated DNP-G and DAF-G, respectively) to determine the tissue-specific effects on stem cell fate, such as specific components and different culturing methods, as well as in vivo regeneration. Distinct differences in their protein compositions were identified by proteomic analysis. Interestingly, the fate of human bone marrow mesenchymal stem cells (hBMSCs) also responds to both culturing methods and composition. Generally, hBMSCs cultured with DNP-G (3D) differentiated into NP-like cells, while hBMSCs cultured with DAF-G (2D) underwent AF-like differentiation, indicating a close correlation with the native microenvironments of NP and AF cells, respectively. Furthermore, we found that the integrin-mediated RhoA/LATS/YAP1 signaling pathway was activated in DAF-G (2D)-induced AF-specific differentiation. Additionally, the activation of YAP1 determined the tendency of NP- or AF-specific differentiation and played opposite regulatory effects. Finally, DNP-G and DAF-G specifically promoted tissue regeneration in NP degeneration and AF defect rat models, respectively. In conclusion, DNP-G and DAF-G can specifically determine the fate of stem cells through the integrin-mediated RhoA/LATS/YAP1 signaling pathway, and this tissue specificity is both compositional and spatial, supporting the utilization of tissue-specific DTM in advanced treatments of intervertebral disc degeneration.

Reactive Oxygen Species Regulate Endoplasmic Reticulum Stress and ER-Mitochondrial Ca2+ Crosstalk to Promote Programmed Necrosis of Rat Nucleus Pulposus Cells under Compression

Programmed necrosis of nucleus pulposus (NP) cells caused by excessive compression is a crucial factor in the etiopathogenesis of intervertebral disc degeneration (IVDD). The endoplasmic reticulum (ER) and mitochondria are crucial regulators of the cell death signaling pathway, and their involvement in IVDD has been reported. However, the specific role of ER stress (ERS) and ER-mitochondria interaction in compression-induced programmed necrosis of NP cells remains unknown. Our studies revealed that compression enhanced ERS and the association between ER and mitochondria in NP cells. Suppression of ERS via 4-phenylbutyrate (4-PBA) or ER-mitochondrial Ca2+ crosstalk by inhibiting the inositol 1,4,5-trisphosphate receptor, glucose-regulated protein 75, voltage-dependent anion-selective channel 1 complex (IP3R-GRP75-VDAC1 complex) protected NP cells against programmed necrosis related to the poly(ADP-ribose) polymerase (PARP) apoptosis-inducing factor (AIF) pathway. Moreover, excessive reactive oxygen species are critical activators of ERS, leading to mitochondrial Ca2+ accumulation and consequent programmed necrosis. These data indicate that ERS and ER-mitochondrial Ca2+ crosstalk may be potential therapeutic targets for the treatment of IVDD-associated disorders. These findings provide new insights into the molecular mechanisms underlying IVDD and may provide novel therapeutic targets.

Resveratrol-enhanced SIRT1-mediated osteogenesis in porous endplates attenuates low back pain and anxiety behaviors

Low back pain (LBP) is a major clinical problem that lacks effective treatments. The sensory innervation in porous vertebral endplates and anxiety contributes to spinal hyperalgesia. We hypothesized that SIRT1 activator resveratrol alleviates LBP and anxiety via promotion of osteogenesis in the porous endplates. The hyperalgesia and anxiety-related behaviors; sensory innervation, inflammation and porosity of endplates; and osteogenic/osteoclastic factors expression were measured following resveratrol treatment after lumbar spine instability (LSI) surgery. To explore whether resveratrol promotes endplates osteogenesis and thus alleviates LBP through activation of SIRT1 in the osteoprogenitor cells of endplates, SIRT1OSX-/- mice were employed. Additionally, the levels of inflammation markers, phosphorylation of cAMP response element-binding protein (pCREB), and brain-derived neurotrophic factor (BDNF) in hippocampus were evaluated. After 4 or 8 weeks LSI surgery, the mice suffered from hyperalgesia and anxiety, which were efficiently attenuated by resveratrol at 8 weeks. Resveratrol treatment-enhanced osteogenesis and decreased endplates porosities accompanied with the reduction of TNFα, IL-1β, and COX2 levels and CGRP+ nerve fibers innervation in porous endplates. Resveratrol-mediated endplates osteogenesis, decreased endplates porosities, and analgesic and antianxiety effects were abrogated in SIRT1OSX-/- mice. Furthermore, resveratrol relieved inflammation and increased pCREB and BDNF expression in the hippocampus after 8 weeks, which alleviate anxiety-related behaviors. This study provides that resveratrol-mediated porous endplates osteogenesis via the activation of SIRT1 markedly blocked sensory innervation and inflammation in endplates, therefore, alleviating LSI surgery-induced LBP and hippocampus-related anxiety.

[Effect of endoscopic vidian neurectomy in patients with coexisting allergic rhinitis and bronchial asthma]

Objective: To evaluate the clinical significance of endoscopic vidian neurectomy (EVN) on outcomes in patients with coexisting refractory allergic rhinitis (AR) and bronchial asthma, and to analyze its influence factor. Methods: Clinical data of 109 patients with moderate to severe persistent intractable AR and bronchial asthma who were allocated to the bilateral EVN group (surgery group, 70 cases) or conservative medication group (drug group, 39 cases) from 1 May 2008 to 30 April 2013 in Department of Otorhinolaryngology Head and Neck Surgery, Third Xiangya Hospital, Central South University were retrospectively analyzed, including 47 cases of male and 62 cases of female aged (32.7±6.8) years.Ninety-five patients were followed up for at least 3 years. The Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), Visual Analog Scale (VAS), Asthma Quality of Life Questionnaire (AQLQ), Total Asthma Symptom Score (TASS), forced expiratory volume in 1 second of predicted (FEV1) and medication scores were evaluated at 6 months, 1 year and 3 years after undergoing the initial treatments in the two groups. Multiple factor analysis was used to determine the factors influencing the improvement after EVN. Results: Postoperative scores of RQLQ were significantly lower than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 2.39±0.61 (x±s), 0.81±0.43, 0.89±0.32, 1.06±0.24, respectively, all P<0.001). Postoperative scores of VAS were significantly lower than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year,3 years after operation was 7.13±1.04, 2.52±1.47, 2.70±1.42, 2.85±1.64, respectively, all P<0.05). Scores of RQLQ and VAS in surgery group were significantly lower than those of drug group. Postoperative scores of AQLQ were significantly higher than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 3.78±0.81, 4.99±0.45, 4.75±0.71, 4.62±0.64, respectively, all P<0.05), and were significantly higher than those of drug group. The TASS and FEV1 were not significantly changed in surgery group. The postoperative medication scores for AR were gradually reduced after surgery (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 0.99±0.21, 0.37±0.12, 0.39±0.26, 0.45±0.11, respectively, all P<0.05), and the postoperative medication scores for Asthma were gradually reduced after surgery too (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 1.27±0.31, 0.82±0.29, 0.85±0.23, 0.96±0.19, respectively, all P<0.05), and all the postoperative medication scores were significantly lower than those of drug group. At the end of the follow-up, the improvement rates for AR and asthma were 90.6% (58/64) and 45.3% (29/64), respectively. Asthma outcomes were significantly improved by controlling rhinitis symptoms in patients whose asthma attacks were induced by "rhinitis onset" or "climate change" . Conclusion: For patients with AR and bronchial asthma, EVN can significantly control AR symptoms, and improve asthma outcomes in patients whose asthma attacks are induced by rhinitis onset and/or climate change.

Delivery of MutT homolog 1 inhibitor by functionalized graphene oxide nanoparticles for enhanced chemo-photodynamic therapy triggers cell death in osteosarcoma

Photodynamic therapy (PDT) generates highly toxic reactive oxygen species (ROS) during noninvasive cancer treatment. MutT homolog 1 (MTH1) protein is a DNA oxidative damage repair protease and suppressing its function may provide a strategy to enhance PDT efficacy by improving cellular sensitivity to ROS. A nanoparticle, composed of functional graphene oxide (GO) conjugated with polyethylene glycol (PEG), folic acid (FA) and photosensitizer indocyanine green (ICG), was constructed to deliver MTH1 inhibitor (TH287) and doxorubicin. The effects of this nanoparticle on biological properties and cell death of osteosarcoma cells were investigated. We further examined the endoplasmic reticulum (ER) stress and apoptosis in osteosarcoma. A xenograft tumor model was used to validate the results in vivo. This drug-carrying PEG-GO-FA/ICG nanoparticle showed combined chemo-photodynamic therapy (Chemo-PDT) to inhibit the proliferation and migration of osteosarcoma cells. Enhanced Chemo-PDT promoted both apoptosis and autophagy by suppressing the MTH1 protein and promoting the accumulation of ROS. In this study, autophagy served as a rescue pathway against cell death, and suppressing autophagy enhanced the anti-cancer effects of Chemo-PDT. However, Chemo-PDT induced apoptosis was related to the occurrence of ER stress. ROS might contribute to ER stress and further induce apoptosis via the JNK/p53/p21 pathway. These findings provide a mechanistic understanding of nanoparticle-induced cell death in osteosarcoma. The combination of Chemo-PDT with other therapies is promising as a new strategy to treat osteosarcoma. STATEMENT OF SIGNIFICANCE: Administration of chemotherapeutic drugs by traditional methods still has many problems. We designed a functionalized graphene oxide drug delivery system to deliver the photosensitizer indocyanine green, doxorubicin, and MTH1 inhibitor TH287. This nano delivery system showed combined chemo-photodynamic effects to inhibit osteosarcoma. Suppressing MTH1 protein might induce "phenotypic lethality" and enhance chemo-photodynamic therapy efficacy by improving cellular sensitivity to reactive oxygen species.

Surface engineering of nanoparticles with ligands for targeted delivery to osteosarcoma

Osteosarcoma is one of the most common malignant bone tumors which affect adolescents. Neoadjuvant chemotherapy followed by operation has become recommended for osteosarcoma treatment. Whereas, the effects of conventional chemotherapy are unsatisfactory because of multidrug resistance, fast clearance rate, nontargeted delivery, side effects and so on. Accordingly, Nanoparticle-mediated targeted drug delivery system (NTDDS) is recommended to be a novel treatment strategy for osteosarcoma. NTDDS can overcome the above obstacles by enhanced permeability and retention effect and active targeting. The active targeting of the delivery system is mainly based on ligands. In this study, we investigate and summarize the most common ligands used in the latest NTDDS for osteosarcoma. It might provide new insights into nanomedicine for osteosarcoma treatment.

Genipin-crosslinked decellularized annulus fibrosus hydrogels induces tissue-specific differentiation of bone mesenchymal stem cells and intervertebral disc regeneration

Biomaterial-based therapy that can restore annulus fibrosus (AF) function in early stage and promote endogenous repair of AF tissues is a promising approach for AF tissue repair. In this study, we established a genipin-crosslinked decellularized AF hydrogels (g-DAF-G) that are injectable and could manifest better in situ formability than noncrosslinked decellularized AF hydrogel, while preserving the capacity of directing differentiation of human bone mesenchymal stem cells (hBMSCs) towards AF cells. Hematoxylin and eosin staining, 4',6-diamidino-2-phenylindole staining, and so forth showed that the majority of cellular components were removed, whereas extracellular matrix and microstructure were largely preserved. The storage modulus increased from 465.5 ± 9.4 Pa to 3.29 ± 0.24 MPa after 0.02% genipin crosslinking of decellularized AF hydrogels (DAF-G) to form g-DAF-G. AF-specific genes (COL1A1, COL5A1, TNMD, IBSP, FBLN1) were significantly higher in DAF-G and g-DAF-G groups than that in control group after 21 days of culturing. g-DAF-G significantly restored nucleus pulposus water content and preserved intervertebral structure in vivo. Summarily, we produced a novel AF regeneration biomaterial, g-DAF-G, which exhibited well biocompatibility, great bioactivity, and much higher mechanical strength than DAF-G. This study will provide an easy and fast therapeutic alternative to repair AF injuries or tears.

Biomaterials-Induced Stem Cells Specific Differentiation Into Intervertebral Disc Lineage Cells

Stem cell therapy, which promotes stem cells differentiation toward specialized cell types, increases the resident population and production of extracellular matrix, and can be used to achieve intervertebral disc (IVD) repair, has drawn great attention for the development of IVD-regenerating materials. Many materials that have been reported in IVD repair have the ability to promote stem cells differentiation. However, due to the limitations of mechanical properties, immunogenicity and uncontrollable deviations in the induction of stem cells differentiation, there are few materials that can currently be translated into clinical applications. In addition to the favorable mechanical properties and biocompatibility of IVD materials, maintaining stem cells activity in the local niche and increasing the ability of stem cells to differentiate into nucleus pulposus (NP) and annulus fibrosus (AF) cells are the basis for promoting the application of IVD-regenerating materials in clinical practice. The purpose of this review is to summarize IVD-regenerating materials that focus on stem cells strategies, analyze the properties of these materials that affect the differentiation of stem cells into IVD-like cells, and then present the limitations of currently used disc materials in the field of stem cell therapy and future research perspectives.

Ultrafast Low-Temperature Photothermal Therapy Activates Autophagy and Recovers Immunity for Efficient Antitumor Treatment

Conventional therapeutic approaches to treat malignant tumors such as surgery, chemotherapy, or radiotherapy often lead to poor therapeutic results, great pain, economic burden, and risk of recurrence and may even increase the difficulty in treating the patient. Long-term drug administration and systemic drug delivery for cancer chemotherapy would be accompanied by drug resistance or unpredictable side effects. Thus, the use of photothermal therapy, a relatively rapid tumor elimination technique that regulates autophagy and exerts an antitumor effect, represents a novel solution to these problems. Heat shock protein 90 (HSP90), a protein that reduces photothermal or hypothermic efficacy, is closely related to AKT (protein kinase B) and autophagy. Therefore, it was hypothesized that autophagy could be controlled to eliminate tumors by combining exogenous light with a selective HSP90 inhibitor, for example, SNX-2112. In this study, an efficient tumor-killing strategy using graphene oxide loaded with SNX-2112 and folic acid for ultrafast low-temperature photothermal therapy (LTPTT) is reported. A unique mechanism that achieves remarkable therapeutic performance was discovered, where overactivated autophagy induced by ultrafast LTPTT led to direct apoptosis of tumors and enabled functional recovery of T cells to promote natural immunity for actively participating in the attack against tumors. This LTPTT approach resulted in residual tumor cells being rendered in an "injured" state, opening up the possibility of concurrent antitumor and antirecurrence treatment.

Prognostic significance of 8-hydroxy-2'-deoxyguanosine in solid tumors: a meta-analysis

Background

High level of reactive oxygen species (ROS) has been detected in almost all cancers, which make it become one of the best-characterized phenotypes in cancers. Though ROS plays an important role in tumors, the degree of oxidative stress can be better evaluated by assessing stable metabolites of oxidative reactions because of its high instability. 8-hydroxy-2′-deoxyguanosine (8-OHdG), a product of oxidative damage to 2′-deoxyguanosine, is known as a useful marker for assessing oxidative DNA damage and has been a feature of carcinogenesis in several researches. But the exact prognostic value of 8-OHdG expression in patients with cancer is still unclear.

Methods

A comprehensive search was performed in PubMed, Web of Science, EMBASE. Eligible studies were included based on defined exclusion and inclusion criteria to perform a meta-analysis. STATA 14.0 was used to estimate pooled hazard ratios (HRs) with 95% confidence interval (95% CI), the heterogeneity among studies and publication bias to judge the prognostic value.

Results

A total of 2121 patients from 21 eligible studies were included in the meta-analysis. A significant association was found between elevated 8-OHdG expression and poor OS (overall survival) in cancer patients (pooled HR 1.921, 95% CI: 1.437–2.570); In the subgroup analysis, race of sample, cancer types, detection method of 8-OHdG, sample classification, detection location of 8-OHdG and paper quality (score more or less than 7) did not alter the association between 8-OHdG expression and cancer prognosis. Furthermore, 8-OHdG expression was an independent prognostic marker for overall survival in patients with cancer (pooled HR 2.110, 95% CI: 1.482–3.005) using Cox multivariate analyses.

Conclusions

This meta-analysis found that highly expressed 8-OHdG in tumor tissues may be a predictor of prognosis in most solid tumors. However, especially in breast cancer, low 8-OHdG expression is associated with poor prognosis, which is partly because of the increased antioxidant mechanisms in breast cancer tissues. This study demonstrates for the first time that 8-OHdG expression is associated with the prognosis of cancer patients. In the future, whether the expression level of 8-OHdG can be used as a biomarker for the prognosis of all human cancers requires more research.

Bruceine D inhibits tumor growth and stem cell-like traits of osteosarcoma through inhibition of STAT3 signaling pathway

Patients with osteosarcoma exhibiting resistance to chemotherapy or presenting with metastasis usually have a poor prognosis. Osteosarcoma stem cells (OSCs) are a potential cause of tumor metastasis, relapse, and chemotherapy resistance. Therefore, it is necessary to develop novel therapeutic drugs, which not only kill osteosarcoma cells but also target OSCs. This study aims to explore the anti‐osteosarcoma effects of Bruceine D (BD), a natural compound derived from Brucea javanica, and investigate its underlying mechanisms. Results demonstrated that BD could significantly inhibit cell proliferation and migration, induce cell cycle arrest, and promote apoptosis in osteosarcoma cells. Besides, BD could also suppress the sphere‐forming and self‐renewal ability of OSCs. Mechanistically, the inhibitory role of BD on osteosarcoma cell growth and migration including OSC stemness was partially executed through the inhibition of STAT3 signaling pathway. More importantly, BD showed significant anti‐osteosarcoma activity without obvious side effects in vivo. Collectively, the results of this study demonstrated that BD exerts a strong inhibitory effect on tumor growth and stem cell like traits of osteosarcoma which may be partially due to STAT3 inhibition, suggesting that BD maybe a promising therapeutic candidate against osteosarcoma.

Dynasore suppresses cell proliferation, migration, and invasion and enhances the antitumor capacity of cisplatin via STAT3 pathway in osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor. The prognosis of metastatic and recurrent OS patients still remains unsatisfactory. Cisplatin reveals undeniable anti-tumor effect while induces severe side effects that threatening patients’ health. Dynasore, a cell-permeable small molecule that inhibits dynamin activity, has been widely studied in endocytosis and phagocytosis. However, the anti-tumor effect of dynasore on OS has not yet been ascertained. In the present study, we suggested that dynasore inhibited cell proliferation, migration, invasion, and induced G0/G1 arrest of OS cells. Besides, dynasore repressed tumorigenesis of OS in xenograft mouse model. In addition, we demonstrated that dynasore improved the anti-tumor effect of cisplatin in vitro and in vivo without inducing nephrotoxicity and hepatotoxicity. Mechanistically, dynasore repressed the expression of CCND1, CDK4, p-Rb, and MMP-2. Furthermore, we found that dynasore exerts anti-tumor effects in OS partially via inhibiting STAT3 signaling pathway but not ERK-MAPK, PI3K-Akt or SAPK/JNK pathways. P38 MAPK pathway served as a negative regulatory mechanism in dynasore induced anti-OS effects. Taken together, our study indicated that dynasore does suppress cell proliferation, migration, and invasion via STAT3 signaling pathway, and enhances the antitumor capacity of cisplatin in OS. Our results suggest that dynasore is a novel candidate drug to inhibit the tumor growth of OS and enhance the anti-tumor effects of cisplatin.

TIM-3 expression and its association with overall survival in primary osteosarcoma

T-cell immunoglobulin and mucin domain-containing-3 (TIM-3) performs a critical function in immune tolerance by suppressing the activation and proliferation of T cells. TIM-3 serves an important role in tumor progression in a number of carcinomas, including non-small cell lung cancer, hepatitis B virus-associated hepatocellular carcinoma, Langerhans cell sarcoma, head and neck cancer and follicular B cell non-Hodgkin lymphoma. The aim of the present study was to evaluate the possible association of TIM-3 with the prognosis of osteosarcoma. TIM-3 expression was assessed by immunohistochemical analysis in osteosarcoma tissues. The association between TIM-3 expression and prognosis was examined. To assess the association between TIM-3 expression levels and clinicopathological features, a Fisher's exact test was used. TIM-3 overexpression was indicated to be associated with surgical treatment and survival. Kaplan-Meier analysis indicated that TIM-3 is an independent predictor of overall survival, and its overexpression was indicated to be associated with poor prognosis in patients with osteosarcoma. Additionally, reverse transcription-quantitative polymerase chain reaction and western blot analysis were carried out to evaluate TIM-3 expression levels in fresh tumor tissue samples, adjacent-tissue samples, osteosarcoma cell lines, and in an osteoblastic cell line. TIM-3 was indicated to be overexpressed in fresh osteosarcoma tissue samples and in osteosarcoma cell lines. In conclusion, TIM-3 overexpression is associated with poor survival among patients with osteosarcoma and may be a possible therapeutic target in these types of tumors.

LncRNA AFAP1-AS1 promotes tumorigenesis and epithelial-mesenchymal transition of osteosarcoma through RhoC/ROCK1/p38MAPK/Twist1 signaling pathway

Background

An increasing number of studies have demonstrated that long non-coding RNAs (lncRNAs) play pivotal roles in cancer onset and development. LncRNA AFAP1-AS1 has been validated to be abnormally upregulated and play oncogenic roles in various malignant tumors. The biological role and mechanism of AFAP1-AS1 in OS (osteosarcoma) remains unclear.

Methods

Quantitative reverse transcription PCR (qRT-PCR) is applied to examine AFAP1-AS1 expression in OS tissues and OS cell lines. The function of AFAP1-AS1 in OS cells is investigated via in-vitro and in-vivo assays. Western bolt and rescue experiments are applied to detect the expression changes of key molecules including epithelial-mesenchymal transition markers and identify the underlying molecular mechanism. RNA immunoprecipitation is performed to reveal the interaction between AFAP1-AS1 and RhoC.

Results

AFAP1-AS1 expression is upregulated in human OS tissues and cell lines. AFAP1-AS1 knockdown induces OS cell apoptosis and cell cycle G0/G1 arrest, suppresses OS cells growth, migration, invasion, vasculogenic mimicry formation and epithelial-mesenchymal transition (EMT), and affects actin filament integrity. AFAP1-AS1 knockdown suppresses OS tumor formation and growth in nude mice. AFAP1-AS1 knockdown elicits a signaling inhibition including decreased levels of RhoC, ROCK1, p38MAPK and Twist1. Moreover, AFAP1-AS1 interacts with RhoC. Overexpression of RhoC can partly reverse AFAP1-AS1 downregulation-induced cell EMT inhibition.

Conclusions

AFAP1-AS1 is overexpressed in osteosarcoma and plays an oncogenic role in osteosarcoma through RhoC/ROCK1/p38MAPK/Twist1 signaling pathway, in which RhoC acts as the interaction target of AFAP1-AS1. Our findings indicated a novel molecular mechanism underlying the tumorigenesis and progression of osteosarcoma. AFAP1-AS1 could serve as a promising therapeutic target in OS treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1363-0) contains supplementary material, which is available to authorized users.

Investigation of MiR-92a as a Prognostic Indicator in Cancer Patients: a Meta-Analysis

Background: MiR-92a has been discovered to be involved in the malignant behavior of various types of cancers. However, the particular clinical and prognostic roles of miR-92a in tumors still need to be identified more precisely. The current meta-analysis assessed the prognostic value of miR-92a in various carcinomas.

Methods: Systematic literature searches of PubMed, PMC, Web of Science (WOS), Embase in English and Wanfang, SinoMed and the China National Knowledge Infrastructure (CNKI) in Chinese up to Jan 15^th 2019 were conducted for eligible studies. Twenty studies involving a total of 2573 patients were included in the analysis. Pooled hazard ratios (HR) for overall survival (OS) and disease-free survival (DFS), progression-free survival (PFS) and recurrence-free survival (RFS) were assessed using fixed-effects and random-effects models. Meta-regression and subgroup analyses were carried out to explore the source of heterogeneity. Odds ratio (OR) and 95%CIs were applied to evaluate the relationship between miR-92a expression levels and clinicopathological characteristics.

Results: A significant association between miR-92a levels and OS (HR=2.18) was identified. The random pooling model also revealed significance of consistency (HR=2.14), indicating that the stability of the results. Subgroup analyses were performed and the corresponding significance was recognized in Chinese cancer patients (HR=2.35), studies of specimen derived from tissues (HR=2.43), non-hematological cancer (HR=2.35), osteosarcoma (HR=2.54), non-small cell lung cancer (HR=2.33), hepatocellular carcinoma (HR=2.40) and so on. There were significant relations observed of the expression level of miR-92a to tumor size (≥5 vs <5 cm) (OR=2.13), lymph node metastasis (present vs. absent) (OR=1.87), distant metastasis (present vs. absent) (OR=2.99) and so on.

Conclusions: the over expression of miR-92a is associated with unfavorable prognosis of Chinese cancer patients. In addition, patients of elevated miR-92a expression level are likely to develop the cancers of more malignant behaviors.

The Physicochemical Properties of Graphene Nanocomposites Influence the Anticancer Effect

Graphene nanocomposite is an inorganic nanocomposite material, which has been widely used in the treatment of tumor at present due to its ability of drug loading, modifiability, photothermal effect, and photodynamic effect. However, the application of graphene nanocomposite is now limited due to the fact that the functions mentioned above are not well realized. This is mainly because people do not have a systematic understanding of the physical and chemical properties of GO nanomolecules, so that we cannot make full use of GO nanomolecules to make the most suitable materials for the use of medicine. Here, we are the first to discuss the influence of the physicochemical properties of graphene nanocomposite on the various functions related to their antitumor effects. The relationship between some important physicochemical properties of graphene nanocomposite such as diameter, shape, and surface chemistry and their functions related to antitumor effects was obtained through analysis, which provides evidence for the application of related materials in the future.

Dysregulated Expression of Circular RNAs Serve as Prognostic and Clinicopathological Markers in Cancer

Purpose: Circular RNAs (circRNAs) as prognostic biomarkers have spurred considerable interest in several types of tumors. In the present study, we aimed to elucidate the clinicopathological and prognostic values of circRNAs in human cancer.

Methods: We systematically searched PubMed Central (PMC), PubMed, Web of Science, EMBASE, Scopus, CBM and the Cochrane Library databases up to Nov 29, 2018. Eligible studies reporting on the association between circRNAs expression and clinicopathological and prognostic outcomes in cancer were incorporated. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess clinicopathological parameters, and hazard ratios (HRs) and 95% CIs to estimate overall survival (OS).

Results: Thirty-two studies involving 4529 patients were incorporated into our meta-analysis. Pooled results showed that high expression of oncogenic circRNAs was significantly associated with poor clinicopathological characteristics (tumor size: OR=1.29, 95%Cl: 1.10-1.51; TNM stage: OR=1.62, 95%Cl: 1.41-1.87; differentiation grade: OR=1.41, 95%Cl: 1.11-1.78; lymph node metastasis: OR=1.69; 95%Cl: 1.34-2.13; distant metastasis: OR=2.75; 95%Cl: 1.92-3.95) and a poor prognosis (OS: HR=2.75; 95%Cl: 2.34-3.15). Furthermore, we found that high expression of tumor-suppressor circRNAs was correlated with improved clinical characteristics (tumor size: OR=0.72; 95%Cl: 0.56-0.92; TNM stage: OR=0.77, 95%Cl: 0.68-0.88) and longer survival times (OS: HR=0.49; 95%Cl: 0.42-0.56). Subgroup analyses based on cancer types and circRNA types were also performed.

Conclusion: Our study indicates that circRNAs may serve as important biomarkers for clinicopathologic features and prognosis in human cancer.

Correction: Prognostic value of long non-coding RNA CCAT1 expression in patients with cancer: A meta-analysis

[This corrects the article DOI: 10.1371/journal.pone.0179346.].

Downregulation of DEPTOR inhibits the proliferation, migration, and survival of osteosarcoma through PI3K/Akt/mTOR pathway

Accumulating evidence reveals that DEP-domain containing mTOR-interacting protein (DEPTOR) plays pivotal roles in the pathogenesis and progression of many tumors. However, the expression level of DEPTOR and its function in the tumorigenesis of osteosarcoma (OS) remain unknown. In this study, we conducted quantitative real-time polymerase chain reaction, Western blot, and immunohistochemistry to detect DEPTOR expression level in human OS tissues and cell lines. To assess DEPTOR function, DEPTOR siRNA was designed and transfected into OS cells, which were then used in a series of in vitro assays. Our results indicated that DEPTOR was highly expressed in some OS tissues and cell lines. DEPTOR knockdown by siRNA dramatically inhibited cell proliferation, migration, invasion, and the formation of vasculogenic mimicry in OS cells. In addition, DEPTOR knockdown induced cell cycle arrest in the G0/G1 phase and apoptosis in the OS cell lines, MG63 and MNNG/HOS. Furthermore, we found that DEPTOR knockdown notably activated mTOR and inhibited the PI3K/Akt pathway. Taken together, these results suggest that DEPTOR overexpression is necessary for the proliferation, migration, invasion, formation of vasculogenic mimicry, and survival of OS cells and may be a potential target for the treatment of OS.

Prognostic value of long non-coding RNA CCAT1 expression in patients with cancer: A meta-analysis

Background

LncRNA CCAT1 is significantly overexpressed in various types of cancers, suggesting that it might be associated with prognosis and clinicopathological features in patients with cancer.

Methods

A comprehensive search was performed in Pubmed, Web of Science, OVID and CNKI databases. We also retrieved articles from other sources, such as retrieving from the reference lists of relevant articles. Eligible studies were included based on defined exclusion and inclusion criteria to perform a meta-analysis. STATA 14.0 was used to estimate pooled hazard ratios (HRs) with 95% confidence interval (95% CI), the heterogeneity among studies and publication bias to judge the prognostic value.

Results

A total of 1587 patients from 11 eligible studies were included in the meta-analysis. The results showed that high expression level of CCAT1 was significantly associated with shorter overall survival in cancer patients (HR 2.335, 95% CI:1.551–3.517); in the subgroup analysis, region (China or UK), sample size (more or less than 100), type of cancer (digestive or non-digestive disease) and paper quality (score more or less than 7) did not alter the association between CCAT1 expression and cancer prognosis but preoperative treatment did. And CCAT1 expression was an independent prognostic marker for overall survival in patients with cancer (pooled HR 2.195, 95%CI:1.316–3.664) using Cox multivariate analyses. The clinicopathological parameters analysis further showed that increased expression level of CCAT1 was correlated with tumor size, lymph node metastasis, TNM stage, distant metastasis, microvascular invasion and capsular formation in relevant cancers.

Conclusions

The meta-analysis results from present study suggested that increased expression level of CCAT1 was associated with poor prognosis and can serve as an independent biomarker. And the expression level of CCAT1 was associated with clinicopathological features in relevant cancers.

Kinetics of the endocytotic pathway of Low Density Lipoprotein (LDL) in human endothelial cells line under shear stress: an in vitro confocal microscopy study

We studied the effect of mechanical forces (shear stress) on the kinetics of internalization of native LDL and ox-LDL in endothelial cell line ECV304. This study was performed by using Confocal microscopy and FRET with two carbocyanine dyes, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiO) as the donor and 3,3'-dioctadecyloxacarbocyanine perchlorate (DiI) as the receptor. The cells were incubated with a culture medium containing either 10 microg/ml DiI-LDL or DiO-LDL in static conditions or subjected to a laminar flow under a Confocal Laser Scanning Microscope (SP2 Leica, Germany). The results showed: (1) the possibility to evaluate the kinetics of LDL endocytosis in living cells, (2) shear stress in comparison with control group more effectively enhanced LDL uptake, (3) ox-LDL (>50 microg/ml) >4 hours incubation was found to affect the cells as reflected by their detachment at low shear stress.

Antigenic triggers and molecular targets for anti-double-stranded DNA antibodies

While anti-double-stranded (ds)DNA antibodies are a characteristic serologic hallmark for SLE, the triggering antigen is unknown. Using phage display libraries, we identified DWEYSVWLSN as a peptide mimic of DNA for a pathogenic anti-dsDNA antibody. Peptide immunization of non-autoimmune mice induced anti-dsDNA as well as other lupus-associated antibodies. Molecular analysis of the induced anti-dsDNA antibodies revealed several similarities with anti-dsDNA antibodies that appear spontaneously in lupus mice. Furthermore, lupus-prone mice immunized with this peptide DNA mimic had higher autoantibody titers as well as more severe nephritis. Anti-DNA antibodies may contribute to lupus nephritis via cross-reactivity with renal antigen. Using western blotting of lysates of mesangial cells from a lupus mouse, we found that a pathogenic anti-DNA antibody binds to alpha-actinin. High titers of anti-alpha-actinin antibodies were present in the sera and kidney eluates of lupus mice with active disease. Binding to alpha-actinin was diminished in mesangial cells derived from BALB/c mice, suggesting that target antigen expression may play a role in determining autoantibody binding to the kidney. We conclude that a pathogenic, lupus-like autoantibody response can be induced by a peptide antigen, and that alpha-actinin is a cross-reactive renal target for the pathogenic anti-dsDNA autoantibody response in lupus mice.

[Modulation of endothelin-1 on pulmonary surfactant synthesis of cultured alveolar type II cells]

The effects of endothelin-1(ET-1) on pulmonary surfactant(PS) synthesis of cultured AT II cells were observed. The results showed that: 1. ET-1(10(-11)-10(-8) mol.L-1) enhanced PS synthesis of cultured AT II cells in a dose-dependent manner. 2. The minimum effective concentration of ET-1 enhanced PS synthesis of cultured AT II cells was higher than that of lung explants. 3. ETA antagonist BQ123 decreased the effect of ET-1 on PS synthesis, but ETB antagonist BQ788 did not change the effect. 4. ET-1 (10(-12) and 10(-10) mol.L-1) had no effect on the proliferation of AT II cells. These results confirmed that ET-1 can enhance directly and indirectly on the PS synthesis of AT II cells mediated via ETA receptor. The effect of ET-1 on PS synthesis was not induced by changing the number of AT II cells.

mRNA expression of novel CGRP1 receptors and their activity-modifying proteins in hypoxic rat lung

Calcitonin gene-related peptide (CGRP) is a potent vasodilator. Our group has reported that exogenous CGRP may prevent or reverse hypoxic pulmonary hypertension in rats. The vasodilatory action of CGRP is mediated primarily by CGRP1 receptors. The calcitonin receptor-like receptor (CRLR) and the orphan receptor RDC-1 have been proposed as CGRP1 receptors, and recent evidence suggests that CRLR can function as either a CGRP1 receptor or an adrenomedullin (ADM) receptor. Receptor activity-modifying proteins (RAMPs) determine the ligand specificity of CRLR: coexpression of CRLR and RAMP1 results in a CGRP1 receptor, whereas coexpression of CRLR and RAMP2 or -3 results in an ADM receptor. We used qualitative, semiquantitative, and real-time quantitative RT-PCR to detect and quantitate the relative expression of these agents in the lungs of rats exposed to normoxia (n = 3) and 1 and 2 wk of chronic hypobaric hypoxia (barometric pressure 380 mmHg, equivalent to an inspired O(2) level of 10%; n = 3/time period). Our results show upregulation of RDC-1, RAMP1, and RAMP3 mRNAs in hypoxic rat lung and no change in CRLR and RAMP2 mRNAs. These findings support a functional role for CGRP and ADM receptors in regulating the adult pulmonary circulation.

Influence of overlying tissue and probe geometry on the sensitivity of a near-infrared tissue oximeter

In this paper, the influences of overlying tissue and detecting distance between the source and the detector on the measurement of a tissue oximeter were discussed. The signal-noise-ratio of the detector was also examined. A semi-infinite multi-layer Monte Carlo model was induced to simulate the migration of the photons in the skin, adipose and muscle. The thickness of the adipose layer and the separation between the source and the detector in the muscle were changed to simulate the clinical application. Partial pathlength was introduced as a characteristic parameter to evaluate the sensitivity of the oximeter. A two-wavelength (700 and 830 nm) tissue oximeter was developed to verify the results of the simulation. The Monte Carlo simulation results showed that the sensitivity of the near infrared spectroscopy (NIRS) oximeter declined greatly with increasing overlying tissue thickness. Increasing the distance between the light source and the detector improved the sensitivity. However, in order to achieve a sufficiently high signal-to-noise ratio, it was necessary to limit this distance. The results of a bicycle ergometer exercise verified the above results and showed that, for a special adipose thickness (AT), there may be a reasonable range of the emitter-detector separation.

[Modulation of endothelin-1 on pulmonary surfactant synthesis in lung explants]

The effect of endothelin-1(ET-1) on pulmonary surfactant(PS) synthesis was studied in cultured lung explants without serum. The results showed that: 1. ET-1 increased [3H] choline incorporation with dose-dependence and time-dependence. 10(-10) mol.L-1 ET-1 increased the contents of total phospholipids, phosphatidylcholine and phosphatidylglcerol in lung tissues. The major membrane characteristic phospholipids, such as phosphatidylethanolamine, phosphatidylinostitol, phosphatidylserine and sphingomyelin, did not show changes. 2. BQ123, a ETA receptor selective antagonist, could decline the [3H] choline incorporation induced by ET-1(10(-12) and 10(-10) mol.L-1) (P < 0.01). 3. PMA, a protein kinase C(PKC) activator, increased [3H] choline incorporation into lung tissues (P < 0.01); the PKC inhibitor H7 decreased [3H] choline incorporation induced by ET-1(P < 0.01). The results demonstrated that ET-1 at physiological level can enhance the PS synthesis mediated by ETA receptor and PKC.

Left ventricular diastolic dysfunction in patients with angina decubitus

OBJECTIVE

To investigate the relationship between left ventricular diastolic dysfunction and episodes of angina decubitus.

METHODS

The study population consisted of three groups, groups I (20 controls) had no cardiovascular diseases. Group II (20 patients) had coronary artery disease (CAD) without angina decubitus. Group III (24 cases with ejection fraction (EF) > 45%) were selected from 26 patients with angina decubitus.

RESULTS

Left ventriculography (LVG) showed that left ventricular (LV) first 1/3 filling fraction (1/3FF) was significantly reduced in groups III as compared with groups II and I (P < 0.01). Left ventricular end-diastolic pressure (LVEDP) significantly increased in patients with angina decubitus after LVG as compared with that before LVG (P < 0.01). However, there were no statistically differences in LVEDP, before and after LVG in both groups II and I.

CONCLUSIONS

Patients with angina decubitus have abnormalities of LV diastolic filling and decrease in LV compliance.

[Clinical and angiographic characteristics of renovascular hypertension]

Clinical and angiographic characteristics of renovascular hypertension were studied in 95 patients. The patients were divided into 3 groups: 55 cases with aortic arteritis (group AA), 27 with fibromuscular dysplasia (group FMD) and 9 with atherosclerosis (group AS). The patients in group AS were significantly older in age and had longer history of hypertension. Abdominal bruit was heard significantly more often in group AA and serum potassium was significantly lower in group FMD. Angiographic data showed that in group AA lesions in thoracic aorta and abdominal aorta was found in 81.4% and those involving both renal arteries in 52.5%. In group FMD, 82.5% of patients had lesion in renal artery on one side and none had lesion in thoracic and abdominal aorta. In group AS, lesions were found mainly in thoracic and abdominal aorta, accounting for 77.7% and lesions in renal arteries were mainly unilateral. In group AA, lesions were found in 90 renal arteries altogether. Among them, 58.9% was in the proximal part of the renal artery; the lesion was either localized stenosis (67.8%) or obstruction (17.7%). In group FMD, lesions were found in 33 renal arteries altogether. Among them, 48.5% was in the middle or distal part of the renal artery and 27.3% resembled string of beads. In group AS, a total of 10 renal arteries were involved with 4 (40%) of ostial stenosis and 4 (40%) total obstruction.

Optical fringe multiplication in moiré interferometry

An optical method for multiplication of moiré fringes is proposed to increase the sensitivity of moireé interferometry. The process involves two recording steps. In the first step, a traditional moiré interferometry setup is used. The moiré pattern containing carrier fringes and load fringes is recorded onto a glass-based holographic plate. The carrier frequency is much lower than that of the original specimen grating. The plate is then developed. In the second step, the holographic plate, regarded as a distorted specimen grating, is further examined by a similar moiré interferometry system. The frequency of the second virtual grating is arranged to be 2n times that of the carrier fringes contained in the recorded plate. As a result, the load fringes are revealed with a multiplication factor of 2n. The interpretation of the optical multiplication method from wave-front interference theory is given and an experiment is conducted.