Hapln1 promotes dedifferentiation and proliferation of iPSC-derived cardiomyocytes by promoting versican-based GDF11 trapping.

Hyaluronan and proteoglycan link protein 1 (Hapln1) supports active cardiomyogenesis in zebrafish hearts, but its regulation in mammal cardiomyocytes is unclear. This study aimed to explore the potential regulation of Hapln1 in the dedifferentiation and proliferation of cardiomyocytes and its therapeutic value in myocardial infarction with human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CMs) and an adult mouse model of myocardial infarction. HiPSC-CMs and adult mice with myocardial infarction were used as in vitro and in vivo models, respectively. Previous single-cell RNA sequencing data were retrieved for bioinformatic exploration. The results showed that recombinant human Hapln1 (rhHapln1) promotes the proliferation of hiPSC-CMs in a dose-dependent manner. As a physical binding protein of Hapln1, versican interacted with Nodal growth differentiation factor (NODAL) and growth differentiation factor 11 (GDF11). GDF11, but not NODAL, was expressed by hiPSC-CMs. GDF11 expression was unaffected by rhHapln1 treatment. However, this molecule was required for rhHapln1-mediated activation of the transforming growth factor (TGF)-ß/Drosophila mothers against decapentaplegic protein (SMAD)2/3 signaling in hiPSC-CMs, which stimulates cell dedifferentiation and proliferation. Recombinant mouse Hapln1 (rmHapln1) could induce cardiac regeneration in the adult mouse model of myocardial infarction. In addition, rmHapln1 induced hiPSC-CM proliferation. In conclusion, Hapln1 can stimulate the dedifferentiation and proliferation of iPSC-derived cardiomyocytes by promoting versican-based GDF11 trapping and subsequent activation of the TGF-ß/SMAD2/3 signaling pathway. Hapln1 might be an effective hiPSC-CM dedifferentiation and proliferation agent and a potential reagent for repairing damaged hearts.

Avulsion fracture of the anterior superior iliac crest following autograft for anterior lumbar fusion: case report and literature review.

Avulsion fracture of the anterior superior iliac crest (ASIC) following autogenous bone grafting for anterior lumbar fusion (ALF) is an extremely rare complication. We describe a very rare case of avulsion fracture of the ASIC following autograft for ALF in a revision surgery for treating lumbar tuberculosis. A 68-year-old woman with lumbar tuberculosis underwent posterior debridement and posterior iliac crest bone graft fusion; however, her lumbar tuberculosis recurred 9 months after surgery. She then underwent a lumbar revision surgery, including removal of the posterior instrumentation and debridement, followed by anterior L2 corpectomy, debridement, anterior left iliac crest bone graft fusion, and internal fixation. When walking for the first time on postoperative day 3, she experienced a sharp, sudden-onset pain in the anterior iliac crest harvest area. X-ray revealed an avulsion fracture of the ASIC. Considering her failure to respond to conservative treatment for one week and large displacement of the fracture ends, an open reduction and internal fixation surgery was scheduled. Her pain symptoms were significantly relieved after the operation. Although rare, fracture of the ASIC following autograft for ALF should not be ignored. Fracture of the ASIC is usually treated conservatively. Additional surgical treatment is required only when intractable pain fails to respond to conservative treatment or when there is a large displacement of fracture ends that are not expected to heal spontaneously.

Mechanical bone strength decreases considerably after microwave ablation-Ex-vivo and in-vivo analysis in sheep long bones.

BACKGROUND: Bone metastases are on the rise due to longer survival of cancer patients. Local tumor control is required for pain relief. Microwave ablation (MWA) is a technique for minimally invasive local tumor treatment. Tumor tissue is destroyed by application of local hyperthermia to induce necrosis. Given the most common setting of palliative care, it is generally considered beneficial for patients to start mobilizing directly following treatment. No data on mechanical strength in long bones after MWA have been published so far. MATERIALS AND METHODS: In- and ex-vivo experiments on sheep tibias were performed with MWA in various combinations of settings for time and power. During the in-vivo part sheep were sacrificed one or six weeks after ablation. Mechanical strength was examined with a three-point bending test for ablations in the diaphysis and with an indentation test for ablations in the metaphysis. RESULTS: MWA does not decrease mechanical strength in the diaphysis. In the metaphysis strength decreased up to 50% six weeks after ablation, which was not seen directly after ablation. CONCLUSION: MWA appears to decrease mechanical strength in long bone metaphysis up to 50% after six weeks, however strength remains sufficient for direct mobilization. The time before normal strength is regained after the remodeling phase is not known.

The proposed modification of TNM staging and therapeutic strategy for skip metastasis in papillary thyroid carcinoma: A multicenter retrospective cohort study.

BACKGROUND: Skip metastasis is a special type of lateral lymph node metastasis, which is not classified definitely by the eighth edition of the AJCC TNM staging system. The aim of the research was to study the prognosis of skip metastasis in PTC patients, and carry out a more appropriate N staging for skip metastasis. METHODS: Study subjects were 3167 patients with papillary thyroid carcinoma (PTC), who underwent thyroidectomy at three clinical centers from 2016 to 2019. We identified two well-balanced cohorts matched on the basis of propensity score. RESULTS: During a median follow-up of 42 months, recurrence occurred in 68 (4.3%) patients with lymph node metastasis. 34 cases recurred in 1120 patients with central lymph node metastasis (N1a), and 34 recurred in 461 patients with lateral lymph node metastasis (N1b), among which 73 patients were diagnosis with skip metastasis. The RFS of N1a was significantly lower than that of N1b (p < 0.001). After propensity-score matching, recurrence rate was significantly lower in the skip metastasis group than in the LLNM group (p = 0.039), whereas the rate was similar in the skip metastasis groups and the CLNM group (p = 0.29). CONCLUSIONS: In conclusion, our study indicated that, among patients with LLNM, those with positive skip metastasis showed significantly lower recurrence, exhibiting a similar rucurrence tendency as patients with CLNM. Thus, skip metastasis could be categorized into N1a stage rather than N1b stage based on the AJCC TNM staging system. The downstaging of skip metastasis may reveal more conservative treatment strategy.

Roles of p38 MAPK signalling in intervertebral disc degeneration.

Intervertebral disc degeneration (IVDD) is a common degenerative disease mediated by multiple factors. Because of its complex aetiology and pathology, no specific molecular mechanisms have yet been identified and no definitive treatments are currently available for IVDD. p38 mitogen-activated protein kinase (MAPK) signalling, part of the serine and threonine (Ser/Thr) protein kinases family, is associated with the progression of IVDD, by mediating the inflammatory response, increasing extracellular matrix (ECM) degradation, promoting cell apoptosis and senescence and suppressing cell proliferation and autophagy. Meanwhile, the inhibition of p38 MAPK signalling has a significant effect on IVDD treatment. In this review, we first summarize the regulation of p38 MAPK signalling and then highlight the changes in the expression of p38 MAPK signalling and their impact on pathological process of IVDD. Moreover, we discuss the current applications and future prospects of p38 MAPK as a therapeutic target for IVDD treatment.

Does the Choice of Operative Side Affect the Clinical Outcome of Unilateral Percutaneous Kyphoplasty for Osteoporotic Vertebral Compression Fracture?

BACKGROUND: Studies have found that the rate of improvement in pain after percutaneous kyphoplasty (PKP) is 49% to 90%, and there are still some patients who may continue to sustain intractable back pain after surgery. OBJECTIVES: To compare the clinical efficacy and imaging results between unilateral PKP performed from the symptom-dominating side and the non-dominating side in OVCF treatment. STUDY DESIGN: Prospective study. SETTING: All data were from Honghui Hospital in Xi'an. METHODS: One hundred forty-two patients of osteoporotic vertebral compression fracture (OVCF) treated with unilateral PKP were eventually recruited and randomly assigned to either the A or B group. Patients in group A received PKP from the symptom-dominating side; patients in group B received PKP from the symptom non-dominating side. The demographic characteristics, related surgical information, and complications observed within both groups were recorded. The clinical outcomes evaluation included the visual analog scale (VAS) score for low back pain and the Oswestry Disability Index (ODI). Evaluation of imaging results included anterior height (AH), kyphosis angulation (KA), and contralateral distribution rate of bone cement. RESULTS: One hundred eighteen patients (48 men and 70 women; age range: 60-83 years), including 59 patients in the A group and 59 patients in the B group, were available for the complete assessment. There were 5 cases and 7 cases of bone cement leakage in groups A and B, respectively, which were asymptomatic para-vertebral or inter-vertebral leakage without intra-spinal leakage. Compared with the preoperative data, significant improvements in the VAS scores and ODI were observed at each follow-up interval. The VAS score and ODI in the A group were significantly lower than in the B group only within 2 months (P < 0.05). Compared with the preoperative data, the AH and KA in the 2 groups were improved (P < 0.05). There was no significant difference in AH and KA between the 2 groups at each follow-up interval (P > 0.05). LIMITATIONS: A single-center study. CONCLUSIONS: The unilateral PKP performed via the symptom-dominating side can effectively relieve back pain and improve the patient's quality of life at the early stage.

Screw Pullout Strength After Pedicle Screw Reposition: A Finite Element Analysis.

RESEARCH DESIGN: Finite element analysis based on computed tomography images from the lumbar spine. OBJECTIVE: Determined the pullout strength of unsatisfactorily placed screws and repositioned screws after unsatisfactory place in lumbar spine surgery. BACKGROUND: Pedicle screws are widely used to stabilize the spinal vertebral body. Unsatisfactory screws could lead to surgical complications, and may need to be repositioned. Screw removal and reposition, however, may decrease pullout strength. METHODS: We conducted a three-dimensional finite element analysis based on high-resolution computed tomography images from a 39-year-old healthy woman. Pullout strength was determined with the screw placed in different orientations at the same entry point (as selected by the Magerl method), as well as after removal and reposition. The material properties of the vertebral body and the screw were simulated by using grayscale values and verified data, respectively. A load along the screw axis was applied to the end of the screw to simulate the pullout. RESULTS: The pullout strength was 1840.0 N with the Magerl method. For unsatisfactorily placed screws, the pullout strength was 1500.8 N at 20% overlap, 1609.6 N at 40% overlap, 1628.9 N at 60% overlap, and 1734.7 N at 80% overlap with the hypothetical screw path of the Magerl method. For repositioned screws, the pullout strength was 1763.6 N, with 20% overlap, 1728.3 N at 40% overlap, 1544.0 N at 60% overlap, and 1491.1 N at 80% overlap, with the original path. Comparison of repositioned screw with unsatisfactorily placed screw showed 14.04% decrease in pullout strength at 80% overlap, 5.21% decrease at 60% overlap, 7.37% increase at 40% overlap, and 17.51% increase at 20% overlap, with the screw path of the Magerl method. CONCLUSIONS: Removal and reposition increased the pullout strength at 20% and 40% overlap, but decreased the pullout strength at 60% and 80% overlap. For clinical translation, we recommend removal and reposition of the screw when the overlap is in the range of 20% to 40% or less. In vitro specimen studies are needed to verify these preliminary findings.

Cuproptosis-Related 4-Gene Risk Model for Predicting Immunotherapy Drug Response and Prognosis of Kidney Renal Clear Cell Carcinoma / 中国医学科学杂志(英文版)

Background Kidney renal clear cell carcinoma (KIRC) is one of the most common renal malignancies with a high mortality rate. Cuproptosis, a novel form of cell death, is strongly linked to mitochondrial metabolism and is mediated by protein lipoylation, leading to a proteotoxic stress response and cell death. To date, few studies have ellucidated the holistic role of cuproptosis-related genes (CRGs) in the pathogenesis of KIRC.Methods We comprehensively and completely analyzed the RNA sequencing data and corresponding clinical information from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We screened for differentially expressed CRGs and constructed a prognostic risk model using univariate and multivariate Cox proportional regression analyses. Kaplan-Meier analysis was performed and receiver operating characteristic (ROC) curves were plotted to predict the prognosis of KIRC patients. Functional enrichment analysis was utilized to explore the internal mechanisms. Immune-related functions were analyzed using single-sample gene set enrichment analysis (ssGSEA), tumour immune dysfunction and exclusion (TIDE) scores, and drug sensitivity analysis.Results We established a concise prognostic risk model consisting of four CRGs (DBT, DLAT, LIAS and PDHB) to predict the overall survival (OS) in KIRC patients. The results of the survival analysis indicated a significantly lower OS in the high-risk group as compared to the patients in the low-risk group. The area under the time-dependent ROC curve (AUC) at 1, 3, and 5 year was 0.691, 0.618, and 0.614 in KIRC. Functional enrichment analysis demonstrated that CRGs were significantly enriched in tricarboxylic acid (TCA) cycle-related processes and metabolism-related pathways. Sorafenib, doxorubicin, embelin, and vinorelbine were more sensitive in the high-risk group.Conclusions We constructed a concise CRGs risk model to evaluate the prognosis of KIRC patients and this may be a new direction for the diagnosis and treatment of KIRC.

Puncture and Needle Picking Action of Venipuncture Manipulator / 医用生物力学

Objective To propose a new multi-joint series venipuncture system, explore the mechanics and kinematics-based related control problems involved in needle insertion and needle picking during the puncture process, and verify feasibility of this system. Methods A puncture manipulator was built, and needle displacement control algorithm was proposed by combing with the puncture mechanics model. The the forward kinematics was calculated by using DH method, so as to obtain the tip coordinates. Then the inverse kinematics was calculated by using the geometric method. The forward and inverse processes were closely connected. The position error of the end coordinates before and after needle picking was compared by using the method of kinematics positive solution-inverse solution-re-positive solution. Finally, experimental verification and simulation were conducted by combining with the physical object. Results Through simulation and experiments, accuracy of the theoretical model was verified. The needle insertion algorithm could be used to achieve success with only one needle insertion, which provided theoretical basis for the control of robot arm. The position error before and after needle picking could be controlled within 1 mm from the end trajectory. The end needle tip of robot arm was almost kept fixed during the needle picking process. Therefore, this needle picking scheme was feasible and could basically verify that the needle picking action of robot arm met the accuracy and safety requirements. Conclusions The venipuncture manipulator truly simulates the needle insertion and needle picking action during the puncture process, and can safely and accurately realize the needle insertion and needle picking action with needle tip as the fixed point, indicating that it has certain clinical value.

Clinical and bronchoscopy features of tracheobronchial tuberculosis in children / 中国当代儿科杂志

OBJECTIVES@#To study the clinical and bronchoscopic characteristics of tracheobronchial tuberculosis (TBTB) in children and to identify factors influencing residual airway obstruction or stenosis.@*METHODS@#The clinical data of children with TBTB were retrospectively collected. The children were divided into two groups based on the last bronchoscopic result within one year of follow-up: a group with residual airway obstruction or stenosis (n=34) and a group without residual airway obstruction or stenosis (n=58). A multivariate logistic regression analysis was used to identify the factors influencing residual airway obstruction or stenosis in children with TBTB. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of the factors influencing residual airway obstruction or stenosis in children with TBTB.@*RESULTS@#A total of 92 children with TBTB were included, and the main symptoms were cough (90%) and fever (68%). In children under 1 year old, the incidence rates of dyspnea and wheezing were significantly higher than in other age groups (P<0.008). Chest CT findings included mediastinal or hilar lymph node enlargement (90%) and tracheobronchial stenosis or obstruction (61%). The lymphatic fistula type was the main type of TBTB observed bronchoscopically (77%). All children received interventional treatment, and the effective rate was 84%. During one year of follow-up, 34 children had residual airway obstruction or stenosis. The TBTB diagnostic time and the initiation of interventional treatment were significantly delayed in the group with residual airway obstruction or stenosis compared with the group without residual airway obstruction or stenosis (P<0.05). The multivariate logistic regression analysis showed that the TBTB diagnostic time was closely related to residual airway obstruction or stenosis in children (P<0.05). ROC curve analysis showed that at the cut-off value of 92 days of TBTB diagnostic time, the area under the curve for predicting residual airway obstruction or stenosis in children with TBTB was 0.707, with a sensitivity of 58.8% and a specificity of 75.9%.@*CONCLUSIONS@#The clinical manifestations of TBTB are nonspecific, and symptoms are more severe in children under 1 year old. TBTB should be suspected in children with tuberculosis and chest imaging indicating airway involvement. Delayed diagnosis of TBTB is associated with the development of residual airway obstruction or stenosis.

Resting-state electroencephalogram relevance state recognition of Parkinson's disease based on dynamic weighted symbolic mutual information and k-means clustering / 生物医学工程学杂志

At present, the incidence of Parkinson's disease (PD) is gradually increasing. This seriously affects the quality of life of patients, and the burden of diagnosis and treatment is increasing. However, the disease is difficult to intervene in early stage as early monitoring means are limited. Aiming to find an effective biomarker of PD, this work extracted correlation between each pair of electroencephalogram (EEG) channels for each frequency band using weighted symbolic mutual information and k-means clustering. The results showed that State1 of Beta frequency band ( P = 0.034) and State5 of Gamma frequency band ( P = 0.010) could be used to differentiate health controls and off-medication Parkinson's disease patients. These findings indicated that there were significant differences in the resting channel-wise correlation states between PD patients and healthy subjects. However, no significant differences were found between PD-on and PD-off patients, and between PD-on patients and healthy controls. This may provide a clinical diagnosis reference for Parkinson's disease.

In vivo delivery process and regulating mechanisms of lipid-based nanomedicines / 药学学报

Lipid-based nanocarrier is a classic drug delivery system with great biocompatibility and biodegradability. It can effectively reduce the toxicity of anti-tumor and anti-infective drugs in clinical practice. However, it has not yet met the clinical demand for enhanced therapeutic efficacy, and the clinical application is still very limited. The complex in vivo delivery process of lipid-based nanomedicine and the reciprocal interactions with body lead to unexpected changes in in vivo performance of nanomedicine and seriously hinder clinical translation. Therefore, the in-depth study of the relationships among intrinsic properties of lipid-based nanomedicine, the in vivo delivery process, and the regulatory mechanisms will not only provide guidance for the rational design of nanocarriers, but also promote the clinical translation and precision medicine of new lipid-based nanomedicine. In this review, we summarize the in vivo delivery process, regulating factors and intervention strategies for the in vivo delivery of lipid-based nanomedicine.

Clinical features and prognosis analysis of 31 cases of extramedullary plasmacytoma of the head and neck / 中华放射肿瘤学杂志

Objective:To investigate the clinical features, treatment options and prognostic factors of extramedullary plasmacytoma of the head and neck.Methods:Clinical data of 31 cases of extramedullary plasmacytoma of the head and neck treated in Eye Ear Nose and Throat Hospital of Fudan University from January 2005 to January 2020 were retrospectively analyzed. According to the involvement sites, the lesions were divided into the Waldeyer's ring involvement and non-involvement groups. The differences between two groups were compared by one-way ANOVA. The overall survival (OS) was analyzed by Kaplan-Meier method. The OS rate and local recurrence free survival (LRFS) rate between two groups were compared by log-rank test.Results:All 31 patients received radiotherapy. The median follow-up time was 98 months (7-192 months). Among them, 16 patients received radiotherapy and surgery, 10 patients received radiochemotherapy, and 2 patients received surgery and radiochemotherapy. Waldeyer's ring involvement was found in 15 patients, and Waldeyer's ring was not involved in 16 patients. The 10-year OS rate was 84.8%. Two cases showed local recurrence and 2 cases progressed to multiple myeloma. The 10-year OS rate in patients ≤55 years old was 100% vs. 67% in those >55 years old ( P=0.039). The 10-year OS rates in patients with and without Waldeyer's ring involvement were 93.3% vs. 75.2% ( P=0.031). The 10-year LRFS rate in patients with Waldeyer's ring involvement was 100% vs. 66.7% in those without Waldeyer's ring involvement ( P=0.022). The 10-year OS rate was 95% and 35.7% for patients with longest diameter of tumor ≤5 cm and >5 cm before radiotherapy, respectively ( P=0.02). Conclusions:Extramedullary plasmacytoma of the head and neck patients with longest diameter of tumor ≤5 cm obtain higher 10-year OS rate. Those with Waldeyer's ring involvement have better 10-year OS and LRFS rates.

Research progress of CAR-T in the treatment of esophageal squamous cell carcinoma / 国际肿瘤学杂志

Chimeric antigen receptor T cell (CAR-T) therapy, an emerging immunotherapy, has achieved remarkable results in the treatment of hematologic tumors. However, it's limited in the treatment of solid tumors such as esophageal squamous cell carcinoma due to various factors. Clarifying the reasons for the limitation of CAR-T therapy and exploring the corresponding solutions can provide new ideas and insights for the treatment of esophageal squamous cell carcinoma.

OECs Prevented Neuronal Cells from Apoptosis Partially Through Exosome-derived BDNF.

It is known that neurotrophic factors are a major source of the neuroprotective effects of olfactory ensheathing cells (OECs). However, the form of neurotrophic factors that originate from OECs is not fully understood. Our previous study demonstrated that OECs could secrete exosome (OECs-Exo), which provided neuroprotection by switching the phenotype of macrophages/microglia. Considering that exosomes could also be taken up by neurons, we explored the direct effect of OECs-Exo on neuronal survival and the underlying mechanism. Electron microscopy, nano-traffic analysis, and Western blotting were applied to identify the OECs-Exo. The effect of OECs-Exo on neuronal survival was tested by flow cytometry and TUNEL staining. Western blotting and ELISA were used to detect neurotrophic factors in purified OECs-Exo. We first isolated OECs-Exo and found that OECs-Exo exerted protective effects on neuronal survival in response to TNF-α challenge. Brain-derived neurotrophic factor (BDNF) was then identified in OECs-Exo, and its receptor TrkB in neurons was activated by OECs-Exo treatment. Furthermore, we demonstrated that OECs prevented TNF-α-induced apoptosis in neurons partially through exosome-derived BDNF. Our data showed that OECs attenuated TNF-α-induced apoptosis in neurons partially through OEC-Exo-derived BDNF, which might provide a novel strategy for the neuroprotective effect of OEC-Exo-based treatment.

Bioprinting for bone tissue engineering.

The shape transformation characteristics of four-dimensional (4D)-printed bone structures can meet the individual bone regeneration needs, while their structure can be programmed to cross-link or reassemble by stimulating responsive materials. At the same time, it can be used to design vascularized bone structures that help establish a bionic microenvironment, thus influencing cellular behavior and enhancing stem cell differentiation in the postprinting phase. These developments significantly improve conventional three-dimensional (3D)-printed bone structures with enhanced functional adaptability, providing theoretical support to fabricate bone structures to adapt to defective areas dynamically. The printing inks used are stimulus-responsive materials that enable spatiotemporal distribution, maintenance of bioactivity and cellular release for bone, vascular and neural tissue regeneration. This paper discusses the limitations of current bone defect therapies, 4D printing materials used to stimulate bone tissue engineering (e.g., hydrogels), the printing process, the printing classification and their value for clinical applications. We focus on summarizing the technical challenges faced to provide novel therapeutic implications for bone defect repair.

Integrated analysis of microRNAs, circular RNAs, long non-coding RNAs, and mRNAs revealed competing endogenous RNA networks involved in brown adipose tissue whitening in rabbits.

BACKGROUND: The brown adipose tissue (BAT) is a target for treating obesity. BAT losses thermogenic capacity and gains a "white adipose tissue-like" phenotype ("BAT whitening") under thermoneutral environments, which is a potential factor causing a low curative effect in BAT-related obesity treatments. Circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) can act as competing endogenous RNAs (ceRNA) to mRNAs and function in various processes by sponging shared microRNAs (miRNAs). However, the roles of circRNA- and lncRNA-related ceRNA networks in regulating BAT whitening remain litter known. RESULTS: In this study, BATs were collected from rabbits at day0 (D0), D15, D85, and 2 years (Y2). MiRNA-seq was performed to investigate miRNA changes during BAT whitening. Then, a combined analysis of circRNA-seq and whole-transcriptome sequencing was used for circRNA assembly and quantification during BAT whitening. Our data showed that 1187 miRNAs and 6204 circRNAs were expressed in the samples, and many of which were identified as significantly changed during BAT whitening. Target prediction showed that D0-selective miRNAs were significantly enriched in the Ras, MAPK, and PI3K-Akt signaling pathways, and Y2-selective miRNAs were predicted to be involved in cell proliferation. The cyclization of several circRNAs could form novel response elements of key thermogenesis miRNAs at the back-splicing junction (BSJ) sites, and in combination with a dual-luciferase reporter assay confirmed the binding between the BSJ site of novel_circ_0013792 and ocu-miR-378-5p. CircRNAs and lncRNAs have high cooperativity in sponging miRNAs during BAT whitening. Both circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA triple networks were significantly involved in immune response-associated biological processes. The D15-selective circRNA might promote BAT whitening by increasing the expression of IDH2. The Y2-selective circRNA-related ceRNA network and lncRNA-related ceRNA network might regulate the formation of the WAT-like phenotype of BAT via MAPK and Ras signaling pathways, respectively. CONCLUSIONS: Our work systematically revealed ceRNA networks during BAT whitening in rabbits and might provide new insight into BAT-based obesity treatments.

lncRNA HHIP-AS1/HHIP modulates osteogenic differentiation of BM-MSCs by regulating Hedgehog signaling pathway.

BACKGROUND: lncRNA, a type of non-coding RNA, plays an important role in the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs). In this study, lncRNA and mRNA microarrays were performed to study the change of gene expression during osteogenic differentiation of BM-MSCs. We focused on Hedgehog interacting protein (HHIP), because HHIP mRNA and lncRNA HHIP-AS1 were gradually down-regulated on days 0, 7, and 14 during osteogenic differentiation. In addition, the gene coding lncRNA HHIP-AS1 is located on the anti-sense of Hhip gene, implying the potential interaction between lncRNA HHIP-AS1 and HHIP mRNA. METHODS: BM-MSCs with over-expressed or silenced lncRNA HHIP-AS1 were constructed to explore the biological role of HHIP-AS1 in osteogenic differentiation. BM-MSCs were lysed to determine the alkaline phosphatase activity. Fluorescence in situ hybridization and immunofluorescence were performed to analyze HHIP-AS1, HHIP, RUNX2 and osteocalcin. RESULTS: Overexpression of lncRNA HHIP-AS1 increased HHIP expression, which suppressed Hedgehog signaling pathway, as indicated by the reduction of SMO, Gli1 and Gli2. The suppression of Hedgehog signal was associated with the inhibited osteogenesis. HHIP knockdown abolished the suppression of osteogenesis induced by lncRNA HHIP-AS1 overexpression. Through binding to HHIP mRNA, lncRNA HHIP-AS1 recruited ELAVL1 to HHIP mRNA, whereby increasing the mRNA stability and the protein level. CONCLUSIONS: This study revealed that down-regulation of HHIP due to lncRNA HHIP-AS1 reduction promoted the osteogenic differentiation of BM-MSCs though removing the suppression of Hedgehog signal.

Necroptosis of nucleus pulposus cells involved in intervertebral disc degeneration through MyD88 signaling.

Background context: Low back pain, affecting nearly 40% of adults, mainly results from intervertebral disc degeneration (IVDD), while the pathogenesis of IVDD is still not fully elucidated. Recently, some researches have revealed that necroptosis, a programmed necrosis, participated in the progression of IVDD, nevertheless, the underlying mechanism remains unclear. Purpose: To study the mechanism of necroptosis of Nucleus Pulposus (NP) cells in IVDD, focusing on the role of MyD88 signaling. Study design: The expression and co-localization of necroptotic indicators and MyD88 were examined in vivo, and MyD88 inhibitor was applied to determine the role of MyD88 signaling in necroptosis of NP cells in vitro. Methods: Human disc specimens were collected from patients receiving diskectomy for lumbar disc herniation (LDH) or traumatic lumbar fractures after MRI scanning. According to the Pfirrmann grades, they were divided into normal (Grades 1, 2) and degenerated groups (4, 5). Tissue slides were prepared for immunofluorescence to assess the co-localization of necroptotic indicators (RIP3, MLKL, p-MLKL) and MyD88 histologically. The combination of TNFα, LPS and Z-VAD-FMK was applied to induce necroptosis of NP cells. Level of ATP, reactive oxygen species (ROS), live-cell staining and electron microscope study were employed to study the role of MyD88 signaling in necroptosis of NP cells. Results: In vivo, the increased expression and co-localization of necroptotic indicators (RIP3, MLKL, p-MLKL) and MyD88 were found in NP cells of degenerated disc, while very l low fluorescence intensity in tissue of traumatic lumbar fractures. In vitro, the MyD88 inhibitor effectively rescued the necroptosis of NP cells, accompanied by increased viability, ATP level, and decreased ROS level. The effect of MyD88 inhibition on necroptosis of NP cells was further confirmed by ultrastructure of mitochondria shown by Transmission Electron Microscope (TEM). Conclusion: Our results indicated that the involvement of MyD88 signaling in the necroptosis of NP cells in IVDD, which will replenish the pathogenesis of IVDD and provide a novel potential therapeutic target for IVDD.