LIPUS inhibits inflammation and catabolism through the NF-κB pathway in human degenerative nucleus pulposus cells.

BACKGROUND: Low-intensity pulsed ultrasound (LIPUS) is a safe and noninvasive rehabilitative physical therapy with anti-inflammatory effects. The current study investigated the effect of LIPUS on the inflammation of nucleus pulposus (NP) cells and its underlying mechanism. METHODS: Human NP cells were acquired from lumbar disc herniation tissue samples and cultured for experiments. Human NP cells were treated with LPS and then exposed to LIPUS (15 mW/cm2, 30 mW/cm2 and 60 mW/cm2) for 20 min daily for 3 days to determine the appropriate intensity to inhibit the expression of the inflammatory factors TNF-α and IL-1ß. The gene and protein expression of aggrecan, collagen II, MMP-3 and MMP-9 was measured by real-time PCR and western blotting, respectively. The activity of the nuclear factor-kappa B (NF-κB) pathway was examined by western blotting and immunofluorescence. After pretreatment with the NF-κB inhibitor PDTC, the expression of TNF-α, IL-1ß, MMP-3 and MMP-9 was measured by real-time PCR. RESULTS: LIPUS at intensities of 15 mW/cm2, 30 mW/cm2 and 60 mW/cm2 inhibited LPS-induced NP cell expression of the inflammatory factors TNF-α and IL-1ß, especially at 30 mW/cm2. LIPUS significantly upregulated the gene and protein expression of aggrecan and collagen II and downregulated the gene and protein expression of MMP-3 and MMP-9 in LPS-induced NP cells. The NF-κB signaling pathway was inhibited by LIPUS through inhibiting the protein expression of p-P65 and the translocation of P65 into the nucleus in LPS-induced NP cells. In addition, LIPUS had similar effects as the NF-κB inhibitor PDTC by inhibiting the NF-κB signaling pathway, inflammation and catabolism in LPS-induced human degenerative nucleus pulposus cells. CONCLUSION: LIPUS inhibited inflammation and catabolism through the NF-κB pathway in human degenerative nucleus pulposus cells.

Anticoagulant management by low-dose of low molecular weight heparin in patients with nonvalvular atrial fibrillation following hemorrhagic transformation and complicated with venous thrombosis: Five case reports and literature review.

ABSTRACT: For patients with nonvalvular atrial fibrillation (NVAF) following hemorrhagic infarction (HI)/hemorrhage transformation (HT) and complicated with venous thrombosis, the management of anticoagulation is controversial. Our study intends to explore the safety and effectiveness of using low-dose of low molecular weight heparin (LMWH) to treat NVAF patients with HI (or HT) and complicated with venous thrombosis.Between January 2018 and January 2019, NVAF related acute ischemic stroke patients with HT/HI, hospitalized in the department of neurology or rehabilitation in our hospital, are enrolled retrospectively. Among them, those who were found to have venous thrombosis and undergo anticoagulation (LMWH) during the treatment were extracted. We investigate the efficacy and safety in those patients who have been treated with anticoagulant of LMWH.Five cases accepted LMWH within 3 weeks attributed to the appearance of venous thrombosis, and all of them did not display new symptomatic bleeding or recurrent stroke. However, based on the results of a head computed tomography scan, there were 2 cases of slightly increased intracranial hemorrhage, and then we reduced the dose of anticoagulant. In addition, color ultrasound showed that venous thrombosis disappeared or became stable.Patients with NVAF following HI/HT have a higher risk of thromboembolism. Early acceptance of low-dose LMWH as an anticoagulant is relatively safe and may gain benefit. However, in the process of anticoagulant therapy, we should follow-up head computed tomography/magnetic resonance imaging frequently, as well as D-dimer values, limb vascular ultrasound. Besides, the changes of symptoms and signs should be focused to judge the symptomatic bleeding or recurrent stroke. Furthermore, it is better to adjust anticoagulant drug dosage according to specific conditions.

Mitochondrial pathway and endoplasmic reticulum stress participate in the photosensitizing effectiveness of AE-PDT in MG63 cells.

Photodynamic therapy (PDT) is a promising treatment in cancer therapy, with a photosensitizer activated by visible light. Aloe-emodin (AE) is a promising photosensitive agent. In this study, the photosensitizing effects and possible mechanisms of AE-PDT in MG63 cells were evaluated. The efficiency of AE-PDT was analyzed by MTT assay. The mode of cell death was investigated by Hoechst 33,342 staining and flow cytometer. The intracellular distribution of AE was detected with confocal microscopy. The formation of reactive oxygen species (ROS) was detected by DCFH-DA. The mitochondrial membrane potential (MMP) was measured by Rhodamine 123. The expression of proteins including cytochrome c, caspase-3, -9, and -12, CHOP and GRP78 was detected by western blot. Apoptosis is the primary mode of cell death in our study, which occurs in a manner of depending on AE concentration and irradiation dose. Confocal microscopy showed that AE was primarily localized on the mitochondria and endoplasmic reticulum (ER) of MG63 cells. AE-PDT resulted in rapid increases of intracellular ROS production, which reached a peak at 2 h, followed by declining of mitochondrial membrane potential, releasing of cytochrome c from mitochondria into the cytoplasm, and up-regulation of caspase-3, -9, and -12, CHOP and GRP78. These results suggest that death of MG63 cells induced by AE-PDT is triggered by ROS. Meanwhile, Mitochondria and ER serve as the subcellular targets, which are responsible for AE-PDT-induced death of MG63 cells.

SDF­1/CXCR4 axis induces apoptosis of human degenerative nucleus pulposus cells via the NF­κB pathway.

Intervertebral disc degeneration (IVDD) is a major cause of lower back pain, and increased cell apoptosis is a key characteristic of IVDD. The present study aimed to investigate the effects and mechanism of the stromal cell­derived factor­1 (SDF­1)/C­X­C motif chemokine receptor 4 (CXCR4) axis on apoptosis in human degenerative nucleus pulposus cells (NPCs). The expression levels of SDF­1 and CXCR4 in human intervertebral discs (IVD) were determined using immunohistochemistry and western blot analysis. Apoptosis of primary cultured NPCs was quantified by Annexin V/propidium iodide staining following stimulation with SDF­1 and knockdown of CXCR4 using small interfering RNA (siRNA). The association with the nuclear factor­κB (NF­κB) signaling pathway was investigated using CXCR4­siRNA and NF­κB inhibitor, pyrrolidine dithiocarbamate (PDTC), treatment. The results demonstrated that SDF­1 and its receptor, CXCR4, were upregulated in degenerative IVD samples compared with normal samples. Stimulation with SDF­1 increased the level of apoptosis in cultured NPCs, and conversely, the apoptosis level was suppressed post­transfection with CXCR4 siRNA compared with SDF­1 stimulation alone. Furthermore, SDF­1 treatment increased the level of phosphorylated NF­κB subunit P65, which was downregulated following CXCR4 siRNA and PDTC treatment. In addition, CXCR4 siRNA and PDTC inhibited the nuclear translocation of P65, which was induced by SDF­1. Taken together, SDF­1­mediated apoptosis was suppressed by NF­κB inhibition using PDTC. In conclusion, the SDF­1/CXCR4 axis promoted cell apoptosis in human degenerative NPCs via the NF­κB pathway, thus suggesting that SDF­1/CXCR signaling may be a therapeutic target for the treatment of degenerative IVD diseases.

SIRT1 alleviates senescence of degenerative human intervertebral disc cartilage endo-plate cells via the p53/p21 pathway.

Cartilage end plates (CEP) degeneration plays an integral role in intervertebral disc (IVD) degeneration resulting from nutrient diffusion disorders. Although cell senescence resulting from oxidative stress is known to contribute to degeneration, no studies concerning the role of senescence in CEP degeneration have been conducted. SIRT1 is a longevity gene that plays a pivotal role in many cellular functions, including cell senescence. Therefore, the aim of this study was to investigate whether senescence is more prominent in human degenerative CEP and whether SIRT1-regulated CEP cells senescence in degenerative IVD as well as identify the signaling pathways that control that cell fate decision. In this study, the cell senescence phenotype was found to be more prominent in the CEP cells obtained from disc degenerative disease (DDD) patients than in the CEP cells obtained from age-matched lumbar vertebral fractures (LVF) patients. In addition, the results indicated that p53/p21 pathway plays an important role in the senescence of CEP cells in vivo and vitro. Furthermore, SIRT1 was found to be capable of alleviating the oxidative stress-induced senescence of CEP cells in humans via p53/p21 pathway. Thus, the information presented in this study could be used to further investigate the underlying mechanisms of CEP.

SIRT1 Inhibits the Catabolic Effect of IL-1ß Through TLR2/SIRT1/NF-κB Pathway in Human Degenerative Nucleus Pulposus Cells.

BACKGROUND: Low back pain (LBP), one of the most prominent problems worldwide, lacks effective disease-modifying medical therapy. Intervertebral disc degeneration (IVDD) is a major cause of LBP, and proinflammatory cytokines are the key factors involved in the development of IVDD-induced back pain. Sirtuin 1 (SIRT1) is implicated in the molecular control of aging and immune responses in various diseases; however, its effect on IVDD is not clearly understood. OBJECTIVE: To investigate the effects of SIRT1 on proinflammatory stress and signal transduction pathways induced by interleukin-1ß (IL-1ß) in human degenerative nucleus pulposus (NP) cells. STUDY DESIGN: Research study. SETTING: Chongqing Key Laboratory of Ophthalmology. METHODS: Anti-apoptotic and anti-catabolic effects of SIRT1 on IL-1ß were investigated using a three-dimensional cell culture model of prestimulated human NP cells transfected with a lentiviral vector overexpressing SIRT1 or a small-interfering RNA (siRNA) against the gene encoding SIRT1. In addition, molecular mechanisms underlying the association of SIRT1 with Toll-like receptor-2 (TLR2) and nuclear factor kappa B (NF-κB) were investigated. RESULTS: Our results indicated that decreased SIRT1 expression was associated with IVDD. Direct regulation of SIRT1 expression did not affect the synthesis of extracellular matrix (ECM). However, SIRT1 overexpression mediated by the lentiviral vector suppressed IL-1ß-induced ECM degradation and cell apoptosis. In contrast, knockdown of the gene encoding SIRT1 by the siRNA increased MMP expression and cell apoptosis induced by IL-1ß. Furthermore, SIRT1 deacetylated RelA/p65 to inhibit the nuclear translocation of NF-κB, thus inhibiting inflammation. On the other hand, IL-1ß downregulated SIRT1 expression by activating TLR2. However, inhibition of TLR2 expression by an siRNA did not inhibit IL-1ß-induced nuclear translocation of NF-κB. LIMITATIONS: Limitations of this study were the in vitro study design and lack of in vivo validation of the observed effects of SIRT1 on IVDD. CONCLUSIONS: Our results indicated that SIRT1 exerted anti-inflammatory effects againstIL-1ß-mediated degeneration of NP cells through the TLR2/SIRT1/NF-κB pathway, suggesting that it could be used as a potential candidate for treating IVDD-mediated back pain.

SIRT1 protects against apoptosis by promoting autophagy in degenerative human disc nucleus pulposus cells.

SIRT1 could protect degenerative human NP cells against apoptosis, and there were extensive and intimate connection between apoptosis and autophagy. Up to now, the role of autophagy in the process of human IVD degeneration is unclear. We sought to explore the relationship between autophagy and human IVD degeneration and to understand whether autophagy is involved in the protective effect of SIRT1 against apoptosis in NP cells. Our results showed that the autophagosomes number, the mRNA level of LC3 and Beclin-1, the protein expression of LC3-II/I and Beclin-1, decreased in NP from DDD. Resveratrol could increase the protein expression of LC3-II/I and Beclin-1, and reduce apoptosis in degenerative NP cells. In contrast, the protein levels of LC3-II/I and Beclin-1 were down-regulated and apoptosis level was significantly up-regulated in treatment with nicotinamide or SIRT1-siRNA transfection. Further analysis identified that the expression of cleaved Caspase3 and apoptosis incidence significantly increased with the pretreatment of bafilomycin A, whether resveratrol was added or not. These suggested that autophagy may play an important role in IVD degeneration, and SIRT1 protected degenerative human NP cells against apoptosis via promoting autophagy. These findings would aid in the development of novel therapeutic approaches for degenerative disc disease treatment.

[Purification and biological osteoinductive activity analysis of recombinant human bone morphogenetic protein 9 by eukaryotic expression].

The present paper is aimed to explore the biological osteoinductive activity of recombinant human bone morphogenetic protein 9 (rhBMP-9) by various biological technologies. In this study, we firstly obtained hBMP-9 cDNA by PCR and inserted it into vector pcDNA4/His Max to reconstruct hBMP-9 eukaryotic expression vector pcDNA4/His Max-BMP-9. Recombinant Chinese hamster ovary (rCHO) cell line expressing high-level rhBMP-9 was reconstructed by co-transfecting the expression vectors pcDNA4/His* Max-hBMP-9 and plasmid pSV2-dhfr into dihydrofolate reductase (dhfr)-deficient CHO cells and the subsequent gene amplification by the methotrexate. We finally obtained a monoclonal cell line expressing the highest level protein. We purified the medium after culturing the highest-producing monoclonal by Ni-NTA His-Bind Resin columns and concentrated to by a Centricon 50 at 4 degrees C and stored at 70 degrees C until it was used. Western blot and SDS-PAGE analyses showed a specific band of about 32kD in pro-region lane and a specific band of about 50kD in pro-region complex lane. Biological activities of rhBMP-9 were tested by colorimetric determination and histochemical staining of Alkaline Phosphatase (ALP) Activity, osteocalcin and oesteopontin for C3H10 T1/2 cells, which were stimulated culture by different concentration (20, 50, 100 microg/mL) of rhBMP-9. The results showed that the rhBMP-9 could induce osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro, and were proportional to the amount. This study can provide experimental data for further tests in vivo and clinical applications.

[Restoring phenotype of dedifferentiated normal nucleus pulposus cells by resveratrol].

OBJECTIVE: To investigate the effects of in-vitro monolayer culture and three-dimensional (3-D) alginate microsphere culture on the differentiation of normal human nucleus pulposus cells (NPCs), and to discuss the regulatory mechanism of restoring the phenotype of dedifferentiated NPCs by culturing resveratrol (RES) in 3-D alginate microsphere. METHODS: Normal human nucleus pulposus tissues were harvested for culture and identification of NPCs from 6 patients with burst lumbar vertebra fracture. NPCs at passages 1, 3, 5, and 7 in the in-vitro monolayer culture were harvested to observe the morphology, cell aging, and proteoglycan expression. The cell proliferation rates of NPCs at passage 1 in-vitro in monolayer culture and in 3-D alginate microsphere culture were detected. NPCs at passage 7 were randomly divided into 3-D alginate microsphere control group (group A), RES group (group B), silent mating type information regulation 2 homolog 1 (SIRT1)- small interfering RNA (siRNA) + RES group (group C), and negative control-siRNA + RES group (group D); and NPCs in the in-vitro monolayer culture was monolayer control group (group E). After corresponding treatment, Western blot was used for determining the protein expressions of SIRT1, Aggrecan, and collagen type II; real-time fluorescence quantitative PCR was used for detecting SIRT1 mRNA expression. RESULTS: The cultured cells were identified to be NPCs. Morphological observation, senescence-associated P-galactosidase (SA-P-gal) staining, and toluidine blue staining showed that dedifferentiation of normal NPCs tended to occur under continuous in-vitro monolayer culture, which was more obvious with increase of passage number. NPCs in 3-D alginate microsphere culture showed significantly lower proliferation rate than NPCs in the in-vitro monolayer culture (P < 0.05), but it could significantly improve the protein expressions of collagen type II and Aggrecan in dedifferentiated NPCs, showing significantly difference between groups E and A (P < 0.05). The protein expressions of SIRT1, collagen type II, and Aggrecan in group B were significantly improved when compared with that in group A (P < 0.05). Real-time fluorescence quantitative PCR and Western blot showed that the expressions of SIRT1 mRNA and proteins in group C were significantly inhibited after transfected with SIRT1-siRNA when compared with those in groups B and D (P < 0.05), and the protein expressions of collagen type II and Aggrecan in group C were significantly lower than those in groups B and D (P < 0.05). CONCLUSION: Continuous in-vitro monolayer culture could efficiently cultivate numerous seeding NPCs, but it is liable to dedifferentiate. In 3-D alginate microsphere culture, RES could restore the phenotype of dedifferentiated NPCs and synthesize more extracellular matrix, which is related to the regulation of SIRT1.

SIRT1 inhibits apoptosis of degenerative human disc nucleus pulposus cells through activation of Akt pathway.

Many studies have demonstrated that SIRT1, an NAD(+)-dependent deacetylase, reduces apoptosis in several different cells. However, the role of SIRT1 in apoptosis of disc nucleus pulposus (NP) cells remains unclear. The present study was performed to determine whether degenerative human NP would express SIRT1, and to investigate the role of SIRT1 in NP cells apoptosis. The expression of SIRT1 in disc NP of patients (>55 years) with lumbar disc degenerative disease (DDD) and the disc NP of patients (<25 years) with lumbar vertebra fracture (LVF) was assessed by immunohistochemistry, reverse transcription polymerase chain reaction, and Western blot analysis. The results showed that SIRT1 mRNA and protein levels were greater in LVF disc NP than those in DDD disc NP. Degenerative human NP cells were treated in culture with activator or inhibitor of SIRT1, resveratrol or nicotinamide, or SIRT1 small interfering RNA (siRNA), and cell apoptosis was quantified via flow cytometry. The rate of apoptosis was far fewer in resveratrol-treated NP cells than in SIRT1 siRNA-transfected or nicotinamide-treated NP cells. After SIRT1 siRNA was transfected, NP cells decreased phosphorylation of Akt, while resveratrol phosphorylated Akt. Treatment with LY294002 or Akt siRNA increased the rate of apoptosis. Our results suggested that SIRT1 plays a critical role in survival of degenerative human NP cells through the Akt anti-apoptotic signaling pathway.

[Determination of longistylin A and longistylin C in Cajanus cajan].

OBJECTIVE: To establish quality control criteria for medicinal herb Cajanus cajan based on the determination of longistylin A and longistylin C, two bioactive and specific stilbenes of the plant. METHOD: Longistylin A and longistylin C were obtained from the leaves of C. cajan by silica gel column chromatography and identified as marker compounds of this plant by spectroscopic analysis. A RP-HPLC method was established to determine the two compounds. RESULT: Longistylin A and longistylin C were well separated on a Thermo BDS Hypersil C18 column (4.6 mm x 250 mm, 5 microm) with a mobile phase methanol-water (8:2), and showed good linearity in the range of 0.00288 - 0.0576 microg and 0.0112 - 0.224 microg, respectively. The average recoveries were 98.9% and 97.2% with RSD of 2.4% and 2.2% for these two compounds, respectively. CONCLUSION: The established analysis method is simple and accurate, whicn can be used for quality control of C. cajan.