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2.
Cell Death Dis ; 11(2): 103, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32029706

RESUMO

N6 methyladenosine (m6A) is one of the most prevalent epitranscriptomic modifications of mRNAs, and plays a critical role in various bioprocesses. Bone-derived mesenchymal stem cells (BMSCs) can attenuate apoptosis of nucleus pulposus cells (NPCs) under compression; however, the underlying mechanisms are poorly understood. This study showed that the level of m6A mRNA modifications was decreased, and the autophagic flux was increased in NPCs under compression when they were cocultured with BMSCs. We report that under coculture conditions, RNA demethylase ALKBH5-mediated FIP200 mRNA demethylation enhanced autophagic flux and attenuated the apoptosis of NPCs under compression. Specific silencing of ALKBH5 results in impaired autophagic flux and a higher proportion of apoptotic NPCs under compression, even when cocultured with BMSCs. Mechanistically, we further identify that the m6A "reader" YTHDF2 is likely to be involved in the regulation of autophagy, and lower m6A levels in the coding region of FIP200 lead to a reduction in YTHDF2-mediated mRNA degradation of FIP200, a core molecular component of the ULK1 complex that participates in the initiating process of autophagy. Taken together, our study reveals the roles of ALKBH5-mediated FIP200 mRNA demethylation in enhancing autophagy and reducing apoptosis in NPCs when cocultured with BMSCs.

3.
Comput Methods Programs Biomed ; 189: 105352, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31991316

RESUMO

BACKGROUND AND OBJECTIVE: To compare the biomechanical changes of adjacent segment degeneration (ASD) after one- or two-level anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA). METHODS: A three-dimensional finite element (FE) model of intact C2-C7 segments was constructed and validated. In the one-level surgery model, the cage with plate implant or Prestige LP cervical disc prosthesis were integrated at C5-C6 segment into the FE model; while in the two-level surgery model, the prostheses were integrated at both C4-C5 and C5-C6 segments into the FE model. A pure moment of 1.0 Nm combined with a follower load of 73.6 N were imposed on C2 to investigate the flexion-extension, lateral bending, and axial rotation of different segments in the FE model. The segmental range of motion (ROM) and intradiscal pressure of the surgery models were investigated and compared with the intact model. RESULTS: In the one-level model of ACDF, the ROM at C5-C6 was decreased, the ROM and intradiscal pressure at C4-C5 and C6-C7 segments were increased. In the two-level model of ACDF, the ROM at C4-C5 and C5-C6 were decreased, the ROM and intradiscal pressure at C3-C4 and C6-C7 were increased. However, in both one- and two-level models of CDA, the ROM of surgery segments were preserved, avoiding the increase of the ROM and intradiscal pressure at the adjacent segments. CONCLUSIONS: Abnormal ROM and intradiscal pressure at the adjacent segments may contribute to the higher risk of ASD after ACDF compared with CDA.

4.
World Neurosurg ; 133: e84-e88, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31470152

RESUMO

BACKGROUND: Spinopelvic sagittal parameters have a significant influence on adjacent segment degeneration (ASD) after fusion surgery. The association between ASD and sagittal balance is not well understood. The purpose of this study was to investigate the biomechanical influence of various sacral slope (SS) degrees on adjacent segments after transforaminal lumbar interbody fusion (TLIF) at the L4-L5 level. METHODS: We conducted a finite element model of the L1-S1 based on computed tomography scan images. The L1-S1 model with L4-L5 TLIF was modified with various SS degrees (33°, 38°, 43°, and 48°) to investigate the biomechanical influence of SS on adjacent segments. The range of motion (ROM) and intradiscal pressure (IDP) of the adjacent segments (L3-L4 and L5-S1) were compared among models using various SS angles. RESULTS: When the SS angle increased, the ROM and IDP in L5-S1 decreased gradually after TLIF at the L4-L5 level in all motion patterns. Nevertheless, the ROM and IDP in L3-L4 were not significantly different among various SS angles. CONCLUSIONS: Decreased SS after lumbar fusion surgery may pose a higher risk of ASD. Therefore, restoring appropriate SS should be considered during decision-making prior to fusion surgery to reduce the risk of degenerative changes.


Assuntos
Vértebras Lombares/cirurgia , Sacro/diagnóstico por imagem , Fusão Vertebral/métodos , Antropometria , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Disco Intervertebral/fisiopatologia , Vértebras Lombares/diagnóstico por imagem , Pressão , Amplitude de Movimento Articular , Sacro/patologia , Tomografia Computadorizada por Raios X
5.
J Cell Physiol ; 235(3): 2195-2208, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31478571

RESUMO

Intervertebral disc degeneration (IDD) is a complex and chronic disease that involves disc cell senescence, death, and extracellular matrix (ECM) degradation. HOTAIR, a long non-coding RNA (lncRNA) is reportedly associated with autophagy, whereas autophagy is shown to promote IDD. However, how it affects nucleus pulposus (NP) cells, the primary component of intervertebral discs is still unclear. We hypothesized that HOTAIR promotes NP cell apoptosis and senescence through upregulating autophagy. Thus, silencing HOTAIR should inhibit autophagy and exert a therapeutic effect on IDD. Our in vitro experiments in human NP cells revealed that HOTAIR expression positively correlated with IDD grade, and overexpression enhanced autophagy. Autophagy inhibition via 3-methyladenine reversed HOTAIR stimulatory effects on apoptosis, senescence, and ECM catabolism, while the AMP-activated protein kinase (AMPK) inhibitor Compound C suppressed HOTAIR-induced autophagy through regulating AMPK/mTOR/ULK1 pathways. Our in vivo experiment then illustrated that silencing HOTAIR ameliorates IDD in rats. Collectively, we demonstrated that HOTAIR stimulates autophagy to promote NP cell apoptosis, senescence, and ECM catabolism. Therefore, silencing HOTAIR has the potential to become a treatment option for IDD.

6.
Biochim Biophys Acta Mol Basis Dis ; 1866(1): 165575, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31666206

RESUMO

Intervertebral disc degeneration (IVDD) is a well-known cause of lower back pain. Icariin has been shown to exert a protective effect on human nucleus pulposus (NP) cells and accordingly has implications for the prevention and treatment of IVDD; however, the molecular mechanisms underlying its action are not fully established. In this study, the mechanisms underlying its protection against hydrogen peroxide (H2O2)-induced oxidative stress injury were investigated. In vitro, we demonstrated that icariin inhibits H2O2-induced mitochondria-mediated apoptosis. It upregulates oxidative stress mediators, i.e., reactive oxygen species, and downregulates mitochondrial membrane potential. Nuclear factor erythroid 2-related factor 2 (Nrf-2) is a key factor involved in the regulation of the endogenous defense system. It was proved that icariin could activate the Nrf-2 signaling pathway, upregulate the protein expression of nuclear respiratory factor-1 and the mitochondrial transcription factor, promoting mitochondrial biogenesis in human NP cells. An Nrf-2 agonist and inhibitor promoted or partly abolished the protective effects of icariin on mitochondrial homeostasis. Moreover, it was demonstrated that the Nrf-2 signaling pathway could be inhibited by the phosphatidylinositol 3-Kinase/AKT pathway. In vivo, icariin ameliorated IVDD in a rat model by promoting Nrf-2 activity, and preserving extracellular matrix in NP cells. These data suggest that icariin could ameliorate IVDD in rat models in vivo. In summary, the protective effects of icariin on human NP cells may suppress the pathogenesis of IVDD via the Nrf-2 signaling pathway. Our findings suggest that the Nrf-2 signaling pathway is a novel therapeutic target for the treatment of IVDD.

7.
FEBS Open Bio ; 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31788976

RESUMO

Long-term or heavy use of glucocorticoids can cause severe necrosis of the femoral head, but the underlying mechanisms are still unclear. Recent studies have found that mitochondrial dynamics play an important role in femoral head necrosis. Here, we investigated the effect of dexamethasone on the mitochondrial function of mesenchymal stem cells. We observed that high concentrations of dexamethasone (10-6  mol·L-1 ) decreased cell activity, promoted apoptosis, elevated levels of reactive oxygen species and disrupted mitochondrial dynamics. Furthermore, dexamethasone (10-6  mol·L-1 ) inhibited osteogenesis of stem cells and promoted adipogenesis. These findings may facilitate greater understanding of the adverse effects of dexamethasone on the femoral head.

8.
Spine (Phila Pa 1976) ; 44(24): 1697-1704, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31794507

RESUMO

MINI: The surgical results of modified and traditional open-door laminoplasties were retrospectively compared. There were no differences in neurological outcomes and postoperative complications. However, compared with traditional laminoplasty, modified laminoplasty was associated with better maintenance of cervical curvature and ROM, as well as a lower incidence of postoperative axial symptoms. STUDY DESIGN: A retrospective comparative study. OBJECTIVE: The aim of this study was to evaluate the efficacy of modified unilateral open-door laminoplasty with posterior muscle-ligament complex preservation in treating cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: The prevalence of axial symptoms after open-door laminoplasty ranges from 5% to 86%. Current modified laminoplasty techniques cannot satisfactorily reduce postoperative axial symptoms. METHODS: From June 2014 to July 2016, 36 patients with CSM underwent modified laminoplasty with posterior muscle-ligament complex preservation (modified group) and 27 patients underwent traditional laminoplasty (control group). The demographics, operation duration, blood loss volume, cervical curvature, cervical curvature index (CCI), range of motion (ROM), cervical posterior muscle volume on magnetic resonance imaging (MRI), axial symptoms, visual analog scale (VAS) score, Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and complications were recorded and analyzed before operation, after operation, and at the final follow-up. RESULTS: Cervical flexion curvature, cervical curvature, ROM, and CCI were better in the modified group than in controls at the final follow-up (P < 0.01). Postoperative VAS and NDI scores were significantly reduced in the modified group compared with controls (1.15 ±â€Š0.76 vs. 2.63 ±â€Š1.06, 5.67 ±â€Š2.57 vs. 8.89 ±â€Š5.37, respectively) (P < 0.01). Posterior muscle volume at the hinge side in the modified group was not different at final follow-up relative to that before the operation, whereas it was reduced in controls (P < 0.01). Finally, the incidence of axial symptoms was significantly lower in the modified group than in controls (6% vs. 22%) (P = 0.03). CONCLUSION: Modified unilateral open-door laminoplasty with posterior muscle-ligament complex preservation is effective for treating CSM with good recovery of neurological functions and satisfactory maintenance of cervical curvature and ROM. Furthermore, it reduces the incidence of postoperative axial symptoms compared with conventional open-door laminoplasty. LEVEL OF EVIDENCE: 3.

9.
Stem Cell Res Ther ; 10(1): 376, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31806004

RESUMO

BACKGROUND: The umbilical cord blood (UCB) has been widely accepted as an alternative source of hematopoietic stem/progenitor cells (HSPCs) for transplantation, and its use in adults is still restricted because of low absolute numbers. To overcome this obstacle, expansion of UCB-HSPCs under feeder cell-based coculture is a promising possibility. In this study, we explored UCB-CD34+ cells ex vivo expansion using Wharton's jelly mesenchymal stem cells (WJ-MSCs) or umbilical vein endothelial cells (UVECs) as feeder layer-based serum-free coculture system with a cocktail of cytokines. METHODS: UCB-CD34+ cells were cultured in five different coculture conditions composed of umbilical cord stromal cells (WJ-MSCs or UVECs) with or without a cocktail of cytokines (SCF, FLT3L, and TPO). The cultured cells were harvested at day 10 and analyzed for phenotypes and functionalities, including total nuclear cells (TNCs), CD34+ cells, CD34+CD38- cells, colony-forming unit (CFU) for committed progenitors, and long-term culture initiating cells (LTC-ICs) for HSPCs. RESULTS: Our work showed the numbers of TNC cells, CD34+ cells, and CD34+CD38- cells were expanded under five coculture conditions, and the feeder layer-based cocultures further promoted the expansion. The numbers of colonies of CFU-GM, CFU-E/BFU-E, and CFU-GEMM in the cocultures with cytokines were significantly higher than their counterparts at day 0 (p < 0.05), while no significant difference (p > 0.05) in those without the addition of cytokines. The numbers of LTC-ICs were increased both under the WJ-MSCs and UVECs with cytokine cocultures, but only in the UVECs group showed a significant difference (p < 0.05), and were decreased under conditions without cytokine (p < 0.05). CONCLUSION: Our data demonstrate that both WJ-MSCs and UVECs as feeder layer could efficiently support the expansion of UCB-CD34+ cells in synergy with SCF, FLT3L, and TPO under serum-free culture condition. The UVECs combined with the 3GF cytokine cocktail could maintain the growth of LTC-ICs derived from UCB-CD34+ cells and even expand to some extent.

10.
Spine (Phila Pa 1976) ; 44(23): E1409-E1410, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31725691
11.
Proc Inst Mech Eng H ; 233(12): 1310-1317, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31617820

RESUMO

This study aimed to evaluate the safety and accuracy of mixed reality-based intraoperative three-dimensional navigated pedicle screws in three-dimensional printed model of fractured upper cervical spine. A total of 27 cervical model from patients of upper cervical spine fractures formed the study group. All the C1 and C2 pedicle screws were inserted under mixed reality-based intraoperative three-dimensional image-guided navigation system. The accuracy and safety of the pedicle screw placement were evaluated on the basis of postoperative computerized tomography scans. A total of 108 pedicle screws were properly inserted into the cervical three-dimensional models under mixed reality-based navigation, including 54 C1 pedicle screws and 54 C2 pedicle screws. Analysis of the dimensional parameters of each pedicle at C1/C2 level showed no statistically significant differences in the ideal and the actual entry points, inclined angles, and tailed angles. No screw was misplaced outside the pedicle of the three-dimensional printed model, and no ionizing X-ray radiation was used during screw placement under navigation. It is easy and safe to place C1/C2 pedicle screws under MR surgical navigation. Mixed reality-based navigation is feasible within upper cervical spinal fractures with improved safety and accuracy of C1/C2 pedicle screw insertion.

12.
ACS Appl Mater Interfaces ; 11(44): 41758-41769, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31610117

RESUMO

Bone repair and regeneration are greatly influenced by the local immune microenvironment. In this regard, the immunomodulatory capability of biomaterials should be considered when evaluating their osteogenic effects. In this study, we investigated the modulatory effects of gold nanoparticle (AuNP)-loaded mesoporous silica nanoparticles (Au-MSNs) on macrophages and the subsequent effects on the behavior of osteoblastic lineage cells. The results demonstrate that Au-MSNs could generate a favorable immune microenvironment by stimulating an anti-inflammatory response and promoting the secretion of osteogenic cytokines by macrophages. As a result, there is an enhancement of osteogenic differentiation in preosteoblastic MC3T3 cells as assessed by the increased expression of osteogenic markers, alkaline phosphatase (ALP) production, and calcium deposition. The immunomodulatory effects and direct osteogenic stimulation by Au-MSNs synergistically increased the osteogenic differentiation capability of MC3T3 cells as a result of crosstalk between Au-MSN-conditioned macrophages and Au-MSN-treated osteoblasts in a coculture system. An in vivo study further revealed that Au-MSNs could accelerate new bone formation in a critical-sized cranial defect site in rats based on computed tomography analysis and histological examination. Together, this novel Au-MSNs could significantly promote osteogenic activity by modulating the immune microenvironment, showing its therapeutic potential for bone tissue repair and regeneration.

13.
Exp Ther Med ; 18(4): 2933-2941, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31572536

RESUMO

Traumatic soft tissue defects such as bedsores, chronic skin ulcers, limb necrosis, osteonecrosis and other ischemic orthopedic diseases are the most clinically intractable and common problems in orthopedics due to unsatisfactory conventional treatments. The present study designed poly(ethylene glycol; PEG) hydrogels with covalently binded arginylglycylaspartic acid (RGD). Endothelial progenitor cells (EPCs) were encapsulated in the modified hydrogel along with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Results demonstrated that the modified hydrogel displayed good mechanical properties appropriate for a sustained release carrier. RGD modification significantly promoted EPC biocompatibility. VEGF and bFGF encapsulation enhanced the adhesion of EPCs, promoted the production of extracellular matrix and facilitated EPC proliferation. In addition, bFGF and VEGF induced angiogenesis. The combination of growth factors and EPCs in the hydrogel displayed a strong synergy to improve biocompatibility. The present results provided a potential novel treatment approach for soft tissue defects such as bone exposure, chronic skin ulcers, bedsores, limb necrosis, osteonecrosis and other ischemic diseases.

14.
ACS Cent Sci ; 5(9): 1591-1601, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31572786

RESUMO

Herein, a core-shell dual metal-organic framework (MOF) heterointerface is synthesized. The Prussian blue (PB) MOF acts as a core for the growth of a porphyrin-doped MOF which is named PB@MOF. Porphyrins can significantly enhance the transfer of photoinspired electrons from PB and suppress the recombination of electrons and holes, thus enhancing the photocatalytic properties and consequently promoting the yields of singlet oxygen rapidly under 660 nm illumination. PB@MOF can exhibit a better photothermal conversion efficiency up to 29.9% under 808 nm near-infrared irradiation (NIR). The PB@MOF heterointerface can possess excellent antibacterial efficacies of 99.31% and 98.68% opposed to Staphylococcus aureus and Escherichia coli, separately, under the dual light illumination of 808 nm NIR and 660 nm red light for 10 min. Furthermore, the trace amount of Fe and Zr ions can trigger the immune system to favor wound healing, promising that PB@MOF achieves the rapid therapy of bacterial infected wounds and environmental disinfection.

16.
Exp Mol Med ; 51(9): 110, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31554783

RESUMO

Intervertebral disc degeneration (IDD) is characterized by excessive apoptosis of nucleus pulposus (NP) cells and hyperactive extracellular matrix (ECM) catabolism. Our previous studies revealed the relationship between human islet amyloid polypeptide (hIAPP) and NP cell apoptosis. However, the role of hIAPP aggregates in IDD has not yet been investigated. This study aimed to determine whether the accumulation of hIAPP aggregates promotes IDD progression. The aggregation of hIAPP increased in human NP tissues during IDD. The deposition of hIAPP aggravated the compression-induced IDD that promoted NP cell apoptosis and ECM degradation via IL-1ß/IL-1Ra signaling in an ex vivo rat disc model. Moreover, neutralizing IL-1ß augmented the protective effects of hIAPP overexpression by decreasing hIAPP aggregation in human NP cells. These results suggest that the aggregation of hIAPP promotes NP cell apoptosis and ECM degradation ex vivo and in vitro by disrupting the balance of IL-1ß/IL-1Ra signaling.

17.
ACS Appl Mater Interfaces ; 11(39): 35513-35524, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31507175

RESUMO

Surface topography has been reported to play a key role in modulating cell behaviors, yet the mechanism through which it modulates these behaviors is not fully understood, especially in the case of three-dimensional (3D) topographies. In this study, a series of novel hemispherical 3D imprints ranging from the nanoscale to the microscale were prepared on titanium (Ti) surfaces using a customized interfacial lithography method. Mouse embryo osteoblast precursor cells (MC3T3-E1) were selected to investigate the solitary effect of specific hemispherical 3D imprints on cellular behaviors. The results indicated that varied hemispherical 3D imprints can affect the formation of filopodia and the arrangement of the cytoskeleton in different ways. Specifically, they can alter the spreading morphologies of cells and lead to deformation of the nucleus, which eventually affects cell proliferation and osteogenic differentiation. Cells cultured on different hemispherical 3D imprints exhibited promoted proliferation and osteogenic differentiation to different degrees; for example, cells cultured on 90 and 500 nm hemispherical imprints formed abundant filopodia and exhibited the highest alkaline phosphatase activity and osteogenic gene expression, respectively. Four-week tibia implantation also confirmed that 90 nm hemispherical imprints improved the osteogenic ability in vivo compared with an unpatterned Ti substrate. In addition to promoted proliferation, colonization of more cells on the surface of implants and induction of rapid osteogenic differentiation can occur. Our work provides a rational way to balance cell proliferation and differentiation, which can accelerate bone integration of an implant and host tissue.

18.
Environ Pollut ; 255(Pt 2): 113226, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546075

RESUMO

In this paper, Fe3O4@MIL-68 (Al), a magnetic aluminum-based metal organic framework, was synthesized by a simple method and used as a novel and effective adsorbent for the removal of minocycline (MC) from aqueous solutions. The material was thoroughly characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and N2 adsorption isotherms. The characterization results showed that the original structure of MIL-68(Al) was unchanged by the addition of Fe3O4 nanoparticles, and that the obtained material had a strong magnetic response which also promoted its adsorption. Batch adsorption experiments were conducted by the varying the adsorption time, temperature, initial MC concentration and pH. The maximum adsorption amount of MC onto Fe3O4@MIL-68 (Al) was 248.05 mg g-1 (t = 160 min, pH = 6, Co = 60 mg L-1), and the adsorption kinetics followed a pseudo-second-order model, and the adsorption isotherms conformed to the Freundlich equation. The adsorption mechanism of the magnetic metal organic framework materials were determined to involve complex interactions, including Al-N and Fe-N covalent bonds, hydrogen bonding, electrostatic adsorption, and π-π stacking. Combined the results indicate that Fe3O4@MIL-68 (Al) is an outstanding adsorbent for the removal of MC from water.


Assuntos
Minociclina/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Alumínio/química , Ligações de Hidrogênio , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Magnetismo , Estruturas Metalorgânicas , Microscopia Eletrônica de Varredura , Água/química , Poluentes Químicos da Água/química , Difração de Raios X
19.
Arthritis Res Ther ; 21(1): 201, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481088

RESUMO

BACKGROUND: Intervertebral disc degeneration (IDD) has a complicated and enigmatic pathogenic process. Accumulating evidence shows that long non-coding RNAs (LncRNAs) play a role in the pathogenesis of IDD. This study aimed to investigate the expression and role of the LncRNA HOTAIR in IDD pathogenesis. METHODS: Nucleus pulposus (NP) tissue samples from 10 patients with idiopathic scoliosis and 10 patients with lumbar disc herniation were collected. qRT-PCR was used to assess the expression of HOTAIR and ECM-related genes; western blotting was used to detect the expression of senescence biomarkers, apoptosis-related proteins, and Wnt/ß-catenin pathway; flow cytometry was used to detect apoptosis; and the MTT assay was used to determine cell proliferation. Moreover, a classic needle-punctured rat tail model was used to investigate the role of HOTAIR in IDD in vivo. RESULTS: The results showed that the expression of HOTAIR significantly increased during IDD progression. The overexpression of HOTAIR was found to induce nucleus pulposus (NP) cell senescence, apoptosis, and extracellular matrix (ECM) degradation. HOTAIR silencing by RNA interference in NP cells prevented interleukin-1ß-induced NP cell senescence, apoptosis, and ECM degradation. Furthermore, we found that the Wnt/ß-catenin pathway played a role in regulating HOTAIR to induce these changes in NP cells. Moreover, HOTAIR inhibition in a rat model effectively attenuated IDD symptoms in vivo. CONCLUSIONS: Our findings confirmed that HOTAIR promoted NP cell senescence, apoptosis, and ECM degradation via the activation of the Wnt/ß-catenin pathway, while silencing HOTAIR attenuated this degeneration process, indicating a potential therapeutic target against IDD.

20.
Chemosphere ; 237: 124493, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31398611

RESUMO

Aluminum-based metal-organic framework/sodium alginate-chitosan (Al-MOF/SA-CS) composite beads were synthesized and employed as an adsorbent for the removal of bisphenol A (BPA). Several methods, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), nitrogen adsorption-desorption isotherms and X-ray photoelectron spectroscopy (XPS), were used to characterize the prepared adsorbents. Results demonstrated that the introduction of CS could change the porosity of the beads and the obtained Al-MOF/SA-CS composite beads possessed higher surface area and total pore volume comparing with the beads without CS. Batch experiments were carried out to explore the adsorption performance and the results displayed that the enhanced adsorption capacity was achieved by Al-MOF/SA-CS beads compared to the Al-MOF/SA ones. It is also found from the fitting results that the adsorption process fitted well with the pseudo-second-order kinetics model and followed the Freundlich isotherm model. Importantly, the composite beads could be easily recycled and regenerated by methanol and the adsorption efficiency still maintained as high as 96% even after five cycles. Furthermore, it can be inferred from the experimental results that the π-π stacking, hydrogen bonding and cation-π interaction could be the primary adsorption mechanisms. Considering the high adsorption properties, good water stability, especially easy separation, and excellent recyclability, Al-MOF/SA-CS composite beads could be a promising adsorbent for the removal of BPA from contaminated water.


Assuntos
Alumínio/química , Compostos Benzidrílicos/análise , Fenóis/análise , Poluentes Químicos da Água/análise , Adsorção , Alginatos/química , Quitosana/química , Ligações de Hidrogênio , Concentração de Íons de Hidrogênio , Cinética , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Água , Difração de Raios X
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