Anion Modulation of Ag-Imidazole Cuboctahedral Cage Microenvironments for Efficient Electrocatalytic CO2 Reduction.

How to achieve CO2 electroreduction in high efficiency is a current challenge with the mechanism not well understood yet. The metal-organic cages with multiple metal sites, tunable active centers, and well-defined microenvironments may provide a promising catalyst model. Here, we report self-assembly of Ag4L4 type cuboctahedral cages from coordination dynamic Ag+ ion and triangular imidazolyl ligand 1,3,5-tris(1-benzylbenzimidazol-2-yl) benzene (Ag-MOC-X, X=NO3, ClO4, BF4) via anion template effect. Notably, Ag-MOC-NO3 achieves the highest CO faradaic efficiency in pH-universal electrolytes of 86.1 % (acidic), 94.1 % (neutral) and 95.3 % (alkaline), much higher than those of Ag-MOC-ClO4 and Ag-MOC-BF4 with just different counter anions. In situ attenuated total reflection Fourier transform infrared spectroscopy observes formation of vital intermediate *COOH for CO2-to-CO conversion. The density functional theory calculations suggest that the adsorption of CO2 on unsaturated Ag-site is stabilized by C-H⋅⋅⋅O hydrogen-bonding of CO2 in a microenvironment surrounded by three benzimidazole rings, and the activation of CO2 is dependent on the coordination dynamics of Ag-centers modulated by the hosted anions through Ag⋅⋅⋅X interactions. This work offers a supramolecular electrocatalytic strategy based on Ag-coordination geometry and host-guest interaction regulation of MOCs as high-efficient electrocatalysts for CO2 reduction to CO which is a key intermediate in chemical industry process.

Atsttrin regulates osteoblastogenesis and osteoclastogenesis through the TNFR pathway.

Osteoporosis is a systemic metabolic bone disorder for which inflammatory cytokines play an important role. To develop new osteoporosis treatments, strategies for improving the microenvironment for osteoblast and osteoclast balance are needed. Tumor necrosis factor-α (TNF-α) plays an important role in the initiation and development of osteoporosis. Atsttrin is an engineered protein derived from the growth factor, progranulin (PGRN). The present study investigates whether Atsttrin affects osteoclast formation and osteoblast formation. Here we show Atsttrin inhibits TNF-α-induced osteoclastogenesis and inflammation. Further mechanistic investigation indicates Atsttrin inhibits TNF-α-induced osteoclastogenesis through the TNFR1 signaling pathway. Moreover, Atsttrin rescues TNF-α-mediated inhibition of osteoblastogenesis via the TNFR1 pathway. Importantly, the present study indicates that while Atsttrin cannot directly induce osteoblastogenesis, it can significantly enhance osteoblastogenesis through TNFR2-Akt-Erk1/2 signaling. These results suggest that Atsttrin treatment could potentially be a strategy for maintaining proper bone homeostasis by regulating the osteoclast/osteoblast balance. Additionally, these results provide new insights for other bone metabolism-related diseases.

Melittin acupoint injection in attenuating bone erosion in collagen-induced arthritis mice via inhibition of the RANKL/NF-κB signaling pathway.

Background: Rheumatoid arthritis (RA) is an autoimmune disease leading to chronic joint inflammation. Bone erosion is the most serious pathological condition of RA and the main cause of joint deformities and disability. Melittin acupoint injection (MAI) is an effective traditional Chinese medicine (TCM) method for RA treatment. This study aimed to investigate the effect of MAI on RA bone erosion and to elucidate the underlying mechanism. Methods: A collagen-induced arthritis (CIA) mouse model was established as the experimental subject. MAI was administrated once every other day for 28 days to mice with CIA. The effects of MAI on joint diseases were assessed by body weight, arthritis index (AI) score, swollen joint count (SJC) score, and hind paw thickness. Ankle radiological changes were captured by micro-computed tomography (micro-CT) and histological changes were observed by pathological staining. Organ histological changes, spleen index, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine (Crea) levels of serum were tested to evaluate the toxicity of MAI. Cytokine expression levels were confirmed by enzyme-linked immunosorbent assay (ELISA) to evaluate the immunity of CIA mice. Results: MAI administration markedly improved the clinical signs of CIA in mice, including hind paw thickness, AI, and the number of swollen paw joints (most of them P<0.05 or even <0.01). According to histopathological analysis, MAI ameliorated inflammatory cell infiltration, synovial hyperplasia, pannus formation, and bone erosion (all P<0.01). Micro-CT and tartrate-resistant acid phosphatase (TRAP) staining (P<0.01) also revealed that MAI could relieve bone erosion via reducing the formation of osteoclasts. Not only could MAI relieve the immunological boost [P<0.05 for the high-dose MAI (HM) group], but also it had no liver or kidney side effects (P>0.05). In addition, it decreased the serum levels of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) and increased the serum levels of IL-4 and IL-10 (the majority of P<0.05 or even <0.01). Transcriptome sequencing results indicated that MAI affected the expression of osteoclast differentiation pathway genes, which was connected with the receptor activator of the nuclear factor κB ligand/nuclear factor kappa B (RANKL/NF-κB) pathway. Conclusions: Based on our findings, MAI could suppress joint inflammation and inhibit RANKL/NF-κB-mediated osteoclast differentiation to rescue bone erosion in CIA mice, suggesting that MAI can be a potentially therapeutic substance for RA.

Application of a new body surface-assisting puncture device in percutaneous transforaminal endoscopic lumbar discectomy.

BACKGROUND: Accurate puncture and localization are critical for percutaneous transforaminal endoscopic lumbar discectomy surgery. However, several punctures are often required, followed by X-ray fluoroscopy, which can increase surgical risk and complications. The aim of this study was to demonstrate a new body surface-assisting puncture device that can be used in percutaneous transforaminal endoscopic lumbar discectomy and to assess its clinical effectiveness. METHODS: Three hundred and forty-four patients were treated with percutaneous transforaminal endoscopic lumbar discectomy surgery in the Spinal Surgery Department of Taian City Central Hospital, China, between January 2020 and February 2022. Of these, 162 patients (the locator group) were punctured using a body surface-assisting puncture device while and 182 patients (the control group) were punctured using the traditional blind puncture method. The number of punctures, radiation dose during X-ray fluoroscopy, operation time, and surgical complications were compared between the two groups. RESULTS: The average number of punctures was 2.15 ± 1.10 in the locator group which was significantly lower than that in the control group (5.30 ± 1.74; P < 0.001). The average X-ray fluoroscopy radiation dose in the locator group was significantly lower at 2.34 ± 0.99 mGy, compared with 5.13 ± 1.29 mGy in the control group (P < 0.001). The mean operation time was also significantly less in locator group (47.06 ± 5.12 vs. 62.47 ± 5.44 min; P = 0.008). No significant differences in surgical complications were found between the two groups (P > 0.05). CONCLUSION: The use of a new body surface-assisting puncture device in percutaneous transforaminal endoscopic lumbar discectomy surgery can significantly reduce the number of punctures and X-ray fluoroscopy radiation dose, as well as shortening the operation time, without increasing surgical complications. This device is cheap, easy to operate, and suitable for all hospitals and spine surgeons, especially for small hospitals, with also no extra costs for patients.

The Classification of Axial Deformity in Patients with Basilar Invagination.

OBJECTIVE: To summarize the variation types of the axis in patients with basilar invagination (BI), then propose a classification scheme of the axis deformity. METHODS: From December 2013 to September 2020, 92 patients (male 42, female 50) who were diagnosed with BI were studied retrospectively. Based on the imaging data of CT, the width and height of the axis pedicle and the sagittal diameter of the lateral mass were measured in each patient. According to the development of axis pedicle and lateral mass, the types of axis variation were summarized, and then the classification scheme of axis deformity was put forward. RESULTS: All cases were analyzed and axis deformities were divided into four types. Type I: the axis is basically normal (53 cases, 57.6%). Type II: axis lateral mass is dysplasia (eight cases, 8.7%), which includes two subtypes: type IIA, the axis unilateral lateral mass is dysplasia (three cases); type IIB, the axis bilateral lateral masses are all dysplasia (five cases). Type III: axis pedicle is dysplasia (11 cases, 12%), which is subdivided into two subtypes: type IIIA, the axis unilateral pedicle is dysplasia (six cases); type IIIB, the axis bilateral pedicles are all dysplasia (five cases). Type IV: axis pedicle and lateral mass are all dysplasia (20 cases, 21.7%), this type contains the following four subtypes: type IVA, the unilateral axis pedicle and unilateral lateral mass (contralateral or ipsilateral) are all hypoplasia (four cases); type IVB, the unilateral axis pedicle and bilateral lateral masses are all hypoplasia (five cases); type IVC, the bilateral axis pedicles and unilateral lateral mass are all dysplasia (seven cases); type IVD, the bilateral axis pedicles and bilateral lateral masses are all dysplasia (four cases). The left and right abnormal lateral mass sagittal diameter (Type II) was (7.23 ± 1.39) mm and (5.96 ± 1.37) mm, respectively, the left and right abnormal pedicle width (Type III) was (2.61 ± 1.01) mm and (3.23 ± 0.66) mm, respectively, left and right abnormal pedicle height (Type III) was (5.43 ± 2.19) mm and (4.92 ± 1.76) mm, respectively. Moreover, the classification scheme has good repeatability and credibility. CONCLUSIONS: The classification about axis deformity could provide personalized guidance for axis screw placement in the BI and other upper cervical surgery, and axis screw placement errors would be effectively avoided.

Scutellarin Protects Against Mitochondrial Reactive Oxygen Species-Dependent NLRP3 Inflammasome Activation to Attenuate Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IVDD) is a predominant cause of disc herniation and is widespread worldwide. Inflammatory responses, mitochondrial dysfunction, and extracellular matrix degradation are known to be involved in IVDD. Scutellarin, an active ingredient extracted from Erigeron breviscapus (Vaniot) Ha, Hand-Mazz, is reported to exhibit therapeutic potential in several degenerative diseases by suppressing inflammation and regulating metabolism. However, whether scutellarin can improve IVDD remains unknown. Human primary nucleus pulposus cells (HNPCs) were cultured and stimulated with TNF-α in the presence or absence of scutellarin. Furthermore, a rat needle puncture model was established, and scutellarin was injected into the IVD to verify its protective function against IVDD. Scutellarin attenuated the inflammatory reaction and retained the production of major IVD components both in vitro and in vivo. Mechanistically, scutellarin reduced the amount of reactive oxygen species (ROS), alleviated mitochondrial damage, and decreased the expression levels of apoptosis-related biomarkers upon stimulation with TNF-α. In addition, scutellarin antagonized the activation of the nuclear factor κ-light-chain-enhancer of activated B (NF-κB) signaling pathway and the mitogen-activated protein kinase (MAPK) signaling pathway and suppressed the activity of the NLRP3 inflammasome mediated by TNF-α. This study reveals that scutellarin protects against degeneration of nucleus pulposus cells, which might shed light on treatment of IVDD in the future.

TGF-ß1-induced bone marrow mesenchymal stem cells (BMSCs) migration via histone demethylase KDM6B mediated inhibition of methylation marker H3K27me3.

Mesenchymal stem cells (MSCs) are widely used in clinical research and therapy. Since the number of MSCs migration is extremely crucial at the lesion site, exploring the mechanisms to enhance the migration of MSCs is necessary. Therefore, this study focused on the epigenetic mechanisms in MSCs migration. TGF-ß1 stimulated bone marrow mesenchymal stem cells (BMSCs) to promote cell migration at lesion sites in vitro and in vivo. The mRNA and protein levels of several migration-related genes (N cadherin, CXCR4, FN1) were enhanced. The trimethylation marker H3K27me3 recruitment on the promoter of these genes were studied to dissect the epigenetic mechanisms. TGF-ß1 elevated the levels of KDM6B leading to removal of repression marker H3K27me3 in the promoter region of N cadherins and FN1. Congruently, knockdown of demethylase KDM6B substantially affected the TGF-ß1 induced BMSCs migration. This promoted the down-regulation of various migration-related genes. Collectively, epigenetic regulation played an important role in BMSCs migration, and H3K27me3 was at least partially involved in the migration of BMSCs induced by TGF-ß1.

Synergistic stimulation of osteoblast differentiation of rat mesenchymal stem cells by leptin and 25(OH)D3 is mediated by inhibition of chaperone-mediated autophagy.

BACKGROUND: Vitamin D is important for the mineralization of bones by stimulating osteoblast differentiation of bone marrow mesenchymal stem cells (BMMSCs). BMMSCs are a target of vitamin D action, and the metabolism of 25(OH)D3 to biologically active 1α,25(OH)2D3 in BMMSCs promotes osteoblastogenesis in an autocrine/paracrine manner. Our previous study with human BMMSCs showed that megalin is required for the 25(OH)D3-DBP complex to enter cells and for 25(OH)D3 to stimulate osteoblast differentiation in BMMSCs. Furthermore, we reported that leptin up-regulates megalin in those cells. Leptin is a known inhibitor of PI3K/AKT-dependent chaperone-mediated autophagy (CMA). In this study, we tested the hypothesis that leptin acts synergistically with 25(OH)D3 to promote osteoblastogenesis in rat BMMSCs by a mechanism that entails inhibition of PI3K/AKT-dependent CMA. METHODS: BMMSCs were isolated from rat bone marrow (4-week-old male SD rats); qRT-PCR and western immunoblots or immunofluorescence were used to evaluate the expression of megalin, ALP, COL1A1, RUNX2, OSX, OSP, and CMA in rBMMSCs. The osteoblast differentiation was evaluated by ALP activity, ALP staining, and calcium deposition. The viability of rBMMSCs was assessed with the CCK-8 kit. Biosynthesis of 1α,25(OH)2D3 was measured by a Rat 1α,25(OH)2D3 ELISA Kit. RESULTS: The combination of leptin and 25(OH)D3 treatment significantly enhanced osteoblast differentiation as shown by ALP activity, ALP staining, and calcium deposition, the expression of osteogenic genes ALP, COL1A1, RUNX2, OSX, and OSP by qRT-PCR and western immunoblots in rBMMSCs. Leptin enhanced the expression of megalin and synthesis of 1α,25(OH)2D3 in rBMMSCs. Our data showed that leptin inhibited CMA activity of rBMMSCs by activating PI3K/AKT signal pathway; the ability of leptin to enhance 25(OH)D3 promoted osteoblast differentiation of rBMMSCs was weakened by the PI3K/AKT signal pathway inhibitor. CONCLUSIONS: Our data reveal the mechanism by which leptin and 25(OH)D3 promote osteoblast differentiation in rBMMSCs. Leptin promoted the expression of megalin by inhibiting CMA, increased the utilization of 25(OH)D3 by rBMMSCs, and enhanced the ability of 25(OH)D3 to induce osteoblast differentiation of rBMMSCs. PI3K/AKT is at least partially involved in the regulation of CMA. These data indicate the importance of megalin in BMMSCs for vitamin D's role in skeletal health.

TNF-α induces up-regulation of MicroRNA-27a via the P38 signalling pathway, which inhibits intervertebral disc degeneration by targeting FSTL1.

The mechanism of intervertebral disc degeneration is still unclear, and there are no effective therapeutic strategies for treating this condition. miRNAs are naturally occurring macromolecules in the human body and have many biological functions. Therefore, we hope to elucidate whether miRNAs are associated with intervertebral disc degeneration and the underlying mechanisms involved. In our study, differentially expressed miRNAs were predicted by the GEO database and then confirmed by qPCR and in situ hybridization. Apoptosis of nucleus pulposus cells was detected by flow cytometry and Bcl2, Bax and caspase 3. Deposition of extracellular matrix was assessed by Alcian blue staining, and the expression of COX2 and MMP13 was detected by immunofluorescence, Western blot and qPCR. Moreover, qPCR was used to detect the expression of miR27a and its precursors. The results showed that miR27a was rarely expressed in healthy intervertebral discs but showed increased expression in degenerated intervertebral discs. Ectopic miR27a expression inhibited apoptosis, suppressed the inflammatory response and attenuated the catabolism of the extracellular matrix by targeting FSTL1. Furthermore, it seems that the expression of miR27a was up-regulated by TNF-α via the P38 signalling pathway. So we conclude that TNF-α and FSTL1 engage in a positive feedback loop to promote intervertebral disc degeneration. At the same time, miR27a is up-regulated by TNF-α via the P38 signalling pathway, which ameliorates inflammation, apoptosis and matrix degradation by targeting FSTL1. Thus, this negative feedback mechanism might contribute to the maintenance of a low degeneration load and would be beneficial to maintain a persistent chronic disc degeneration.

Follistatin-Like 1 Attenuation Suppresses Intervertebral Disc Degeneration in Mice through Interacting with TNF-α and Smad Signaling Pathway.

BACKGROUND: Inflammation plays an important role in intervertebral disc degeneration (IDD). The protein follistatin-like 1 (FSTL1) plays a proinflammatory role in a variety of inflammatory diseases. OBJECTIVES: The purpose of this study was to investigate whether IDD could be delayed by inhibiting FSTL-1 expression. METHODS: We established a puncture-induced IDD model in wild-type and FSTL-1+/- mice and collected intervertebral discs (IVDs) from the mice. Safranin O staining was used to detect cartilage loss of IVD tissue, and HE staining was used to detect morphological changes of IVD tissue. We measured the expression of FSTL-1 and related inflammatory indicators in IVD tissues by immunohistochemical staining, real-time PCR, and Western blotting. RESULTS: In the age-induced model of IDD, the level of FSTL-1 increased with the exacerbation of degeneration. In the puncture-induced IDD model, FSTL-1-knockdown mice showed a reduced degree of degeneration compared with that of wild-type mice. Further experiments showed that FSTL-1 knockdown also significantly reduced the level of related inflammatory factors in IVD. In vitro experiments showed that FSTL-1 knockdown significantly reduced TNF-α-induced inflammation. Specifically, the expression levels of the inflammatory factors COX-2, iNOS, MMP-13, and ADAMTS-5 were reduced. Knockdown of FSTL-1 attenuated inflammation by inhibiting the expression of P-Smad1/5/8, P-Erk1/2, and P-P65. CONCLUSION: Knockdown of FSTL-1 attenuated inflammation by inhibiting the TNF-α response and Smad pathway activity and ultimately delayed IDD.

Stromal cell-derived factor-1 promotes osteoblastic differentiation of human bone marrow mesenchymal stem cells via the lncRNA-H19/miR-214-5p/BMP2 axis.

BACKGROUND: Stromal cell-derived factor-1 (SDF-1) plays an important role in the osteoblastic differentiation of human bone marrow mesenchymal stem cells (hBMMSCs), but the specific mechanism remains unclear. Our study aimed to clarify the role of the lncRNA-H19/miR-214-5p/BMP2 axis in the osteoblastic differentiation of hBMMSCs induced by SDF-1. METHODS: We used reverse-transcriptase polymerase chain reaction, western blotting, alkaline phosphatase activity test, and Alizarin red staining to evaluate the osteoblastic differentiation of primary hBMMSCs and the luciferase reporter assay to determine if lncRNA-H19 binds with miR-214-5p. RESULTS: Our results indicated that SDF-1 (50 ng/mL) promotes the osteoblastic differentiation of hBMMSCs, significantly upregulates osteoblastogenic genes (OCN, OSX, RUNX2, and ALP), and increases Alizarin red staining, alkaline phosphatase activity, and lncRNA-H19 expression. Luciferase reporter assay verified that lncRNA-H19 binds with and represses miR-214-5p, thereby upregulating BMP2 expression. Use of miR-214-5p inhibitor or overexpression of lncRNA-H19 can promote the osteoblastic differentiation of hBMMSCs, but miR-214-5p or shH19 inhibits the osteoblastic differentiation of hBMMSCs. Treatment with an miR-214-5p inhibitor could rescue the inhibitory effect of shH19 on the osteoblastic differentiation of hBMMSCs. CONCLUSIONS: Taken together, SDF-1 promotes the osteoblastic differentiation of hBMMSCs through the lncRNA-H19/miR-214-5p/BMP2 axis. Increased osteoblastic differentiation by an miR-214-5p inhibitor reveals a new possible strategy for the treatment of bone defect and osteoporosis.

Corrigendum to "Controlled Release of Interleukin-1 Receptor Antagonist from Hyaluronic Acid-Chitosan Microspheres Attenuates Interleukin-1ß-Induced Inflammation and Apoptosis in Chondrocytes".

[This corrects the article DOI: 10.1155/2016/6290957.].

Controlled Release of Interleukin-1 Receptor Antagonist from Hyaluronic Acid-Chitosan Microspheres Attenuates Interleukin-1ß-Induced Inflammation and Apoptosis in Chondrocytes.

This paper investigates the protective effect of interleukin-1 receptor antagonist (IL-1Ra) released from hyaluronic acid chitosan (HA-CS) microspheres in a controlled manner on IL-1ß-induced inflammation and apoptosis in chondrocytes. The IL-1Ra release kinetics was characterized by an initial burst release, which was reduced to a linear release over eight days. Chondrocytes were stimulated with 10 ng/ml IL-1ß and subsequently incubated with HA-CS-IL-1Ra microspheres. The cell viability was decreased by IL-1ß, which was attenuated by HA-CS-IL-1Ra microspheres as indicated by an MTT assay. ELISA showed that HA-CS-IL-1Ra microspheres inhibited IL-1ß-induced inflammation by attenuating increases in NO2- and prostaglandin E2 levels as well as increase in glycosaminoglycan release. A terminal deoxyribonucleotide transferase deoxyuridine triphosphate nick-end labeling assay revealed that the IL-1ß-induced chondrocyte apoptosis was decreased by HA-CS-IL-1Ra microspheres. Moreover, HA-CS-IL-1Ra microspheres blocked IL-1ß-induced chondrocyte apoptosis by increasing B-cell lymphoma 2 (Bcl-2) and decreasing Bcl-2-associated X protein and caspase-3 expressions at mRNA and protein levels, as indicated by reverse-transcription quantitative polymerase chain reaction and western blot analysis, respectively. The results of the present study indicated that HA-CS-IL-1Ra microspheres as a controlled release system of IL-1Ra possess potential anti-inflammatory and antiapoptotic properties in rat chondrocytes due to their ability to regulate inflammatory factors and apoptosis associated genes.