Oxygen Electrode PrBa0.5Sr0.5Co1.5Fe0.5O5+δ-BaZr0.1Ce0.7Y0.1Yb0.1O3-δ with Different Composite Proportions for Proton-Conducting Solid Oxide Electrolysis Cells.

Proton-conducting solid oxide electrolysis cell (H-SOEC), as a hydrogen production device using proton conductor oxides as an electrolyte, has gained attention due to its various advantages of being more suitable for operating conditions at intermediate and low temperatures. However, its commercialization urgently needs to address the issue of insufficient catalytic activity of the oxygen electrode at lower temperatures. In this work, PrBa0.5Sr0.5Co1.5Fe0.5O5+δ-BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (PBSCF-BZCYYb) series composite materials (denoted as PBSCF-BZCYYb46, PBSCF- BZCYYb55, and PBSCF-BZCYYb64 based on the mass ratios of PBSCF and BZCYYb as 4:6, 5:5, and 6:4, respectively) are prepared and applied as oxygen electrodes for H-SOECs. The H-SOECs with the structure of PBSCF-BZCYYb|BZCYYb|NiO-BZCYYb (active layer)|NiO-BZCYYb (support layer) are prepared and recorded as Cell 1, Cell 2, and Cell 3 with PBSCF-BZCYYb46, PBSCF-BZCYYb55, and PBSCF-BZCYYb64 as oxygen electrodes. The H-SOECs exhibit electrolysis current densities of 669.00, 743.80, and 503.30 mA cm-2 under 1.3 V at 650 °C, respectively. The cells also show considerable stability in the constant voltage electrolysis of 179.5, 152.8, and 83.0 h, respectively. Through the comparison of various electrochemical properties, PBSCF-BZCYYb55 is considered the most promising oxygen electrode material in this work.

Exogenous Indian hedgehog antagonist damages intervertebral discs homeostasis in adult mice.

Background: Vismodegib, as an exogenous Indian hedgehog (Ihh) antagonist, has been approved by the Food and Drug Administration (FDA) for the clinical treatment of patients with basal cell carcinoma, and previous observations implicate the potential therapeutic of vismodegib in osteoarthritis treatment. However, there is no direct evidence for the role of Ihh signaling in intervertebral discs (IVDs) homeostasis of adult mice. The aim of the present study is to assess the effect of systemic administration of Smoothened inhibitor (SMOi) - vismodegib on IVDs homeostasis during the adult stage. Methods: The expression of glioma-associated oncogene homolog 1 (Gli1), the downstream targeting gene of Ihh signaling, in IVDs of adult mice after receiving systemic administration of SMOi was examined by immunohistochemistry. The pathological changes of vertebral bodies after SMOi treatment were evaluated by X-ray and micro-CT. The effects of SMOi on homeostasis of IVDs including cartilaginous endplates (CEP), growth plates (GP) and annulus fibrous (AF) were evaluated by histological analysis. The expressions of Aggrecan, Matrix metalloproteinase 13 (MMP13) and Runt-related transcription factor 2 (Runx2), in IVDs were also investigated by immunohistochemistry. Changes in chondrocyte apoptosis and proliferation in IVDs were evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and analyzing the expression of the cell proliferation antigen Ki-67. Results: Systemic administration of SMOi significantly decreased the expression of Gli1 in IVDs that indicating effective inhibition of Ihh signaling. Bone mass of vertebral bodies was diminished after SMOi treatment. Moreover, IVDs degeneration (IDD) like defects including CEP sclerosis, degenerative nucleus pulposus (NP) and fissure within AF, as well as narrowed or fused GP and loss bone mass of vertebral bodies was observed in SMOi-treated mice. The severity of IDD was time-dependent with the administration of SMOi treatment after 2-8 weeks. The expressions of Aggrecan, MMP13 and Runx2 in IVDs of mice receiving SMOi treatment were significantly decreased. In addition, chondrocyte apoptosis was significantly enhanced, while chondrocyte proliferation was significantly inhibited. Conclusions: Our study propose that systemic administration of vismodegib damages IVDs homeostasis via inhibition of Ihh signaling in adult mice. The clinical application of Ihh signaling antagonists such as vismodegib should be careful considering these side adverse. The Translational Potential of this Article: Vismodegib as an exogenous antagonist of Ihh signaling has been approved by the FDA for the clinical treatment of patients with basal cell carcinoma. However, it is still unknown whether vismodegib will has adverse effects on the patient or animal model of IVDs cartilage homeostasis. Based on our study, systemic administration of vismodegib damages IVDs homeostasis via inhibition of Ihh signaling in adult mice and special attention should be paid to the clinical application of vismodegib.

Transcranial direct-current stimulation protects against cerebral ischemia-reperfusion injury through regulating Cezanne-dependent signaling.

Transcranial direct-current stimulation (tDCS) is proved safe and shows therapeutic effect in cerebral ischemic stroke in clinical trials. But the underlying molecular mechanisms remain unclear. Here we show that tDCS treatment reduces the infarct volume after rat cerebral ischemia-reperfusion (I/R) injury and results in functional improvement of stroke animals. At the cellular and molecular level, tDCS suppresses I/R-induced upregulation of Cezanne in the ischemic neurons. Cezanne inhibition confers neuroprotection after rat I/R and oxygen glucose deprivation (OGD) in the cortical neuronal cultures. Inhibiting Cezanne increases the level of SIRT6 that is downregulated in the ischemic neurons. Suppressing SIRT6 blocks Cezanne inhibition-induced neuroprotective effect and overexpressing SIRT6 attenuates OGD-induced neuronal death. We further show that downregulating Cezanne reduces DNA double-strand break (DSB) through upregulation of SIRT6 in OGD-insulted neurons. Together, this study suggests that Cezanne-dependent SIRT6-DNA DSB signaling pathway may mediate the neuroprotective effect of tDCS in ischemic neurons.

[Experimental study on the effect of zinc finger protein A20 on lumbar intervertebral disc degeneration in rabbits].

OBJECTIVE: To investigate the effect of zinc finger protein A20 on lumbar intervertebral disc degeneration in rabbits. METHODS: Twenty-six 3-month-old New Zealand rabbits, 2.0-2.5 kg in weight, were used to establish the model of intervertebral disc degeneration at L 3, 4, L 4, 5, and L 5, 6 by transabdominal needle puncture. At 4 weeks after operation, the 24 rabbits were randomly divided into 4 groups after successful modeling, which checked by MRI. The target intervertebral discs of each group were injected with zinc finger protein A20 overexpressed adenovirus (Ov-A20 group), empty carrier adenovirus (NC group), phosphate buffer saline (control group), and shRNA-A20 adenovirus (Sh-A20 group). The biological responses of animals in each group were comprehensive scored before 1 day of injection and after 1, 2, 3, and 6 days of injection. At 2, 4, and 8 weeks after injection, the animals in each group were observed by MRI to obtain the exact T2 relaxation time (T2 signal value). After MRI examination, the animals were killed to take the degenerative intervertebral disc tissue; and the tissue was detected by Alcian blue staining to observed the intervertebral disc degeneration. The expressions of zinc finger protein A20, collagen Ⅱ, and aggrecan were detected by immunohistochemistry staining. The expressions of zinc finger protein A20, nuclear factor κB binding protein [P65, phosphate P65 (P-P65), collagen Ⅱ, aggrecan], inflammatory factors [tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß)], autophagy-related protein [LC3 (LC3Ⅱ/LC3Ⅰ) and P62] were detected by Western blot. RESULTS: The comprehensive score of biological response in each group after injection was significantly lower than that before injection ( P<0.05). At 6 days after injection, the comprehensive score of biological response in the Sh-A20 group was significantly lower than that in other groups ( P<0.05), and there was no significant difference among other groups ( P>0.05). The detection of MRI showed that the T2 signal value in the Ov-A20 group was the highest at 2, 4, and 8 weeks after injection ( P<0.05), and the T2 signal value in the Sh-A20 group was the lowest at 2 and 4 weeks after injection ( P<0.05). There was no significant difference between other groups ( P>0.05). Alcian blue staining showed that the expression of aggrecan was the highest in Ov-A20 group and the lowest in Sh-A20 group at 4 weeks ( P<0.05); the expression of aggrecan in Ov-A20 group was the highest at 8 weeks ( P<0.05), and there was no significant difference between other groups ( P>0.05). Immunohistochemical staining showed that the expressions of zinc finger protein A20, collagen Ⅱ, and aggrecan were the highest in Ov-A20 group and lowest in Sh-A20 group ( P<0.05). Western blot showed that the expressions of zinc finger protein A20, collagen Ⅱ, aggrecan, and LC3 (LC3Ⅱ/LC3Ⅰ) proteins were the highest in the Ov-A20 group and the lowest in Sh-A20 group ( P<0.05), while the expressions of P-P65, TNF-α, IL-1ß, and P62 proteins were the lowest in Ov-A20 group and the highest in Sh-A20 group ( P<0.05). There was no significant difference in the expression of p65 protein between groups ( P>0.05). CONCLUSION: Zinc finger protein A20 can effectively regulate the process of lumbar intervertebral disc degeneration in rabbits by inhibiting inflammation.

A20 regulates inflammation through autophagy mediated by NF-κB pathway in human nucleus pulposus cells and ameliorates disc degeneration in vivo.

Intervertebral disc degeneration (IDD) is closely related to loss of the extracellular matrix (ECM), apoptosis and inflammation in nucleus pulposus cells (NPCs). It has been reported that Zinc finger protein A20/TNFAIP3 (A20) can inhibit the activity of the NF-κB pathway and promote autophagy. Therefore, we speculated that A20 can regulate inflammation and ameliorate IDD through autophagy mediated by NF-κB in human NPCs. Our results indicated that the expression of A20 and inflammatory factors in IDD tissues was increased. A20 is an essential negative regulator in the NF-κB pathway. Constructed adenoviral shRNA and overexpression vectors for A20 could effectively regulate the inflammation, autophagy, and activity of NF-κB, which in turn affected the progression of IDD. Inhibition of NF-κB on the basis of knocking down A20 results in increased autophagy, suggesting that A20-regulated autophagy was mediated by NF-κB. In vivo, A20 overexpression could ameliorate the progression of IDD and promote autophagy at the same time, while deletion of A20 leads to low levels of autophagy and severe degeneration. In summary, A20 plays an important role in inhibiting inflammation through autophagy mediated by NF-κB in NPCs and ameliorating IDD.

TNFAIP3 ameliorates the degeneration of inflammatory human nucleus pulposus cells by inhibiting mTOR signaling and promoting autophagy.

Autophagy is involved in degenerative diseases such as osteoarthritis and disc degeneration. Although, tumor necrosis factor α-induced protein 3 (TNFAIP3) is well-known as a key regulator of inflammation and autophagy, it is still not clear whether TNFAIP3 regulates autophagy to protect from human disc cells degeneration. We hypothesize that TNFAIP3 may also regulate autophagy to inhibit pro-inflammatory cytokines expression in human nucleus pulposus cells (NPCs). In this study, TNFAIP3 expression was increased in degenerative disc tissue as well as LPS-stimulated human NPCs, and the effect of TNFAIP3 in LPS-induced NPCs was further explored. The results demonstrated that pro-inflammatory cytokines expression in TNFAIP3-His cells was decreased, while it was increased in TNFAIP3-siRNA cells. Further molecular mechanism research showed that TNFAIP3-siRNA cells enhanced the phosphorylation of mammalian target of rapamycin (mTOR) and inhibited autophagy. Meanwhile, after treatment of TNFAIP3-siRNA cells with the mTOR inhibitor Torin1, the level of autophagy increased and the decrease of extracellular matrix was reversed. In summary, overexpressed TNFAIP3 can promote autophagy and reduce inflammation in LPS-induced human NPCs. Moreover, autophagy triggered by TNFAIP3 can ameliorate the degeneration of inflammatory human NPCs, providing a potential and an attractive therapeutic strategy for degenerative disease.

[Comparative study on effectiveness of modified-transforaminal lumbar interbody fusion and posterior lumbar interbody fusion surgery in treatment of mild to moderate lumbar spondylolisthesis in middle-aged and elderly patients].

OBJECTIVE: To compare the effectiveness of modified transforaminal lumbar interbody fusion (modified-TLIF) and posterior lumbar interbody fusion (PLIF) for mild to moderate lumbar spondylolisthesis in middle-aged and elderly patients. METHODS: The clinical data of 106 patients with mild to moderate lumbar spondylolisthesis (Meyerding classification≤Ⅱ degree) who met the selection criteria between January 2015 and January 2017 were retrospectively analysed. All patients were divided into modified-TLIF group (54 cases) and PLIF group (52 cases) according to the different surgical methods. There was no significant difference in preoperative clinical data of gender, age, disease duration, sliding vertebra, Meyerding grade, and slippage type between the two groups ( P>0.05). The intraoperative blood loss, operation time, postoperative drainage volume, postoperative bed time, hospital stay, and complications of the two groups were recorded and compared. The improvement of pain and function were evaluated by the visual analogue scale (VAS) score and Japanese Orthopedic Association (JOA) score at preoperation, 1 week, and 1, 6, 12 months after operation, and last follow-up, respectively. The effect of slip correction was evaluated by slip angle and intervertebral altitude at preoperation and last follow-up, and the effectiveness of fusion was evaluated according to Suk criteria. RESULTS: All patients were followed up, the modified-TLIF group was followed up 25-36 months (mean, 32.7 months), the PLIF group was followed up 24-38 months (mean, 33.3 months). The intraoperative blood loss, operation time, postoperative drainage volume, postoperative bed time, and hospital stay of the modified-TLIF group were significantly less than those of the PLIF group ( P<0.05). The VAS score and JOA score of both groups were significantly improved at each time point after operation ( P<0.05); the scores of the modified-TLIF group were significantly better than those of the PLIF group at 1 and 6 months after operation ( P<0.05). The slip angle and intervertebral altitude of both groups were obviously improved at last follow-up ( P<0.05), and there was no significant difference between the two groups at preoperation and last follow-up ( P>0.05). At last follow-up, the fusion rate of the modified-TLIF group and the PLIF group was 96.3% (52/54) and 98.1% (51/52), respectively, and no significant difference was found between the two groups ( χ 2=0.000, P=1.000). About complications, there was no significant difference between the two groups in nerve injury on the opposite side within a week, incision infection, and pulmonary infection ( P>0.05). No case of nerve injury on the operation side within a week or dural laceration occurred in the modified-TLIF group, while 8 cases (15.4%, P=0.002) and 4 cases (7.7%, P=0.054) occurred in the PLIF group respectively. CONCLUSION: Modified-TLIF and PLIF are effective in the treatment of mild to moderate lumbar spondylolisthesis in middle-aged and elderly patients. However, modified-TLIF has relatively less trauma, lower blood loss, lower drainage volume, lower incidence of dural laceration and nerve injury, which promotes enhanced recovery after surgery.

HO-1 overexpression alleviates senescence by inducing autophagy via the mitochondrial route in human nucleus pulposus cells.

Intervertebral disc degeneration (IDD) is closely associated with aging. Our previous studies have confirmed that heme oxygenase-1 (HO-1) can inhibit nucleus pulposus (NP) cell apoptosis. However, whether or not HO-1 is involved in NP cell senescence and autophagy is unclear. Our results indicated that HO-1 expression was reduced in IDD tissues and replicative senescent NP cells. HO-1 overexpression using a lentiviral vector reduced the NP cell senescence level, protected mitochondrial function, and promoted NP cell autophagy through the mitochondrial pathway. Autophagy inhibitor 3-MA pretreatment reversed the anti-senescent and protective effects on the mitochondrial function of HO-1, which promoted the degradation of the extracellular matrix (ECM) in the intervertebral disc. In vivo, HO-1 overexpression inhibited IDD and enhanced autophagy. In summary, these results suggested that HO-1 overexpression alleviates NP cell senescence by inducing autophagy via the mitochondrial route.

Impact of NF-κB pathway on the apoptosis-inflammation-autophagy crosstalk in human degenerative nucleus pulposus cells.

The NF-κB pathway has been reported to play a very important role in the process of intervertebral disc degeneration (IVDD). Our results demonstrated that knockdown of NF-κB with P65-siRNA can significantly decrease cell apoptosis and the expression of pro-inflammation factors TNF-α and IL-1ß in LPS-induced nucleus pulposus cells (NPCs). However, the molecular mechanism of NF-κB pathway exerting anti-inflammation and anti-apoptosis function remains unclear. Some researchers reported that inhibiting NF-κB pathway can attenuate the catabolic effect by promoting autophagy during inflammatory conditions in rat nucleus pulposus cells. Therefore, we hypothesized that in human NPCs, inhibiting NF-κB pathway may also promote autophagy. Our results indicated that after knockdown of NF-κB, the autophagy was significantly increased and the expression of p-AKT and p-mTOR protein markedly decreased, but the level of autophagy was inhibited after treatment with AKT activator SC79, suggesting the involvement of AKT/mTOR-mediated autophagy was under autophagy activation. However, both LPS-induced NPCs apoptosis and expression of pro-inflammation factors were further increased by pretreatment with the autophagy inhibitor chloroquine (CQ). These suggested that inhibiting NF-κB pathway can promote autophagy and decrease apoptosis and inflammation response in LPS-induced NPCs. Meanwhile, autophagy triggered by NF-κB inhibition plays a protective role against apoptosis and inflammation.