[Corrigendum] NEP1­40 promotes myelin regeneration via upregulation of GAP­43 and MAP­2 expression after focal cerebral ischemia in rats.

Subsequently to the publication of this paper, an interested reader drew to the authors' attention that, in Fig. 4A on p. 6 showing the effects of NEP1­40 on MBP expression as determined via immunohistochemical analysis, certain of the data panels appeared to be overlapping, such that they may have been derived from the same original source. After having examined their original data, the authors have realized that these data panels were inadvertently assembled incorrectly. A corrected version of Fig. 4 is shown below, incorporating data from one of the alternative experiments in Fig. 4A. Note that these errors did not significantly affect the results or the conclusions reported in this paper, and all the authors agree to this Corrigendum. The authors are grateful to the Editor of Molecular Medicine Reports for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [Molecular Medicine Reports 24: 844, 2021; DOI: 10.3892/mmr.2021.12484].

The Shh/Gli1 signaling pathway regulates regeneration via transcription factor Olig1 expression after focal cerebral ischemia in rats.

OBJECTIVE: Ischemic stroke is a major cause of death in the global population, with a high disability and mortality rate. Lack of regenerative ability is considered to be the fundamental cause. This study aims to determine the effect of Shh pathway, which mediates regenerative signaling in response to CNS injury, on myelin repair and Olig1 expression in focal ischemic lesions in the rat. METHODS: A model of middle cerebral artery occlusion (MCAO) was established using the intraluminal suture method where the middle cerebral artery (MCA) was restricted for 120 min. Cyclopamine, a specific inhibitor of Shh, or saline was administered 12h after MCAO surgery and lasted for 7d. After MCA occlusion, male Sprague-Dawley rats were randomly allocated to cyclopamine- or saline-treated groups. A group of no-injection animals after MCAO were used as control. The Shh signaling pathway, myelinogenesis-related factor MBP and Olig1 were tested using immunohistochemistry and RT-PCR assay. RESULTS: The levels of Shh and its component Gli1 were elevated from 1d up to 14d following ischemia, indicating that the Shh-Gli1 axis was broadly reactivated. Treatment with cyclopamine can partially block the Shh signaling pathway, prevent myelin repair, and decrease the Olig1 expression following ischemic stroke. CONCLUSION: That blockade of Shh signaling concurrently with the creation of a lesion aggravated ischemic myelin damage, probably via its downstream effects on Olig1 transcription. Shh plays a contributory role during regeneration in the CNS, thereby providing promising new therapeutic strategies to assist in recovery from ischemic stroke.

Short-Chain Fatty Acids Produced by Ruminococcaceae Mediate α-Linolenic Acid Promote Intestinal Stem Cells Proliferation.

SCOPE: The proliferation and differentiation of intestinal stem cells (ISCs) are the basis of intestinal renewal and regeneration, and gut microbiota plays an important role in it. Dietary nutrition has the effect of regulating the activity of ISCs; however, the regulation effect of α-linolenic acid (ALA) has seldom been reported. METHODS AND RESULTS: After intervening mice with different doses of ALA for 30 days, it is found that ALA (0.5 g kg-1 ) promotes small intestinal and villus growth by activating the Wnt/ß-catenin signaling pathway to stimulate the proliferation of ISCs. Furthermore, ALA administration increases the abundance of the Ruminococcaceae and Prevotellaceae, and promotes the production of short-chain fatty acids (SCFAs). Subsequent fecal transplantation and antibiotic experiments demonstrate that ALA on the proliferation of ISCs are gut microbiota dependent, among them, the functional microorganism may be derived from Ruminococcaceae. Administration of isobutyrate shows a similar effect to ALA in terms of promoting ISCs proliferation. Furthermore, ALA mitigates 5-fluorouracil-induced intestinal mucosal damage by promoting ISCs proliferation. CONCLUSION: These results indicate that SCFAs produced by Ruminococcaceae mediate ALA promote ISCs proliferation by activating the Wnt/ß-catenin signaling pathway, and suggest the possibility of ALA as a prebiotic agent for the prevention and treatment of intestinal mucositis.

Corrigendum: Moringa oleifera Alkaloids Inhibited PC3 Cells Growth and Migration Through the COX-2 Mediated Wnt/ß-Catenin Signaling Pathway.

[This corrects the article DOI: 10.3389/fphar.2020.523962.].

NEP1­40 promotes myelin regeneration via upregulation of GAP­43 and MAP­2 expression after focal cerebral ischemia in rats.

Axon regeneration after lesions to the central nervous system (CNS) is largely limited by the presence of growth inhibitory molecules expressed in myelin. Nogo­A is a principal inhibitor of neurite outgrowth, and blocking the activity of Nogo­A can induce axonal sprouting and functional recovery. However, there are limited data on the expression of Nogo­A after CNS lesions, and the mechanism underlying its influences on myelin growth remains unknown. The aim of the present study was to observe the time course of Nogo­A after cerebral ischemia/reperfusion in rats using immunohistochemistry and western blot techniques, and to test the effect of its inhibitor Nogo extracellular peptide 1­40 (NEP1­40) on neural plasticity proteins, growth­associated binding protein 43 (GAP­43) and microtubule associated protein 2 (MAP­2), as a possible mechanism underlying myelin suppression. A classic model of middle cerebral artery occlusion (MCAO) was established in Sprague­Dawley rats, which were divided into three groups: i) MCAO model group; ii) MCAO + saline group; and iii) MCAO + NEP1­40 group. Rats of each group were divided into five subgroups by time points as follows: days 1, 3, 7, 14 and 28. Animals that only received sham operation were used as controls. The Nogo­A immunoreactivity was located primarily in the cytoplasm of oligodendrocytes. The number of Nogo­A immunoreactive cells significantly increased from day 1 to day 3 after MCAO, nearly returning to the control level at day 7, increased again at day 14 and decreased at day 28. Myelin basic protein (MBP) immunoreactivity in the ipsilateral striatum gradually decreased from day 1 to day 28 after ischemia, indicating myelin loss appeared at early time points and continuously advanced during ischemia. Then, intracerebroventricular infusion of NEP1­40, which is a Nogo­66 receptor antagonist peptide, was administered at days 1, 3 and 14 after MCAO. It was observed that GAP­43 considerably increased from day 1 to day 7 and then decreased to a baseline level at day 28 compared with the control. MAP­2 expression across days 1­28 significantly decreased after MCAO. Administration of NEP1­40 attenuated the reduction of MBP, and upregulated GAP­43 and MAP­2 expression at the corresponding time points after MCAO compared with the MCAO + saline group. The present results indicated that NEP1­40 ameliorated myelin damage and promoted regeneration by upregulating the expression of GAP­43 and MAP­2 related to neuronal and axonal plasticity, which may aid with the identification of a novel molecular mechanism of restriction in CNS regeneration mediated by Nogo­A after ischemia in rats.

Engineering Microdomains of Oxides in High-Entropy Alloy Electrodes toward Efficient Oxygen Evolution.

One important goal of the current electrocatalysis is to develop integrated electrodes from the atomic level design to multilevel structural engineering in simple ways and low prices. Here, a series of oxygen micro-alloyed high-entropy alloys (O-HEAs) is developed via a metallurgy approach. A (CrFeCoNi)97 O3 bulk O-HEA shows exceptional electrocatalytic performance for the oxygen evolution reaction (OER), reaching an overpotential as low as 196 mV and a Tafel slope of 29 mV dec-1 , and with stability longer than 120 h in 1 m KOH solution at a current density of 10 mA cm-2 . It is shown that the enhanced OER performance can be attributed to the formation of island-like Cr2 O3 microdomains, the leaching of Cr3+ ions, and structural amorphization at the interfaces of the domains. These findings offer a technological-orientated strategy to integrated electrodes.

Moringa oleifera Alkaloids Inhibited PC3 Cells Growth and Migration Through the COX-2 Mediated Wnt/ß-Catenin Signaling Pathway.

Moringa oleifera Lam. (M. oleifera) is valuable plant distributed in many tropical and subtropical countries. It has a number of medicinal uses and is highly nutritious. M. oleifera has been shown to inhibit tumor cell growth, but this effect has not been demonstrated on prostate cancer cells. In this study, we evaluated the inhibitory effect of M. oleifera alkaloids (MOA) on proliferation and migration of PC3 human prostate cancer cells in vitro and in vivo. Furthermore, we elucidated the mechanism of these effects. The results showed that MOA inhibited proliferation of PC3 cells and induced apoptosis and cell cycle arrest. Furthermore, MOA suppressed PC3 cell migration and inhibited the expression of matrix metalloproteinases (MMP)-9. In addition, MOA significantly downregulated the expression of cyclooxygenase 2 (COX-2), ß-catenin, phosphorylated glycogen synthase 3ß, and vascular endothelial growth factor, and suppressed production of prostaglandin E2 (PGE2). Furthermore, FH535 (ß-catenin inhibitor) and MOA reversed PGE2-induced PC3 cell proliferation and migration, and the effects of MOA and FH535 were not additive. In vivo experiments showed that MOA (150 mg/kg) significantly inhibited growth of xenograft tumors in mice, and significantly reduced the protein expression levels of COX-2 and ß-catenin in tumor tissues. These results indicate that MOA inhibits the proliferation and migration, and induces apoptosis and cell cycle arrest of PC3 cells. Additionally, MOA inhibits the proliferation and migration of PC3 cells through suppression of the COX-2 mediated Wnt/ß-catenin signaling pathway.

Effects of the transcription factor Olig1 on the differentiation and remyelination of oligodendrocyte precursor cells after focal cerebral ischemia in rats.

The differentiation and maturation of oligodendrocyte precursor cells (OPCs) is important for remyelination in the central nervous system. Nevertheless, this process is often limited and incomplete in ischemic injury. Oligodendrocyte transcription factor 1 (Olig1) is important for the maturation of OPCs and the repair of demyelinated lesions. However, how Olig1 modulates the development of OPCs or the remyelination associated with ischemic injury remains unclear. The present study aimed to examine alterations in OPCs, and the expression of myelin and Olig1, at different time-points after focal cerebral ischemia using immunohistochemistry and western blot techniques to elucidate the role of Olig1 in the maturation of OPCs and remyelination. The present results showed that the expression of Olig1 significantly decreased at 1 day after middle cerebral artery occlusion (MCAO) and returned to normal levels from day 3 to 28. Additionally, Olig1 was found to translocate into the nucleus following ischemia in the brain. The number of OPCs in the ischemic striatum significantly declined at days 1 and 3 following MCAO, and increased at days 7, 14 and 28 compared with the control. The expression of myelin basic protein, a marker of mature oligodendrocytes and myelin, gradually decreased from day 1 to 7 after ischemia and recovered at day 14 and 28; however, the levels were lower than those in the control group. The present results indicated that the restored normal level of Olig1 following ischemia may play an important role in the maturation of OPCs through its translocation into the nucleus, where it may promote the growth and development of myelin under pathological conditions. However, this endogenous recovery mechanism fails to fully repair the demyelinated lesion. The data of the present study may help clinicians understand the expression pattern of Olig1 and its potential role in endogenous remyelination after ischemia, which may have implications for the treatment of diseases that lead to demyelination.

Ultrasensitive Detection of MicroRNA via a Au@Ag Nanosnowman.

MicroRNAs (miRNAs) play key roles in many serious diseases, such as cancer. As a consequence, miRNAs are of great interest as biomarkers in clinical diagnostics. Simple, fast, selective, and sensitive detection of miRNAs, however, is challenged by their short length, homogeneous sequence, susceptibility to degradation, and low abundance in human serum. Here, we present a new strategy for highly sensitive and selective detection of miRNA based on the formation of a plasmonic Au@Ag nanosnowman. When triggered by miRNA-21, bimetallic nanoparticles with an asymmetric Au@Ag head-body structure were formed with significant red shift of the localized surface plasmon resonance (LSPR) scattering wavelength and clear color change from green to red. When combined with exonuclease III (Exo III)-assisted target recycling and hybridization chain reaction (HCR) amplification strategy, the proposed bioassay showed excellent selectivity toward miRNA-21 with a proportional band from 1 fM to 100 pM and ultrahigh sensitivity with a limit of detection of 0.60 fM under dark-field microscopy. The proposed strategy is universal, which shows good application prospects in clinical analysis.

Electrogenerated Chemiluminescence Imaging of Electrocatalysis at a Single Au-Pt Janus Nanoparticle.

Noble metal nanoparticles are promising catalysts in electrochemical reactions, while understanding the relationship between the structure and reactivity of the particles is important to achieve higher efficiency of electrocatalysis, and promote the development of single-molecule electrochemistry. Electrogenerated chemiluminescence (ECL) was employed to image the catalytic oxidation of luminophore at single Au, Pt, and Au-Pt Janus nanoparticles. Compared to the monometal nanoparticles, the Janus particle structure exhibited enhanced ECL intensity and stability, indicating better catalytic efficiency. On the basis of the experimental results and digital simulation, it was concluded that a concentration difference arose at the asymmetric bimetallic interface according to different heterogeneous electron-transfer rate constants at Au and Pt. The fluid slip around the Janus particle enhanced local redox reactions and protected the particle surface from passivation.

Purified isolation of vacuoles from Sedum alfredii leaf-derived protoplasts.

This study aims to develop a method for isolating and purifying protoplasts/vacuoles from fresh leaves of the Cd hyperaccumulator plant species, Sedum alfredii. The results revealed that preheating cellulase and macerozyme at 50 °C for 5 min significantly accelerated the cell wall degradation. For the most optimal conditions for mesophyll protoplast isolation, the mixture of fresh leaves and cell lysates was followed by a 2-h-long vibration. The protoplast lysate for vacuole isolation was diluted, and 0.675 mmol/L was identified as the most appropriate 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonic acid (CHAPS) level, in which S. alfredii large vacuoles are characterized by a high metal and malic acid content. For the best vacuole purification results, we established that 0.8 mol/L was the most optimal mannitol level in the vacuole buffer in terms of vacuole protection during centrifugation, whereas a Ficoll concentration of 0.10 g/ml was adopted in the density-gradient centrifugation.

Role of thymosin beta 4 in hair growth.

Although thymosin beta 4 (Tß4) is known to play a role in hair growth, its mechanism of action is unclear. We examined the levels of key genes in a Tß4 epidermal-specific over-expressing mouse model and Tß4 global knockout mouse model to explore how Tß4 affects hair growth. By depilation and histological examination of the skin, we confirmed the effect of Tß4 on hair growth, the number of hair shafts and hair follicle (HF) structure. The mRNA and protein expression of several genes involved in hair growth were detected by real-time PCR and western blotting, respectively. Changes in the expression of ß-catenin and Lef-1, the two key molecules in the Wnt signaling pathway, were similar to the changes observed in Tß4 expression. We also found that compared to the control mice, the mRNA and protein expression of MMP-2 and VEGF were increased in the Tß4 over-expressing mice, while the level of E-cadherin (E-cad) remained the same. Further, in the Tß4 global knockout mice, the mRNA and protein levels of MMP-2 and VEGF decreased dramatically and the level of E-cad was stable. Based on the above results, we believe that Tß4 may regulate the levels of VEGF and MMP-2 via the Wnt/ß-catenin/Lef-1 signaling pathway to influence the growth of blood vessels around HFs and to activate cell migration. Tß4 may have potential for the treatment of hair growth problems in adults, and its effects should be further confirmed in future studies.

PPM1D overexpression predicts poor prognosis in non-small cell lung cancer.

It has been reported that protein phosphatase, Mg(2+)/Mn(2+) dependent, 1D (PPM1D) plays an important role in cancer tumorigenesis. However, the clinical and functional significance of PPM1D expression has not been characterized previously in non-small cell lung cancer (NSCLC). The purpose of this study was to assess PPM1D expression and to explore its contribution to NSCLC. We examined PPM1D messenger RNA (mRNA) expression in 53 NSCLC tissues and matched adjacent noncancerous tissues by quantitative reverse transcription PCR (qRT-PCR). Furthermore, the PPM1D protein expression was analyzed by immunohistochemistry in 157 NSCLC samples. The relationship between PPM1D expression and clinicopathological features was analyzed by appropriate statistics. Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the correlation between PPM1D expression and prognosis of NSCLC patients. The relative mRNA expression of PPM1D was significantly elevated in NSCLC tissues as compared with adjacent noncancerous tissues (P < 0.001). The high expression of PPM1D in NSCLC tissues was significantly correlated with tumor grade (P = 0.006), tumor size (P = 0.017), clinical stage (P = 0.001), and lymph node metastases (P = 0.002). Kaplan-Meier survival analysis revealed that high PPM1D expression correlated with poor prognosis of NSCLC patients (P < 0.001). Multivariate analysis showed that PPM1D expression was an independent prognostic marker for overall survival of NSCLC patients. In conclusion, PPM1D plays an important role in the progression of NSCLC. PPM1D may potentially be used as an independent biomarker for the prognostic evaluation of NSCLC.

Transcriptional activation of insulin-like growth factor binding protein 6 by 17beta-estradiol in SaOS-2 cells.

Osteoblasts can synthesize the insulin-like growth factors (IGFs) and the IGF-binding proteins (IGFBPs), which may either enhance or attenuate IGF-stimulated bone cell proliferation. Since estrogen induced osteoblastic differentiation and proliferation through an estrogen-responsive gene in target cells, we investigated the effects of estrogen on IGFBP-6 expression in the human osteoblastic-like cell line SaOS-2. Expressions of IGFBP-6 protein and mRNA increased 2.8 and 2-fold, respectively, in the presence of 17-beta-estradiol (E2) (0.01 to 1 micronM) and estrogen receptor (ER) in SaOS-2 cells. On the other hand, E2 induced a 2-fold increase in SaOS-2 cell proliferation. To identify genomic sequences associated with estrogen responsiveness, the 5'-promoter region (-44 to +118) of the IGFBP-6 gene was cloned into a chloramphenicol acetyltransferase (CAT) reporter vector. E2 induced a 3-fold increase in CAT activity in SaOS-2 cells transiently transfected with this construct. Identification of the estrogen-responsive element (ERE) [5-CCTTCA CCTG-3] (-9 to +1) in this IGFBP-6 gene promoter region was confirmed using electromobility shift assays and deletion analysis. This functional ERE was important for E2-induced trans-activation of the IGFBP-6 gene. These results demonstrate that E2 exhibits a positive effect on IGFBP-6 gene transcription through estrogen-liganded ER binding to the functional ERE in the IGFBP-6 gene promoter in SaOS-2 cells.

[Effect of dioxin on apoptosis of osteogenic sarcoma cells and regulation on gene expression of insulin-like growth factor binding protein 6].

OBJECTIVE: To investigate the effect of the environmental carcinogenic factor-TCDD (2, 3, 7, 8-tetrachlorodibenzo-p-dioxin) on cell apoptosis and gene regulation of insulin-like growth factor binding protein 6 (IGFBP-6) in osteogenic sarcoma (SaOS-2) cells. METHODS: The SaOS-2 cells were cultured with TCDD (1 x 10(-9), 1 x 10(-8), 1 x 10(-7) mol/L) for 24 hours. The MTT reduction assay and flow cytometry were used to measure the cell proliferation and the cell apoptosis in TCDD-treated SaOS-2 cells. The Nitrophenol phosphate salt method was used to measure activity of alkaline phosphatase (ALP) in SaOS-2 cells. The IGFBP-6 mRNA and protein in SaOS-2 cells were detected by reverse transcription polymerase chain reaction (RT-PCR) and western blotting analysis. RESULTS: SaOS-2 cell proliferation was up-regulated with TCDD (1 x 10(-9), 1 x 10(-8), and 1 x 10(-7) mol/L) about 20%, 47% and 93% (18.4 +/- 4.5, 22.5 +/- 3.6 and 29.4 +/- 4.2), respectively. The synthesis of ALP was up-regulated about 28%, 95%, and 142% (1.12 +/- 0.28, 1.58 +/- 0.14 and 1.96 +/- 0.17), respectively (P < 0.05). The cell apoptosis was down-regulated in dose-dependent biological manner about 5%, 26% and 52%, respectively (P < 0.05). The expression of IGFBP-6 mRNA and protein was decreased in 1 x 10(-7) mol/L TCDD-treated SaOS-2 cells about 76% and 72% (P < 0.05). CONCLUSION: TCDD at low concentration may have the negative effect on cell apoptosis and down-regulation on gene expression of IGFBP-6 in SaOS-2 cells.

Retinoic acid down-regulates bone morphogenetic protein 7 expression in rat with cleft palate.

OBJECTIVE: To evaluate the effects of retinoic acid (RA) on expression of bone morphogenetic protein 7 (BMP-7) in rat fetus with cleft palate, and the effects of RA on proliferation and apoptosis of osteoblasts. METHODS: All-trans RA (ATRA) was used to induce congenital cleft palate in Wistar rat BMP-7 mRNA expression in maxillary bone tissue of fetal rats was measured by Northern blotting analysis. Flow cytometry and MTT assay were used to measure the apoptosis and proliferation of ATRA-treated MC-3T3-E1 cells. BMP-7 mRNA and protein expressions in ATRA-treated MC-3T3-E1 cells were detected by RT-PCR and Western blotting analysis. RESULTS: ATRA could induce cleft palate of rat fetus. The incidence rate of cleft palate induced by 100 mg/kg AT-RA (45.5%) was significantly higher than 50 mg/kg ATRA (12.5%, P < 0.05). BMP-7 mRNA expression decreased in maxillary bone tissue of rat fetus with cleft palate. MC-3T3-E1 cells proliferation treated with 1 x 10(-6) mol/L ATRA decreased by 60%, the cell apoptosis increased by 2 times. BMP-7 mRNA and protein levels in MC-3T3-E1 cells treated with 1 x 10(-6) mol/L ATRA decreased by 60% and 80%, respectively, compared with ATRA-untreated cells (P < 0.05). CONCLUSIONS: BMP-7 may play an important role in embryonic palate development RA may possess the ability to down-regulate cell proliferation through regulation of BMP-7 gene expression.

[HLA-DQB1 allele polymorphism and clinical characteristics of 15 familial myasthenia gravis cases in north China].

OBJECTIVE: To investigate the relationship between the HLA-DQB1 allele polymorphisms and the clinical features of 15 familial myasthenia gravis (MG) cases in north China. METHODS: By polymerase chain reaction-sequence specific primers (PCR-SSP), the HLA-DQB1 gene polymorphisms were determined in 64 MG patients (15 familial and 49 sporadic) and 52 healthy individuals as control group. The clinical characteristics of 15 familial MG patients and 49 sporadic were analyzed. The measurement data was analyzed by t test and enumeration data by chi-square test. RESULTS: The frequency of DQB1*0501 was significantly increased in familial MG, especially in the ocular type, compared with sporadic MG (P<0.05, OR=3.08) and healthy controls (P<0.01, OR=4.439). Comparing with healthy controls, the frequency of DQB1*0301/4 was increased (P<0.05, OR=2.56), while the frequency of DQB1*0601 was significantly decreased (P<0.05, OR=0.33) in sporadic MG. The familial patients had an early age of disease onset, but less severity and good prognosis. CONCLUSION: The familial MG has distinctive clinical features. DQB1*0501 allele is positively related to the genetic susceptibility to familial MG patients in north China, especially to the ocular type. DQB1*0301/4 allele is positively related to the pathogenesis of sporadic MG. DQB1*0601 may be a protecting allele for sporadic MG. The phenotype of MG may be the result of interaction of hereditary defects and environmental factors. The familial MG may be different from sporadic patients in genetic immune mechanism.