Targeting MicroRNA-144/451-AKT-GSK3β Axis Affects the Proliferation and Differentiation of Radial Glial Cells in the Mouse Hippocampal Dentate Gyrus

It is well known that aging induces a progressive decline in the proliferation and neural differentiation of radial glial cells (RGCs) in the hippocampal dentate gyrus (DG). The function of miR-144/451 is to activate stress-regulated molecular gene expression switches for cell proliferation and differentiation. We found that the miR-144/451 expression in the hippocampus was significantly reduced in aged mice compared to adult mice. Furthermore, the proliferation and neural differentiation of RGCs in the mouse hippocampal DG was decreased by miR-144/451 knockout (miR-144/451^-/-). Antioxidant agents, superoxide dismutases (SODs) and catalase, and the expression of melatonin's receptor in the hippocampus were decreased in the miR-144/451^-/- mice. In addition, the (protein kinase B) AKT/(glycogen synthase kinase 3β) GSK3β/(catenin beta-1) β-catenin signaling pathway was weakly activated in the hippocampus of miR-144/451^-/- mice, which was related to brain neurogenesis. Melatonin treatment improved the expression of miR-144/451 and antioxidant enzymes and activated the AKT/GSK3β/β-catenin pathway in the hippocampus of miR-144/451^-/- mice. When the AKT pathway was inhibited by LY294002, the neurogenerative and antioxidant effects of melatonin were significantly limited in the hippocampus of miR-144/451^-/- mice. In brief, our results indicated that miR-144/451 plays crucial roles in the proliferation and neural differentiation of RGCs via the regulation of the antioxidant and AKT/GSK3β/β-catenin pathways.

Expression of Long Non-coding RNA RGD1566344 in the Brain Cortex of Male Mice After Focal Cerebral Ischemia-Reperfusion and the Neuroprotective Effect of a Non-coding RNA RGD1566344 Inhibitor

Ischemic stroke (IS) remains a major cause of disability and death. The changes in long non-coding RNA (lncRNA) RGD1566344 expression in the mouse cerebral cortex, including the infarct and penumbra regions after IS, are not clear. Less is known about the impact and underlying mechanisms of RGD1566344 in IS. In this study, we found that RGD1566344 levels were elevated in the ischemic infarct and penumbra regions 12 h after middle cerebral artery occlusion/reperfusion (MCAO/R) in male mice and in PC12 cells with oxygen glucose deprivation/reperfusion (OGD/R). The inhibition of RGD1566344 by small interference RNA (siRNA) significantly alleviated apoptosis in OGD/R PC12 cells. In cell transfection, quantitative real-time PCR, and Western blot experiments, we demonstrated the possible interaction of non-POU domain-containing octamer-binding protein (NONO) with RGD1566344. The NONO level in OGD/R PC12 cells was obviously increased after inhibiting the RGD1566344 treatment; subsequently the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway was activated. This demonstrated the effect of the RGD1566344-NONO-AKT axis on neural protection after IS. These results revealed a new molecular mechanism of lncRNA RGD1566344 inhibitors through targeting NONO/AKT/mTOR signaling to protect against ischemic neuronal injury, providing strong evidence for the development of promising therapeutic strategies against IS.

Hyperoside alleviates epilepsy-induced neuronal damage by enhancing antioxidant levels and reducing autophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Hypericum perforatum L. (genus Hypericum, family Hypericaceae), a plant commonly used in traditional Chinese medicine, is believed to confer a wide range of benefits, including fever reduction, detoxification, calming, and pain relief via decoctions of its stems and leaves. Hyperoside (HYP), a natural compound extracted from Hypericum perforatum L., has been shown to demonstrate a wide array of bioactivities including antioxidative, anti-inflammatory, and anti-apoptotic effects. In this study, we investigated the effects of HYP on epilepsy-induced neuronal damage in mice and the associated regulatory factors.

AIM OF THE STUDY

This study examined the potential therapeutic use of HYP for the treatment of neuronal damage in a mouse model of epilepsy and explored the relationships of the potential neuroprotective effects of HYP pretreatment with antioxidant levels and autophagy.

MATERIALS AND METHODS

ICR mice were randomly divided into six groups: sham group, sham-HYP group, KA group, KA-HYP group, KA-HYP-DDC group and KA-CQ group. Immunohistochemical staining was used to assess changes in NeuN, IBA-1, and GFAP expression in the CA3 region of the hippocampus. Immunofluorescence staining was used to assess the effects of HYP on the number of autophagosomes that accumulated in neurons in the hippocampal CA3 region. The levels of SOD1, SOD2, LC3I/II, Beclin1, and PI3K/AKT and MAPK signaling-related proteins were detected by Western blot.

RESULTS

Pretreatment with 50 mg/kg HYP protected against epilepsy-induced neuronal damage in the hippocampal CA3 region. Additionally, HYP enhanced antioxidant levels and reduced the levels of autophagy-related proteins via the PI3K/AKT and MAPK pathways.

CONCLUSION

HYP protected the hippocampal CA3 region against epilepsy-induced neuronal damage via enhancing antioxidant levels and reducing autophagy. The mechanism of action may be related to the maintenance of antioxidant levels and the suppression of autophagy via the PI3K/Akt and MAPK pathways.

Neuroprotective Effects of Gabapentin Against Cerebral Ischemia Reperfusion-Induced Neuronal Autophagic Injury via Regulation of the PI3K/Akt/mTOR Signaling Pathways

Gabapentin (GBP), an analgesic, adjunct antiepileptic, and migraine prophylactic drug, reduces neuronal injury induced by cerebral ischemia reperfusion (IR). However, the underlying biological molecular mechanism of GBP neuroprotection is not clear. In this study, we confirmed that dose-dependent (75 and 150 mg/kg) GBP treatment could significantly reduce IR-induced neuronal death. IR-induced neuronal death was inhibited by pretreatment with 150 mg/kg GBP in a middle cerebral artery occlusion rat model. In addition, 150 mg/kg GBP treatment remarkably promoted the levels of antioxidants and reduced the autophagy of neurons in the infarct penumbra. Moreover, the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway was activated by pretreatment with 150 mg/kg GBP, as detected by Western blot analyses. In vitro, pretreatment of PC12 cells with 450 µM GBP significantly reduced cell death induced by oxygen-glucose deprivation, increased antioxidant function, and reduced the levels of autophagy and reactive oxygen species via activation of the PI3K/Akt/mTOR pathway. This neuroprotection by GBP was inhibited significantly by 10 µM LY294002. In summary, dose-dependent pretreatment with GBP protected against cerebral IR injury via activation of the PI3K/Akt/mTOR pathway, which provided a neuroprotective function to inhibit oxidative stress-related neuronal autophagy.

Pentraxin 3 in bronchoalveolar lavage fluid and plasma in non-neutropenic patients with pulmonary aspergillosis

OBJECTIVES

Pentraxin 3 (PTX3) contributes to resistance to Aspergillus infections. This study aimed to evaluate the presence of PTX3 in bronchoalveolar lavage fluid (BALF) and plasma in non-neutropenic patients with pulmonary aspergillosis.

METHODS

BALF (n = 211) and plasma samples (n = 307) were collected from patients initially suspected of having pulmonary aspergillosis. Among these, 112 cases (51 BALF samples and 89 plasma samples) were proven to be pulmonary aspergillosis. These cases were classified as invasive pulmonary aspergillosis (IPA), subacute invasive aspergillosis (SAIA) and chronic pulmonary aspergillosis (CPA). The remaining cases were non-aspergillosis controls and were diagnosed with community-acquired pneumonia (CAP), lung cancer and pulmonary cryptococcosis. Plasma samples from healthy controls (n = 30) were also collected.

RESULTS

The median (interquartile range, IQR) BALF PTX3 for aspergillosis cases was significantly higher than for non-aspergillosis cases: 6.97 (2.91-13.51) ng/mL versus 1.26 (0.76-1.76) ng/mL. When the PTX3 threshold was set at 1.9 ng/mL, sensitivity and specificity of BALF PTX3 for aspergillosis were 86.3% (95%CI 83.8-88.4%) and 82.5% (95%CI 79.7-85.0%), respectively. The median (IQR) plasma PTX3 for aspergillosis cases was significantly higher than for non-aspergillosis cases and healthy controls: 7.10 (3.36-9.53) ng/mL versus 1.57 (0.86-2.35) ng/mL versus 1.10 (0.49-1.51) ng/mL. With a PTX3 threshold of 2.3 ng/mL, sensitivity and specificity were 79.8% (95%CI 70.1-81.2%) and 72.1% (95%CI 69.5-74.5%) respectively.

CONCLUSIONS

BALF and plasma PTX3 may be biomarkers for differentiating aspergillosis from other conditions such as CAP, lung cancer, and pulmonary cryptococcosis in non-neutropenic patients.

Non-malignant pathological results on transthoracic CT guided core-needle biopsy: when is benign really benign?

AIM

To determine true negatives and characterise the variables associated with false-negative results when interpreting non-malignant results of computed tomography (CT)-guided lung biopsy.

MATERIALS AND METHODS

Nine hundred and fifty patients with initial non-malignant findings on their first transthoracic CT-guided core-needle biopsy (TTNB) were included in the study. Initial biopsy results were compared to definitive diagnoses established later.

RESULTS

The negative predictive value (NPV) of non-malignant diseases upon initial TTNB was 83.6%. When the biopsy results indicated specific infection or benign tumour (n=225, 26.1%), they all were confirmed true negative for malignancy later. Only one inconclusive "granuloma" diagnosis was false negative. All 141 patients (141/861, 16.4%) who were false negative for malignancy were from the "infection not otherwise specified (NOS)", "inflammatory diseases", or "inconclusive" groups. Age (p=0.002), cancer history (p<0.001), target size (p=0.003), and pneumothorax during lung biopsy (p=0.003) were found to be significant predictors of false-negative results; 47.6% (410/861) of patients underwent additional invasive examinations to reach a final diagnosis. Ultimately, 52.7% (216/410) were successfully diagnosed.

CONCLUSION

Specific infection, benign tumour, and granulomatous inflammation of first TTNBs were mostly true negative. Older age, history of cancer, larger target size, and pneumothorax were highly predictive of false-negative results for malignancies. In such cases, additional invasive examinations were frequently necessary to obtain final diagnoses.

Apoptotic block in colon cancer cells may be rectified by lentivirus mediated overexpression of caspase-9

BACKGROUND AND AIM

At present, the inhibition of apoptosis during pathogenesis of colorectal cancer is widely recognized while the role of caspase-9 in this process remains controversial. We aimed to investigate the differential expression of caspase-9 and evaluate the therapeutic potential of expression intervention in this study.

METHODS

We first examined the different expression of caspase-9 in normal colon mucosa, adenoma and cancer, investigating the relationship between its expression and clinico-pathological characteristics. Secondly, overexpression of caspase-9 was established in colon cancer cell lines by lentivirus infection to study the changes in growth, proliferation and apoptosis.

RESULTS

Compared with normal colon mucosa, the expression of caspase-9 was higher in adenoma while lower in cancer both at mRNA and protein level (P < 0.05). In addition, the down-regulation of caspase-9 expression is more common in poorly differentiated cancers (P < 0.05). Concerning cell lines, overexpression cell groups showed higher expression of caspase-9, poorer colony formation and slower cell proliferation. In terms of apoptosis related indicators, caspase-9 overexpression leads to higher apoptosis rate and GO/G1 arrest, while up-regulating the expression of caspase-3 (P <0.05). Interestingly, down-regulation of carcinoembryonic antigen secretion was also observed in caspase-9 overexpression cells (P <0.05).

CONCLUSION

The change of caspase-9 expression from colon mucosa, adenoma to cancer suggested it may be involved in the carcinogenesis of colon cancer. The overexpression of caspase-9 exhibits an inhibitory role in cancer growth and proliferation while promoting apoptosis. However, a non-apoptotic role of caspase-9 facilitating differentiation was also implied.

[Simultaneous detection and differentiation of O1 classical E1 Tor, O139 and nonO1 nonO139 strains of Vibrio cholerae by using multiplex PCR]

OBJECTIVE

To explore the rapid and sensitive procedures for detection and differentiation of O1 classical(CVC), El Tor(EVC), O139 and nonO1 nonO139 strains of Vibrio cholerae.

METHODS

Four pairs of primers were designed from toxin sub-unit A(ctxA) gene, O139 special gene, Haemolytic subunit A gene and Toxin coregulated pilus subunit A gene. Multiplex PCR was established to simultaneously detect those four genes. CVC, EVC, O139 and nonO1 nonO139 strains can be detected and differentiated by the size and numbers of Multiplex PCR bands via electrophoresis. Two pairs of inside primers were designed from ctx A and O139 special gene, and a nested PCR was established.

RESULTS

60 EVC, 2 CVC, 15 O139 and 30 nonO1 nonO139 strains isolated from patients were detected with multiplex PCR and nested PCR, and the results were correct. 10 EVC and 15 O139 strains isolated from environment samples were detected, and the results meant that EVC were toxic and O139 were non-toxic. The sensitivity of multiplex PCR reached 100 cfu, and that of nested PCR reached 1-10 cfu.

CONCLUSION

This method is rapid, specific, and sensitive, and possess great value for practical application.

[An epidemiological study on acute diarrhea during a filed exercise in PLA unit in an area in southern China]

OBJECTIVE

To explore the epidemiological characteristics and risk factors of acute diarrheal disease during a filed exercise.

METHODS

Epidemiological study of a certain artillery acute diarrheal disease during a filed exercise and multiple linear stepwise regression analysis, multiple stepwise discriminate analysis were used.

RESULTS

Result showed that the incidence rate of training troops was significantly higher than that of the local troops at the corresponding period (7.32% vs 0.98% P<0.05). The incidence rate among officers was significantly lower than that of the soldiers (0.99% vs 8.20% P<0.05). The incidence rate was significantly higher at the beginning of assemble for training but smooth and steady afterwards with several outbreaks. There was highly significant difference in the incidence rate of 39 companies. Regression and discrimination analysis suggested that the incidence rate was correlated with the density of flies and average boiled water volume provided everyday. The correct classifying rate of the discrimination was 91.9% in total.

CONCLUSION

These results provided a basis for prevention of acute diarrheal disease during filed exercise of military action.

Structural analysis of membrane-bound retrovirus capsid proteins

We have developed a system for analysis of histidine-tagged (His-tagged) retrovirus core (Gag) proteins, assembled in vitro on lipid monolayers consisting of egg phosphatidylcholine (PC) plus the novel lipid DHGN. DHGN was shown to chelate nickel by atomic absorption spectrometry, and DHGN-containing monolayers specifically bound gold conjugates of His-tagged proteins. Using PC + DHGN monolayers, we examined membrane-bound arrays of an N-terminal His-tagged Moloney murine leukemia virus (M-MuLV) capsid (CA) protein, His-MoCA, and in vivo studies suggest that in vitro-derived His-MoCA arrays reflect some of the Gag protein interactions which occur in assembling virus particles. The His-MoCA proteins formed extensive two-dimensional (2D) protein crystals, with reflections out to 9.5 A resolution. The image-analyzed 2D projection of His-MoCA arrays revealed a distinct cage-like network. The asymmetry of the individual building blocks of the network led to the formation of two types of hexamer rings, surrounding protein-free cage holes. These results predict that Gag hexamers constitute a retrovirus core substructure, and that cage hole sizes define an exclusion limit for entry of retrovirus envelope proteins, or other plasma membrane proteins, into virus particles. We believe that the 2D crystallization method will permit the detailed analysis of retroviral Gag proteins and other His-tagged proteins.

Triggerable plasmalogen liposomes: improvement of system efficiency

A photoactivated liposome release system that is generally applicable for triggered release of encapsulated hydrophilic materials is described. This approach to phototriggered release, derived from the known effects of plasmalogen photooxidation on membrane permeability in whole cells and model membrane systems, relies on producing a lamellar phase change or increase in permeability upon cleaving its constitutive lipids to single-chain surfactants using 630-820 nm light to sensitize the photooxidation of the plasmalogen vinyl ether linkage. Semi-synthetic plasmenylcholine liposomes containing encapsulated calcein and a membrane-bound sensitizer, such as zinc phthalocyanine, tin octabutoxyphthalocyanine, or bacteriochlorophyll a, were prepared by extrusion. Irradiation of air-saturated liposome solutions enhanced membrane permeability toward calcein and Mn2+, and promoted membrane fusion processes compared to non-irradiated or anaerobic controls. Bacteriochlorophyll a sensitization produced the fastest observed photoinitiated release rate from these liposomes (100% calcein release in less than 20 min; 800 nm irradiation at 300 mW); the observed release rate was two orders of magnitude slower for egg lecithin liposomes prepared and irradiated under identical experimental conditions. Liposome aggregation, interlipidic particle formation, and membrane fusion between adjoining liposomes was observed by 31P-NMR, freeze-fracture/freeze-etch TEM, and cryo-TEM as a function of irradiation time. The use of near-infrared sensitizers and the capacity of photolyzed plasmenylcholine liposomes to undergo membrane fusion processes make photodynamic therapy with these liposome-borne sensitizers an attractive adjunct to biochemical targeting methods.