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Alzheimer's disease (AD) is a chronic and irreversible neurodegenerative disorder. Abnormal aggregation of the neurotoxic amyloid‑β (Aβ) peptide is an early event in AD. The activation of astrocytic α7 nicotinic acetylcholine receptor (α7 nAChR) can inhibit Aβ aggregation; thus, the molecular mechanism between α7 nAChR activation and Aβ aggregation warrants further investigation. In the present study, Aβ oligomer levels were assessed in astrocytic cell lysates after treatment with PNU282987 (a potent agonist of α7 nAChRs) or co‑treatment with LY294002, a p‑Akt inhibitor. The levels of heat shock factor‑1 (HSF‑1), heat shock protein 70 (HSP‑70), and αB‑crystallin (Cryab) in astrocytes treated with PNU282987 at various time‑points or co‑treated with methyllycaconitine (MLA), a selective α7 nAChR antagonist, as well as co‑incubated with LY294002 were determined by western blotting. HSP‑70 and Cryab levels were determined after HSF‑1 knockdown (KD) in astrocytes. PNU282987 markedly inhibited Aβ aggregation and upregulated HSF‑1, Cryab, and HSP‑70 in primary astrocytes, while the PNU282987‑mediated neuroprotective effect was reversed by pre‑treatment with MLA or LY294002. Moreover, the HSF‑1 KD in astrocytes effectively decreased Cryab, but not HSP‑70 expression. HSF‑1 is necessary for the upregulation of Cryab expression, but not for that of HSP‑70. HSF‑1 and HSP‑70 have a neuroprotective effect. Furthermore, the neuroprotective effect of PNU282987 against Aβ aggregation was mediated by the canonical PI3K/Akt signaling pathway activation.

Borna disease virus (BDV) is a neurotropic and non‑cytolytic virus, which causes behavioral disorders in a wide range of warm‑blooded species. It is well established that BDV induces neurodegeneration by impairing neurogenesis and interfering with neuronal functioning in the limbic system. In the present study, the potential role of BDV infection in SH‑SY5Y cells was identified, and comparisons of two original BDV strains (the human Hu‑H1 and the laboratory Strain V) were performed to further elucidate the phenotypes of BDV pathogenesis with strain differences. Cell Counting Kit‑8 and flow cytometric analyses revealed that the two BDV strain‑infected groups exhibited marked anti‑proliferation and cell cycle arrest compared with the control group, and the Hu‑H1 strain caused more evident effects. However, the Hu‑H1 strain did not exert effects on the apoptosis of SH‑SH5Y cells, while Strain V led to a marked increase in apoptosis upon initial infection. Western blot analysis confirmed the upregulation of apoptosis regulator BAX protein and the downregulation of apoptosis regulator Bcl‑2 protein caused by the two BDV strains. The results of the present study provided evidence that infection with BDV suppressed SH‑SY5Y cellular functioning and exhibited divergent antiproliferative and apoptotic roles in cells between the two strains. The present study provided an insight for future investigation of strain differences and underlying pathomechanisms.

Borna disease virus (BDV) is a neurotropic RNA virus that infects the limbic system of mammals and results in behavioral disorders. The hippocampus is a core region in the limbic system, which contributes to memory and learning and is important in the regulation of emotion. However, no validated microRNA housekeeping genes have yet been identified in BDV‑infected rat primary hippocampal neurons. Proper normalization is key in accurate miRNA expression analysis. The present study used reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) to evaluate the expression stability of 10 commonly used reference genes [miR‑92a, 5S, U6, miR‑103, miR‑101a, miR-let-7a, miR‑16, E2 small nucleolar RNA (snoRNA), U87 and miR‑191] in BDV‑infected rat hippocampal neurons and non‑infected controls across 12 days post‑infection. The data was analyzed by four statistical algorithms: geNorm, NormFinder, BestKeeper, and the comparative Δ‑Ct method. Subsequently, the most suitable reference genes (miR‑101a and U87) and the least suitable (snoRNA) were determined by the RankAggreg package. miR‑155 was selected as a standard by which to evaluate the most and least suitable reference genes. When normalized to the most stable reference gene there were significant differences between the two groups. However, when the data were normalized to the less stably expressed gene, the results were not significant. miR‑101a was recommended as a suitable reference gene for BDV-infected rat primary hippocampal neurons.

MicroRNAs (miRNAs) are recognized as important regulators of gene expression via translational depression or mRNA degradation. Previously, dysregulated miRNAs have been found in neurodegenerative and neuropsychiatric disorders. Borna disease virus (BDV) is a neurotropic, negative single‑stranded RNA virus, which may be a cause of human neuropsychiatric disease. BDV is regarded as an ideal model to analyze the molecular mechanisms of mental disorders caused by viral infection. In the present study, 10 miRNAs were dysregulated in human oligodendrocytes (OL cells) infected with the BDV strain, Hu‑H1 (OL/BDV). The predicted target genes of those different miRNAs were closely associated with DNA binding, receptor activity, cytoplasm and membrane, biopolymer metabolic process and signal transduction, which were ranked highest using Gene Ontology (GO) analysis, and were predominantly involved in 'Immune system and adaptive Immune system pathways' on pathway analysis. Reverse transcription‑quantitative polymerase chain reaction analysis confirmed that seven miRNAs (miR‑1290, miR‑1908, miR‑146a‑5p, miR‑424‑5p, miR‑3676‑3p, miR‑296‑3p and miR‑7‑5p) were significantly downregulated in the OL/BDV cells, whereas two miRNAs (miR‑1244 and miR‑4521) showed no significant differences between the two groups. The present study revealed for the first time, to the best of our knowledge, the miRNA profile of BDV Hu‑H1‑infected human OL cells. Based on GO and pathway analyses, further investigation of the signaling processes in BDV‑infected oligodendrocytes may offer particular promise in improving understanding of the neuropathogenesis of BDV.

Alda-1, an aldehyde dehydrogenase 2 (ALDH2) agonist, has been demonstrated to reduce injury caused by acute myocardial infarction (MI) and ischemia/reperfusion. The present study aimed to investigate whether oral administration of Alda-1 improved long-term survival of rats with chronic heart failure (CHF) post-MI. MI model rats treated daily with Alda-1 exhibited an increase in 20-week survival rate compared with untreated MI rats. Alda-1 treatment decreased the heart weight/body weight ratio, collagen volume, left ventricular (LV) internal diameter at the end of diastole and LV internal diameter at the end of systole, while increasing LV ejection fraction with evident LV fractional shortening. Myocardial cell apoptosis index, the activity of caspase-3 and the expression of cleaved-caspase-3 were also reduced by Alda-1 treatment. The protective effects of Alda-1 were associated with reduced 4-hydroxynonenal accumulation. The results of the present study revealed that the long-term treatment with Alda-1 prevented the progression of ventricular remodeling and improved the long-term survival of rats with CHF post-MI.

Substantial evidence from previous studies has suggested an association between major depressive disorder (MDD) and inflammation, and previous studies have associated prefrontal cortex (PFC) dysfunction with MDD. Systemic administration of bacterial lipopolysaccharide has been used to study inflammation-associated behavioral changes in rodents. However, proteomic studies investigating PFC protein expression in an LPS-induced mouse model of depression have yet to be conducted. Using two-dimensional electrophoresis coupled with matrix-assisted laser desorption ionization-time of flight-tandem mass spectrometry, PFC proteomes were comparatively assessed in LPS-induced acute inflammation reaction mice, LPS-induced depressive-like behavior mice (Dep), and control mice. A total of 26 differentially expressed proteins were identified, two of which were selected for western blot analysis, the results of which revealed a significant increase in the expression levels of creatine kinase B and dihydropyrimidinase-like 3 in Dep mice, suggesting that changes in energy metabolism and neuro-genesis occur in the PFC of Dep mice. Further investigation on these processes and on the proteins of the PFC are required in order to elucidate the pathophysiological mechanism underlying MDD.

Despite the well-established role of all-trans-retinoic acid (ATRA) in congenital clubfoot (CCF)-like deformities in in vivo models, the essential cellular and molecular targets and the signaling mechanisms for ATRA-induced CCF-like deformities remain to be elucidated. Recent studies have demonstrated that p53 and p21, expressed in the hindlimb bud mesenchyme, regulate cellular proliferation and differentiation, contributing to a significant proportion of embryonic CCF-like abnormalities. The objective of the present study was to investigate the mechanisms for ATRA-induced CCF, by assessing ATRA-regulated chondrogenesis in rat embryo hindlimb bud mesenchymal cells (rEHBMCs) in vitro. The experimental study was based on varying concentrations of ATRA exposure on embryonic day 12.5 rEHBMCs in vitro. The present study demonstrated that ATRA inhibited the proliferation of cells by stimulating apoptotic cell death of rEHBMCs. It was also observed that ATRA induced a dose-dependent reduction of cartilage nodules compared with the control group. Reverse transcription-polymerase chain reaction and western blotting assays revealed that the mRNA and protein expression of cartilage-specific molecules, including aggrecan, Sox9 and collagen, type II, α 1 (Col2a1), were downregulated by ATRA in a dose-dependent manner; the mRNA levels of p53 and p21 were dose-dependently upregulated from 16 to 20 h of incubation with ATRA, but dose-dependently downregulated from 24 to 48 h. Of note, p53 and p21 were regulated at the translational level in parallel with the transcription with rEHBMCs treated with ATRA. Furthermore, the immunofluorescent microscopy assays indicated that proteins of p53 and p21 were predominantly expressed in the cartilage nodules. The present study demonstrated that ATRA decreases the chondrogenesis of rEHBMCs by inhibiting cartilage-specific molecules, including aggrecan, Sox9 and Col2al, via regulating the expression of p53 and p21.

Major depressive disorder is a severe neuropsychiatric disease that negatively impacts the quality of life of a large portion of the population. However, the molecular mechanisms underlying depression are still unclear. The pathogenesis of depression involves several brain regions. However, most previous studies have focused only on one specific brain region. Plasma and brain tissues exchange numerous components through the blood‑brain barrier. Therefore, in the present study, plasma samples from control (CON) mice and mice subjected to chronic unpredictable mild stress (CUMS) were used to investigate the molecular pathogenesis of depression, and the association between the peripheral circulation and the central nervous system. A total of 47 significant differentially expressed proteins were identified between the CUMS and CON group by an isobaric tag for relative and absolute quantitation (iTRAQ) coupled with tandem mass spectrometry approach. These 47 differentially expressed proteins were analyzed with ingenuity pathway analysis (IPA) software. This revealed that the acute phase response, LXR/RXR and FXR/RXR activation, the complement system and the intrinsic prothrombin activation pathway were significantly changed. Four of the significant differentially expressed proteins (lipopolysaccharide binding protein, fibrinogen β chain, α‑1 antitrypsin, and complement factor H) were validated by western blotting. the present findings provide a novel insight into the molecular pathogenesis of depression.

In order to study the application of antibodies against recombinant proteins for detecting Borna disease virus (BDV) phosphoprotein (p24) and nucleoprotein (p40) (BDV‑p24/p40) on paraffin sections by immunohistochemistry. The purified fusion p24 and p40 proteins were used for the preparation of polyclonal and monoclonal anti‑p24 and anti‑40 antibodies, which were confirmed by ELISA and western blotting. Paraffin sections were made from BDV‑infected Sprague‑Dawley (SD) rats (n=20), PBS‑injected SD rats (n=20), normal SD rats (n=20) and normal C57 mice (n=20). Immunohistochemical staining was performed according to the EnVision™ two‑step protocol. Heat‑mediated antigen retrieval was performed using the retrieval buffer sodium citrate (1 mM; pH 6.0). All the antibodies against recombinant proteins exhibited good sensitivity and specificity. There were significant differences between the BDV‑infected group and the BDV‑uninfected group for poly‑ and monoclonal anti‑p24 and ‑p40 antibodies. These antibodies against recombinant proteins may be used effectively to detect BDV p24 and p40 in paraffin sections.

MicroRNAs (miRNAs) regulate gene expression by inhibiting transcription or translation and are involved in diverse biological processes, including development, cellular differentiation and tumor generation. miRNA microarray technology is a high‑throughput global analysis tool for miRNA expression profiling. Here, the hippocampi of four borna disease virus (BDV)‑infected and four non‑infected control neonatal rats were selected for miRNA microarray and bioinformatic analysis. Reverse transcription quantitative polymerase chain reaction (RT‑qPCR) analysis was subsequently performed to validate the dysregulated miRNAs. Seven miRNAs (miR‑145*, miR‑146a*, miR‑192*, miR‑200b, miR‑223*, miR‑449a and miR‑505), showed increased expression, whereas two miRNAs (miR‑126 and miR‑374) showed decreased expression in the BDV‑infected group. By RT‑qPCR validation, five miRNAs (miR‑126, miR‑200b, miR‑374, miR‑449a and miR‑505) showed significantly decreased expression (P