Lovastatin impairs cellular proliferation and enhances hyaluronic acid production in fibroblast-like synoviocytes.

INTRODUCTION: Statins have demonstrated chondroprotective effects by reducing inflammation and mitigating extracellular matrix degradation. However, statins are also reported to be cytotoxic to several types of cells. Early-onset osteoarthritis (OA) is characterized by synovial inflammation, which adversely affects hyaluronan (HA) production in fibroblast-like synoviocytes (FLSs). Nevertheless, the precise effects of statins on the synovium remain unclear. METHODS: This study investigated the impact of lovastatin on human FLSs, and HA secretion-related genes, signaling pathways, and production were evaluated. RESULTS: The findings revealed that high doses of lovastatin (20 or 40 µM) decreased FLS viability and increased cell death. FLS proliferation ceased when cultured in a medium containing 5 or 10 µM lovastatin. mRNA expression analysis demonstrated that lovastatin (5 and 10 µM) upregulated the gene level of hyaluronan synthase 1 (HAS1), HAS2, and proteoglycan 4 (PRG4), but not HAS3. While the expression of multidrug resistance-associated protein 5 transporter gene remained unaffected, both inward-rectifying potassium channel and acid-sensing ion channel 3 were upregulated. Western blot further confirmed that lovastatin increased the production of HAS1 and PRG4, and activated the PKC-α, ERK1/2, and p38-MAPK signaling pathways. Additionally, lovastatin elevated intracellular cAMP levels and HA production in FLSs. CONCLUSION: Lovastatin impairs cellular proliferation but enhances HA production in human FLSs.

Conjunctive Analysis of BSA-Seq and SSR Markers Unveil the Candidate Genes for Resistance to Rice False Smut.

Rice false smut (RFS) caused by the fungus Ustilaginoidea virens (Cook) leads to serious yield losses in rice. Identification of the gene or quantitative trait loci (QTLs) is crucial to resistance breeding and mitigation of RFS damage. In this study, we crossed a resistant variety, IR77298-14-1-2::IRGC117374-1, with a susceptible indica cultivar, 9311, and evaluated recombinant inbred lines in a greenhouse. The genetic analysis showed that the RFS resistance of IR77298-14-1-2::IRGC117374-1 was controlled by multiple recessive loci. We identified a novel QTL, qRFS12.01, for RFS resistance in IR77298-14-1-2::IRGC117374-1 by combining bulked segregant analysis with whole genome resequencing (BSA-seq) and simple sequence repeat (SSR) marker mapping approaches. The phenotypic effect of qRFS12.01 on RFS resistance reached 28.74%, suggesting that SSR markers linked to qRFS12.01 are valuable for marker-assisted breeding of RFS resistance in rice. The prediction of putative candidate genes within qRFS12.01 revealed five disease resistance proteins containing NB-ARC domains. In conclusion, our findings provide a new rice chromosome region carrying genes/QTLs for resistance to RFS.

Transcriptomic and Metabolomic Analyses Provide Insights into the Pathogenic Mechanism of the Rice False Smut Pathogen Ustilaginoidea virens.

Rice false smut, caused by the fungal pathogen Ustilaginoidea virens, is a worldwide rice fungal disease. However, the molecular mechanism of the pathogenicity of the fungus U. virens remains unclear. To understand the molecular mechanism of pathogenesis of the fungus U. virens, we performed an integrated analysis of the transcriptome and metabolome of strongly (S) and weakly (W) virulent strains both before and after the infection of panicles. A total of 7932 differential expressed genes (DEGs) were identified using transcriptome analysis. Gene ontology (GO) and metabolic pathway enrichment analysis indicated that amino acid metabolism, autophagy-yeast, MAPK signaling pathway-yeast, and starch and sucrose metabolism were closely related to the pathogenicity of U. virens. Genes related to pathogenicity were significantly upregulated in the strongly virulent strain, and were ATG, MAPK, STE, TPS, and NTH genes. However, genes involved in the negative regulation of pathogenesis were significantly downregulated and contained TOR kinase, TORC1, and autophagy-related protein genes. Metabolome analysis identified 698 differentially accumulated metabolites (DAMs), including 13 categories of organic acids and derivatives, lipids and lipid-like molecules, organoheterocyclic compounds. The significantly enriched pathways of DAMs mainly included amino acids and carbohydrates, and they accumulated after infection by the S strain. To understand the relevance of DEGs and DAMs in the pathogenicity of U. virens, transcriptomic and metabolomic data were integrated and analyzed. These results further confirmed that the pathogenesis of U. virens was regulated by DEGs and DAMs related to these four pathways, involving arginine and proline metabolism, lysine biosynthesis, alanine, aspartate and glutamate metabolism, and starch and sugar metabolism. Therefore, we speculate that the pathogenicity of U. virens is closely related to the accumulation of amino acids and carbohydrates, and to the changes in the expression of related genes.

Diversity Analysis of the Rice False Smut Pathogen Ustilaginoidea virens in Southwest China.

Rice false smut caused by Ustilaginoidea virens is a destructive disease in rice cropping areas of the world. The present study is focused on the morphology, pathogenicity, mating-type loci distribution, and genetic characterization of different isolates of U. virens. A total of 221 strains of U. virens were collected from 13 rice-growing regions in southwest China. The morphological features of these strains exhibited high diversity, and the pathogenicity of the smut fungus showed significant differentiation. There was no correlation between pathogenicity and sporulation. Mating-type locus (MAT) analysis revealed that all 221 isolates comprised heterothallic and homothallic forms, wherein 204 (92.31%) and 17 (7.69%) isolates belonged to heterothallic and homothallic mating types, respectively. Among 204 strains of heterothallic mating types, 62 (28.05%) contained MAT1-1-1 idiomorphs, and 142 isolates (64.25%) had the MAT1-2-1 idiomorph. Interestingly, strains isolated from the same fungus ball had different mating types. The genetic structure of the isolates was analyzed using simple sequence repeats (SSRs) and single-nucleotide polymorphisms (SNPs). All isolates were clustered into five genetic groups. The values of Nei's gene diversity (H) and Shannon's information index (I) indicated that all strains as a group had higher genetic diversity than strains from a single geographical population. The pairwise population fixation index (FST) values also indicated significant genetic differentiation among all compared geographical populations. The analysis of molecular variation (AMOVA) indicated greater genetic variation within individual populations and less genetic variation among populations. The results showed that most of the strains were not clustered according to their geographical origin, showing the rich genetic diversity and the complex and diverse genetic background of U. virens in southwest China. These results should help to better understand the biological and genetic diversity of U. virens in southwest China and provide a theoretical basis for building effective management strategies.

Transcription Profiling of Rice Panicle in Response to Crude Toxin Extract of Ustilaginoidea virens.

Ustilaginoidea virens infects rice, causing rice false smut disease and reduced yields. During its growth, U. virens can also produce some toxins but less is known about the response mechanisms of the plant to U. virens toxins. U. virens toxins can inhibit the accumulation of total sugar in rice panicles. We used RNA sequencing to analyze the differential expression profile induced by infiltrating crude toxins into early growth-stage rice panicles. We compared the transcriptomes of the control and crude toxin-treated rice panicles and determined variable transcriptional responses under the action of the crude toxins. A total of 6,127 differentially expressed genes (DEGs) were identified. Among these genes, 3,150 were upregulated and 2,977 were downregulated. Gene Ontology (GO) and metabolic pathway enrichment analyses indicated that U. virens toxins mainly influenced glycometabolism, amino acid metabolism, and secondary metabolism of rice panicles. DEG analysis showed that the gene expression levels of 10 transcription factor families were significantly changed. Genes involved in phenylpropanoid biosynthesis, flavonoid biosynthesis, sugar transporters, and starch synthesis-related were significantly downregulated, including cytochrome P450, beta-glucosidase, CHS1, sucrose transporters, SWEETs, starch-branching enzymes, and UDP-glucose pyrophosphorylase. However, genes involved in programmed cell death (PCD) were significantly upregulated and contained cytochrome c, metacaspase, and protein kinase genes. The results indicate that U. virens toxins may act as the pathogenic factors to reduce stress resistance, disrupt total sugar accumulation and starch formation, and induce PCD.

Genome sequence and transcriptome profiles of pathogenic fungus Paecilomyces penicillatus reveal its interactions with edible fungus Morchella importuna.

Paecilomyces penicillatus is one of the pathogens of morels, which greatly affects the yield and quality of Morchella spp.. In the present study, we de novo assembled the genome sequence of the fungus P. penicillatus SAAS_ppe1. We analyzed the transcriptional profile of P. penicillatus SAAS_ppe1 infection of Morchella importuna at different stages (3 days and 6 days after infection) and the response of M. importuna using the transcriptome. The assembled genome sequence of P. penicillatus SAAS_ppe1 was 39.78 Mb in length (11 scaffolds; scaffold N50, 6.50 Mb), in which 99.7% of the expected genes were detected. A total of 7.48% and 19.83% clean transcriptional reads from the infected sites were mapped to the P. penicillatus genome at the early and late stages of infection, respectively. There were 3,943 genes differently expressed in P. penicillatus at different stages of infection, of which 24 genes had increased expression with the infection and infection stage, including diphthamide biosynthesis, aldehyde reductase, and NAD (P)H-hydrate epimerase (P < 0.05). Several genes had variable expression trends at different stages of infection, indicating P. penicillatus had diverse regulation patterns to infect M. importuna. GO function, involving cellular components, and KEGG pathways, involving glycerolipid metabolism, and plant-pathogen interaction were significantly enriched during infection by P. penicillatus. The expression of ten genes in M. importuna increased during the infection and infection stage, and these may regulate the response of M. importuna to P. penicillatus infection. This is the first comprehensive study on P. penicillatus infection mechanism and M. importuna response mechanism, which will lay a foundation for understanding the fungus-fungus interactions, gene functions, and variety breeding of pathogenic and edible fungi.

Silymarin modulates catabolic cytokine expression through Sirt1 and SOX9 in human articular chondrocytes.

BACKGROUND: Silymarin (SMN), a polyphenolic flavonoid, is involved in multiple bioactive functions including anti-inflammation. Pretreatment with SMN demonstrated chondroprotection against tumour necrosis factor-alpha (TNF-α) stimulation in a chondrocyte cell line. However, pre- and posttreatment with phytochemicals have varying effects on osteoarthritis (OA) chondrocytes, and the therapeutic potential of SMN after catabolic cytokine stimulation is not fully elucidated. METHODS: The cytotoxicity of SMN (12.5, 25, 50 and 100 µM) was evaluated in human primary chondrocytes. The chondrocytes were supplemented with SMN (25 and 50 µM) after interleukin-1beta (IL-1ß) stimulation. The mRNA expression and protein production of catabolic/anabolic cytokines as well as extracellular matrix (ECM) components were evaluated. RESULTS: High-dose SMN (100 µM) impaired the mitochondrial activity in chondrocytes, and 50 µM SMN further caused cell death in IL-1ß-stimulated cells. The addition of 25 µM SMN ameliorated cell senescence; downregulated the catabolic genes of inducible nitric oxide synthase, IL-1ß, TNF-α, matrix metalloproteinase-3 (MMP-3), MMP-9 and MMP-13; upregulated the anabolic genes of tissue inhibitor of metalloproteinase-1 (TIMP-1) and collagen type II alpha 1; and restored the expression of chondrogenic phenotype genes SOX9 and sirtuin-1 (Sirt1). In addition, the production of IL-1ß, MMP-3 and MMP-9 decreased with an increase in TIMP-1 secretion. However, the mRNA levels of IL-6, IL-8 and IL-10 and protein production remained high. The addition of nicotinamide, a Sirt1 inhibitor, downregulated SOX9 and attenuated the therapeutic effects of SMN on IL-1ß-stimulated chondrocytes. CONCLUSION: SMN regulates the chondrocyte phenotype through Sirt1 and SOX9 to improve ECM homeostasis and may serve as a complementary therapy for early-stage knee OA.

Comparative mitochondrial genome analysis reveals intron dynamics and gene rearrangements in two Trametes species.

Trametes species are efficient wood decomposers that are widespread throughout the world. Mitogenomes have been widely used to understand the phylogeny and evolution of fungi. Up to now, two mitogenomes from the Trametes genus have been revealed. In the present study, the complete mitogenomes of two novel Trametes species, Trametes versicolor and T. coccinea, were assembled and compared with other Polyporales mitogenomes. Both species contained circular DNA molecules, with sizes of 67,318 bp and 99,976 bp, respectively. Comparative mitogenomic analysis indicated that the gene number, length and base composition varied between the four Trametes mitogenomes we tested. In addition, all of the core protein coding genes in Trametes species were identified and subjected to purifying selection. The mitogenome of T. coccinea contained the largest number of introns among the four Trametes species tested, and introns were considered the main factors contributing to size variations of Polyporales. Several novel introns were detected in the Trametes species we assembled, and introns identified in Polyporales were found to undergo frequent loss/gain events. Large-scale gene rearrangements were detected between closely related Trametes species, including gene inversions, insertions, and migrations. A well-supported phylogenetic tree for 77 Basidiomycetes was obtained based on the combined mitochondrial gene set using 2 phylogenetic inference methods. The results showed that mitochondrial genes are effective molecular markers for understanding the phylogeny of Basidiomycetes. This study is the first to report the mitogenome rearrangement and intron dynamics of Trametes species, which shed light on the evolution of Trametes and other related species.

Mitogenomes of Two Phallus Mushroom Species Reveal Gene Rearrangement, Intron Dynamics, and Basidiomycete Phylogeny.

Phallus indusiatus and Phallus echinovolvatus are edible bamboo mushrooms with pharmacological properties. We sequenced, assembled, annotated, and compared the mitogenomes of these species. Both mitogenomes were composed of circular DNA molecules, with sizes of 89,139 and 50,098 bp, respectively. Introns were the most important factor in mitogenome size variation within the genus Phallus. Phallus indusiatus, P. echinovolvatus, and Turbinellus floccosus in the subclass Phallomycetidae have conservative gene arrangements. Large-scale gene rearrangements were observed in species representing 42 different genera of Basidiomycetes. A variety of intron position classes were found in the 44 Basidiomycete species analyzed. A novel group II intron from the P. indusiatus mitogenome was compared with other fungus species containing the same intron, and we demonstrated that the insertion sites of the intron had a base preference. Phylogenetic analyses based on combined gene datasets yielded well-supported Bayesian posterior probability (BPP = 1) topologies. This indicated that mitochondrial genes are reliable molecular markers for analyzing the phylogenetic relationships of the Basidiomycetes. This is the first study of the mitogenome of the genus Phallus, and it increases our understanding of the population genetics and evolution of bamboo mushrooms and related species.

Chitosan-cartilage extracellular matrix hybrid scaffold induces chondrogenic differentiation to adipose-derived stem cells.

INTRODUCTION: Adipose-derived stem cells (ASCs) are potential cell sources for cartilage tissue engineering. Chitosan has been shown to enhance the stemness and differentiation capability of ASCs, and the native extracellular matrix (ECM) derived from articular cartilage has been also reported to induce chondrogenic differentiation of ASCs. Here we tested the hypothesis that a porous three-dimensional (3D) hybrid scaffold composed of chitosan and cartilage ECM can provide a better environment to induce ASC chondrogenesis. METHODS: Mixed solution composed of chitosan and cartilage ECM was frozen and lyophilized to form a composite construct. The porous 3D scaffolds were further crosslinked by genipin and used for ASC culture. RESULTS: Cultivation of ASCs in the chitosan/cartilage ECM composite 3D scaffolds induced the formation of cell spheroids with profound glycosaminoglycan production after 14 and 28 days culture. Chondrogenesis of ASCs seeded in the 3D scaffolds was also evident by mRNA expressions of cartilage-specific gene COL2A1 and ACAN on day 14. Histology and immunohistochemistry on day 28 also showed abundant cartilage-specific macromolecules, namely collagen type II and proteoglycan, deposited in a surface layer of the composite scaffold with tangential layer, transitional layer, and lacunae-like structures. Otherwise, hypertrophic markers collagen type I and X were concentrated in the area beneath the surface. CONCLUSION: Our findings demonstrated spatial chondrogenic differentiation of ASCs in the chitosan-cartilage ECM composite scaffolds. This 3D hybrid scaffold exhibits great potentials for ASC-based cartilage tissue engineering.

Evaluation of the post-treatment anti-inflammatory capacity of osteoarthritic chondrocytes: An in vitro study using baicalein.

INTRODUCTION: Targeting inflammatory cascades is considered a promising way to prevent knee osteoarthritis (OA) progression. In terms of down-regulating the expression of inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and matrix metalloproteinases (MMPs), pre-treatment with the flavonoid baicalein reportedly protects articular chondrocytes against the cytotoxicity of IL-1ß. However, the benefits of post-treatment baicalein on osteoarthritic chondrocytes are not fully elucidated. METHODS: In this study, primary human chondrocytes were stimulated with IL-1ß prior to baicalein application to evaluate the therapeutic effect of post-treatment. RESULTS: Post-treatment baicalein alleviated cell death and partially restored mitochondrial viability, while the senescence-associated secretory phenotype was not improved in IL-1ß-stimulated chondrocytes. Post-treatment baicalein down-regulated the expressions of IL-1ß, tumor necrosis factor-alpha, MMP-3, MMP-9, and MMP-13 mRNA as well as the protein production in stimulated cells. Even so, the levels of these factors were relative higher than those in un-treated chondrocytes. Moreover, iNOS, IL-6, IL-8, and COL1A1 expressions were consistently high, and IL-10 protein synthesis steadily increased in IL-1ß-treated chondrocytes under baicalein treated status. Moreover, Western blot analyses showed that post-treatment baicalein suppressed nuclear factor kappa-light-chain-enhancer of activated B cells and p50 production while downstream cyclooxygenase-2 was still highly expressed. CONCLUSION: Baicalein post-treatment to osteoarthritic chondrocytes had a minor benefit to the homeostasis of cartilaginous extracellular matrix.

The complete mitochondrial genome of Cladobotryum mycophilum (Hypocreales: Sordariomycetes).

Cladobotryum mycophilum is the causal agent of cobweb disease in many important mushroom crops. In this study, we report the complete mitochondrial genome of C. mycophilum for the first time. The genome is 78,729 bp long and comprises 52 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNA), and 26 transfer RNA (tRNA) genes. The nucleotide composition of C. mycophilum mitochondrial genome is as follows: A (38.06%), T (34.68%), C (12.19%), and G (15.07%). Phylogenetic analysis revealed that C. mycophilum had a close relationship with Cladobotryum varium from Hypocreaceae. This study provided a basis for studies of the mitochondrial evolution of Hypocreaceae.

Characterization of the mitochondrial genome of the pathogenic fungus Scytalidium auriculariicola (Leotiomycetes) and insights into its phylogenetics.

Scytalidium auriculariicola is the causative pathogen of slippery scar disease in the cultivated cloud ear fungus, Auricularia polytricha. In the present study, the mitogenome of S. auriculariicola was sequenced and assembled by next-generation sequencing technology. The circular mitogenome is 96,857 bp long and contains 56 protein-coding genes, 2 ribosomal RNA genes, and 30 transfer RNA genes (tRNAs). The high frequency of A and T used in codons contributed to the high AT content (73.70%) of the S. auriculariicola mitogenome. Comparative analysis indicated that the base composition and the number of introns and protein-coding genes in the S. auriculariicola mitogenome varied from that of other Leotiomycetes mitogenomes, including a uniquely positive AT skew. Five distinct groups were found in the gene arrangements of Leotiomycetes. Phylogenetic analyses based on combined gene datasets (15 protein-coding genes) yielded well-supported (BPP = 1) topologies. A single-gene phylogenetic tree indicated that the nad4 gene may be useful as a molecular marker to analyze the phylogenetic relationships of Leotiomycetes species. This study is the first report on the mitochondrial genome of the genus Scytalidium, and it will contribute to our understanding of the population genetics and evolution of S. auriculariicola and related species.

The chondroprotective effect of diosmin on human articular chondrocytes under oxidative stress.

Excessive oxidative stress, which can amplify inflammatory responses, is involved in the pathologic progression of knee osteoarthritis. Diosmin is known to possess a variety of biological functions such as antiinflammatory and antioxidant activities. We therefore demonstrated the chondroprotective potentials of diosmin on human articular chondrocytes under oxidative stress. The cytotoxicity of diosmin (5, 10, 50, and 100 µM) to chondrocytes was first evaluated. Subsequently, the cells were treated with diosmin (5 and 10 µM) after hydrogen peroxide (H2 O2 ) exposure. We found that the cytotoxicity of diosmin occurred in a dose-dependent manner (10, 50, and 100 µM), and low-dose diosmin (5 µM) slightly impaired cell viability. Diosmin supplementations (5 and 10 µM) did not show beneficial effects on mitochondrial activity, cytotoxicity, proliferation, and survival and the cell senescence was ameliorated in H2 O2 -exposed chondrocytes. On the other hand, diosmin down-regulated the mRNA levels of iNOS, COX-2, IL-1ß, COL1A1, MMP-3, and MMP-9; up-regulated TIMP-1 and SOX9; and improved COL2A1 in chondrocytes under oxidative stresses. Furthermore, diosmin also regulated glutathione reductase and glutathione peroxidase of H2 O2 -exposed chondrocytes. In conclusion, diosmin displayed a remarkable antiinflammatory effect compared with the antioxidant capacity on human chondrocytes. Diosmin can maintain the homeostasis of extracellular matrix of articular cartilage.

Characterization of the complete mitochondrial genome of Corynespora cassiicola (Pleosporales: Dothideomycetes), with its phylogenetic analysis.

Corynespora cassiicola is a well-known plant pathogen with a broad host range and diverse lifestyles. In this study, we presented the complete mitochondrial genome (mitogenome) of C. cassiicola for the first time. It has a total length of 40,752 bp, which encodes 17 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNA), and 27 transfer RNA (tRNA) genes. The nucleotide composition of the mitogenome is: A (36.24%), T (34.62%), G (15.74%), and C (13.39%). Phylogenetic analysis revealed that C. cassiicola has a close relationship with Didymella pinodes from Didymellaceae.

Role of Neuroinflammation in Opioid Tolerance: Translational Evidence from Human-to-Rodent Studies.

Opioid analgesics remain the most effective and widely used analgesics for the management of moderate to severe pain, including cancer pain and chronic non-cancer pain. However, the efficacy of long-term opioid analgesics is attenuated by tolerance and/or hyperalgesia after long-term use, preventing adequate pain relief under stable opioid dosages for chronic pain patients. Classical neuron-centered concepts about tolerance, such as internalization of opioid receptors, upregulation of N-methyl-D-aspartate receptor function, or downregulation of glutamate transporter activity, can only partially explain the phenomenon of tolerance. Recent evidence revealing glial activation and upregulation of inflammatory mediators in the rodent central nervous system has confirmed the pivotal role of neuroinflammation in neuropathic pain or opioid tolerance, or both. However, human evidence is still sparse.Based on our clinical practice, we conducted translational research by investigating the cerebrospinal fluid (CSF) cytokine and chemokine profiles of opioid-tolerant patients after research ethic committee approval. CSF samples from opioid-tolerant patients and opioid-naive subjects were compared. We found CXCL1, CXCL12, and leukemia inhibitory factor (LIF) were significantly upregulated among the opioid-tolerant patients and positively correlated with the opioid dosage.We translated these findings back to lab animal experiment; after induction of tolerance by morphine infusion, the spinal cord expression of CXCL1, CXCL12, and LIF were all upregulated. Although CXCL1 and CXCL12 infusion alone did not affect baseline tail-flick latency, morphine analgesic efficacy dropped significantly after intrathecal infusion of CXCL1 and CXCL12. After establishing tolerance by intrathecal continuous infusion of morphine, tolerance development was accelerated by co-administration of CXCL1 and CXCL12. In parallel, the effect was attenuated by co-administration of CXCL1- or CXCL12-neutralizing antibody or concordant receptor antagonists.On the contrary, although chronic morphine administration still induced LIF upregulation in rat spinal cords, intrathecal injection of LIF potentiated the analgesic action of morphine and delayed the development of morphine tolerance. Upregulation of endogenously released LIF by long-term use of opioids might counterbalance the tolerance induction effects of other pro-inflammatory cytokines.CXCL1, CXCL12, and LIF are upregulated in both opioid-tolerant patients and rodents. The onset and extent of opioid tolerance were affected by modulating the intrathecal CXCL1/CXCR2, CXCL12/CXCR4, and LIF signaling and could be novel drug targets for the treatment of opioid tolerance.

Impairment of social behaviors in Arhgef10 knockout mice.

Background: Impaired social interaction is one of the essential features of autism spectrum disorder (ASD). Our previous copy number variation (CNV) study discovered a novel deleted region associated with ASD. One of the genes included in the deleted region is ARHGEF10. A missense mutation of ARHGEF10 has been reported to be one of the contributing factors in several diseases of the central nervous system. However, the relationship between the loss of ARHGEF10 and the clinical symptoms of ASD is unclear. Methods: We generated Arhgef10 knockout mice as a model of ASD and characterized the social behavior and the biochemical changes in the brains of the knockout mice. Results: Compared with their wild-type littermates, the Arhgef10-depleted mice showed social interaction impairment, hyperactivity, and decreased depression-like and anxiety-like behavior. Behavioral measures of learning in the Morris water maze were not affected by Arhgef10 deficiency. Moreover, neurotransmitters including serotonin, norepinephrine, and dopamine were significantly increased in different brain regions of the Arhgef10 knockout mice. In addition, monoamine oxidase A (MAO-A) decreased in several brain regions. Conclusions: These results suggest that ARHGEF10 is a candidate risk gene for ASD and that the Arhgef10 knockout model could be a tool for studying the mechanisms of neurotransmission in ASD. Trial registration: Animal studies were approved by the Institutional Animal Care and Use Committee of National Taiwan University (IACUC 20150023). Registered 1 August 2015.

Transcriptional profiling provides new insights into the role of nitric oxide in enhancing Ganoderma oregonense resistance to heat stress.

Ganoderma is well known for its use in traditional Chinese medicine and is widely cultivated in China, Korea, and Japan. Increased temperatures associated with global warming are negatively influencing the growth and development of Ganoderma. Nitric oxide is reported to play an important role in alleviating fungal heat stress (HS). However, the transcriptional profiling of Ganoderma oregonense in response to HS, as well as the transcriptional response regulated by NO to cope with HS has not been reported. We used RNA-Seq technology to generate large-scale transcriptome data from G. oregonense mycelia subjected to HS (32 °C) and exposed to concentrations of exogenous NO. The results showed that heat shock proteins (HSPs), "probable stress-induced proteins", and unigenes involved in "D-amino-acid oxidase activity" and "oxidoreductase activity" were significantly up-regulated in G. oregonense subjected to HS (P < 0.05). The significantly up-regulated HSPs, "monooxygenases", "alcohol dehydrogenase", and "FAD/NAD(P)-binding domain-containing proteins" (P < 0.05) regulated by exogenous NO may play important roles in the enhanced HS tolerance of G. oregonense. These results provide insights into the transcriptional response of G. oregonense to HS and the mechanism by which NO enhances the HS tolerance of fungi at the gene expression level.

Antagonism of proteasome inhibitor-induced heme oxygenase-1 expression by PINK1 mutation.

PTEN-induced putative kinase 1 (PINK1) is an integral protein in the mitochondrial membrane and maintains mitochondrial fidelity. Pathogenic mutations in PINK1 have been identified as a cause of early-onset autosomal recessive familial Parkinson's disease (PD). The ubiquitin proteasome pathway is associated with neurodegenerative diseases. In this study, we investigated whether mutations of PINK1 affects the cellular stress response following proteasome inhibition. Administration of MG132, a peptide aldehyde proteasome inhibitor, significantly increased the expression of heme oxygenase-1 (HO-1) in rat dopaminergic neurons in the substantia nigra and in the SH-SY5Y neuronal cell line. The induction of HO-1 expression by proteasome inhibition was reduced in PINK1 G309D mutant cells. MG132 increased the levels of HO-1 through the Akt, p38, and Nrf2 signaling pathways. Compared with the cells expressing WT-PINK1, the phosphorylation of Akt and p38 was lower in those cells expressing the PINK1 G309D mutant, which resulted in the inhibition of the nuclear translocation of Nrf2. Furthermore, MG132-induced neuronal death was enhanced by the PINK1 G309D mutation. In this study, we demonstrated that the G309D mutation impairs the neuroprotective function of PINK1 following proteasome inhibition, which may be related to the pathogenesis of PD.