Complete genome sequence of a novel badnavirus infecting Fatsia japonica in China.

The complete genome sequence of a novel badnavirus, tentatively named "fatsia badnavirus 1" (FaBV1, OM540428), was identified in Fatsia japonica. The infected plant displayed virus-like symptoms on leaves, including yellowing and chlorosis. The genome of FaBV1 is 7313 bp in length and similar in size and organization to other members of the genus Badnavirus (family Caulimoviridae), containing four open reading frames (ORFs), three of which are found in all known badnaviruses, and the other of which is only present in some badnaviruses. The virus has the genome characteristics of badnaviruses, including a tRNAMet binding site (5'-TCTGAATTTATAGCGCTA-3') and two cysteine-rich domains (C-X-C-2X-C-4X-H-4X-C and C-2X-C-11X-C-2X-C-4X-C-2X-C). Pairwise sequence comparisons of the RT+RNase H region indicated that FaBV1 shares 61.4-71.2% nucleotide (nt) sequence identity with other known badnaviruses, which is below the threshold (80% nt sequence identity in the RT+RNase H region) used for species demarcation in the genus Badnavirus. Phylogenetic analysis revealed that FaBV1, ivy ringspot-associated virus (IRSaV, MN850490.1), and cacao mild mosaic virus (CMMV, KX276640.1) together form a separate clade within the genus Badnavirus, suggesting that FaBV1 is a new member of the genus Badnavirus in the family Caulimoviridae. To our knowledge, this is the first report of a badnavirus infecting F. japonica.

External validation and comparison of MR-based radiomics models for predicting pathological complete response in locally advanced rectal cancer: a two-centre, multi-vendor study.

OBJECTIVES: The aim of this study was two-fold: (1) to develop and externally validate a multiparameter MR-based machine learning model to predict the pathological complete response (pCR) in locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT), and (2) to compare different classifiers' discriminative performance for pCR prediction. METHODS: This retrospective study includes 151 LARC patients divided into internal (centre A, n = 100) and external validation set (centre B, n = 51). The clinical and MR radiomics features were derived to construct clinical, radiomics, and clinical-radiomics model. Random forest (RF), support vector machine (SVM), logistic regression (LR), K-nearest neighbor (KNN), naive Bayes (NB), and extreme gradient boosting (XGBoost) were used as classifiers. The predictive performance was assessed using the receiver operating characteristic (ROC) curve. RESULTS: Eleven radiomics and four clinical features were chosen as pCR-related signatures. In the radiomics model, the RF algorithm achieved 74.0% accuracy (an AUC of 0.863) and 84.4% (an AUC of 0.829) in the internal and external validation sets. In the clinical-radiomics model, RF algorithm exhibited high and stable predictive performance in the internal and external validation datasets with an AUC of 0.906 (87.3% sensitivity, 73.7% specificity, 76.0% accuracy) and 0.872 (77.3% sensitivity, 88.2% specificity, 86.3% accuracy), respectively. RF showed a better predictive performance than the other classifiers in the external validation datasets of three models. CONCLUSIONS: The multiparametric clinical-radiomics model combined with RF algorithm is optimal for predicting pCR in the internal and external sets, and might help improve clinical stratifying management of LARC patients. KEY POINTS: • A two-centre study showed that radiomics analysis of pre- and post-nCRT multiparameter MR images could predict pCR in patients with LARC. • The combined model was superior to the clinical and radiomics model in predicting pCR in locally advanced rectal cancer. • The RF classifier performed best in the current study.

Complete genome sequence analysis of Valeriana jatamansi tymovirus 1: a novel member of the genus Tymovirus infecting Valeriana jatamansi Jones.

A new positive-sense, single-stranded RNA virus, tentatively named "Valeriana jatamansi tymovirus 1" (VaJV1, OQ730267), was isolated from Valeriana jatamansi Jones displaying symptoms of vein-clearing in Yunnan Province, China. The complete genome of VaJV1 consists of 6,215 nucleotides and contains three open reading frames (ORFs). The genome structure of VaJV1 is typical of members of the genus Tymovirus. BLASTn analysis and multiple sequence alignments showed that the complete genome and coat protein of VaJV1 shared the most sequence similarity (65.5% nucleotides and 50.5% amino acid sequence identity) with an isolate of the tymovirus okra mosaic virus (NC_009532). Phylogenetic analysis confirmed that VaJV1 clustered most closely with other tymoviruses. We propose that Valeriana jatamansi tymovirus 1 represents a new species within the genus Tymovirus.

Complete genome sequence of a novel fusarivirus from the phytopathogenic fungus Fusarium sp.

Fusarium diseases include wilts, blights, rots, and cankers of many horticultural, field, ornamental, and forest crops in both agricultural and natural ecosystems, and they significantly hinder food plant production. Here, we describe a novel mycovirus, tentatively designated as "Fusarium fusarivirus 1" (FuFV1), which was discovered in an isolate of the phytopathogenic fungus Fusarium sp. FuFV1 has a positive-sense single-stranded RNA (+ssRNA) genome of 6,391 nucleotides (nt) containing three open reading frames (ORFs). ORF1 encodes a large polypeptide of 1,501 amino acids (aa) with conserved RNA-dependent RNA polymerase (RdRp) and helicase (Hel) domains. ORF2, overlapping ORF1 by 122 nucleotides, encodes a polypeptide with a conserved Smc domain. The third and smaller ORF (ORF3) encodes a polypeptide with an unknown function. BLASTp analysis of the ORF1-encoded polypeptide revealed that FuFV1 shares the highest aa sequence similarity (68.5% identity, E-value 0.0) with Fusarium poae fusarivirus 1 (FpFV1, genus Alphafusarivirus). Phylogenetic analysis of the RdRp and helicase (Hel) sequences indicated that FuFV1 clustered closely with FpFV1 in a separate branch within the clade containing members of the genus Alphafusarivirus. Based on these results, we propose that FuFV1 should be considered a novel mycovirus belonging to the genus Alphafusarivirus of the family Fusariviridae.

Complete genome sequence of a novel closterovirus isolated from Dregea volubilis.

The complete genome sequence of a putative novel closterovirus, tentatively named "Dregea volubilis closterovirus 1" (DvCV1, GenBank accession no. MZ779122), infecting Dregea volubilis in China was determined using high-throughput sequencing (HTS). The complete genome sequence of DvCV1 consists of 16,165 nucleotides (nt) and contains nine ORFs. The genome structure of DvCV1 is typical of members of the genus Closterovirus. Complete genome sequence analysis showed that DvCV1 shares 41.4-48.4% nucleotide sequence identity with other known closteroviruses. The putative RNA-dependent RNA polymerase (RdRp), heat shock protein 70-like protein (HSP70h), and coat protein (CP) of DvCV1 share 46.80-62.65%, 31.06-51.80%, and 28.34-37.37% amino acid sequence identity, respectively, with the RdRp, HSP70h and CP of other closteroviruses. Phylogenetic analysis based on HSP70h aa sequences placed DvCV1 alongside other members of the genus Closterovirus in the family Closteroviridae. These results suggest that DvCV1 is a new member of the genus Closterovirus. This is the first report of a closterovirus infecting D. volubilis.

Complete genome sequence analysis of a novel citlodavirus isolated from the leaves of Myrica rubra in Yunnan.

Through high-throughput sequencing, a novel citlodavirus, tentatively named "Myrica rubra citlodavirus 1" (MRV1, accession no. OP374189), was isolated from the leaves of Myrica rubra in Yunnan exhibiting narrow deformity of leaf tips, shrinkage, and chlorosis along the veins. The complete genome sequence was determined and analyzed using cloning and Sanger sequencing. MRV1 is a single-stranded circular non-enveloped DNA virus with a genome size of 3775 nucleotides and contains six open reading frames (ORFs). The virion-sense genome strand encodes a coat protein (CP, nt 750-1,493, 247 aa), two hypothetical movement proteins (V3, nt 382-666, 94 aa; and V2, nt 461-895, 144 aa), and one movement protein (MP, nt 1,527-2,438, 303 aa). The complementary strand of the genome encodes two replication proteins (RepA, nt 3,712-2,834, 292 aa; Rep, nt 2,867-2,553, 104 aa). The MRV1 genome contains the stem-loop motif 5'-TAATATTAC-3', which is a highly conserved nonanucleotide motif found in the origin of virion-strand replication in geminiviruses. Genome sequence alignment analysis showed that citrus chlorotic dwarf associated virus (CCDaV, accession no. JQ920490) shared the highest nucleotide sequence similarity (66.10% identity) with MRV1. Phylogenetic analysis showed that CCDaV is the closest known relative of MRV1, and that these viruses clustered in a single branch within a clade consisting of citlodaviruses. These results indicate that MRV1 should be regarded as a new species of the genus Citlodavirus in the family Geminiviridae.

First report of Lily virus X infecting Paris polyphylla var. yunnanensis in Yunnnan, China.

Lily virus X (LVX) is a positive-sense ssRNA virus belonging to the genus Potexvirus in the family Alphaflexiviridae. LVX is known to infect plants of the genera Lilium and Tricyrtis in the family Liliacea. LVX was first reported in an asymptomatic lily (Lilium formosanum) from England (Stone, 1980), but has been shown to infect plants in the Netherlands (Chen et al. 2005), the United States (Jordan et al. 2008) and Japan (Nijo et al. 2018). To date, the complete genomes of two LVX isolates from the Netherlands and Japan have been reported. Paris polyphylla var. yunnanensis, known as Dianchonglou in China, is a perennial plant of the family Melanthiaceae (formerly belonging to the family Trillium). In China, its rhizome is commonly used as an antispasmodic agent for stroke and cancer treatment (Chang et al. 2017). From 2019 to 2022, leaf mottle and shrinkage which are typical symptoms of viral infections were observed on the leaves of P. polyphylla var. yunnanensis plants in Dianchonglou fields in Qujing, Yunnan. Disease incidence ranged from 19% to 45% across 5 fields (90 plants per field) in Qujing. To identify the possible viral pathogen(s) associated with the disease, the mirVanaTM miRNA isolation Kit was used to extract total RNA was from a mixed sample pool of 5 symptomatic leaf samples collected from the 5 fields. RNA sequencing library was constructed using TruSeqTM RNA sample preparation kit. Sequencing on the Illumina HiSeqTM 2500 platform (Illumina, USA) with 125-bp paired-end reads yielded 23,077,786 raw reads. 22,534,100 clean reads were obtained by removing reads of low quality and poly-N using Trimmomatic software (Bolger et al. 2014). By utilizing the paired-end splicing method in Trinity software (Grabherr et al. 2011) the the raw reads were De novo assembled into 184,596 contigs, of which 303 were related to viruses, including Paris mosaic necrosis virus (PMNV), Pear alphapartitivirus (PAPV), Dahlia mosaic virus (DMV), and Lily virus X (LVX). BLASTn analysis revealed that 12 contigs (lengths ranging from 344 nt to 5,981 nt, query cover 6% to 99%) were most similar (57.32% to 91.67% nt identities) to the genome sequences of LVX, suggesting a possible infection of LVX in the plants. To confirm the result, a full-length genomic sequence of LVX was obtained by reverse transcription polymerase chain reaction (RT-PCR) using specific primers designed based on the sequence of the assembled contigs. The PCR products were cloned into pGEM-T vector (Promega Corporation, USA) and sequenced using the Sanger method (Sangon Biotech, Shanghai, China). The obtained full-length genomic sequence of the LVX isolate (LVX-PP, accession number OM100017) was 5,981 nt in length. BLASTp analysis demonstrated that the putative Rep and CP of LVX-PP shared 76.27% to 81.05% and 80.81% to 81.82% aa sequence similarities with that of other LVX isolates, respectively. Maximum-likelihood phylogenetic trees inferred from the Rep and CP aa sequences showed that LVX-PP clustered closely with LVX isolates. The leaf samples were further analyzed using a lily virus X (LVX) ELISA kit (DEIAPV181, Creative Diagnostics, U.S.A.). Healthy P. polyphylla var. yunnanensis leaves were taken as a negative control and buffer solution as a blank control. The results showed a positive reaction for all five symptomatic plants (OD = 1.259 ± 0.007) relative to the negative (OD = 0.099) and blank (OD = 0.073) controls. These results indicate that LVX can infect P. polyphylla var. yunnanensis. To our knowledge, this is the first report that LVX has been detected in P. polyphylla var. yunnannensis. This study will serve as an important reference for the study of the host range of LVX. Further studies will be required to determine how LVX spreads between P. polyphylla var. yunnannensis and other host plants.

The CADM2 Gene and Behavior: A Phenome-Wide Scan in UK-Biobank.

The cell adhesion molecule 2 (CADM2) gene has appeared among the top associations in a wide range of genome-wide association studies (GWASs). This study aims to: (1) examine how widespread the role of CADM2 is in behavioural traits, and (2) investigate trait-specific effects on CADM2 expression levels across tissues. We conducted a phenome-wide association study in UK Biobank (N = 12,211-453,349) on 242 psycho-behavioral traits, both at the SNP and the gene-level. For comparison, we repeated the analyses for other large (and high LD) genes. We found significant associations between CADM2 and 50 traits (including cognitive, risk taking, and dietary traits), many more than for the comparison genes. We show that many trait associations are reduced when taking geographical stratification into account. S-Predixcan revealed that CADM2 expression in brain tissues was significantly associated with many traits; highly significant effects were also observed for lung, mammary, and adipose tissues. In conclusion, this study shows that the role of CADM2 extends to a wide range of psycho-behavioral traits, suggesting these traits may share a common biological denominator.

Complete genome sequence analysis of Paris alphapartitivirus 1: a novel member of the genus Alphapartitivirus infecting Paris polyphylla var. yunnanensis.

A novel double-stranded RNA (dsRNA) virus, tentatively named "Paris alphapartitivirus 1" (ParAPV1, OL960006-OL960007), was detected in Paris polyphylla var. yunnanensis plants exhibiting leaf chlorosis and shrinkage symptoms in Yunnan. Its complete genome sequence was determined using Illumina and Sanger sequencing. ParAPV1 has a bipartite genome that consists of dsRNA1 (1,917 bp) encoding the viral RNA-dependent RNA polymerase (RdRp), and dsRNA2 (1,818 bp) encoding the putative coat protein (CP). Sequence comparisons showed that the RdRp and CP of ParAPV1 are most similar to those of pear alphapartitivirus (PpPV2), with 69.97% and 54.21% amino acid sequence identities respectively. Phylogenetic analysis of the RdRp amino acid sequences of ParAPV1 and other partitiviruses showed that ParAPV1 cluster with viruses in a clade containing alphapartitiviruses, and that its closest known relatives are PpPV2 (BBA66577) and rose partitivirus (RoPV, ANQ45203S). Taken together, these results suggest that ParAPV1 should be regarded as a new member of genus Alphapartitivirus in the family Partitiviridae. This is the first report of a partitivirus infecting P. polyphylla var. yunnanensis.

Complete genome sequence of a novel mitovirus detected in Paris polyphylla var. yunnanensis.

Paris mitovirus 1 (ParMV1) is a positive-sense RNA virus that was detected in diseased Paris polyphylla var. yunnanensis plants in Wenshan, Yunnan. The complete genome sequence of ParMV1 is 2,751 nucleotides in length, and the genome structure is typical of mitoviruses. The ParMV1 genome has a single open reading frame (ORF; nt 358-2,637) that encodes an RNA-dependent RNA polymerase (RdRp) with a predicted molecular mass of 86.42 kDa. ParMV1 contains six conserved motifs (Ι-VΙ) that are unique to mitoviruses. The 5' and 3' termini of the genome are predicted to have a stable secondary structure, with the reverse complementary sequence forming a panhandle structure. Comparative genome analysis revealed that the RdRp of ParMV1 shares 23.1-40.6% amino acid (aa) and 32.3-45.7% nucleotide (nt) sequence identity with those of other mitoviruses. Phylogenetic analysis based on RdRp aa sequences showed that ParMV1 clusters with mitoviruses and hence should be considered a new member of the genus Mitovirus in the family Mitoviridae. This is the first report of a novel mitovirus infecting Paris polyphylla var. yunnanensis.

Adjusted femtosecond laser capsulotomy distance in white cataracts to decrease incomplete capsulotomy: a randomized comparative cohort study.

BACKGROUND: To compare safety and effectiveness between standard position and adjusted distance pre- and post-anterior capsule of femtosecond laser capsulotomy in white cataracts surgery. METHODS: Selected white cataracts that underwent LenSx femtosecond laser capsulotomy were randomized into groups A (standard position, with 300 µm symmetrically pre- and post-anterior capsule), B (increased distance with 400 µm symmetrically pre- and post-anterior capsule), and C (unsymmetrical distances of 200 µm pre- and 400 µm post-anterior capsule, respectively). All these surgeries were performed by the same experienced surgeon. Complications, including incomplete capsulotomy and capsule tears, were recorded. In addition, femtosecond capsulotomy and phacoemulsification parameters, IOLs centrality and corrected distance visual acuity were assessed. RESULTS: A total of 113 eyes were included in this study. There were 8 (21.6%) incomplete capsulotomy and 1 anterior capsule tear in group A. Meanwhile, only 2 eyes (5.1%) had incomplete capsulotomy with none showing capsule tear in group B. In group C, only 1 eye (2.7%) had incomplete capsulotomy and no capsule tear occurred. Mean femtosecond laser capsulotomy time was longer in group B compared with groups A and C. Average cumulative dispersed energy, IOL centrality and corrected distance visual acuity were similar in all groups. CONCLUSIONS: Appropriate adjustment on femtosecond laser capsulotomy distance by reducing pre-anterior capsule and increasing post-anterior distance, may decrease incomplete capsulotomy and be more effective in white cataracts surgery. TRIAL REGISTRATION: Clinical trial registration number: ChiCTR2100043863.

Characterization of a novel Tombusviridae species isolated from Paris polyphylla var. yunnanensis.

A novel virus, Paris virus 2 (ParV2), was isolated from diseased Paris polyphylla var. yunnanensis, and its complete genome sequence was determined and analyzed. ParV2 is a positive-sense single-stranded RNA (+ssRNA) virus with a genome size of 4,118 nucleotides. The ParV2 genome contains six putative open reading frames (ORFs) that encode proteins with predicted molecular weights of 40.14, 100.26, 7.31, 7.85, 26.09, and 8.77 kDa. The first ORF (ORF1) of ParV2 encodes a putative protein of 40.14 kDa (P40, nt: 20-1,096), whiles the second ORF (ORF2, 888 aa) containing the GDD motif encodes the highly conserved RNA-dependent RNA polymerase protein (RdRP, nt:20-2,683, P100, 100.26 kDa) of viruses in the family Tombusviridae. Multiple sequence alignments analysis showed that the complete genome sequence of ParV2 shares 31.7-55.5% nucleotide sequence identities with viruses in the family Tombusviridae. Ginger chlorotic fleck-associated tombusvirus (GCFaV-1, Accession No. QKE30557) had the highest sequence identity (55.5%) with ParV2. GCFaV-1 also shares 59.2% RdRP and 34.9% CP amino acid sequence identities with ParV2. Sequence comparisons and phylogenetic analysis of RdRP suggested that ParV2 is a novel member of the family Tombusviridae, and its closest known relative is GCFaV-1.

Complete genome sequence analysis of a novel coguvirus isolated from Paris polyphylla var. yunnanensis.

A novel negative-stranded (ns) RNA virus tentatively named "Yunnan paris negative-stranded virus" (YPNSV), was isolated from Paris polyphylla var. yunnanensis plants exhibiting leaf chlorosis and mosaic symptoms in Yunnan. Its complete genome sequence was determined using Illumina and Sanger sequencing. YPNSV has a bipartite genome that consists of a negative-stranded (ns) RNA1 encoding the viral RNA-dependent RNA polymerase (RdRp, p251), an ambisense RNA2 coding for the putative movement protein (MP, p46) and nucleocapsid protein (NP, p39), with the two open reading frames separated by a long intergenic region that is rich in A and U. Sequence comparisons showed that the RdRp, MP, and NP of YPNSV are most similar to those of watermelon crinkle leaf-associated virus 2 (WCLaV-2), with 69.1%, 50.4%, and 60.9% amino acid sequence identity, respectively. Phylogenetic analysis based on deduced amino acid sequences of RdRp and NP showed that YPNSV clustered in a clade with coguviruses and that its closest known relative is WCLaV-2. Based on the above results, YPNSV should be regarded as a new member of genus Coguvirus, family Phenuiviridae.

Whole-genome sequence analysis of paris virus 1: a novel member of the genus Potyvirus infecting Paris polyphylla var. yunnanensis.

The complete genome sequence of a novel potyvirus, tentatively named "paris virus 1" (ParV1, GenBank accession no. MN549985), infecting Paris polyphylla var. yunnanensis was determined in this study. A single large open reading frame (nt 96-9818) encoding a 3240-aa polyprotein that is predicted to be cleaved into 10 mature proteins was detected in the ParV1 genome. Comparative analysis of the ParV1 genome sequence with those of other potyviruses identified nine cleavage sites and conserved motifs that are typical features of potyviruses. Pairwise sequence comparisons showed that the ParV1 polyprotein shares 49.6-65.1% nucleotide and 47.1-68.9% amino acid sequence identity with viruses of the genus Potyvirus. BLAST analysis revealed that ParV1 shares 65.1% nucleotide and 68.9% amino acid sequence identity with Thunberg fritillary mosaic virus (TFMV, accession no. CAI59123), its closest known relative. These results suggest that paris virus 1 (ParV1) is a new member of the genus Potyvirus.

Complete genome sequence of a novel potyvirus isolated from Polygonatum kingianum.

The complete genome sequence of a putative novel potyvirus, tentatively named "Polygonatum kingianum virus 1" (PKgV1), infecting Polygonatum kingianum in China was determined (GenBank accession no. MK427056). PKgV1 has a genome organization that is typical of potyviruses, with a single large open reading frame (nt 123-9236) that encodes a 3037-aa polyprotein that is predicted to be cleaved into 10 mature proteins by virus-encoded proteases. Nine cleavage sites and several conserved motifs were identified in PKgV1 by comparative sequence analysis. Pairwise comparisons revealed that the PKgV1 polyprotein shares 52.0-56.2% nucleotide and 49.2-52.8% amino acid sequence identity with members of the genus Potyvirus. Phylogenetic analysis indicated that PKgV1 clustered with members of the genus Potyvirus and that it is closely related to but distinct from lettuce mosaic virus (LMV, accession no. KJ161186). These results suggest that Polygonatum kingianum virus 1 (PKgV1) is a new member of the genus Potyvirus of the family Potyviridae.

Hydrogen postconditioning promotes survival of rat retinal ganglion cells against ischemia/reperfusion injury through the PI3K/Akt pathway.

Retinal ischemia/reperfusion injury (IRI) plays a crucial role in the pathophysiology of various ocular diseases. Our previous study have shown that postconditioning with inhaled hydrogen (H2) (HPC) can protect retinal ganglion cells (RGCs) in a rat model of retinal IRI. Our further study aims to investigate potential mechanisms underlying HPC-induced protection. Retinal IRI was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1 h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining, retrograde labelling with cholera toxin beta (CTB) and TUNEL staining, respectively. Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). The phosphorylated Akt was analysed by RT-PCR and western blot. The results showed that administration of HPC significantly inhibited the apoptosis of RGCs and protected the visual function. Simultaneously, HPC treatment markedly increased the phosphorylations of Akt. Blockade of PI3K activity by inhibitors (LY294002) dramatically abolished its anti-apoptotic effect and lowered both visual function and Akt phosphorylation levels. Taken together, our results demonstrate that HPC appears to confer neuroprotection against retinal IRI via the PI3K/Akt pathway.

Methane rescues retinal ganglion cells and limits retinal mitochondrial dysfunction following optic nerve crush.

Secondary degeneration is a common event in traumatic central nervous system disorders, which involves neuronal apoptosis and mitochondrial dysfunction. Exogenous methane exerts the therapeutic effects in many organ injury. Our study aims to investigate the potential neuroprotection of methane in a rat model of optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC and administrated intraperitoneally with methane-saturated or normal saline (10 ml/kg) once per day for one week after ONC. The retinal ganglion cells (RGCs) density was assessed by hematoxylin and eosin staining and Fluoro-Gold retrogradely labeling. Visual function was evaluated by flash visual evoked potentials (FVEP). The retinal apoptosis was measured by terminal-deoxy-transferase-mediated dUTP nick end labeling (TUNEL) assay and the expression of apoptosis-related factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3ß (pGSK-3ß), Bcl-2 associated X protein (Bax) and Bcl-2 extra large (Bcl-xL). Retinal mitochondrial function was assessed by the mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), the mitochondrial DNA (mtDNA) copy number, citrate synthase activity and ATP content. Methane treatment significantly improved the RGC loss and visual dysfunction following ONC. As expected, methane also remarkably inhibited the retinal neural apoptosis, such as the fewer TUNEL-positive cells in ganglion cell layer, accompanied by the up-regulations of anti-apoptotic factors (pGSK-3ß, pBAD, Bcl-xL) and the down-regulation of pro-apoptotic factor (Bax). Furthermore, methane treatment suppressed up-regulations of critical mitochondrial components (PGC-1α, NRF1 and TFAM) mRNA and mtDNA copy number, as well as improved the reduction of functional mitochondria markers, including citrate synthase activity and ATP content, in retinas with ONC. Taken together, methane treatment promotes RGC survival and limits retinal mitochondrial dysfunction against ONC insult. Methane can be a potential neuroprotective agent for traumatic and glaucomatous neurodegeneration.

Low-dose carbon monoxide inhalation protects neuronal cells from apoptosis after optic nerve crush.

Glaucomatous optic neuropathy, including axonal degeneration and apoptotic death of retinal ganglion cells (RGCs), eventually leads to irreversible visual impairment. Carbon monoxide (CO) acts as a therapeutic agent against neural injury via its anti-apoptotic effect. Here we hypothesized that low-dose CO inhalation can protect RGCs in a rat model of optic nerve crush (ONC). ONC was performed on adult male Sprague Dawley rats to imitate glaucomatous optic damage. Low-dose CO (250 ppm) or air was inhaled for 1 h immediately after ONC, and all the tests were carried out 2 weeks later. Flash visual evoked potentials (FVEP) and pupil light relax (PLR) were recorded for the assessment of visual function. RGC density was evaluated by hematoxylin and eosin staining and Fluorogold labeling. Retinal apoptotic process was assessed by TUNEL staining and caspase-3 activity measurement. Low-dose CO treatment significantly ameliorated the abnormalities of FVEP and PLR induced by ONC. As expected, the RGC density was increased remarkably by CO inhalation after the glaucomatous optic nerve insult. Moreover, CO treatment after ONC significantly decreased the number of TUNEL-positive cells in ganglion cell layer and attenuated the retinal caspase-3 activity. Low-dose CO inhalation protects RGCs from optic nerve injury via inhibiting caspase-3 dependent apoptosis.

Protective effects of methane-rich saline on diabetic retinopathy via anti-inflammation in a streptozotocin-induced diabetic rat model.

As the commonest complication of diabetes mellitus (DM), diabetic retinopathy (DR) is a neuro-vascular disease with chronic inflammatory. Methane could exert potential therapeutic interest in inflammatory pathologies in previous studies. Our study aims to evaluate the protective effects of methane-rich saline on DR and investigate the potential role of related MicroRNA (miRNA) in diabetic rats. Streptozotocin-induced diabetic Sprague-Dawley rats were injected intraperitoneally with methane-rich or normal saline (5 ml/kg) daily for eight weeks. Morphology changes and blood-retinal barrier (BRB) permeability were assessed by hematoxylin eosin staining and Evans blue leakage. Retinal inflammatory cytokines levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL1-ß) were evaluated by immunohistochemistry. Retinal protein expressions of glial fibrillary acidic protein (GFAP) and vascular endothelial growth factor (VEGF) were determined by western blotting. Retinal miRNA expressions were examined by miRNA-specific microarray, verified by quantitative RT-PCR and predicted by GO enrichment and KEGG pathway analysis. There was no significant changes in blood glucose level and body weight of diabetic rats with methane-rich or normal saline treatment, but the decreased retinal thickness, retinal ganglial cell loss and BRB breakdown were all significantly suppressed by methane treatment. DM-induced retinal overexpressions of TNF-α, IL-1ß, GFAP and VEGF were also significantly ameliorated. Moreover, the methane treatment significantly up-regulated retinal levels of miR-192-5p (related to apoptosis and tyrosine kinase signaling pathway) and miR-335 (related to proliferation, oxidative stress and leukocyte). Methane exerts protective effect on DR via anti-inflammation, which may be related to the regulatory mechanism of miRNAs.