Morphological Changes of Medial Epicondyle-Olecranon Ligament and Ulnar Nerve in the Cubital Tunnel Syndrome: An Ultrasonic Study.

OBJECTIVE: Few studies have performed detailed ultrasound measurements of medial epicondyle-olecranon (MEO) ligament that cause the entrapment of ulnar nerve. This study aims to comprehensively evaluate dynamic ultrasonographic characteristics of MEO ligament and ulnar nerve for clinical diagnosis and accurate treatment of cubital tunnel syndrome (CuTS). METHODS: Thirty CuTS patients (CuTS group) and sixteen healthy volunteers (control group) who underwent ultrasound scanning from October 2016 to October 2020 were retrospectively collected, with 30 elbows in each group. Primary outcomes were thickness at six points, length and width of MEO ligament. Secondary outcomes were thickness of ulnar nerve under MEO ligament at seven parts and the cross-sectional area (CSA) of ulnar nerve at proximal end of MEO ligament (P0 mm ). The thickness of MEO ligament and ulnar nerve in different points of each group was compared by one-way ANOVA analysis with Bonferroni post hoc test, other outcomes were compared between two elbow positions or two groups using independent-samples t test. RESULTS: Thickness of MEO ligament in CuTS group at epicondyle end, midpoint in transverse view, olecranon end, proximal end, midpoint in axial view, and distal end was 0.67 ± 0.31, 0.37 ± 0.18, 0.89 ± 0.35, 0.39 ± 0.21, 0.51 ± 0.38, 0.36 ± 0.25 at elbow extension, 0.68 ± 0.34, 0.38 ± 0.27, 0.77 ± 0.39, 0.32 ± 0.20, 0.48 ± 0.22, 0.32 ± 0.12 (mm) at elbow flexion, respectively. Compared with control group, they were significantly thickened except for proximal end at elbow flexion. MEO ligament thickness at epicondyle end and olecranon end was significantly larger than midpoint in two groups. No significant difference was found in length and width of MEO ligament among different comparisons. Ulnar nerve thickness at 5 mm proximal to MEO ligament (P5 mm , 3.25 ± 0.66 mm) was significantly increased than midpoint of MEO ligament (Mid), distal end of MEO ligament (D0 mm ), 5 mm (D5 mm ), 10 mm (D10 mm ) distal to MEO ligament at extension in CuTS group. Compared with control group, ulnar nerve thickness at P5 mm in CuTS group was significantly increased at extension position, at D5 mm and D10 mm was significantly decreased at flexion position. CSA of ulnar nerve at extension position (14.44 ± 4.65 mm2 ) was significantly larger than flexion position (11.83 ± 3.66 mm2 ) in CuTS group, and CuTS group was significantly larger than control group at two positions. CONCLUSIONS: MEO ligament in CuTS patients was thickened, which compressed ulnar nerve and caused its proximal end swelling. Ultrasonic image of MEO ligament thickness was a significant indicator for CuTS and can guide surgeons in selecting the appropriate treatment.

[Research progress on metabolomics of acute respiratory distress syndrome].

Acute respiratory distress syndrome (ARDS) is a clinically and biologically heterogeneous disease. Given the heterogeneity of ARDS due to the wide range of etiological, clinical, and molecular manifestations, the current scientific consensus is that ARDS is not a single disease, but rather a set of diseases that require further research to properly classify and identify. Metabonomics, as a rapidly developing field of systems biology, has made many breakthroughs in science and medicine as an interdisciplinary platform. Metabonomics provides an important opportunity for the discovery and analysis of biomarkers in the diagnosis of ARDS, which is expected to reveal the biological process behind ARDS and show great potential in solving the heterogeneity and severity assessment of ARDS. This review focuses on the literature of ARDS metabonomics and summarizes the progress of ARDS metabonomics research and the main obstacles.

PDCD6 cooperates with C-Raf to facilitate colorectal cancer progression via Raf/MEK/ERK activation.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignancies, and it's expected that the CRC burden will substantially increase in the next two decades. New biomarkers for targeted treatment and associated molecular mechanism of tumorigenesis remain to be explored. In this study, we investigated whether PDCD6 plays an oncogenic role in colorectal cancer and its underlying mechanism. METHODS: Programmed cell death protein 6 (PDCD6) expression in CRC samples were analyzed by immunohistochemistry and immunofluorescence. The prognosis between PDCD6 and clinical features were analyzed. The roles of PDCD6 in cellular proliferation and tumor growth were measured by using CCK8, colony formation, and tumor xenograft in nude mice. RNA-sequence (RNA-seq), Mass Spectrum (MS), Co-Immunoprecipitation (Co-IP) and Western blot were utilized to investigate the mechanism of tumor progression. Immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) were performed to determine the correlation of PDCD6 and MAPK pathway. RESULTS: Higher expression levels of PDCD6 in tumor tissues were associated with a poorer prognosis in patients with CRC. Furthermore, PDCD6 increased cell proliferation in vitro and tumor growth in vivo. Mechanistically, RNA-seq showed that PDCD6 could affect the activation of the MAPK signaling pathway. PDCD6 interacted with c-Raf, resulting in the activation of downstream c-Raf/MEK/ERK pathway and the upregulation of core cell proliferation genes such as MYC and JUN. CONCLUSIONS: These findings reveal the oncogenic effect of PDCD6 in CRC by activating c-Raf/MEK/ERK pathway and indicate that PDCD6 might be a potential prognostic indicator and therapeutic target for patients with colorectal cancer.

TaMCA1, a regulator of cell death, is important for the interaction between wheat and Puccinia striiformis.

Metacaspase orthologs are conserved in fungi, protozoa and plants, however, their roles in plant disease resistance are largely unknown. In this study, we identified a Triticum aestivum metacaspase gene, TaMCA1, with three copies located on chromosomes 1A, 1B and 1D. The TaMCA1 protein contained typical structural features of type I metacaspases domains, including an N-terminal pro-domain. Transient expression analyses indicated that TaMCA1 was localized in cytosol and mitochondria. TaMCA1 exhibited no caspase-1 activity in vitro, but was able to inhibit cell death in tobacco and wheat leaves induced by the mouse Bax gene. In addition, the expression level of TaMCA1 was up-regulated following challenge with the Puccinia striiformis f. sp. tritici (Pst). Knockdown of TaMCA1 via virus-induced gene silencing (VIGS) enhanced plant disease resistance to Pst, and the accumulation of hydrogen peroxide (H2O2). Further study showed that TaMCA1 decreased yeast cell resistance similar to the function of yeast metacaspase, and there was no interaction between TaMCA1 and TaLSD1. Based on these combined results, we speculate that TaMCA1, a regulator of cell death, is important during the compatible interaction of wheat and Pst.

PsANT, the adenine nucleotide translocase of Puccinia striiformis, promotes cell death and fungal growth.

Adenine nucleotide translocase (ANT) is a constitutive mitochondrial component that is involved in ADP/ATP exchange and mitochondrion-mediated apoptosis in yeast and mammals. However, little is known about the function of ANT in pathogenic fungi. In this study, we identified an ANT gene of Puccinia striiformis f. sp. tritici (Pst), designated PsANT. The PsANT protein contains three typical conserved mitochondrion-carrier-protein (mito-carr) domains and shares more than 70% identity with its orthologs from other fungi, suggesting that ANT is conserved in fungi. Immuno-cytochemical localization confirmed the mitochondrial localization of PsANT in normal Pst hyphal cells or collapsed cells. Over-expression of PsANT indicated that PsANT promotes cell death in tobacco, wheat and fission yeast cells. Further study showed that the three mito-carr domains are all needed to induce cell death. qRT-PCR analyses revealed an in-planta induced expression of PsANT during infection. Knockdown of PsANT using a host-induced gene silencing system (HIGS) attenuated the growth and development of virulent Pst at the early infection stage but not enough to alter its pathogenicity. These results provide new insight into the function of PsANT in fungal cell death and growth and might be useful in the search for and design of novel disease control strategies.

TaADF7, an actin-depolymerizing factor, contributes to wheat resistance against Puccinia striiformis f. sp. tritici.

The actin cytoskeleton is involved in plant defense responses; however, the role of the actin-depolymerizing factor (ADF) family, which regulates actin cytoskeletal dynamics, in plant disease resistance, is largely unknown. Here, we characterized a wheat (Triticum aestivum) ADF gene, TaADF7, with three copies located on chromosomes 1A, 1B, and 1D, respectively. All three copies encoded the same protein, although there were variations in 19 nucleotide positions in the open reading frame. Transcriptional expression of the three TaADF7 copies were all sharply elevated in response to avirulent Puccinia striiformis f. sp. tritici (Pst) infection, with similar expression patterns. TaADF7 regulated the actin cytoskeletal dynamics by targeting the actin cytoskeleton to execute actin binding/severing activities. When the TaADF7 copies were all silenced by virus-induced gene silencing, the growth of Pst hypha increased and sporadic urediniospores were observed, as compared with control plants, upon inoculation with avirulent Pst. In addition, the accumulation of reactive oxygen species (ROS) and the hypersensitive response (HR) were greatly weakened, whereas cytochalasin B partially rescued the HR in TaADF7 knock-down plants. Together, these findings suggest that TaADF7 is likely to contribute to wheat resistance against Pst infection by modulating the actin cytoskeletal dynamics to influence ROS accumulation and the HR.

TaMDHAR4, a monodehydroascorbate reductase gene participates in the interactions between wheat and Puccinia striiformis f. sp. tritici.

Reactive oxygen species (ROS) in plants are induced in various cellular compartments upon pathogen infection and act as an early signal during plant-pathogen interactions. Monodehydroascorbate reductase (MDHAR) is involved in plant disease resistance through the regulation of the ROS level via the ascorbate-glutathione (AsA-GSH) cycle. In this study, TaMDHAR4 was firstly isolated from wheat cultivar Suwon 11, and this protein exhibits high similarity to MDHAR proteins from other plant species. Bioinformatics analyses indicated that TaMDHAR4 contains typical structural features, such as mPTS-like sequences in the C-terminal extension and trans-membrane domain followed by five basic arginine residues (-RKRRR), which predicted that this protein may be localized in the peroxisome. qRT-PCR analyses demonstrated that TaMDHAR4 could be induced by various exogenous hormones, such as ABA, MeJA, and ETH. TaMDHAR4 is sharply down-regulated at 12 and 18 hpi only in wheat leaves challenged with Puccinia striiformis f. sp. tritici (Pst) race CYR23 and induced at 48 hpi with both Pst races CYR23 and CYR31. SOD and APX injection analyses demonstrated that TaMDHAR4 may be involved in the interaction between wheat and Pst through the regulation of its expression. Moreover, the knockdown of TaMDHAR4 through virus-induced gene silencing (VIGS) enhanced the wheat resistance to Pst by inhibiting sporulation in the compatible interaction. Histological observations also demonstrated that silenced wheat resulted in an increased proportion of necrotic area at the infection sites and suppressed Pst hypha elongation. The study provided novel insights into the molecular functions of TaMDHAR4 during plant-pathogen interactions.

The target gene of tae-miR164, a novel NAC transcription factor from the NAM subfamily, negatively regulates resistance of wheat to stripe rust.

microRNA (miRNA) participates in various physiological and biochemical processes in plants by regulating corresponding target genes. NAC [NAM (no apical meristem), ATAF (Arabidopsis transcription activation factor) and CUC (cup-shaped cotyledon)] transcription factors, usually as the targets of miR164, play important roles in the regulation of plant development and responses to abiotic and biotic stresses. In a previous study, the target gene of tae-miR164 in wheat was sequenced through degradome sequencing. In this study, we isolated the full-length cDNA of the candidate target gene, which is a NAC transcription factor gene in the NAM subfamily, and designated it as TaNAC21/22 after bioinformatics analysis. The interaction between TaNAC21/22 and tae-miR164 was confirmed experimentally through co-transformation of both genes in tobacco leaves. Transcript accumulation of TaNAC21/22 and tae-miR164 showed contrasting divergent expression patterns in wheat response to Puccinia striiformis f. sp. tritici (Pst). TaNAC21/22 was confirmed to be located in the nucleus and could function as a transcriptional activator. Silencing of the individual gene showed that TaNAC21/22 negatively regulates resistance to stripe rust. These results indicate that the target of tae-miR164, a novel NAC transcription factor from the NAM subfamily of wheat, plays an important role in regulating the resistance of host plants to stripe rust.

A novel TaMYB4 transcription factor involved in the defence response against Puccinia striiformis f. sp. tritici and abiotic stresses.

MYB transcription factors are a large family of proteins involved in the regulation of secondary metabolism and cell shape, the enhancement of disease resistance and the response to different stresses. In this study, the role of TaMYB4 in wheat against biotic and abiotic stresses was investigated. TaMYB4 was cloned from wheat cv. Suwan11 [the leaves were infected with Puccinia striiformis f.sp. tritici (Pst)]; the TaMYB4 protein is 243 amino acids in length. In addition, TaMYB4 exhibited high similarity with BdMYB4 from Brachypodium distachyon, which was also identified as a member of the R2R3-MYB family of genes. Furthermore, transient expression analysis showed that the deduced TaMYB4 protein was localised in the nucleus of onion epidermal cells. Additionally, a yeast one-hybrid assay revealed that TaMYB4 exhibits transcriptional activity and the C-terminus is necessary for the activation of transcription. The transcript levels of TaMYB4 were observed directly and were found to be significantly upregulated in the early stage and 48 h after inoculation with the incompatible Pst. The transcripts of TaMYB4 were detected in the wheat roots, culms and leaves. Moreover, the transcription of TaMYB4 was induced by salicylic acid, ethylene, abscisic acid and methyl jasmonate hormones. The same results were obtained with cold and wound treatments. Furthermore, the knockdown of TaMYB4 expression using virus-induced gene silencing enhanced the susceptibility of wheat cultivar Suwon11 to the incompatible race of Pst. These results demonstrate that TaMYB4 plays a role in the wheat response to biotic stress.

Functions of the lethal leaf-spot 1 gene in wheat cell death and disease tolerance to Puccinia striiformis.

Pheophorbide a oxygenase (PaO) is a key enzyme in chlorophyll catabolism that is known to suppress cell death in maize and Arabidopsis. The catalytic activity of PaO in chlorophyll degradation has been clearly demonstrated, but the function of PaO in the regulation of cell death and plant-microbe interactions is largely unknown. In this study, we characterized a PaO homologue in wheat of the lethal leaf-spot 1 gene, TaLls1, that was induced in leaves infected by Puccinia striiformis f.sp. tritici (Pst) and wounding treatment. The TaLls1 protein contains a conserved Rieske [2Fe-2S] motif and a mononuclear iron-binding site typical of PaOs. Silencing of TaLls1 by virus-induced gene silencing in wheat led to leaf cell death without pathogen attacks, possibly due to the accumulation of pheophorbide a (upstream substrate of PaO), indicating a suppressor role of TaLls1, while overexpression of TaLls1 also triggered cell death in both tobacco and wheat leaves, probably owing to the accumulation of the red chlorophyll catabolite (downstream product of PaO). Further deletion mutant analysis showed that the conserved Rieske domain, but not the iron-binding site, was essential for cell death induction. These results thus suggest a threshold for TaLls1 in maintaining cell homeostasis to adapt in various stresses, and shed new light on the role of TaLls1 in cell death regulation. Furthermore, silencing of TaLls1 in wheat did not change the disease symptoms but enhanced tolerance to Pst via an significant increase in H2O2 generation, elevated cell death occurrence, and upregulation of pathogenesis-related genes.

TaEIL1, a wheat homologue of AtEIN3, acts as a negative regulator in the wheat-stripe rust fungus interaction.

Transcription factors (TFs) play crucial roles in the transcriptional regulation of plant development and defence responses. Increasing evidence has implicated ETHYLENE INSENSITIVE3 (EIN3) in the plant defence response to pathogen infection and environmental stimuli. However, the role of EIN3 in wheat resistance to Puccinia striiformis f. sp. tritici (Pst) is not clear. Here, TaEIL1 was isolated by rapid amplification of cDNA ends (RACE) based on a sequence fragment from a wheat-Pst interaction cDNA library. The TaEIL1 protein contains a typical EIN3-binding domain, and transient expression analyses indicated that TaEIL1 is localized in the nucleus. Yeast one-hybrid assay revealed that TaEIL1 exhibits transcriptional activity, and its C-terminus is necessary for the activation of transcription. TaEIL1 transcripts were regulated by environmental stress stimuli and were decreased under salicylic acid (SA) treatment. When wheat leaves were challenged with Pst, the transcript level of TaEIL1 in the compatible interaction was approximately three times higher than that in the incompatible interaction. Knocking down TaEIL1 through the Barley stripe mosaic virus (BSMV) virus-induced gene silencing (VIGS) system attenuated the growth of Pst, with shortened hyphae and reduced hyphal branches, haustorial mother cells and colony size. Moreover, enhanced necrosis was triggered by the Pst avirulent race CYR23, indicating that the hypersensitive response was strengthened in TaEIL1-silenced wheat plants. Thus, the up-regulation of defence-related genes and increased sucrose abundance might contribute to the enhanced disease resistance of wheat to the virulent race CYR31. Taken together, the results suggested that the suppression of TaEIL1 transcripts could enhance the resistance of wheat to stripe rust fungus.

vsiRNAs derived from the miRNA-generating sites of pri-tae-miR159a based on the BSMV system play positive roles in the wheat response to Puccinia striiformis f. sp. tritici through the regulation of taMyb3 expression.

Plants live in a complex environment, exposed to stresses, such as unsuitable climates, pests and pathogenic microorganisms. Pathogens are one of the most serious factors that threaten plant growth. Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive diseases worldwide. Virus-induced gene silencing (VIGS) is a popular tool for the functional analysis of wheat genes, generating abundant small RNAs (sRNAs). sRNAs are key components in gene regulatory networks, silencing corresponding genes at the post-transcriptional level. In this study, we transduced pri-tae-miR159a into plant tissues using the barley stripe mosaic virus (BSMV) system, and demonstrated that vsiRNAs were generated from the same miRNAs generating sites of pri-tae-miR159a, with the function of Dicer RNase III-like classes of endonucleases (DCL4). In addition, the accumulation of vsiRNAs in wheat leaves challenged with Pst Chinese yellow rust 23 (CYR23), resulted in a resistant phenotype, and in the compatible interaction, the sporation of Pst was limited. Whereas, infection with a control construct had no effect on the resistance or susceptibility. The results of the histological observation also supported these phenotype changes. Interestingly, vsiRNAs were also involved in the interactions between wheat and Pst through the tae-miR159-mediated regulation of taMyb3 expression. Moreover, these results also supported the speculation that vsiRNAs were generated from the same sites of pri-tae-miR159a. These studies indicated that vsiRNAs from miRNAs generating sites of pri-tae-miR159a based on the BSMV system play positive roles in the wheat response to Pst through the regulation of taMyb3 expression.