Phospho-eIF4E stimulation regulates coronavirus entry by selective expression of cell membrane-residential factors.

The eukaryotic translation initiation factor eIF4E can regulate cellular translation via phosphorylation on serine 209. In a recent study, by two rounds of TMT relative quantitative proteomics, we found that phosphorylated eIF4E (p-eIF4E) favors the translation of selected mRNAs, and the encoded proteins are mainly involved in ECM-receptor, focal adhesion, and PI3K-Akt signaling. The current paper is focused on the relationship between p-eIF4E and the downstream host cell proteins, and their presumed effect on efficient entry of PEDV. We found that the depletion of membrane-residential factor TSPAN3, CD63, and ITGB2 significantly inhibited viral invasion of PEDV, and reduced the entry of pseudotyped particles PEDV-pp, SARS-CoV-pp, and SARS-CoV-2-pp. The specific antibodies of TSPAN3, CD63, and ITGB2 blocked the adsorption of PEDV into host cells. Moreover, we detected that eIF4E phosphorylation was increased at 1 h after PEDV infection, in accordance with the expression of TSPAN3, CD63, and ITGB2. Similar trends appeared in the intestines of piglets in the early stage of PEDV challenge. Compared with Vero cells, S209A-Vero cells in which eIF4E cannot be phosphorylated showed a decrease of invading PEDV virions. MNK kinase inhibitor blocked PEDV invasion, as well as reduced the accumulation of TSPAN3, CD63, and ITGB2. Further study showed that the ERK-MNK pathway was responsible for the regulation of PEDV-induced early phosphorylation of eIF4E. This paper demonstrates for the first time the connections among p-eIF4E stimulation and membrane-residential host factors. Our findings also enrich the understanding of the biological function of phosphorylated eIF4E during the viral life cycle.IMPORTANCEThe eukaryotic translation initiation factor eIF4E can regulate cellular translation via phosphorylation. In our previous study, several host factors susceptible to a high level of p-eIF4E were found to be conducive to viral infection by coronavirus PEDV. The current paper is focused on cell membrane-residential factors, which are involved in signal pathways that are sensitive to phosphorylated eIF4E. We found that the ERK-MNK pathway was activated, which resulted in the stimulation of phosphorylation of eIF4E in early PEDV infection. Phospho-eIF4E promoted the viral invasion of PEDV by upregulating the expression of host factors TSPAN3, CD63, and ITGB2 at the translation level rather than at the transcription level. Moreover, TSPAN3, CD63, or ITGB2 facilitates the efficient entry of coronavirus SARS-CoV, SARS-CoV-2, and HCoV-OC43. Our findings broaden our insights into the dynamic phosphorylation of eIF4E during the viral life cycle, and provide further evidence that phosphorylated eIF4E regulates selective translation of host mRNA.

hsa_circ_0007919 promotes pancreatic cancer metastasis by modulating Sp1-mediated THBS1 transcription.

CircRNAs are abnormally expressed in various cancers and play an important role in the occurrence and development of cancers. However, their biological functions and the underlying molecular mechanisms in pancreatic cancer (PC) metastasis are incompletely understood. Differentially expressed circRNAs were identified by second-generation transcriptome sequencing in three pairs of PC tissues and adjacent tissues. The expression and prognostic significance of hsa_circ_0007919 were evaluated by qRT-PCR and Kaplan-Meier survival curves. Gain- and loss-of-function assays were conducted to detect the role of hsa_circ_0007919 in PC metastasis in vitro. A lung metastasis model and IHC experiments were conducted to confirm the effects of hsa_circ_0007919 on tumor metastasis in vivo. Mechanistically, RNA immunoprecipitation and chromatin immunoprecipitation assays were conducted to explore the interplay among hsa_circ_0007919, Sp1, and the THBS1 promoter. hsa_circ_0007919 was significantly upregulated in PC tissues and cells and was correlated with lymph node metastasis, TNM stage, and poor prognosis. Knockdown of hsa_circ_0007919 significantly suppressed the migration and invasion of PC cells in vitro and inhibited tumor metastasis in vivo. However, overexpression of hsa_circ_0007919 exerted the opposite effects. Mechanistically, hsa_circ_0007919 could recruit the transcription factor Sp1 to inhibit THBS1 transcription, thereby facilitating PC metastasis. hsa_circ_0007919 can promote the metastasis of PC by inhibiting THBS1 expression. hsa_circ_0007919 may be a potential therapeutic target in PC.

CA19­9 is a significant prognostic factor in stage III gastric cancer patients undergoing radical gastrectomy.

BACKGROUND: Due to the great heterogeneity of gastric cancer (GC), the prognosis of patients within a stage is very different. Therefore, it is necessary to identify the high risk factors for postoperative recurrence and metastasis and take appropriate therapeutic strategies to improve the prognosis of patients. In this study, we aimed to explore the prognostic significance of preoperative and postoperative serum carcinoembryonic antigen (CEA), carbohydrate antigen 19 - 9 (CA19-9) and carbohydrate antigen 72 - 4 (CA72-4) in patients with stage I, II and III GC who underwent radical gastrectomy. METHODS: A total of 580 patients who underwent curative surgical resection and had not received neoadjuvant chemotherapy were included in this study. The relationship between clinicopathological features and recurrence was analysed. Survival analysis was performed by Kaplan-Meier curve. Univariate and multivariate Cox regression analyses were performed to determine prognostic factors in GC patients. RESULTS: Among patients with stage III GC, the recurrence free survival (RFS) and overall survival (OS) of patients with CA19-9>35 U/mL were significantly lower than those with CA19-9 ≤ 35 U/mL; CA19-9 was always a significant independent marker. CEA and CA72-4 were sometime useful to predict RFS or OS alternatively in the pre- or postoperative period. The only other independent significant factors for prognosis in our study were lymph node metastases for RFS and postoperative adjuvant chemotherapy for OS. CONCLUSION: Preoperative and postoperative CA19-9 values are independent risk factors for predicting prognosis in stage III GC after curative gastrectomy.

hsa_circ_0007919 induces LIG1 transcription by binding to FOXA1/TET1 to enhance the DNA damage response and promote gemcitabine resistance in pancreatic ductal adenocarcinoma.

BACKGROUND: Circular RNAs (circRNAs) play important roles in the occurrence and development of cancer and chemoresistance. DNA damage repair contributes to the proliferation of cancer cells and resistance to chemotherapy-induced apoptosis. However, the role of circRNAs in the regulation of DNA damage repair needs clarification. METHODS: RNA sequencing analysis was applied to identify the differentially expressed circRNAs. qRT-PCR was conducted to confirm the expression of hsa_circ_0007919, and CCK-8, FCM, single-cell gel electrophoresis and IF assays were used to analyze the proliferation, apoptosis and gemcitabine (GEM) resistance of pancreatic ductal adenocarcinoma (PDAC) cells. Xenograft model and IHC experiments were conducted to confirm the effects of hsa_circ_0007919 on tumor growth and DNA damage in vivo. RNA sequencing and GSEA were applied to confirm the downstream genes and pathways of hsa_circ_0007919. FISH and nuclear-cytoplasmic RNA fractionation experiments were conducted to identify the cellular localization of hsa_circ_0007919. ChIRP, RIP, Co-IP, ChIP, MS-PCR and luciferase reporter assays were conducted to confirm the interaction among hsa_circ_0007919, FOXA1, TET1 and the LIG1 promoter. RESULTS: We identified a highly expressed circRNA, hsa_circ_0007919, in GEM-resistant PDAC tissues and cells. High expression of hsa_circ_0007919 correlates with poor overall survival (OS) and disease-free survival (DFS) of PDAC patients. Hsa_circ_0007919 inhibits the DNA damage, accumulation of DNA breaks and apoptosis induced by GEM in a LIG1-dependent manner to maintain cell survival. Mechanistically, hsa_circ_0007919 recruits FOXA1 and TET1 to decrease the methylation of the LIG1 promoter and increase its transcription, further promoting base excision repair, mismatch repair and nucleotide excision repair. At last, we found that GEM enhanced the binding of QKI to the introns of hsa_circ_0007919 pre-mRNA and the splicing and circularization of this pre-mRNA to generate hsa_circ_0007919. CONCLUSIONS: Hsa_circ_0007919 promotes GEM resistance by enhancing DNA damage repair in a LIG1-dependent manner to maintain cell survival. Targeting hsa_circ_0007919 and DNA damage repair pathways could be a therapeutic strategy for PDAC.

Clinicopathological and prognostic significance of elevated BTF3 expression in gastric cancer.

The purpose of this paper was to explore the significance of basic transcription factor 3 (BTF3) in the process and clinicopathological parameters of gastric cancer (GC) patients. GC tissues were collected in our hospital to detect the mRNA expression of BTF3 by quantitative real-time polymerase chain reaction (Q-PCR). Western blot analysis was performed to detect the protein expression of BTF3. Kaplan-Meier method and Log-rank analysis were used to analyze the progression-free survival time and overall time of GC patients, while the Chi-square test was used to investigate the association between BTF3 and clinicopathological parameters of GC patients. SiRNA was designed to suppress the expression of BTF3. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and transwell assay were conducted to determine the viability and invasion ability of GC cells. BTF3 was found abnormally up-regulated in GC tissues and cells and was related to the Grade, Lymph node metastasis and stage of GC patients, as well as the poor progression-free survival and overall survival of them. Besides, inhibition of BTF3 in GC cells could trigger the reduction of cell viability and invasion ability. Our results demonstrated that BTF3 played an important role in the process of GC and could be regarded as a new target for the diagnosis and therapy of GC.

LINC01615 maintains cell survival in adaptation to nutrient starvation through the pentose phosphate pathway and modulates chemosensitivity in colorectal cancer.

Numerous mechanisms involved in promoting cancer cell survival under nutrient starvation have been described. Long noncoding RNAs (lncRNAs) have emerged as critical players in colorectal cancer (CRC) progression, but the role of lncRNAs in the progression of CRC under nutrient starvation has not been well clarified. Here, we identified a lncRNA, LINC01615, that was significantly upregulated in response to serum starvation. LINC01615 can contribute to the adaptation of CRC cells to serum-deprived conditions and enhance cell survival under similar conditions. LINC01615 activated the pentose phosphate pathway (PPP) under serum starvation, manifested as decreased ROS production and enhanced nucleotide and lipid synthesis. Glucose-6-phosphate dehydrogenase (G6PD) is a key rate-limiting enzyme of the PPP, and LINC01615 promoted G6PD expression by competitively binding with hnRNPA1 and facilitating G6PD pre-mRNA splicing. Moreover, we also found that serum starvation led to METTL3 degradation by inducing autophagy, which further increased the stability and level of LINC01615 in a m6A-dependent manner. LINC01615 knockdown combined with oxaliplatin achieved remarkable antitumor effects in PDO and PDX models. Collectively, our results demonstrated a novel adaptive survival mechanism permitting tumor cells to survive under limiting nutrient supplies and provided a potential therapeutic target for CRC.

Effect of total laparoscopic versus open pancreaticoduodenectomy on short-term and oncological outcomes: a single-institution comparative study.

BACKGROUND: Recently, the efficacy and outcomes of total laparoscopic pancreaticoduodenectomy (TLPD) have been well established; however, specific data regarding the clinical outcomes of total laparoscopic versus open pancreaticoduodenectomy (OPD) are still limited. The present study aims to directly compare the clinical and oncological outcomes following TLPD versus OPD at a single institution. METHODS: The clinical data of 127 consecutive patients who underwent TLPD (n = 69) and OPD (n = 58) and were admitted to our department between January 2017 and June 2019 were analysed retrospectively. The short-term and oncological outcomes in the two groups were compared. RESULTS: Compared to the OPD group, the TLPD group experienced a longer operative time [(399.1 ± 77.9) min vs. (247.9 ± 61.8) min] and significantly earlier oral intake [5.0 (IQR, 4.0-6.0) days vs. 8.0 (IQR, 6.0-8.0) days], earlier postoperative exhaust [3.0 (IQR, 3.0-4.0) days vs. 4.0 (IQR, 4.0-4.5) days], earlier out-of-bed activity [2.0 (IQR, 1.0-2.3) days vs. 3.0 (IQR, 2.0-3.0) days], earlier nasogastric tube removal [5.5 (IQR, 4.0-7.8) days vs. 8.0 (IQR, 6.0-11.0) days] and shorter postoperative length of hospital stay [14.0 (IQR, 11.0-21.0) days vs. 16.0 (IQR, 12.0-25.0) days] (P < 0.05). The estimated blood loss [(334.4 ± 157.8) mL vs. (344.6 ± 259.1) mL], presence of clinically relevant postoperative pancreatic fistula (grade B/C, 5.8% vs. 5.2%) and the overall complication rate (23.2% vs. 25.9%) did not significantly differ between the two groups (P > 0.05). Regarding the oncological outcomes, there were no significant differences in pathological types, tumour size, lymph nodes harvested, tumour stages or resection margins, or in overall survival (OS) (56.9% vs. 53.2%, P = 0.704) or progression-free survival (PFS) (48.3% vs. 46.8%, P = 0.881) with a median 26-month follow-up. CONCLUSION: TLPD is a safe and feasible procedure in select patients after a certain learning curve. Compared with OPD, TLPD has equivalent short-term and oncological outcomes and offers the advantages of faster postoperative recovery and shorter length of hospital stay.

CircMYH9 drives colorectal cancer growth by regulating serine metabolism and redox homeostasis in a p53-dependent manner.

BACKGROUND: Circular RNAs (circRNAs) play important roles in cancer progression and metabolism regulation. Serine/glycine metabolism supports the growth of cancer cells by contributing to their anabolic demands and epigenome as well as by regulating their redox state. However, the role of circRNA in the regulation of serine/glycine metabolism has not been well elucidated. METHODS: Microarray analysis was used to screen differentially expressed novel circRNAs. qRT-PCR and FISH were utilized to analyzed the expression of circMYH9. CCK8, colony formation and FACS were used to analyze proliferation of colorectal cancer (CRC) cells. Xenograft experiments were used to analyze tumor growth in vivo. RNA-sequencing, immunoblot and LC-MS were used to identify the downstream metabolic pathway of circMYH9. ChIRP, Mass Spectrometry, RIP and RNA pulldown were utilized to test the interaction between circMYH9, hnRNPA2B1 and p53 pre-mRNA. ChIP-qPCR was used to analyze the binding sites of HIF-1α. Chemically-induced CRC mice were generated to evaluate the role of circMYH9 in tumorigenesis. RESULTS: We identified an intron-derived circRNA, circMYH9, which was significantly upregulated in CRC tissues. A higher circMYH9 level correlated with shorter relapse-free survival and overall survival of CRC patients. CircMYH9 promoted serine/glycine metabolism, the NAD + /NADH ratio, and glutathione recycling and inhibited reactive oxygen species (ROS) in a p53-dependent manner, impacting tumour growth. Mechanistically, circMYH9 destabilized the pre-mRNA of p53 by recruiting hnRNPA2B1 in the nucleus. hnRNPA2B1 bound to N6-methyladenosine sites on the 3' untranslated region of p53 pre-mRNA and maintained its stability. Moreover, a lack of amino acids led to an elevated level of ROS, resulting in increased HIF1α, which promoted circMYH9 expression by binding to the promoter region. Furthermore, in vivo AAV9-mediated transfection of circMYH9 could drive chemically-induced carcinogenesis by suppressing p53 in mice. CONCLUSIONS: The overexpression of circMYH9 promotes CRC proliferation though modulating serine/glycine metabolism and redox homeostasis in a p53-dependent manner, and targeting circMYH9 and its pathway may be an effective strategy for the treatment of CRC.

Characterization and whole-genome sequencing of broad-host-range Salmonella-specific bacteriophages for bio-control.

Salmonella Enteritidis (S. Enteritidis), which could cause human disease and death by consuming the contaminated food, is an important zoonotic pathogen. With the rapid increase of antibiotic resistance all over the world, bacteriophage-based bio-control has gradually attracted public attention widely. In order to find a suitable phage treating S. Enteritidis infection, four phages infecting S. Enteritidis were isolated from poultry fecal samples. Host range showed that four phages had a broad-host-range to Salmonella isolates. The morphological analysis illustrated that all of those phages were classified as the Myoviridae family. The one-step growth curve indicated that bacteriophage BPSELC-1 has a short latent period of about 10 min and a large burst size of 500 pfu/cell in comparison to the other three phages. Then phage BPSELC-1 was sequenced and conducted in vitro experiment. The genome of phage BPSELC-1 is 86,996 bp in size and has 140 putative genes containing structure proteins-encoding genes, tRNA genes and DNA replication or nucleotide metabolism genes. Importantly, no known virulence-associated, antibiotic and lysogeny-related genes were identified in the genome of BPSELC-1. In vitro experiment of phage treatment pointed out that the number of viable S. Enteritidis ATCC 13076 was reduced by 5.9×log10 at MOI of 102 after 4 h. To the best of our knowledge, the phage BPSELC-1 exhibited higher efficiency in S. Enteritidis treatment compared to previous studies. Moreover, it is promising to be used as a broad-spectrum candidate against Salmonella infections in commercial owing to its broad-host-range.

A novel cfr-carrying Tn7 transposon derivative characterized in Morganella morganii of swine origin in China.

OBJECTIVES: To characterize the presence and genetic environment of the multiresistance gene cfr in bacterial isolates from a swine farm. METHODS: A total of 97 bacterial isolates, recovered from 32 faecal swabs obtained on one farm, were tested for the presence of the cfr gene by PCR. Species identification of the one cfr-positive strain was conducted using the BD PhoenixTM 100 Automated Microbiology System. Susceptibility testing was carried out by broth microdilution. The genetic environment of the cfr gene was analysed by WGS. RESULTS: The Morganella morganii isolate BCMM24 was the only cfr-positive strain. The cfr gene, as well as 15 other resistance genes, is located on a novel 111238 bp transposon derived from Tn7, designated as Tn6451, which comprises various genetic materials including a novel class 1 integron with five gene cassettes. The cfr-containing region consists of a novel genetic structure IS26-cfr-ΔTn554 tnpB-ΔTn3 family tnpA-IS26, differing from previous reports. Two-step PCR results show that the structure can be looped out and that Tn6451 cannot be excised from the chromosome. CONCLUSIONS: To the best of our knowledge, we report the cfr gene in M. morganii for the first time. The cfr gene and 15 other resistance genes are located on a novel Tn7 transposon derivative, suggesting that the Tn7 transposon may act as a reservoir for various antimicrobial resistance genes and more Tn7 derivatives carrying multiple resistance genes are likely to be discovered in Gram-negative bacteria of both animal and human origin.

Tn6450, a Novel Multidrug Resistance Transposon Characterized in a Proteus mirabilis Isolate from Chicken in China.

A novel 65.8-kb multidrug resistance transposon, designated Tn6450, was characterized in a Proteus mirabilis isolate from chicken in China. Tn6450 contains 18 different antimicrobial resistance genes, including cephalosporinase gene blaDHA-1 and fluoroquinolone resistance genes qnrA1 and aac(6')-Ib-cr It carries a class 1/2 hybrid integron composed of intI2 and a 3' conserved segment of the class 1 integron. Tn6450 is derived from Tn7 via acquisition of new mobile elements and resistance genes.

Distribution of Salmonella Enteritidis in internal organs and variation of cecum microbiota in chicken after oral challenge.

The aim study was to explore the distribution of Salmonella Enteritidis (S. enteritidis) in internal organs and variation of cecum microbiota in newly hatched chicken after oral challenge during a 21-day period. The quantities of S. enteritidis DNA in different internal organs (heart, liver, spleen, stomach, pancreas, small intestine, blood and cecum contents) were determined by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). The result showed that all of the above-mentioned samples were positive at 12 h post inoculation (PI) after oral challenge. The highest copy numbers of S. enteritidis in all tissue were heart and liver, with about 2 × 102 to 6 × 106 copies of DNA target sequences/0.5 g. The copy number of S. enteritidis in the stomach was only lower than the heart and liver. The blood at 8 d PI, the pancreas at 10 d PI, the heart at 14 d PI and the stomach at 17 d PI didn't have a positive result. However, the liver, spleen, cecum contents and small intestine were all positive during the 21-day period. The cecum contents at 0 d PI, 4 d PI and 10 d PI from the control group and experiment group were collected for bacterial 16 S rRNA sequencing targeting the V3-V4 hypervariable region. The result showed that at the 0 d PI, the main cecum microbiota ingredient of the two-day old chicken was Enterobacteriaceae (Proteobacteria) and the other microbiology species were fewer. At the 10 d PI, the microbiota ingredient of cecum became abundant and stable mainly including the families Ruminococcaceae (Firmicutes), Enterobacteriaceae (Proteobacteria), Lachnospiraceae (Firmicutes) and clostridiacaea (Firmicutes) both of the two group, suggesting Salmonella infection with 2-day old chicken might not significantly change cecum microbiota community. The study indicated the major organs, which carried numerous S. enteritidis, providing a significantly guideline for salmonella detection in poultry and revealed the main microbiota ingredient of chicken cecum.

Frequency of antimicrobial resistance and integron gene cassettes in Escherichia coli isolated from giant pandas (Ailuropoda melanoleuca) in China.

Escherichia coli (E. coli) is considered as a common opportunistic pathogen, which causes seriously intestinal infections to giant pandas (Ailuropoda melanoleuca) and other animals. The aim of this investigation was to characterize the antimicrobial resistance and integron gene cassettes in E. coli isolated from the faeces of giant pandas in China. A total of 89 E. coli were isolated, after diagnosis of isolates and genomes were extracted. All the isolates were screened for the presence of related drug-resistance genes and integron gene cassettes through the Polymerase Chain Reaction (PCR) and sequencing. In addition, antimicrobial resistance testing was performed according to the standard disk diffusion method (CLSI 2013). The results demonstrated that all the isolates were multi-drug resistance (MDR). High resistance proportions of the E. coli isolates were to streptomycin (93%), cefazolin (90%), amikacin (75%), tetracycline (65%), ampicillin (62%), cefotaxime and trimethoprim-sulfamethoxazole (54%, each). With respect to the various resistance genes; blaCTX-M, sul1, ant (3')-Ia, tetA, qnrB, tetE, floR, aac (6')-Ib, sul2, rmtA, cmlA, rmtB and tetC were identified with the respective frequencies of 44%, 45%, 38%, 37%, 35%, 27%, 26%, 20%, 18%, 15%, 10%, 7% and 4%. None of the isolates was positive for qnrA and cfr genes. Moreover, a further investigation of integron revealed that the emergence of class 1 and 2 integrons were in 47% and 8% isolates, respectively. While class 3 integron was not screened. Six types of containing in class 1 integron specific gene cassettes (dfrA12-orfF-aadA2, dfrA17-aadA5, aadA1, aadA5, dfrA1 and dfrA7) were identified. However, only one gene cassette (dfrA1-sat2-aadA1) was detected in class 2 integron. These finding emphasize that a high level of E. coli isolates harbored antibiotics resistance and integron gene cassettes, which may bring so many potential threats to the health of giant pandas.

An IncX1 plasmid isolated from Salmonella enterica subsp. enterica serovar Pullorum carrying blaTEM-1B, sul2, arsenic resistant operons.

We have identified an IncX1 plasmid named pQJDSal1 from Salmonella enterica subsp. enterica serovar Pullorum (S. Pullorum). The plasmid is 67,685 bp in size and has 72 putative genes. pQJDSal1 harbors a conserved IncX1-type backbone with predicted regions for conjugation, replication and partitioning, as well as a toxin/antitoxin plasmid addiction system. Two regions (A and B) that have not been previously reported in IncX1 plasmids are inserted into the backbone. Region A (10.7 kb), inserted between parA and taxD, consists of a new Tn6168-like transposon containing an arsenic resistant operon arsB2CHR and sulfonamide resistance gene sul2. Region B contains another arsenic resistant operon arsADHR, resistance gene blaTEM-1B and three transposable elements. Conjugation experiments showed that pQJDSal1 could transfer from S. Pullorum to Escherichia coli (E. coli) J53. Statistical analysis of 70 sequenced IncX1 plasmids revealed that IncX1 plasmids harbored various antibiotic resistance genes. The results highlight the importance of IncX1 plasmids in disseminating antibiotic resistance genes.

Calmodulin-like 5 promotes PEDV replication by regulating late-endosome synthesis and innate immune response.

The infection caused by porcine epidemic diarrhea virus (PEDV) is associated with high mortality in piglets worldwide. Host factors involved in the efficient replication of PEDV, however, remain largely unknown. Our recent proteomic study in the virus-host interaction network revealed a significant increase in the accumulation of CALML5 (EF-hand protein calmodulin-like 5) following PEDV infection. A further study unveiled a biphasic increase of CALML5 in 2 and 12 â€‹h after viral infection. Similar trends were observed in the intestines of piglets in the early and late stages of the PEDV challenge. Moreover, CALML5 depletion reduced PEDV mRNA and protein levels, leading to a one-order-of-magnitude decrease in virus titer. At the early stage of PEDV infection, CALML5 affected the endosomal trafficking pathway by regulating the expression of endosomal sorting complex related cellular proteins. CALML5 depletion also suppressed IFN-ß and IL-6 production in the PEDV-infected cells, thereby indicating its involvement in negatively regulating the innate immune response. Our study reveals the biological function of CALML5 in the virology field and offers new insights into the PEDV-host cell interaction.

Cellular RNA-binding proteins LARP4 and PABPC1 synergistically facilitate viral translation of coronavirus PEDV.

Coronaviruses are causing epizootic diseases and thus are a substantial threat for both domestic and wild animals. These viruses depend on the host translation machinery to complete their life cycle. The current paper identified cellular RNA-binding proteins (RBPs), La-related protein 4 (LARP4) and polyadenylate-binding protein cytoplasmic 1 (PABPC1), as critical regulators of efficient translation of the coronavirus porcine epidemic diarrhea virus (PEDV) mRNA. In Vero cells, PEDV infection caused LARP4 to migrate from the nucleus to the cytoplasm in a chromosome region maintenance1 (CRM1)-independent pathway. In the absence of the nuclear export signal of LARP4, viral translation was not promoted by LARP4. A further study unveiled that the cytoplasmic LARP4 binds to the 3'-terminal untranslated region (3'UTR) of PEDV mRNA with the assistance of PABPC1 to facilitate viral translation. LARP4 knockdown reduced the promotion of the PABPC1-induced 3'UTR translation activity. Moreover, the rabbit reticulocyte lysate (RRL) system revealed that the prokaryotic expressed protein LARP4 and PABPC1 enhance PEDV mRNA translation. To our knowledge, this is the first study demonstrating that PEDV induces nucleo-cytoplasmic shuttling of LARP4 to enhance its own replication, which broadens our insights into how viruses use host's RBPs for the efficient translation of viral mRNA.

Bilateral decompressive craniotomy complicated by postoperative mycoplasma hominis epidural empyema and meningitis: A case report.

RATIONALE: Postoperative intracranial mycoplasma hominis infection was a rare complication. Timely diagnosis was difficult due to its growth characteristics and nonspecific clinical symptoms. PATIENT CONCERNS: A 52-year-old man underwent bilateral decompressive craniotomy for severe traumatic brain injury. On the seventeenth day after surgery, the patient developed an unexplained high fever. Empirical anti-infective therapy was ineffective, and the fever persisted. In addition, viscous pus oozed from the head incision. Empiric therapy was still ineffective, the fever persisted, and the culture result was negative. The lumbar puncture pressure was 150 mmH2O and the cerebrospinal fluid white blood cell count was 3600 × 106/L, suggesting an intracranial infection. DIAGNOSES: Culture growth morphologically consistent with mycoplasma species was obtained from multiple specimens (scalp incision fluid and cerebrospinal fluid) and the identification of mycoplasma hominis was confirmed by 16S rDNA sequencing. INTERVENTION: Targeted anti-infective therapy (Minocycline), change of fresh wound dressing, and continued lumbar cerebrospinal fluid drainage. OUTCOME: At the 3-month follow-up, the patient was still in the rehabilitation department of the local hospital for treatment, but there were no symptoms of intracranial infection. LESSONS: Neurosurgeons should carefully examine postoperative incisions and be aware of the possibility of mycoplasma infection during clinical management.

Proteomic screening identifies RPLp2 as a specific regulator for the translation of coronavirus.

Viral mRNA of coronavirus translates in an eIF4E-dependent manner, and the phosphorylation of eIF4E can modulate this process, but the role of p-eIF4E in coronavirus infection is not yet entirely evident. p-eIF4E favors the translation of selected mRNAs, specifically the mRNAs that encode proteins associated with cell proliferation, inflammation, the extracellular matrix, and tumor formation and metastasis. In the present work, two rounds of TMT relative quantitative proteomics were used to screen 77 cellular factors that are upregulated upon infection by coronavirus PEDV and are potentially susceptible to a high level of p-eIF4E. PEDV infection increased the translation level of ribosomal protein lateral stalk subunit RPLp2 (but not subunit RPLp0/1) in a p-eIF4E-dependent manner. The bicistronic dual-reporter assay and polysome profile showed that RPLp2 is essential for translating the viral mRNA of PEDV. RNA binding protein and immunoprecipitation assay showed that RPLp2 interacted with PEDV 5'UTR via association with eIF4E. Moreover, the cap pull-down assay showed that the viral nucleocapsid protein is recruited in m7GTP-precipitated complexes with the assistance of RPLp2. The heterogeneous ribosomes, which are different in composition, regulate the selective translation of specific mRNAs. Our study proves that viral mRNA and protein utilize translation factors and heterogeneous ribosomes for preferential translation initiation. This previously uncharacterized process may be involved in the selective translation of coronavirus.

Plasma exosome-derived circGAPVD1 as a potential diagnostic marker for colorectal cancer.

BACKGROUND: Although circular RNAs (circRNAs) have recently garnered interest as disease markers, they have been relatively poorly studied as a biomarker in colorectal cancer (CRC). In this study, we aimed to screen the exosome-derived circRNAs in CRC and explore their potential as diagnostic and prognostic biomarkers of CRC METHODS: Exosomes were extracted from the plasma using a kit and validated by immunoblotting, transmission electron microscopy, and particle size analysis. The microarray datasets were employed to identify differentially-expressed circRNAs from plasma exosomes. Real-time quantitative reverse transcription PCR (RT-qPCR) verified the results of the microarray analysis, and Receiver operating characteristic (ROC) curve revealed the diagnostic ability of a single circRNA. The Starbase combined with microT, miRmap, and RNA22 were used to establish a circRNA-miRNA-mRNA network. Gene ontology, Kyoto Encyclopedia of Genes, Genomes pathway enrichment analysis, and Gene Set Enrichment Analysis were applied to determine potential functions of the identified mRNAs RESULTS: Comparing the microarray of plasma exosome-derived circRNAs and the microarray downloaded from the GEO database, 15 candidate circRNAs with up-regulated expression were identified. RT-qPCR verified that hsa_circ_0003270 (circGAPVD1) was upregulated in CRC plasma exosomes. ROC analysis showed that circGAPVD1 in plasma exosomes has potential diagnostic value for CRC. The sensitivity and specificity of circGAPVD1 in the diagnosis of CRC were found to be 75.64 and 71.79%, respectively (area under ROC = 0.7662). Furthermore, the lymph node metastasis and TNM staging of patients were positively correlated with high expression of circGAPVD1. Combined with the ENCORI database and GEO datasets, we identified the circGAPVD1-related ceRNA network. The enrichment analysis revealed that key nodes in the ceRNA network participate in many important signaling pathways such as protein post-translational modifications CONCLUSION: Our results revealed the diagnostic efficiency of circGAPVD1 in plasma exosomes. The highly expressed circGAPVD1 is expected to be a novel diagnostic marker for CRC.