[A Whole-Course Nursing Quality Evaluation System for Liver Transplantation in Children Based on Donabedian Theory].

Objective To build a whole-course nursing quality evaluation system for liver transplantation in children,so as to provide a basis for nursing quality evaluation and management. Methods With Donabedian's "structure-process-outcome" model as the theoretical framework,we employed literature analysis,Delphi method,and hierarchical analysis to determine the contents and weights of indexes in the whole-course nursing quality evaluation system for liver transplantation in children. Results The three rounds of survey based on questionnaires showed the questionnaire recovery rate of 100%,the expert authority coefficients of 0.95,0.96,and 0.98,and the Kendall's coefficients of concordance of 0.165,0.209,and 0.220,respectively(all P<0.001).The established nursing quality evaluation system included 3 first-level indexes,15 second-level indexes,and 67 third-level indexes. Conclusion The whole-course nursing quality evaluation system for liver transplantation in children that was built in this study can provide a basis for the evaluation of the nursing quality.

Multivariate prognostic index and triplet regimen efficacy predictive index in locally advanced and metastatic gastric cancer: pooled analysis from three clinical trials using individual patient data.

Background: To construct an effective prognostic index to predict overall survival (OS) and triplet regimen efficacy for advanced gastric cancer (AGC) patients treated with platinum-based and fluorouracil-based chemotherapy. Objectives: Between 2011 and 2021, 679 patients from two randomized phase III trials and one phase II trial were enrolled. Designs: We collected 11 baseline clinicopathological and 14 hematological parameters to establish a prognostic index. Methods: Univariate and multivariate Cox analyses were used to screen prognostic factors, and a prognostic index nomogram was conducted. Results: Seven prognostic factors were identified: primary tumor site in the non-proximal gastric area, signet-ring cell carcinoma (SRCC)/mucinous carcinoma, peritoneal metastasis, neutrophil count higher than the upper limit of normal value (ULN), lymphocyte count lower than the lower limit of normal value, lactate dehydrogenase level higher than the ULN, and alkaline phosphatase level higher than the ULN as significant for prognosis. A prognostic nomogram named the Fudan advanced gastric cancer prognostic risk score (FARS) index was constructed, and patients in the high-risk group had significantly shorter OS than those in the low-risk group (median OS, 15.5 versus 8.0 months, p < 0.001). The areas under the curve of the FARS index for 1-, 2-, and 3-year OS were 0.70, 0.72, and 0.77, respectively. A validation and external cohort verified the prognostic value of the FARS index. Moreover, three triplet regimen efficacy parameters were identified: SRCC/mucinous adenocarcinoma, primary tumor location in the non-proximal gastric area, and peripheral neutrophil count higher than the ULN; a TRIS index was subsequently conducted. In patients with any two of the three parameters, the triplet regimen showed significantly longer OS than the doublet regimen (p = 0.018). Conclusion: The constructed FARS index to predict the OS of AGC patients and the TRIS index to screen out the dominant population for triplet regimens can be used to aid clinical decision-making and individual risk stratification.

A prognostic index in locally advanced and metastatic gastric cancer To date, no recognized systematic prognostic score has been established for advanced gastric cancer (AGC). Our research aims to construct an effective prognostic index to predict overall survival (OS) for AGC patients to aid clinical decision-making and individual risk stratification. In our research, seven prognostic factors were identified: primary tumor site in the non-proximal gastric area, signet-ring cell carcinoma (SRCC)/mucinous carcinoma, peritoneal metastasis, neutrophil count higher than the upper limit of normal value (ULN), lymphocyte count lower than the lower limit of normal value, lactate dehydrogenase level higher than the ULN, and alkaline phosphatase level higher than the ULN as significant for prognosis. A prognostic index named the Fudan advanced gastric cancer prognostic risk score (FARS) index was constructed, and patients in the high-risk group had significantly shorter OS than those in low-risk group (median OS, 15.5 months vs. 8.0 months, P < 0.001). Moreover, three triplet regimen efficacy parameters were identified: SRCC/mucinous adenocarcinoma, primary tumor location in the non-proximal gastric area, and peripheral neutrophil count higher than the ULN; a TRIS index was subsequently conducted. In patients with any two of the three parameters, the triplet regimen showed significantly longer OS than the doublet regimen (P = 0.018).

Cloning, expression and functional characterization of recombinant tumor necrosis factor α1 (TNFα1) from white crucian carp in gut immune regulation.

TNFα is one of important cytokines belonging to TNF superfamily, which can exhibit a pleiotropic effect in immune modulation, homeostasis as well as pathogenesis. However, its immunoregulatory function on mucosal immunity in fish gut are still unclear. In this study, we aimed to investigated the immunoregulatory role of TNFα1 in midgut of white crucian carp (WCC). WCC-TNFα1 sequence and its deduced structure were firstly identified in WCC. Then, tissue-specific analysis revealed that high-level WCC-TNFα1 expression was detected in gill. After Aeromonas hydrophila and lipopolysaccharide (LPS) stimulated, increased trends of WCC-TNFα1 expressions were detected in immune-related tissues and cultured fish cells, respectively. WCC anal-intubated with WCC-TNFα1 fusion protein showed the increased levels of edema and fuzzy appearance in impaired villi, along with atrophy and reduction of goblet cells (GC). Moreover, the expression levels of tight junction (TJ) genes and mucin genes were consistently lower than those of the control (P < 0.05). WCC-TNFα1 treatment could sharply decrease antioxidant status in midgut, while the expression levels of caspase (CASP) genes, unfolded protein response (UPR) genes and redox response genes increased dramatically. Our results suggested that WCC-TNFα1 could exhibit a detrimental effect on antioxidant and mucosal immune regulation in midgut of WCC.

Alteration of synergistic immune response in gut-liver axis of white crucian carp (Carassius cuvieri) after gut infection with Aeromonas hydrophila.

Aeromonas hydrophila can pose a great threat to the survival of farmed fish. In current study, we investigated the pathological characteristics and immune response in gut-liver axis of white crucian carp (WCC) upon gut infection. WCC anally intubated with A. hydrophila exerted a tissue deformation in damaged midgut with elevated levels of goblet cells along with a significant decrease in tight junction proteins and villi length-to-width ratios. In addition, immune-related gene expressions and antioxidant properties increased dramatically in gut-liver axis of WCC following gut infection with A. hydrophila. These results highlighted the immune modulation and redox alteration in gut-liver axis of WCC in response to gut infection.

Gut-liver immune and redox response in hybrid fish (Carassius cuvieri ♀ × Carassius auratus red var. ♂) after gut infection with Aeromonas hydrophila.

Aeromonas hydrophila can pose a great threat to fish survival. In this study, we investigated the differential immune and redox response in gut-liver axis of hybrid fish (WR) undergoing gut infection. WR anally intubated with A. hydrophila showed severe midgut injury with decreased length-to-width ratios of villi along with GC hyperplasia and enhanced antioxidant activities, but expression profiles of cytokines, chemokines, antibacterial molecules, redox sensors and tight junction proteins decreased dramatically. In contrast, immune-related gene expressions and antioxidant activities increased significantly in liver of WR following gut infection with A. hydrophila. These results highlighted the differential immune regulation and redox balance in gut-liver axis response to bacterial infection.

Randomized phase II study of TX followed by XELOX versus the reverse sequence for chemo-naive patients with metastatic gastric cancer.

This research found that the clinical outcomes (PFS, ORR, OS) of the non-platinum-based doublet regimen (docetaxel capecitabine combination) were similar to those of the platinum-based (oxaliplatin capecitabine combination) when used as first line therapy for MGC patients. Background: Docetaxel, platinum and fluorouracil are the three most important drugs in the treatment of MGC. This study was to compare clinical outcomes of the docetaxel capecitabine combination and the oxaliplatin capecitabine combination as first-line therapy in MGC patients. Methods: In this phase II trial, MGC patients were randomly assigned and treated with either TX (capecitabine 1000 mg/m2/twice daily/1-14 days and docetaxel 60/75 mg/m2 on the 1st day) (because of toxicity, the dose of docetaxel was reduced to 60 mg/m2) or XELOX (capecitabine the same dose with TX and oxaliplatin 130 mg/m2 on the 1st day) as first-line therapy. After progression, patients were crossover to the other group as second-line treatment. Results: Total 134 MGC patients were randomized (69 in TX, 65 in XELOX). There was no significant difference between the PFS of the two groups (TX vs XELOX, 4.6 months vs 5.1 months, p=0.359), and the SFS (9.3 months vs 7.5 months, p=0.705), OS (13.1 months vs 9.6 months, p=0.261), and ORR (46.4% vs 46.2%) were also similar. Among patients with ascites, the TX group had significantly longer PFS and OS than the XELOX group. A total of 85 patients (48 in TX, 37 in XELOX) received second-line treatment, with overall survival of second-line chemotherapy (OS2) of 8.0 m and 5.3 m (p=0.046), respectively. Grade 3 to 4 treatment-related adverse events of first line treatment occurred more in TX group than that in XELOX group(60.6% vs 55.4%). Conclusion: TX regimen is an alternative choice of first-line treatment for MGC patients. We still need to explore the large number of cohort to confirm this results.

XELOX doublet regimen versus EOX triplet regimen as first-line treatment for advanced gastric cancer: An open-labeled, multicenter, randomized, prospective phase III trial (EXELOX).

BACKGROUND: There is no consensus on whether triplet regimen is better than doublet regimen in the first-line treatment of advanced gastric cancer (AGC). We aimed to compare the efficacy and safety of oxaliplatin plus capecitabine (XELOX) and epirubicin, oxaliplatin, plus capecitabine (EOX) regimens in treating AGC. METHODS: This phase III trial enrolled previously untreated patients with AGC who were randomly assigned to receive the XELOX or EOX regimen. The primary endpoint was non-inferiority in progression-free survival (PFS) for XELOX as compared with EOX on an intention-to-treat basis. RESULTS: Between April 10, 2015 and August 20, 2020, 448 AGC patients were randomized to receive XELOX (n = 222) or EOX (n = 226). The median PFS (mPFS) was 5.0 months (95% confidence interval [CI] = 4.5-6.0 months) in the XELOX arm and 5.5 months (95% CI = 5.0-6.0 months) in the EOX arm (hazard ratio [HR] = 0.989, 95% CI = 0.812-1.203; Pnon-inferiority = 0.003). There was no significant difference in median overall survival (mOS) (12.0 vs. 12.0 months, P = 0.384) or objective response rate (37.4% vs. 45.1%, P = 0.291) between the two groups. In patients with poorly differentiated adenocarcinoma and liver metastasis, the EOX arm had a significantly longer mOS (P = 0.021) and a trend of longer mPFS (P = 0.073) than the XELOX arm. The rate of grade 3/4 adverse events (AEs) was 42.2% (90/213) in the XELOX arm and 72.5% (156/215) in the EOX arm (P = 0.001). The global health-related quality of life (QoL) score was significantly higher in the XELOX arm than in the EOX arm during chemotherapy. CONCLUSIONS: This non-inferiority trial demonstrated that the doublet regimen was as effective as the triplet regimen and had a better safety profile and QoL as a first-line treatment for AGC patients. However, the triplet regimen might have a survival advantage in patients with poorly differentiated adenocarcinoma and liver metastasis.

Proteome analysis guided genetic engineering of Corynebacterium glutamicum S9114 for tween 40-triggered improvement in L-ornithine production.

BACKGROUND: L-ornithine is a valuable amino acid with a wide range of applications in the pharmaceutical and food industries. However, the production of L-ornithine by fermentation cannot compete with other methods, because of the low titers produced with this technique. Development of fermentation techniques that result in a high yield of L-ornithine and efficient strategies for improving L-ornithine production are essential. RESULTS: This study demonstrates that tween 40, a surfactant promoter of the production of glutamate and arginine, improves L-ornithine production titers in engineered C. glutamicum S9114. The intracellular metabolism under tween 40 triggered fermentation conditions was explored using a quantitative proteomic approach, identifying 48 up-regulated and 132 down-regulated proteins when compared with the control. Numerous proteins were identified as membrane proteins or functional proteins involved in the biosynthesis of the cell wall. Modulation of those genes revealed that the overexpression of CgS9114_09558 and the deletion of CgS9114_13845, CgS9114_02593, and CgS9114_02058 improved the production of L-ornithine in the engineered strain of C. glutamicum Orn8. The final strain with all the exploratory metabolic engineering manipulations produced 25.46 g/L of L-ornithine, and a yield of 0.303 g L-ornithine per g glucose, which was 30.6% higher than that produced by the original strain (19.5 g/L). CONCLUSION: These results clearly demonstrate the positive effect of tween 40 addition on L-ornithine accumulation. Proteome analysis was performed to examine the impact of tween 40 addition on the physiological changes in C. glutamicum Orn8 and the results showed several promising modulation targets for developing L-ornithine-producing strains.

Conformational restraint as a strategy for navigating towards lysosomes.

Using the conformational restraint strategy, we developed a hydrazonate-derived coumarin into a lysosome targeting probe for imaging native formaldehyde at the subcellular level. Using this probe, we observed the overproduction of formaldehyde in lysosomes when cells were treated with endoplasmic reticulum (ER) stress inducers, suggesting the involvement of formaldehyde in protein misfolding.

MiR-616-3p promotes angiogenesis and EMT in gastric cancer via the PTEN/AKT/mTOR pathway.

Dysregulation of microRNAs has been demonstrated to be involved in a variety of biological events related to cancer, including proliferation, metastasis, angiogenesis and immune escape. MiR-616-3p is located on the chromosome region 12q13.3, however, its potential role and clinical implications in gastric cancer remain poorly understood. The current study aimed to investigate the potential role of miR-616-3p in gastric cancer. The results showed that miR-616-3p was up-regulated in cancer tissues. Higher expression of miR-616-3p in tumor tissues also predicted poor prognosis. Furthermore, loss- and gain-of-function in vitro revealed that miR-616-3p promoted angiogenesis and EMT in gastric cancer cells. Mechanistically, further analysis demonstrated that the effects of miR-616-3p on metastasis and angiogenesis occurred through the down-regulation of PTEN, a direct target of miR-616-3p. We propose that the restoration of PTEN expression may block miR-616-3p-induced EMT and angiogenesis. Collectively, our findings suggest that the miR-616-3p-PTEN signaling axis might be a potential therapeutic target for gastric cancer.

Myt1l induced direct reprogramming of pericytes into cholinergic neurons.

OBJECTIVE: The cholinergic deficit is thought to underlie progressed cognitive decline in Alzheimer Disease. The lineage reprogramming of somatic cells into cholinergic neurons may provide strategies toward cell-based therapy of neurodegenerative diseases. METHODS AND RESULTS: Here, we found that a combination of neuronal transcription factors, including Ascl1, Myt1l, Brn2, Tlx3, and miR124 (5Fs) were capable of directly converting human brain vascular pericytes (HBVPs) into cholinergic neuronal cells. Intriguingly, the inducible effect screening of reprogramming factors showed that a single reprogramming factor, Myt1l, induced cells to exhibit similarly positive staining for Tuj1, MAP2, ChAT, and VAChT upon lentivirus infection with the 5Fs after 30 days. HBVP-converted neurons were rarely labeled even after long-term incubation with BrdU staining, suggesting that induced neurons were directly converted from HBVPs rather than passing through a proliferative state. In addition, the overexpression of Myt1l induced the elevation of Ascl1, Brn2, and Ngn2 levels that contributed to reprogramming. CONCLUSIONS: Our findings provided proof of the principle that cholinergic neurons could be produced from HBVPs by reprogramming factor-mediated fate instruction. Myt1l was a critical mediator of induced neuron cell reprogramming. HBVPs represent another excellent alternative cell resource for cell-based therapy to treat neurodegenerative disease.

CBX7 regulates stem cell-like properties of gastric cancer cells via p16 and AKT-NF-κB-miR-21 pathways.

BACKGROUND: Chromobox protein homolog 7 (CBX7), a member of the polycomb group (PcG) family of proteins, is involved in the regulation of cell proliferation and cancer progression. PcG family members, such as BMI, Mel-18, and EZH2, are integral constituents of the polycomb repressive complexes (PRCs) and have been known to regulate cancer stem cell (CSC) phenotype. However, the role of other PRCs' constituents such as CBX7 in the regulation of CSC phenotype remains largely elusive. This study was to investigate the role of CBX7 in regulating stem cell-like properties of gastric cancer and the underlying mechanisms. METHODS: Firstly, the role of CBX7 in regulating stem cell-like properties of gastric cancer was investigated using sphere formation, Western blot, and xenograft tumor assays. Next, RNA interference and ectopic CBX7 expression were employed to determine the impact of CBX7 on the expression of CSC marker proteins and CSC characteristics. The expression of CBX7, its downstream targets, and stem cell markers were analyzed in gastric stem cell spheres, common cancer cells, and gastric cancer tissues. Finally, the pathways by which CBX7 regulates stem cell-like properties of gastric cancer were explored. RESULTS: We found that CBX7, a constituent of the polycomb repressive complex 1 (PRC1), plays an important role in maintaining stem cell-like characteristics of gastric cancer cells via the activation of AKT pathway and the downregulation of p16. Spearman rank correlation analysis showed positive correlations among the expression of CBX7 and phospho-AKT (pAKT), stem cell markers OCT-4, and CD133 in gastric cancer tissues. In addition, CBX7 was found to upregulate microRNA-21 (miR-21) via the activation of AKT-NF-κB pathway, and miR-21 contributes to CBX7-mediated CSC characteristics. CONCLUSIONS: CBX7 positively regulates stem cell-like characteristics of gastric cancer cells by inhibiting p16 and activating AKT-NF-κB-miR-21 pathway.

A Fluorogenic Probe for Ultrafast and Reversible Detection of Formaldehyde in Neurovascular Tissues.

Formaldehyde (FA) is endogenously produced in live systems and has been implicated in a diverse array of pathophysiological processes. To disentangle the detailed molecular mechanisms of FA biology, a reliable method for monitoring FA changes in live cells would be indispensable. Although there have been several fluorescent probes reported to detect FA, most are limited by the slow detection kinetics and the intrinsic disadvantage of detecting FA in an irreversible manner which may disturb endogenous FA homeostasis. Herein we developed a coumarin-hydrazonate based fluorogenic probe (PFM) based on a finely-tailored stereoelectronic effect. PFM could respond to FA swiftly and reversibly. This, together with its desirable specificity and sensitivity, endows us to track endogenous FA in live neurovascular cells with excellent temporal and spatial resolution. Further study in the brain tissue imaging showed the first direct observation of aberrant FA accumulation in cortex and hippocampus of Alzheimer's mouse model, indicating the potential of PFM as a diagnostic tool.

Molecular cloning, characterization and function of a germinal center kinase MST4 gene from Litopenaeus vannamei in response to Vibrio alginolyticus challenge in TLR-TRAF6 signaling pathway.

The serine/threonine protein kinase MST4 plays multiple roles in the regulation of signaling pathways that govern cellular processes including mitosis, migration, homeostasis, polarity, proliferation, differentiation and apoptosis. Here we report the identification and characterization of the full-length sequence of LvMST4 from the shrimp L. vannamei, and investigations into its role in the shrimp's immune response to infection by the pathogenic bacterium Vibrio alginolyticus. Subcellular localization assays demonstrated the enzyme's presence in the shrimp's cytoplasm, and tissue-specific expression analysis revealed that it is expressed ubiquitously but at different levels in different tissues. Infection with V. alginolyticus increased LvMST4 expression and induced a rapid response via the TLR-TRAF6 signaling pathway, causing a decline in the total hemocyte count (THC) and an increase in respiratory burst (RB) activity. In non-infected shrimp, RNAi silencing of LvMST4 with dsRNA had no significant effect on THC but seemed to activate the TRAF6-MKK6-p38 pathway and reduced RB activity. In shrimp challenged with V. alginolyticus, LvMST4 silencing reduced bacterial clearance and increased the initial upregulation of LvTRAF6 while reducing the expression of LvMKK6 and Lvp38. LvMST4 silencing also slightly reduced the THC but caused pronounced increases in RB activity and cumulative mortality. These findings suggest that LvMST4 contributes to antimicrobial responses via the TLR-TRAF6 signal pathway, and helps maintain immunological homeostasis in L. vannamei.

Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer.

Mel-18, a polycomb group protein, has been reported to act as a tumor suppressor and be down-regulated in several human cancers including gastric cancer. It was also found that Mel-18 negatively regulates self-renewal of hematopoietic stem cells and breast cancer stem cells (CSCs). This study aimed to clarify its role in gastric CSCs and explore the mechanisms. We found that low-expression of Mel-18 was correlated with poor prognosis and negatively correlated with overexpression of stem cell markers Oct4, Sox2, and Gli1 in 101 gastric cancer tissues. Mel-18 was down-regulated in cultured spheroid cells, which possess CSCs, and overexpression of Mel-18 inhibits cells sphere-forming ability and tumor growth in vivo. Besides, Mel-18 was lower-expressed in ovary metastatic lesions compared with that in primary lesions of gastric cancer, and Mel-18 overexpression inhibited the migration ability of gastric cancer cells. Interestingly, overexpression of Mel-18 resulted in down-regulation of miR-21 in gastric cancer cells and the expression of Mel-18 was negatively correlated with the expression of miR-21 in gastric cancer tissues. Furthermore, miR-21 overexpression partially restored sphere-forming ability, migration potential and chemo-resistance in Mel-18 overexpressing gastric cancer cells. These results suggests Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer cells.

The GRIM-19 plays a vital role in shrimps' responses to Vibrio alginolyticus.

GRIM-19 (gene associated with retinoid-interferon-induced mortality 19), a novel cell death regulatory gene, plays important roles in cell apoptosis, mitochondrial respiratory chain and immune response. It has been reported to interact physically with STAT3 and inhibit STAT3-dependent signal transduction. In this study, a new GRIM-19 gene, which is a 789-bp gene encoding a 149 amino acids protein, is identified and characterized from Litopenaeus vannamei. The tissue distribution patterns showed that LvGRIM-19 was widely expressed in all examined tissues, with the highest expression in muscle. Quantitative real-time PCR revealed that LvGRIM-19 was down-regulated in hepatopancreas after infection with the Vibrio alginolyticus. Knockdown of LvGRIM-19 by RNA interference resulted in a lower mortality of L. vannamei under V. alginolyticus infection, as well as an enhancement in the protein expression of STAT gene and JAK gene. V. alginolyticus infection caused an increase apoptotic cell ratio and ROS production of L. vannamei, while LvGRIM-19 silenced shrimps showed significantly lower than GFP group. Our results suggest that the GRIM-19 plays a vital role in shrimps' responses to V. alginolyticus. Interferenced LvGRIM-19 treatment during V. alginolyticus infection could increase 12 h survival rate, which might indicated that LvGRIM-19 is closely related to death of shrimps.

TMEM140 is associated with the prognosis of glioma by promoting cell viability and invasion.

BACKGROUND: Gliomas are the most common types of primary brain tumors in the adult central nervous system. TMEM140 is identified as an amplified gene in the human gastric cancer genome. However, the function of TMEM140 in gliomas has not been thoroughly elucidated. The aim of the current study was to determine the clinical significance of TMEM140 expression in patients with gliomas and its effect on tumor cell malignant phenotypes. METHODS: Immunohistochemical analysis and real-time reverse transcription PCR were performed to detect the expression levels of TMEM140 in 70 glioma brain tissue samples. Next, the correlation between the TMEM140 expression levels and the clinical characteristics and outcomes of glioma patients was statistically analyzed. TMEM140 expression was inhibited in two glioma cell lines (i.e., U87 and U373) using a knockdown method with small interfering RNA. Cell Counting Kit-8 and Transwell assays were used to investigate TMEM140 function during cell proliferation, invasion, and migration, respectively. Using flow cytometry and Western blot analysis, we subsequently determined the cell cycle and apoptosis profile of the TMEM140-silenced cells. RESULTS: TMEM140 protein expression was significantly higher in gliomas than in normal brain tissues (p < 0.0001). TMEM140 overexpression was strongly correlated with tumor size, histologic grade, and overall survival time (P < 0.05). TMEM140 decreased cell viability in vitro and dramatically decreased tumor volume in vivo. This phenomenon might be caused by G1 phase cell cycle arrest and cell apoptosis. TMEM140 silencing could suppress the viability, migration, and invasion of glioma cells. CONCLUSIONS: Our results suggest that TMEM140 expression is a prognostic factor that might play an important role in the viability, migration, and invasion of glioma cells. This study highlights the importance of TMEM140 as a novel prognostic marker and as an attractive therapeutic target for gliomas.

Molecular cloning, expression of a galectin gene in Pacific white shrimp Litopenaeus vannamei and the antibacterial activity of its recombinant protein.

Galectins play crucial roles in innate immune responses in invertebrate by recognizing and eliminating microinvaders. In this study, a cDNA encoding a galectin in the Pacific white shrimp (L. vannamei) was identified and characterized. A recombinant variant of this lectin, rLvgalectin, was expressed in the model organism P. pastoris and its expression was confirmed by Western blot. Biochemical assays indicated that the recombinant protein antibacterial rLvgalectin activity and was expressed in all of the organism's tested tissues Injection of the bacterium V. alginolyticus into L. vannamei induced hemocytes upregulation of Lvgalectin. The recombinant Lvgalectin protein (rLvgalectin) could bind various microorganism including Gram-positive bacteria, Gram-negative bacteria and yeast. And it revealed antimicrobial activity against the test Gram-positive bacteria, Gram-negative bacteria, but did not inhibit the growth of fungus Pichia pastoris. Moreover, rLvgalectin could significantly enhance the clearance activity of V. alginolyticus in vivo. In vivo challenge experiments showed that the recombinant rLvgalectin protein can significantly reduce the mortalities of V. alginolyticus injection. Furthermore, Compared to their wild-type counterparts, Lvgalectin-silenced shrimp exhibited increased mortality and hemocyte apoptosis, decreased bacterial clearance ability and total hemocyte counts, and stronger expression of Lvp53, LvproPO, LvPEN3, and LvCrustin following V. alginolyticus challenge. Taken together, these results suggest that galectin is important in the innate immune response of shrimp to pathogens infection.

A Rac1 GTPase is a critical factor in the immune response of shrimp (Litopenaeus vannamei) to Vibrio alginolyticus infection.

The small GTPase Rac1 acts as a molecular switch for signal transduction that regulates various cellular functions. However, its functions in crustaceans remain unclear. In this study, a cDNA encoding a RAS GTPase (LvRac1) in the Pacific white shrimp (L. vannamei) was identified and characterized. A recombinant variant of this GTPase, rLvRac1, was expressed in the model organism P. pastoris and its expression was confirmed by mass spectrometry. Biochemical assays indicated that the recombinant protein retained GTPase activity and was expressed in all of the organism's tested tissues. Injection of the bacterium V. alginolyticus into L. vannamei induced hepatopancreatic upregulation of LvRac1 expression. Moreover, knocking down LvRac1 in vivo significantly reduced the expression of the L. vannamei p53 and Cu/Zn superoxide dismutase genes (Lvp53 and LvCu/Zn SOD, respectively) while increasing that of the galectin gene (Lvgal). Hemolymph samples from control and LvRac1-silenced L. vannamei individuals were analyzed by flow cytometry, revealing that the latter exhibited significantly reduced respiratory burst activity and total hemocyte counts. Cumulative mortality in shrimp lacking LvRac1 was significantly greater than in control groups following V. alginolyticus challenge. The silencing of LvRac1 by double-stranded RNA injection thus increased the V. alginolyticus challenge sensitivity of L. vannamei and weakened its bacterial clearance ability in vivo. Suppressing LvRac1 also promoted the upregulation of Lvp53, LvCu/ZnSOD, and Lvgal following V. alginolyticus injection. Taken together, these results suggest that LvRac1 is important in the innate immune response of shrimp to V. alginolyticus infection.