Cyclophosphamide activates ferroptosis-induced dysfunction of Leydig cells via SMAD2 pathway†.

Cyclophosphamide (CP) is a widely used chemotherapeutic drug and immunosuppressant in the clinic, and the hypoandrogenism caused by CP is receiving more attention. Some studies found that ferroptosis is a new mechanism of cell death closely related to chemotherapeutic drugs and plays a key role in regulating reproductive injuries. The purpose of this study is to explore ferroptosis' role in testicular Leydig cell dysfunction and molecular mechanisms relating to it. In this study, the level of ferroptosis in the mouse model of testicular Leydig cell dysfunction induced by CP was significantly increased and further affected testosterone synthesis. The ferroptosis inhibitors ferrostatin-1 (Fer-1) and iron chelator deferoxamine (DFO) can improve injury induced by CP. The results of immunohistochemistry showed that Fer-1 and DFO could improve the structural disorder of seminiferous tubules and the decrease of the number of Leydig cells in testicular tissue induced by CP. Immunofluorescence and western blot confirmed that Fer-1 and DFO could improve the expression of key enzymes in testosterone synthesis. The activation of SMAD family member 2 (Smad2)/cyclin-dependent kinase inhibitor 1A (Cdkn1a) pathway can improve the ferroptosis of Leydig cells induced by CP and protect the function of Leydig cells. By inhibiting the Smad2/Cdkn1a signal pathway, CP can regulate ferroptosis, resulting in testicular Leydig cell dysfunction. In this study, CP-induced hypoandrogenism is explained theoretically and a potential therapeutic strategy is provided.

The impact of insomnia on anxiety and depression: a longitudinal study of non-clinical young Chinese adult males.

Insomnia, anxiety, and depression commonly co-occured and were closely related. Most of the prior studies were cross-sectional, with a poor ability to infer causality. Longitudinal study was needed to classify the relationships. The present study conducted a longitudinal study of non-clinical young Chinese males to investigate whether insomnia predicted the likelihood of future anxiety and depression, and vice versa. Convenient sampling method was applied, and 288 participants was recruited from Shanghai in October 2017 with Athens Insomnia Scale (AIS), Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9). 120 of them were re-tested in June 2018. The drop-out rate was 58.33%. Correlation analyses and cross-lagged analysis showed that AIS global score was significantly positively related with scores of depression and anxiety at baseline and follow-up. Insomnia was a predictive factor of anxiety, but it can't predict depression. In sum, insomnia may be an important cause of anxiety, while no predictive relationship was found between insomnia and depression.

Anxiety, depression, and coping styles among patients with chronic pancreatitis in East China.

BACKGROUND: Anxiety and depression are common psychological comorbidities in patients with chronic pancreatitis (CP). There is still a lack of epidemiological studies on anxiety and depression in Chinese CP patients. This study aimed to identify the incidence and related factor of anxiety and depression among East Chinese CP patients and explore the relationship between anxiety, depression, and coping styles. METHODS: This prospective observational study was conducted from June 1, 2019 to March 31, 2021 in Shanghai, China. Patient diagnosed with CP were interviewed using the sociodemographic and clinical characteristics questionnaire, Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS), and Coping Style Questionnaire (CSQ). Multivariate logistic regression analysis was conducted to identify the related factors of anxiety and depression. Correlation test was preformed to analyze the correlation between anxiety, depression, and coping styles. RESULTS: The incidence of anxiety and depression in East Chinese CP patients was 22.64% and 38.61%, respectively. Patients' previous health status, level of disease coping, frequency of abdominal pain episodes, and pain severity were significantly associated with anxiety and depression. Mature coping styles (Problem solving, Seeking for help) had a positive impact on anxiety and depression, while immature coping styles (Self-blame, Fantasy, Repression, Rationalization) had negative effects on anxiety and depression. CONCLUSION: Anxiety and depression were common in patients with CP in China. The factors identified in this study may provide references for the management of anxiety and depression in CP patients.

Unusual metal ion cofactor requirement of Entamoeba histolytica choline and ethanolamine kinase isoforms.

The de novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine in Entamoeba histolytica is largely dependent on the CDP-choline and CDP-ethanolamine pathways. Although the first enzymes of these pathways, EhCK1 and EhCK2, have been previously characterized, their enzymatic activity was found to be low and undetectable, respectively. This study aimed to identify the unusual characteristics of these enzymes in this deadly parasite. The discovery that EhCKs prefer Mn2+ over the typical Mg2+ as a metal ion cofactor is intriguing for CK/EK family of enzymes. In the presence of Mn2+, the activity of EhCK1 increased by approximately 108-fold compared to that in Mg2+. Specifically, in Mg2+, EhCK1 exhibited a Vmax and K0.5 of 3.5 ± 0.1 U/mg and 13.9 ± 0.2 mM, respectively. However, in Mn2+, it displayed a Vmax of 149.1 ± 2.5 U/mg and a K0.5 of 9.5 ± 0.1 mM. Moreover, when Mg2+ was present at a constant concentration of 12 mM, the K0.5 value for Mn2+ was ~ 2.4-fold lower than that in Mn2+ alone, without affecting its Vmax. Although the enzyme efficiency of EhCK1 was significantly improved by about 25-fold in Mn2+, it is worth noting that its Km for choline and ATP were higher than in equimolar of Mg2+ in a previous study. In contrast, EhCK2 showed specific activity towards ethanolamine in Mn2+, exhibiting Michaelis-Menten kinetic with ethanolamine (Km = 312 ± 27 µM) and cooperativity with ATP (K0.5 = 2.1 ± 0.2 mM). Additionally, we investigated the effect of metal ions on the substrate recognition of human choline and ethanolamine kinase isoforms. Human choline kinase α2 was found to absolutely require Mg2+, while choline kinase ß differentially recognized choline and ethanolamine in Mg2+ and Mn2+, respectively. Finally, mutagenesis studies revealed that EhCK1 Tyr129 was critical for Mn2+ binding, while Lys233 was essential for substrate catalysis but not metal ion binding. Overall, these findings provide insight into the unique characteristics of the EhCKs and highlight the potential for new approaches to treating amoebiasis. Amoebiasis is a challenging disease for clinicians to diagnose and treat, as many patients are asymptomatic. However, by studying the enzymes involved in the CDP-choline and CDP-ethanolamine pathways, which are crucial for de novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine in Entamoeba histolytica, there is great potential to discover new therapeutic approaches to combat this disease.

Entropy-Based GLDS Method for Social Capital Selection of a PPP Project with q-Rung Orthopair Fuzzy Information.

The social capital selection of a public-private-partnership (PPP) project could be regarded as a classical multiple attribute group decision-making (MAGDM) issue. In this paper, based on the traditional gained and lost dominance score (GLDS) method, the q-rung orthopair fuzzy entropy-based GLDS method was used to solve MAGDM problems. First, some basic theories related to the q-rung orthopair fuzzy sets (q-ROFSs) are briefly reviewed. Then, to fuse the q-rung orthopair fuzzy information effectively, the q-rung orthopair fuzzy Hamacher weighting average (q-ROFHWA) operator and q-rung orthopair fuzzy Hamacher weighting geometric (q-ROFHWG) operator based on the Hamacher operation laws are proposed. Moreover, to determine the attribute weights, the q-rung orthopair fuzzy entropy (q-ROFE) is proposed and some significant merits of it are discussed. Next, based on the q-ROFHWA operator, q-ROFE, and the traditional GLDS method, a MAGDM model with q-rung orthopair fuzzy information is built. In the end, a numerical example for social capital selection of PPP projects is provided to testify the proposed method and deliver a comparative analysis.

Evidence that dopamine is involved in neuroendocrine regulation, gill intracellular signaling pathways and ion regulation in Litopenaeus vannamei.

The transport of ions and ammonia in gills may be regulated by neuroendocrine factors. In order to explore the mechanism of dopamine (DA) regulation, we investigated hemolymph neuroendocrine hormones, gill intracellular signaling pathways, ion and ammonia transporters, hemolymph osmolality and ammonia concentration in Litopenaeus vannamei after injection of 10-7 and 10-6 mol DA per shrimp. The data showed a significant increase in crustacean hyperglycemic hormone (CHH) concentration at 1-12 h and a transient significant decrease in corticotrophin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and cortisol concentration under DA stimulation. The up-regulation of guanylyl cyclase (GC) mRNA, cyclic guanosine monophosphate (cGMP) and protein kinase G (PKG) concentration, together with the down-regulation of DA receptor D4 mRNA and up-regulation of cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), diacylglycerol (DAG) and protein kinase C (PKC) concentration suggested the activation of complicated intracellular signaling pathways. The expression of cAMP response element-binding protein (CREB), FXYD2 and 14-3-3 protein mRNA was significantly increased by PKA regulation. The increase in Na+/K+-ATPase (NKA) activity and the stabilization of V-type H+-ATPase (V-rATPase) activity were accompanied by an up-regulation of K+ channel, Na+/K+/2Cl- cotransporter (NKCC), Rh protein and vesicle associated membrane protein (VAMP) mRNA, resulting in an increase in hemolymph osmolality and a decrease in hemolymph ammonia concentration. These results suggest that DA stimulates the secretion of CHH and inhibits the release of cortisol, which activates intracellular signaling factors to facilitate ion and ammonia transport across the gills, and may not affect intracellular acidification.

Effects of crustacean hyperglycemic hormone (CHH) on regulation of hemocyte intracellular signaling pathways and phagocytosis in white shrimp Litopenaeus vannamei.

Shrimps like other arthropods rely on innate immune system, and may have some form of adaptive immunity in defending against pathogens. Phagocytosis is one of the oldest cellular processes, serving as a development process, a feeding mechanism and especially as a key defense reaction in innate immunity of all multicellular organisms. It is confirmed that crustacean hyperglycemic hormone (CHH) is one of the most important neuropeptides produced by Neuro-endocrine Immune (NEI) regulatory network, which undertakes important roles in various biological processes, especially in immune function and stress response. In this study, the recombinant Litopenaeus vannamei CHH (rLvCHH) was obtained from a bacterial expression system and the intracellular signaling pathways involved in the mechanism of phagocytosis after rLvCHH injection was investigated. The results showed that the contents of adenylyl cyclase (AC), phospholipase C (PLC) and calmodulin (CaM) in hemocytes were increased significantly after rLvCHH injection. Furthermore, the mRNA expression levels of NF-kB family members (relish and dorsal) and phagocytosis-related proteins in hemocytes were basically overexpressed after rLvCHH stimulation, while the expression level of NF-kB repressing factor (NKRF) gene was down-regulated significantly. Eventually, the total hemocyte count and phagocytic activity of hemocyte were dramatically enhanced within 3 h. Collectively, these results indicate that shrimps L. vannamei could carry out a simple but 'smart' NEI regulation through the action of neuroendocrine factors, which could couple with their receptors and trigger the downstream signaling pathways during the phagocytic responses of hemocytes.

Transcriptome analysis of hemocytes from the white shrimp Litopenaeus vannamei with the injection of dopamine.

As a crucial neuroendocrine-immune factor, dopamine (DA) could regulate the immune system of Litopenaeus vannamei. To understand the immune mechanisms and regulatory pathways of DA in L. vannamei, the transcriptome analysis of hemocytes of L. vannamei with injection of DA (10-6 mol/shrimp) at 3 and 12 h were performed in this study. Moreover, quantitative real-time PCR (qPCR) method was applied to validate the accuracy of transcriptome sequencing and analyze the expression pattern of candidate differentially expressed genes (DEGs) at different time points (0, 3, 6, 12, and 24 h) after DA injection. The results showed that a total of 51382 unigenes with a N50 length of 2341 bp were generated. And 1397 and 457 DEGs were obtained by comparative transcriptome at 3 and 12h respectively. Moreover, the results of functional annotation and enriched pathway showed that the DEGs were involved in phagosome (ko04145), lysosome (ko04142), Endocytosis (ko04144), and NOD-like receptor signaling pathway (ko04621). Besides, the Pearson's correlation coefficient (R) between transcriptome sequencing and qPCR was 0.845, which confirmed the reliability of the transcriptome sequencing results and the accuracy of assembly. Furthermore, the expression pattern of 15 candidate DEGs, containing 9 up-regulated and 6 down-regulated DEGs at 3 h, indicated the regulation of DA in physiological functions especially in the immune system. Therefore, these results revealed that DA induced the expressions of membrane receptors or proteins, activated intracellular signaling pathways, regulated cellular and humoral immune systems, controlled antioxidation and apoptosis, and was involved in the regulation of neuroendocrine system. These findings are helpful to promote the understanding on the effects of biogenic amines on physiological functions and regulatory networks of crustacean, and offer a substantial material and foundation for researching the immune response of crustacean.

Validation of the Chinese version of Addenbrooke's Cognitive Examination III for diagnosing dementia.

OBJECTIVE: The aim of this study was to validate the reliability of the Chinese version of Addenbrooke's Cognitive Examination III (ACE-III) for detecting dementia. Furthermore, the present study compares the diagnostic accuracy of ACE-III with that of mini-mental state examination (MMSE). METHODS: One hundred seventy-seven patients with dementia and 180 healthy controls were included in the study. RESULTS: The reliability of ACE-III was very good (α-coefficient = 0.888). There was a significant negative correlation between Clinical Dementia Rating Scale score and total ACE-III score. Further, there was a positive correlation between MMSE score and total ACE-III score. Age exerted a significant effect on total ACE-III score, memory score, and language score. In the present study, the cutoff score of 83 showed a sensitivity of 91.1% and a specificity of 83.1%. CONCLUSIONS: The present findings support that the Chinese version of ACE-III is a reliable assessment tool for dementia. Copyright © 2017 John Wiley & Sons, Ltd.

Sequential combination therapy with pegylated interferon leads to loss of hepatitis B surface antigen and hepatitis B e antigen (HBeAg) seroconversion in HBeAg-positive chronic hepatitis B patients receiving long-term entecavir treatment.

Nucleos(t)ide analogues rarely result in a durable off-treatment response in chronic hepatitis B infection, whereas pegylated interferon (Peg-IFN) induces a long-lasting response only in a subset of patients. We assessed the effect of sequential combination therapy with Peg-IFN-α2a and entecavir in hepatitis B e antigen (HBeAg)-positive patients with prior long-term entecavir therapy and investigated the predictors of response to treatment. HBeAg-positive individuals who did not achieve HBeAg seroconversion during previous long-term entecavir therapy, receiving Peg-IFN-α2a added to ongoing entecavir therapy (sequential combination [S-C] therapy; n = 81) for 48 weeks or remaining on entecavir monotherapy (n = 116), were retrospectively included. A matched pair was created at a 1:1 ratio from each treatment group. The primary endpoint was HBeAg seroconversion at week 48. Subgroup analysis of response prediction was conducted for 81 patients with S-C therapy. More patients in the S-C therapy group achieved HBeAg seroconversion than those in the entecavir group (44% versus 6%; P < 0.0001). An HBeAg level of <200 signal-to-cutoff ratio (S/CO) at baseline was a strong predictor for higher HBeAg seroconversion than that achieved when HBeAg was ≥200 S/CO (64.2% versus 17.9%; P < 0.0001). Hepatitis B surface antigen (HBsAg) levels at baseline and the decrease in HBsAg levels predicted HBsAg loss in the S-C therapy group. The combination of baseline HBeAg of <200 S/CO and HBsAg of <1,000 IU/ml and an HBsAg decline at week 12 of ≥0.5 log10 IU/ml provided the highest rate of HBeAg seroconversion (92.31%) and HBsAg loss (83.3%) at week 48. Patients receiving sequential combination therapy have a higher rate of HBeAg seroconversion and are more likely to experience HBsAg clearance than do those continuing entecavir monotherapy. Sequential combination therapy can be guided by baseline HBsAg/HBeAg levels and on-treatment HBsAg dynamics.

Experimental verification of significant reduction of turbulence-induced scintillation in a full Poincaré beam.

It is theoretically predicted in [Opt. Lett.37, 1553 (2012)] that a full Poincaré (FP) beam can significantly reduce turbulence-induced scintillation. In this paper, we propose a method for synthesizing a FP beam for different beam orders and report experimental generation of the first-, second- and third-order FP beams. Furthermore, we carry out experimental measurement of the scintillation index of a FP beam passing through thermally induced turbulence. It is demonstrated that the FP beam indeed can significantly reduce the scintillation index compared to a Gaussian beam under certain conditions. Our results will be useful in long-distance free-space optical communications.

Experimental study of turbulence-induced beam wander and deformation of a partially coherent beam.

We carry out an experimental study of the effect of spatial coherence on the beam wander and the deformation of a Gaussian Schell-model (GSM) beam propagating through thermally induced turbulence. It is demonstrated that a GSM beam with lower coherence indeed experiences smaller beam wander and deformation than that with higher coherence. Our experimental results are explained by the beam wander theory of partially coherent beam reasonably, and will be useful in free-space optical communications.

Identification and Characterization of Entamoeba histolytica Choline Kinase.

PURPOSE: Entamoeba histolytica is one of the death-causing parasites in the world. Study on its lipid composition revealed that it is predominated by phosphatidylcholine and phosphatidylethanolamine. Further study revealed that its phosphorylated metabolites might be produced by the Kennedy pathway. Here, we would like to report on the characterizations of enzymes from this pathway that would provide information for the design of novel inhibitors against these enzymes in future. METHODOLOGY: E. histolytica HM-1:IMSS genomic DNA was isolated and two putative choline/ethanolamine kinase genes (EhCK1 and EhCK2) were cloned and expressed from Escherichia coli BL21 strain. Enzymatic characterizations were further carried out on the purified enzymes. RESULTS: EhCK1 and EhCK2 were identified from E. histolytica genome. The deduced amino acid sequences were more identical to its homologues in human (35-48%) than other organisms. The proteins were clustered as ethanolamine kinase in the constructed phylogeny tree. Sequence analysis showed that they possessed all the conserved motifs in choline kinase family: ATP-binding loop, Brenner's phosphotransferase motif, and choline kinase motif. Here, the open reading frames were cloned, expressed, and purified to apparent homogeneity. EhCK1 showed activity with choline but not ethanolamine. The biochemical characterization showed that it had a Vmax of 1.9 ± 0.1 µmol/min/mg. Its Km for choline and ATP was 203 ± 26 µM and 3.1 ± 0.4 mM, respectively. In contrast, EhCK2 enzymatic activity was only detected when Mn2+ was used as the co-factor instead of Mg2+ like other choline/ethanolamine kinases. Highly sensitive and specific antibody against EhCK1 was developed and used to confirm the endogenous EhCK1 expression using immunoblotting. CONCLUSIONS: With the understanding of EhC/EK importance in phospholipid metabolism and their unique characteristic, EhC/EK could be a potential target for future anti-amoebiasis study.

TODIM-VIKOR method based on hybrid weighted distance under probabilistic uncertain linguistic information and its application in medical logistics center site selection.

At a time of global epidemic control, the location of the medical logistics distribution center (MLDC) has an important impact on the operation of the entire logistics system to reduce the operating costs of the company, enhance the service quality and effectively control the COVID-19 on the premise of increasing the company's profits. Thus, the research on the location of MLDC has important theoretical and practical application significance separately. Recently, the TODIM and VIKOR method has been used to solve multiple-attribute group decision-making (MAGDM) issues. The probabilistic uncertain linguistic term sets (PULTSs) are used as a tool for characterizing uncertain information. In this paper, we design the TODIM-VIKOR model to solve the MAGDM in PULT condition. Firstly, some basic concept of PULTSs is reviewed, and TODIM and VIKOR method are introduced. The extended TODIM-VIKOR model is proposed to tackle MAGDM problems under the PULTSs. At last, a numerical case study for medical logistics center site selection (MLCSS) is given to validate the proposed method.

Exosomes derived from BMSCs ameliorate cyclophosphamide-induced testosterone deficiency by enhancing the autophagy of Leydig cells via the AMPK-mTOR signaling pathway.

Cyclophosphamide-induced testosterone deficiency (CPTD) during the treatment of cancers and autoimmune disorders severely influences the quality of life of patients. Currently, several guidelines recommend patients suffering from CPTD receive testosterone replacement therapy (TRT). However, TRT has many disadvantages underscoring the requirement for alternative, nontoxic treatment strategies. We previously reported bone marrow mesenchymal stem cells-derived exosomes (BMSCs-exos) could alleviate cyclophosphamide (CP)-induced spermatogenesis dysfunction, highlighting their role in the treatment of male reproductive disorders. Therefore, we further investigated whether BMSCs-exos affect autophagy and testosterone synthesis in Leydig cells (LCs). Here, we examined the effects and probed the molecular mechanisms of BMSCs-exos on CPTD in vivo and in vitro by detecting the expression levels of genes and proteins related to autophagy and testosterone synthesis. Furthermore, the testosterone concentration in serum and cell-conditioned medium, and the photophosphorylation protein levels of adenosine monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) were measured. Our results suggest that BMSCs-exos could be absorbed by LCs through the blood-testis barrier in mice, promoting autophagy in LCs and improving the CP-induced low serum testosterone levels. BMSCs-exos inhibited cell death in CP-exposed LCs, regulated the AMPK-mTOR signaling pathway to promote autophagy in LCs, and then improved the low testosterone synthesis ability of CP-induced LCs. Moreover, the autophagy inhibitor, 3-methyladenine (3-MA), significantly reversed the therapeutic effects of BMSCs-exos. These findings suggest that BMSCs-exos promote LC autophagy by regulating the AMPK-mTOR signaling pathway, thereby ameliorating CPTD. This study provides novel evidence for the clinical improvement of CPTD using BMSCs-exos.

ß-diversity in temperate grasslands is driven by stronger environmental filtering of plant species with large genomes.

Elucidating mechanisms underlying community assembly and biodiversity patterns is central to ecology and evolution. Genome size (GS) has long been hypothesized to potentially affect species' capacity to tolerate environmental stress and might therefore help drive community assembly. However, its role in driving ß-diversity (i.e., spatial variability in species composition) remains unclear. We measured GS for 161 plant species and community composition across 52 sites spanning a 3200-km transect in the temperate grasslands of China. By correlating the turnover of species composition with environmental dissimilarity, we found that resource filtering (i.e., environmental dissimilarity that includes precipitation, and soil nitrogen and phosphorus concentrations) affected ß-diversity patterns of large-GS species more than small-GS species. By contrast, geographical distance explained more variation of ß-diversity for small-GS than for large-GS species. In a 10-year experiment manipulating levels of water, nitrogen, and phosphorus, adding resources increased plant biomass in species with large GS, suggesting that large-GS species are more sensitive to the changes in resource availability. These findings highlight the role of GS in driving community assembly and predicting species responses to global change.

Dysregulated expression of miR­367 in disease development and its prospects as a therapeutic target and diagnostic biomarker (Review).

MicroRNA (miR)-367 has a wide range of functions in gene regulation and as such plays a critical role in cell proliferation, differentiation and development, making it an essential molecule in various physiological processes. miR-367 belongs to the miR-302/367 cluster and is located in the intronic region of human chromosome 4 on the 4q25 locus. Dysregulation of miR-367 is associated with various disease conditions, including cancer, inflammation and cardiac conditions. Moreover, miR-367 has shown promise both as a tumor suppressor and a potential diagnostic biomarker for breast, gastric and prostate cancer. The elucidation of the essential role of miR-367 in inflammation, development and cardiac diseases emphasizes its versatility in regulating various physiological processes beyond cancer biology. However, further research is necessary to fully understand the complex regulatory mechanisms involving miR-367 in different physiological and pathological contexts. In conclusion, the versatility and significance of miR-367 makes it a promising candidate for further study and in the development of new diagnostic and therapeutic strategies.

Structural modeling and biochemical characterization of recombinant KPN_02809, a zinc-dependent metalloprotease from Klebsiella pneumoniae MGH 78578.

Klebsiella pneumoniae is a Gram-negative, cylindrical rod shaped opportunistic pathogen that is found in the environment as well as existing as a normal flora in mammalian mucosal surfaces such as the mouth, skin, and intestines. Clinically it is the most important member of the family of Enterobacteriaceae that causes neonatal sepsis and nosocomial infections. In this work, a combination of protein sequence analysis, structural modeling and molecular docking simulation approaches were employed to provide an understanding of the possible functions and characteristics of a hypothetical protein (KPN_02809) from K. pneumoniae MGH 78578. The computational analyses showed that this protein was a metalloprotease with zinc binding motif, HEXXH. To verify this result, a ypfJ gene which encodes for this hypothetical protein was cloned from K. pneumoniae MGH 78578 and the protein was overexpressed in Escherichia coli BL21 (DE3). The purified protein was about 32 kDa and showed maximum protease activity at 30 °C and pH 8.0. The enzyme activity was inhibited by metalloprotease inhibitors such as EDTA, 1,10-phenanthroline and reducing agent, 1,4-dithiothreitol (DTT). Each molecule of KPN_02809 protein was also shown to bind one zinc ion. Hence, for the first time, we experimentally confirmed that KPN_02809 is an active enzyme with zinc metalloprotease activity.

Vasa Is a Potential Germ Cell Marker in Leopard Coral Grouper (Plectropomus leopardus).

Vasa (Ddx4, DEAD box polypeptide 4), an extremely specific marker of germ cells in vivo, is an ATP-dependent RNA helicase that plays an essential role in germ cell development and gametogenesis. However, the expression and function information about this gene in groupers remains lacking. Here, vasa homolog termed Plvasa was isolated and identified Plvasa as a putative germ cell marker in the leopard coral grouper, (Plectropomus leopardus). Results indicated that Plvasa contained 17 exons in the genomic sequence and 9 conserved motifs of the DEAD-box protein by sequence analysis. The sequence comparison, phylogenetic analyses and synteny analyses showed that Plvasa was homologous with other teleosts. Additionally, the expression of Plvasa was significantly higher in gonads than in other tissues in adult individuals (p < 0.05). Further, the distribution of Plvasa revealed that it was only expressed in the germ cells, such as spermatids, germline stem cells and oocytes at different stages, and could not be detected in the somatic cells of gonads. The current study verified that the Plvasa gene is a valuable molecular marker of germ cells in leopard coral grouper, which potentially plays an important role in investigating the genesis and development of teleost germ cells.

Phage-choline Kinase Inhibitor Combination to Control Pseudomonas aeruginosa: A Promising Combo.

BACKGROUND: Pseudomonas aeruginosa is one of the most prevalent opportunistic pathogens in humans that has thrived and proved to be difficult to control in this "post-antibiotic era." Antibiotic alternatives are necessary for fighting against this resilient bacterium. Even though phages might not be "the wonder drug" that solves everything, they still provide a viable option to combat P. aeruginosa and curb the threat it imposes. MAIN FINDINGS: The combination of antibiotics with phages, however, poses a propitious treatment option for P. aeruginosa. Choline kinase (ChoK) is the enzyme that synthesizes phosphorylcholine subsequently incorporated into lipopolysaccharide located at the outer membrane of gram-negative bacteria. Recently, inhibition of ChoKs has been proposed as a promising antibacterial strategy. Successful docking of Hemicholinium-3, a choline kinase inhibitor, to the model structure of P. aeruginosa ChoK also supports the use of this inhibitor or its derivatives to inhibit the growth of this microorganism. CONCLUSION: Therefore, the combination of the novel antimicrobial "choline kinase inhibitors (ChoKIs)" with a phage cocktail or synthetic phages as a potential treatment for P. aeruginosa infection has been proposed.