Water bridges as the trigger in an amino functionalized Zn-MOF for highly selective and sensitive fluorescent sensing of water.

Water is a fundamental element for life. The highly selective and sensitive sensing of water is always attractive for mankind in activities such as physiological processes study and extraterrestrial life exploration. Fluorescent MOFs with precise channels and functional groups might specifically recognize water molecules with hydrogen-bond interaction or coordination effects and work as water sensors. As a proof of concept, herein, an amino functionalized Zn-MOF (named as complex 1) with pores that just right for water molecules to form hydrogen bond bridges is revealed for highly selective and sensitive fluorescent sensing of water. The single-crystal X-ray diffraction analysis indicates that the 3D framework of complex 1 is functionalized with free amino groups in the channels. Hydrogen bonds formed in the channel along b-axis as water bridges to connect two adjacent NH2bdc ligands and result in the restriction of intramolecular motions (RIM) which could responsible for the selective turn-on fluorescence response to water. Complex 1 exhibits high sensitive to trace amount of water in organic solvents and could be used for water detection in a wide range water contents. Take advantages of complex 1, portable sensors (complex 1@PMMA) were prepared and used in the highly sensitive water sensing.

An aquaporin and an aquaglyceroporin have roles in low temperature adaptation of mosquitoes (Anopheles sinensis).

Mosquitoes (Anopheles sinensis), widely geographically distributed in Asia including China, are the primary vector of the malaria parasite Plasmodium vivax and other parasitic diseases such as Malayan filariasis. An. sinensis can survive through low winter temperatures. Aquaporin channels are found in all life forms, where they facilitate environmental adaptation by allowing rapid trans-cellular movement of water (classical aquaporins) or water and solutes such as glycerol (aquaglyceroporins). Here, we identified and characterized 2 aquaporin (AQP) homologs in An. sinensis: AsAQP2 (An. sinensis aquaglyceroporin) and AsAQP4 (An. sinensis aquaporin). When expressed in frog (Xenopus laevis) oocytes, AsAQP2 transported water, glycerol, and urea; AsAQP4 transported only water. Water permeation through AsAQP2 and AsAQP4 was inhibited by mercuric chloride. AsAQP2 expression was slightly higher in adult female mosquitoes than in males, and AsAQP4 expression was significantly higher in adult males. The 2 AsAQPs were highly expressed in Malpighian tubules and midgut. AsAQP2 and AsAQP4 expression was up-regulated by blood feeding compared with sugar feeding. At freezing point (0 °C), the AsAQP4 expression level increased and An. sinensis survival time reduced compared with those at normal temperature (26 °C). At low temperature (8 °C), the AsAQP2 and AsAQP4 expression levels decreased and survival time was significantly longer compared with those at 26 °C. These results suggest that AsAQP2 and AsAQP4 have roles in water homeostasis during blood digestion and in low temperature adaptation of A. sinensis. Together, our results show that the 2 AQPs are important for mosquito diuresis after blood feeding and when exposed to low temperatures.

Heterlimnius luyashanensis sp. n. and Zaitzevia triangularis sp. n. from Shanxi Province, China (Coleoptera: Elmidae).

Two new species, Heterlimnius luyashanensis sp. n. and Zaitzevia triangularis sp. n. are described from Shanxi Province, China. The genus Heterlimnius Hinton, 1935 and Zaitzevia Champion, 1923 are reported from Shanxi Province for the first time. Heterlimnius luyashanensis sp. n. belonging to the Heterlimnius trachys species group has the following characteristics: 1. anterior margin of pronotum strongly produced anteriad; 2. median longitudinal sulcus of pronotum extends from basal 0.3 to 0.8. Zaitzevia triangularis sp. n. has a larger body size and a triangular apex of penis.

Application of noninvasive sampling technique in mitochondrial genome intraspecific phylogeny of the endangered butterfly, Teinopalpus aureus (Lepidoptera: Papilionidae).

The butterfly genus of Teinopalpus, endemic to Asia, embodies a distinct species of mountain-dwelling butterflies with specific habitat requirements. These species are rare in the wild and hold high conservation and research value. Similar to other protected species, the genetic analysis of the rare Teinopalpus aureus poses challenges due to the complexity of sampling. In this study, we successfully extracted DNA and amplified mitochondrial genomic DNA from various noninvasive sources such as larval feces, larval exuviae, larval head capsules, pupal exuviaes, and filamentous gland secretions, all integral parts of butterfly metamorphosis. This was conducted as part of a research initiative focused on the artificial conservation of T. aureus population in Jinggang Shan Nature Reserve. Our findings illustrated the successful extraction of DNA from multiple noninvasive sources, achieved through modified DNA extraction methodologies. Although the DNA concentration obtained from noninvasive samples was lower than that from muscle tissues of newly dead larvae during rearing, all samples met the requirements for PCR amplification and sequencing, yielding complete circular sequences. These sequences are pivotal for both interspecific and intraspecific genetic relationship analysis. Our methods can be extended to other insects, especially scarce species.

Potato virus Y viral protein 6K1 inhibits the interaction between defense proteins during virus infection.

14-3-3 proteins play vital roles in plant defense against various pathogen invasions. To date, how 14-3-3 affects virus infections in plants remains largely unclear. In this study, we found that Nicotiana benthamiana 14-3-3h interacts with TRANSLATIONALLY CONTROLLED TUMOR PROTEIN (TCTP), a susceptibility factor of potato virus Y (PVY). Silencing of Nb14-3-3h facilitates PVY accumulation, whereas overexpression of Nb14-3-3h inhibits PVY replication. The antiviral activities of 3 Nb14-3-3h dimerization defective mutants are significantly decreased, indicating that dimerization of Nb14-3-3h is indispensable for restricting PVY infection. Our results also showed that the mutant Nb14-3-3hE16A, which is capable of dimerizing but not interacting with NbTCTP, has reduced anti-PVY activity; the mutant NbTCTPI65A, which is unable to interact with Nb14-3-3h, facilitates PVY replication compared with the wild-type NbTCTP, indicating that dimeric Nb14-3-3h restricts PVY infection by interacting with NbTCTP and preventing its proviral function. As a counter-defense, PVY 6K1 interferes with the interaction between Nb14-3-3h and NbTCTP by competitively binding to Nb14-3-3h and rescues NbTCTP to promote PVY infection. Our results provide insights into the arms race between plants and potyviruses.

Forecast of peak infection and estimate of excess deaths in COVID-19 transmission and prevalence in Taiyuan City, 2022 to 2023.

In this paper, with the method of epidemic dynamics, we assess the spread and prevalence of COVID-19 after the policy adjustment of prevention and control measure in December 2022 in Taiyuan City in China, and estimate the excess population deaths caused by COVID-19. Based on the transmission mechanism of COVID-19 among individuals, a dynamic model with heterogeneous contacts is established to describe the change of control measures and the population's social behavior in Taiyuan city. The model is verified and simulated by basing on reported case data from November 8th to December 5th, 2022 in Taiyuan city and the statistical data of the questionnaire survey from December 1st to 23rd, 2022 in Neijiang city. Combining with reported numbers of permanent residents and deaths from 2017 to 2021 in Taiyuan city, we apply the dynamic model to estimate theoretical population of 2022 under the assumption that there is no effect of COVID-19. In addition, we carry out sensitivity analysis to determine the propagation character of the Omicron strain and the effect of the control measures. As a result of the study, it is concluded that after adjusting the epidemic policy on December 6th, 2022, three peaks of infection in Taiyuan are estimated to be from December 22nd to 31st, 2022, from May 10th to June 1st, 2023, and from September 5th to October 13th, 2023, and the corresponding daily peaks of new cases can reach 400 000, 44 000 and 22 000, respectively. By the end of 2022, excess deaths can range from 887 to 4887, and excess mortality rate can range from 3.06% to 14.82%. The threshold of the infectivity of the COVID-19 variant is estimated 0.0353, that is if the strain infectivity is above it, the epidemic cannot be control with the previous normalization measures.

Endothelial cell-derived RSPO3 activates Gαi1/3-Erk signaling and protects neurons from ischemia/reperfusion injury.

The current study explores the potential function and the underlying mechanisms of endothelial cell-derived R-spondin 3 (RSPO3) neuroprotection against ischemia/reperfusion-induced neuronal cell injury. In both neuronal cells (Neuro-2a) and primary murine cortical neurons, pretreatment with RSPO3 ameliorated oxygen and glucose deprivation (OGD)/re-oxygenation (OGD/R)-induced neuronal cell death and oxidative injury. In neurons RSPO3 activated the Akt, Erk and ß-Catenin signaling cascade, but only Erk inhibitors reversed RSPO3-induced neuroprotection against OGD/R. In mouse embryonic fibroblasts (MEFs) and neuronal cells, RSPO3-induced LGR4-Gab1-Gαi1/3 association was required for Erk activation, and either silencing or knockout of Gαi1 and Gαi3 abolished RSPO3-induced neuroprotection. In mice, middle cerebral artery occlusion (MCAO) increased RSPO3 expression and Erk activation in ischemic penumbra brain tissues. Endothelial knockdown or knockout of RSPO3 inhibited Erk activation in the ischemic penumbra brain tissues and increased MCAO-induced cerebral ischemic injury in mice. Conversely, endothelial overexpression of RSPO3 ameliorated MCAO-induced cerebral ischemic injury. We conclude that RSPO3 activates Gαi1/3-Erk signaling to protect neuronal cells from ischemia/reperfusion injury.

A Cu2+ triggered reversible photochromic system: the structure photochromic response relationship study and potential applications.

Fifteen rhodamine B hydrazide hydrazone (RhBHH) derivatives (compounds a-o) with various substituent groups at different position and their photochromic property triggered by Cu2+ were studied to illustrate the structure photochromic response relationship (SPRR). Three of them (compounds f-h) with a para-position hydroxyl group and two meta-position halogen substituents display Cu2+-triggered photochromic which is significantly different from the previous reports. It was found that halogen atoms, which were generally considered to have no remarkable regulation effect, exhibited great influences on the photochromic behaviour of RhBHH derivatives. Detail photochromic properties of the developed photochromic system were revealed by using compound g as the model substrate, and only Cu2+ displayed high selective trigger effect. Good reversible photochromic phenomenon was observed after stimulated with visible light irradiation and dark (or heat) bleaching consecutively. Furthermore, this photochromic system could be used in the preparation of photochromic glass, special security ink, molecular logic gate and two-dimensional code for security information storage.

Enhanced stability and tunable photoluminescence in Mn2+-doped one-dimensional hybrid lead halide perovskites for high-performance white light emitting diodes.

Organic-inorganic hybrid low-dimensional lead halides have garnered significant interest in the realm of solid-state optical materials due to their unique properties and potential applications. In this study, we report the synthesis, characterization and application of Mn2+-doped one-dimensional (1D) [AEP]PbCl5·H2O hybrid lead halide perovskites with tunable photoluminescence properties. The Mn2+ doping leads to a redshift of the dominant emission wavelength from 463 nm to 630 nm, with the optimal doping concentration resulting in an enhanced photoluminescence quantum yield (PLQY) from less than 1% to 8.96%. The structural and optical stability of these doped perovskites have been thoroughly investigated revealing excellent performance under humid and high-temperature conditions. Perovskite-PVP composite films exhibit high crystallization and bright orange-red emission under UV excitation. Furthermore, we demonstrate the successful fabrication of a white LED device using the Mn2+-doped perovskite in combination with commercial green and blue phosphors. The fabricated LED exhibits a high color rendering index (CRI) of 87.2 and stable electroluminescence performance under various operating currents and extended operation times. Our findings highlight the potential of Mn2+-doped 1D hybrid lead halide perovskites as efficient and stable phosphors for high-performance white light emitting diodes and other optoelectronic applications.

Molecular Characterization of Two Wamide Neuropeptide Signaling Systems in Mollusk Aplysia.

Neuropeptides with the C-terminal Wamide (Trp-NH2) are one of the last common ancestors of peptide families of eumetazoans and play various physiological roles. In this study, we sought to characterize the ancient Wamide peptides signaling systems in the marine mollusk Aplysia californica, i.e., APGWamide (APGWa) and myoinhibitory peptide (MIP)/Allatostatin B (AST-B) signaling systems. A common feature of protostome APGWa and MIP/AST-B peptides is the presence of a conserved Wamide motif in the C-terminus. Although orthologs of the APGWa and MIP signaling systems have been studied to various extents in annelids or other protostomes, no complete signaling systems have yet been characterized in mollusks. Here, through bioinformatics, molecular and cellular biology, we identified three receptors for APGWa, namely, APGWa-R1, APGWa-R2, and APGWa-R3. The EC50 values for APGWa-R1, APGWa-R2, and APGWa-R3 are 45, 2100, and 2600 nM, respectively. For the MIP signaling system, we predicted 13 forms of peptides, i.e., MIP1-13 that could be generated from the precursor identified in our study, with MIP5 (WKQMAVWa) having the largest number of copies (4 copies). Then, a complete MIP receptor (MIPR) was identified and the MIP1-13 peptides activated the MIPR in a dose-dependent manner, with EC50 values ranging from 40 to 3000 nM. Peptide analogs with alanine substitution experiments demonstrated that the Wamide motif at the C-terminus is necessary for receptor activity in both the APGWa and MIP systems. Moreover, cross-activity between the two signaling systems showed that MIP1, 4, 7, and 8 ligands could activate APGWa-R1 with a low potency (EC50 values: 2800-22,000 nM), which further supported that the APGWa and MIP signaling systems are somewhat related. In summary, our successful characterization of Aplysia APGWa and MIP signaling systems represents the first example in mollusks and provides an important basis for further functional studies in this and other protostome species. Moreover, this study may be useful for elucidating and clarifying the evolutionary relationship between the two Wamide signaling systems (i.e., APGWa and MIP systems) and their other extended neuropeptide signaling systems.

Identification of three elevenin receptors and roles of elevenin disulfide bond and residues in receptor activation in Aplysia californica.

Neuropeptides are ubiquitous intercellular signaling molecules in the CNS and play diverse roles in modulating physiological functions by acting on specific G-protein coupled receptors (GPCRs). Among them, the elevenin signaling system is now believed to be present primarily in protostomes. Although elevenin was first identified from the L11 neuron of the abdominal ganglion in mollusc Aplysia californica, no receptors have been described in Aplysia, nor in any other molluscs. Here, using two elevenin receptors in annelid Platynereis dumerilii, we found three putative elevenin GPCRs in Aplysia. We cloned the three receptors and tentatively named them apElevR1, apElevR2, and apElevR3. Using an inositol monophosphate (IP1) accumulation assay, we demonstrated that Aplysia elevenin with the disulfide bond activated the three putative receptors with low EC50 values (ranging from 1.2 to 25 nM), supporting that they are true receptors for elevenin. In contrast, elevenin without the disulfide bond could not activate the receptors, indicating that the disulfide bond is required for receptor activity. Using alanine substitution of individual conserved residues other than the two cysteines, we showed that these residues appear to be critical to receptor activity, and the three different receptors had different sensitivities to the single residue substitution. Finally, we examined the roles of those residues outside the disulfide bond ring by removing these residues and found that they also appeared to be important to receptor activity. Thus, our study provides an important basis for further study of the functions of elevenin and its receptors in Aplysia and other molluscs.

Machine learning combined with radiomics and deep learning features extracted from CT images: a novel AI model to distinguish benign from malignant ovarian tumors.

BACKGROUND: To develop an artificial intelligence (AI) model with radiomics and deep learning (DL) features extracted from CT images to distinguish benign from malignant ovarian tumors. METHODS: We enrolled 149 patients with pathologically confirmed ovarian tumors. A total of 185 tumors were included and divided into training and testing sets in a 7:3 ratio. All tumors were manually segmented from preoperative contrast-enhanced CT images. CT image features were extracted using radiomics and DL. Five models with different combinations of feature sets were built. Benign and malignant tumors were classified using machine learning (ML) classifiers. The model performance was compared with five radiologists on the testing set. RESULTS:  Among the five models, the best performing model is the ensemble model with a combination of radiomics, DL, and clinical feature sets. The model achieved an accuracy of 82%, specificity of 89% and sensitivity of 68%. Compared with junior radiologists averaged results, the model had a higher accuracy (82% vs 66%) and specificity (89% vs 65%) with comparable sensitivity (68% vs 67%). With the assistance of the model, the junior radiologists achieved a higher average accuracy (81% vs 66%), specificity (80% vs 65%), and sensitivity (82% vs 67%), approaching to the performance of senior radiologists. CONCLUSIONS:  We developed a CT-based AI model that can differentiate benign and malignant ovarian tumors with high accuracy and specificity. This model significantly improved the performance of less-experienced radiologists in ovarian tumor assessment, and may potentially guide gynecologists to provide better therapeutic strategies for these patients.

Characterization of an Aplysia vasotocin signaling system and actions of posttranslational modifications and individual residues of the ligand on receptor activity.

The vasopressin/oxytocin signaling system is present in both protostomes and deuterostomes and plays various physiological roles. Although there were reports for both vasopressin-like peptides and receptors in mollusc Lymnaea and Octopus, no precursor or receptors have been described in mollusc Aplysia. Here, through bioinformatics, molecular and cellular biology, we identified both the precursor and two receptors for Aplysia vasopressin-like peptide, which we named Aplysia vasotocin (apVT). The precursor provides evidence for the exact sequence of apVT, which is identical to conopressin G from cone snail venom, and contains 9 amino acids, with two cysteines at position 1 and 6, similar to nearly all vasopressin-like peptides. Through inositol monophosphate (IP1) accumulation assay, we demonstrated that two of the three putative receptors we cloned from Aplysia cDNA are true receptors for apVT. We named the two receptors as apVTR1 and apVTR2. We then determined the roles of post-translational modifications (PTMs) of apVT, i.e., the disulfide bond between two cysteines and the C-terminal amidation on receptor activity. Both the disulfide bond and amidation were critical for the activation of the two receptors. Cross-activity with conopressin S, annetocin from an annelid, and vertebrate oxytocin showed that although all three ligands can activate both receptors, the potency of these peptides differed depending on their residue variations from apVT. We, therefore, tested the roles of each residue through alanine substitution and found that each substitution could reduce the potency of the peptide analog, and substitution of the residues within the disulfide bond tended to have a larger impact on receptor activity than the substitution of those outside the bond. Moreover, the two receptors had different sensitivities to the PTMs and single residue substitutions. Thus, we have characterized the Aplysia vasotocin signaling system and showed how the PTMs and individual residues in the ligand contributed to receptor activity.

Clinical characteristics analysis of Chlamydia psittaci pneumonia detected by metagenomic next-generation sequencing / 中国热带医学

@#Abstract: Objective　To analyze the clinical characteristics of Chlamydia psittaci pneumonia and improve the diagnosis and treatment skills of clinicians on this disease. Methods The clinical data of thirty-nine Chlamydia psittaci pneumonia cases detected by metagenomic next-generation sequencing (mNGS) from September 2020 to January 2022 at the Affiliated Hospital of Southwest Medical University were retrospectively analyzed. Results There was a history of poultry exposure in 89.7%(35 cases) of the patients. The most common clinical manifestations were high fever (92.3%, 36), cough (76.9%,30), muscle soreness (48.7%,19), headache (38.5%,15), etc. Laboratory examinations showed 76.9% of patients had a normal leukocyte count, and 76.9% had decreased lymphocyte count, often accompanied by elevated C-reactive protein (100%), procalcitonin (97.4%), interleukin-6 (95.8%), interleukin-10 (95.8%), alanine aminotransferase (74.4%), and aspartate aminotransferase (84.6%). Univariate analysis indicated that there were statistically significant differences in the levels of aspartate transaminase, blood urea nitrogen, C-reactive protein, and procalcitonin between severe pneumonia patients and non-severe pneumonia patients（P<0.05）. Multivariate logistic regression analysis showed that an elevated blood urea nitrogen (OR=4.899) had guiding significance for predicting the occurrence of severe pneumonia. Bronchoscopy examination showed no abnormalities in 53.6% of the patients. The imaging manifestations of pulmonary lesions were mainly lobar pneumonia (61.5%) and air bronchograms (94.9%). Therapeutically, it was sensitive to tetracyclines, macrocyclic lactones, and fluoroquinolones. A total of 84.6%(33 cases) of the patients were cured and discharged from the hospital at the end of the treatment. Conclusion Chlamydia psittaci pneumonia is a zoonotic disease that can be detected by mNGS. An elevated blood urea nitrogen level has guiding significance for predicting the occurrence of severe pneumonia. Empirically-selected regimens based on doxycycline are effective for the treatment of Chlamydia psittaci pneumonia.

AI protein structure prediction-based modeling and mutagenesis of a protostome receptor and peptide ligands reveal key residues for their interaction.

The protostome leucokinin (LK) signaling system, including LK peptides and their G protein-coupled receptors, has been characterized in several species. Despite the progress, molecular mechanisms governing LK peptide-receptor interactions remain to be elucidated. Previously, we identified a precursor protein for Aplysia leucokinin-like peptides (ALKs) that contains the greatest number of amidated peptides among LK precursors in all species identified so far. Here, we identified the first ALK receptor from Aplysia, ALKR. We used cell-based IP1 activation assays to demonstrate that two ALK peptides with the most copies, ALK1 and ALK2, activated ALKR with high potencies. Other endogenous ALK-derived peptides bearing the FXXWX-amide motif also activated ALKR to various degrees. Our examination of cross-species activity of ALKs with the Anopheles LK receptor was consistent with a critical role for the FXXWX-amide motif in receptor activity. Furthermore, we showed, through alanine substitution of ALK1, the highly conserved phenylalanine (F), tryptophan (W), and C-terminal amidation were each essential for receptor activation. Finally, we used an artificial intelligence-based protein structure prediction server (Robetta) and Autodock Vina to predict the ligand-bound conformation of ALKR. Our model predicted several interactions (i.e., hydrophobic interactions, hydrogen bonds, and amide-pi stacking) between ALK peptides and ALKR, and several of our substitution and mutagenesis experiments were consistent with the predicted model. In conclusion, our results provide important information defining possible interactions between ALK peptides and their receptors. The workflow utilized here may be useful for studying other ligand-receptor interactions for a neuropeptide signaling system, particularly in protostomes.

Synthesis of 4-thiosubstituted flavan derivatives and their hypoglycemic activities.

A series of 4-thiosubstituted flavan derivatives (1-44) were designed and synthesized. The target compounds were assayed for inhibitory activity against α-glucosidase in vitro, and the results indicated that all compounds displayed significant effects in the range of IC50 = 1.03-7.48 µM compared to that of acarbose, the positive control drug. Structure-activity relationship (SAR) studies indicated that the hydroxyl groups in the flavan B ring, the electron withdrawing groups, and the length of the alkyl chains are important for this biological activity. In addition, some compounds were tested for their tolerance to sucrose in mice, and compound 44 exhibited activity comparable to that of acarbose. Docking analysis indicated that compound 44 binds to the enzyme in a pocket close to the catalytic site, similar to acarbose.

N-glycosylation stabilizes MerTK and promotes hepatocellular carcinoma tumor growth.

Despite the evidences of elevated expression of Mer tyrosine kinase (MerTK) in multiple human cancers, mechanisms underlying the oncogenic roles of MerTK in hepatocellular carcinoma (HCC) remains undefined. We explored the functional effects of MerTK and N-Glycosylated MerTK on HCC cell survival and tumor growth. Here, we show that MerTK ablation increases reactive oxygen species (ROS) production and promotes the switching from glycolytic metabolism to oxidative phosphorylation in HCC cells, thus suppressing HCC cell proliferation and tumor growth. MerTK is N-glycosylated in HCC cells at asparagine 294 and 454 that stabilizes MerTK to promote oncogenic transformation. Moreover, we observed that nuclear located non-glycosylated MerTK is indispensable for survival of HCC cells under stress. Pathologically, tissue microarray (TMA) data indicate that MerTK is a pivotal prognostic factor for HCC. Our data strongly support the roles of MerTK N-glycosylation in HCC tumorigenesis and suggesting N-glycosylation inhibition as a potential HCC therapeutic strategy.

Identification of an allatostatin C signaling system in mollusc Aplysia.

Neuropeptides, as pervasive intercellular signaling molecules in the CNS, modulate a variety of behavioral systems in both protostomes and deuterostomes. Allatostatins are neuropeptides in arthropods that inhibit the biosynthesis of juvenile hormones. Based on amino acid sequences, they are divided into three different types in arthropods: allatostatin A, allatostatin B, allatostatin C. Allatostatin C (AstC) was first isolated from Manduca sexta, and it has an important conserved feature of a disulfide bridge formed by two cysteine residues. Moreover, AstC appears to be the ortholog of mammalian somatostatin, and it has functions in common with somatostatin, such as modulating feeding behaviors. The AstC signaling system has been widely studied in arthropods, but minimally studied in molluscs. In this study, we seek to identify the AstC signaling system in the marine mollusc Aplysia californica. We cloned the AstC precursor from the cDNA of Aplysia. We predicted a 15-amino acid peptide with a disulfide bridge, i.e., AstC, using NeuroPred. We then cloned two putative allatostatin C-like receptors and through NCBI Conserved Domain Search we found that they belonged to the G protein-coupled receptor (GPCR) family. In addition, using an inositol monophosphate 1 (IP1) accumulation assay, we showed that Aplysia AstC could activate one of the putative receptors, i.e., the AstC-R, at the lowest EC50, and AstC without the disulfide bridge (AstC') activated AstC-R with the highest EC50. Moreover, four molluscan AstCs with variations of sequences from Aplysia AstC but with the disulfide bridge activated AstC-R at intermediate EC50. In summary, our successful identification of the Aplysia AstC precursor and its receptor (AstC-R) represents the first example in molluscs, and provides an important basis for further studies of the AstC signaling system in Aplysia and other molluscs.

LPCAT1 functions as a novel prognostic molecular marker in hepatocellular carcinoma.

This study aimed to investigate the relationships between LPCAT1 expression and clinicopathologic parameters of hepatocellular carcinoma (HCC), further, to explore the effect of LPCAT1 on overall survival (OS) in patients with HCC, and its possible mechanism. Bioinformatics analysis using high throughput RNA-sequencing data from TCGA was utilized to explore the differential expression of LPCAT1 between normal and tumor tissues, and the associations between LPCAT1 expression and clinicopathological parameters. Survival analyses and subgroup survival analyses were utilized to elucidate the effect of LPCAT1 on OS in patients with HCC. Univariate analysis and multivariate analysis were used to investigate the prognostic factors. Potential LPCAT1 related tumor genes were identified by the methodology of differentially expressed genes (DEGs) screening. GO term enrichment analysis, KEGG pathway analysis and the PPI network were used to explore the potential mechanism. LPCAT1 was significantly overexpressed in HCC tumor tissues compared with normal tissues. The LPCAT1 expression was related to tumor grade, ECOG score, AFP and TNM stage, with P values of 0.000, 0.000, 0.007 and 0.000, respectively. Multivariate analysis demonstrated that LPCAT1 expression was independently associated with OS, with an HR of 1.04 (CI: 1.01-1.06, P = 0.003). The KEGG pathway enrichment analyses showed that overlapped DEGs mainly participate in the cell cycle. Finally, we identified a hub gene, CDK1, which has been reported to act on the cell cycle, consistent with the result of KEGG enrichment analysis. Collectively, these data confirmed LPCAT1 was upregulated in HCC, and was an independent predictor of the prognosis.