Effect of Silencing subolesin and enolase impairs gene expression, engorgement and reproduction in Haemaphysalis longicornis (Acari: Ixodidae) ticks.

IMPORTANCE: Haemaphysalis longicornis is an obligate blood-sucking ectoparasite that has gained attention due its role of transmitting medically and veterinary significant pathogens and it is the most common tick species in Republic of Korea. The preferred strategy for controlling ticks is a multi-antigenic vaccination. Testing the efficiency of a combination antigen is a promising method for creating a tick vaccine. OBJECTIVE: The aim of the current research was to analyze the role of subolesin and enolase in feeding and reproduction of H. longicornis by gene silencing. METHODS: In this study, we used RNA interference to silence salivary enolase and subolesin in H. longicornis. Unfed female ticks injected with double-stranded RNA targeting subolesin and enolase were attached and fed normally on the rabbit's ear. Real-time polymerase chain reaction was used to confirm the extent of knockdown. RESULTS: Ticks in the subolesin or enolase dsRNA groups showed knockdown rates of 80% and 60% respectively. Ticks in the combination dsRNA (subolesin and enolase) group showed an 80% knockdown. Knockdown of subolesin and enolase resulted in significant depletion in feeding, blood engorgement weight, attachment rate, and egg laying. Silencing of both resulted in a significant (p < 0.05) reduction in tick engorgement, egg laying, egg hatching (15%), and reproduction. CONCLUSIONS AND RELEVANCE: Our results suggest that subolesin and enolase are an exciting target for future tick control strategies.

Molecular cloning, identification, transcriptional analysis, and silencing of enolase on the life cycle of Haemaphysalis longicornis (Acari, Ixodidae) tick.

Ticks, blood-sucking ectoparasites, spread diseases to humans and animals. Haemaphysalis longicornis is a significant vector for tick-borne diseases in medical and veterinary contexts. Identifying protective antigens in H. longicornis for an anti-tick vaccine is a key tick control strategy. Enolase, a multifunctional protein, significantly converts D-2-phosphoglycerate and phosphoenolpyruvate in glycolysis and gluconeogenesis in cell cytoplasm. This study cloned a complete open reading frame (ORF) of enolase from the H. longicornis tick and characterized its transcriptional and silencing effect. We amplified the full-length cDNA of the enolase gene using rapid amplification of cDNA ends. The complete cDNA, with an ORF of 1,297 nucleotides, encoded a 432-amino acid polypeptide. Enolase of the Jeju strain H. longicornis exhibited the highest sequence similarity with H. flava (98%), followed by Dermacentor silvarum (82%). The enolase motifs identified included N-terminal and C-terminal regions, magnesium binding sites, and several phosphorylation sites. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that enolase mRNA transcripts were expressed across all developmental stages of ticks and organs such as salivary gland and midgut. RT-PCR showed higher transcript levels in syn-ganglia, suggesting that synganglion nerves influence enolase,s role in tick salivary glands. We injected enolase double-stranded RNA into adult unfed female ticks, after which they were subsequently fed with normal unfed males until they spontaneously dropped off. RNA interference significantly (P<0.05) reduced feeding and reproduction, along with abnormalities in eggs (no embryos) and hatching. These findings suggest enolase is a promising target for future tick control strategies.

Correlations of Expression Levels of Lung Cancer Marker Gene Eno2 and Genes of Carcinogenesis and Apoptosis in the Hypothalamus of Mice with Depression-Like Behavior.

We experimentally demonstrated that chronic social stress during the development of a depression-like state enhances lung metastasis and modifies the expression of many carcinogenesis- and apoptosis-related genes in the hypothalamus of mice, including genes involved in lung cancer pathogenesis in humans. Analysis of the expression of genes encoding the major clinical markers of lung cancer in the hypothalamus of mice with depression-like behavior revealed increased expression of the Eno2 gene encoding neuron-specific enolase, a blood marker of lung cancer progression in humans. It was shown that the expression of this gene in the hypothalamus correlated with the expression of many carcinogenesis- and apoptosis-related genes. The discovered phenomenon may have a fundamental significance and requires further studies.

3-Hydroxytanshinone Inhibits the Activity of Hypoxia-Inducible Factor 1-α by Interfering with the Function of α-Enolase in the Glycolytic Pathway.

Tumor cells in hypoxic conditions control cancer metabolism and angiogenesis by expressing HIF-1α. Tanshinone is a traditional Chinese medicine that has been shown to possess antitumor properties and exerts a therapeutic impact on angiogenesis. However, the precise molecular mechanism responsible for the antitumor activity of 3-Hydroxytanshinone (3-HT), a type of tanshinone, has not been fully understood. Therefore, our study aimed to investigate the mechanism by which 3-HT regulates the expression of HIF-1α. Our findings demonstrate that 3-HT inhibits HIF-1α activity and expression under hypoxic conditions. Additionally, 3-HT inhibits hypoxia-induced angiogenesis by suppressing the expression of VEGF. Moreover, 3-HT was found to directly bind to α-enolase, an enzyme associated with glycolysis, resulting in the suppression of its activity. This inhibition of α-enolase activity by 3-HT leads to the blockade of the glycolytic pathway and a decrease in glycolysis products, ultimately altering HIF1-α expression. Furthermore, 3-HT negatively regulates the expression of HIF-1α by altering the phosphorylation of AMP-activated protein kinase (AMPK). Our study's findings elucidate the mechanism by which 3-HT regulates HIF-1α through the inhibition of the glycolytic enzyme α-enolase and the phosphorylation of AMPK. These results suggest that 3-HT holds promise as a potential therapeutic agent for hypoxia-related angiogenesis and tumorigenesis.

Investigation of ENO2 as a promising novel marker for the progression of colorectal cancer with microsatellite instability-high.

BACKGROUND: Microsatellite instability-high (MSI-H) has emerged as a significant biological characteristic of colorectal cancer (CRC). Studies reported that MSI-H CRC generally had a better prognosis than microsatellite stable (MSS)/microsatellite instability-low (MSI-L) CRC, but some MSI-H CRC patients exhibited distinctive molecular characteristics and experienced a less favorable prognosis. In this study, our objective was to explore the metabolic transcript-related subtypes of MSI-H CRC and identify a biomarker for predicting survival outcomes. METHODS: Single-cell RNA sequencing (scRNA-seq) data of MSI-H CRC patients were obtained from the Gene Expression Omnibus (GEO) database. By utilizing the copy number variation (CNV) score, a malignant cell subpopulation was identified at the single-cell level. The metabolic landscape of various cell types was examined using metabolic pathway gene sets. Subsequently, functional experiments were conducted to investigate the biological significance of the hub gene in MSI-H CRC. Finally, the predictive potential of the hub gene was assessed using a nomogram. RESULTS: This study revealed a malignant tumor cell subpopulation from the single-cell RNA sequencing (scRNA-seq) data. MSI-H CRC was clustered into two subtypes based on the expression profiles of metabolism-related genes, and ENO2 was identified as a hub gene. Functional experiments with ENO2 knockdown and overexpression demonstrated its role in promoting CRC cell migration, invasion, glycolysis, and epithelial-mesenchymal transition (EMT) in vitro. High expression of ENO2 in MSI-H CRC patients was associated with worse clinical outcomes, including increased tumor invasion depth (p = 0.007) and greater likelihood of perineural invasion (p = 0.015). Furthermore, the nomogram and calibration curves based on ENO2 showed potential prognosis predictive performance. CONCLUSION: Our findings suggest that ENO2 serves as a novel prognostic biomarker and is associated with the progression of MSI-H CRC.

ENO1 promotes trophoblast invasion regulated by E2F8 in recurrent miscarriage.

Recurrent miscarriage (RM) is related to the dysfunction of extravillous trophoblast cells (EVTs), but the comprehensive mechanisms remain largely unexplored. We analyzed single-cell RNA sequencing (scRNA-seq), bulk RNA sequencing and microarray datasets obtained from Gene Expression Omnibus (GEO) database to explore the hub genes in the mechanisms of RM. We identified 1724 differentially expressed genes (DEGs) in EVTs from the RM, and they were all expressed along the trajectory of EVTs. These DEGs were associated with hypoxia and glucose metabolism. Single-cell Regulatory Network Inference and Clustering (SCENIC) analysis revealed that E2F transcription factor (E2F) 8 (E2F8) was a key transcription factor for these DEGs. And the expression of ENO1 can be positively regulated by E2F8 via RNA sequencing analysis. Subsequently, we performed immunofluorescence assay (IF), plasmid transfection, western blotting, chromatin immunoprecipitation (ChIP), real-time quantitative polymerase chain reaction (qRT-PCR), and transwell assays for validation experiments. We found that the expression of alpha-Enolase 1 (ENO1) was lower in the placentas of RM. Importantly, E2F8 can transcriptionally regulate the expression of ENO1 to promote the invasion of trophoblast cells by inhibiting secreted frizzled-related protein 1/4 (SFRP1/4) to activate Wnt signaling pathway. Our results suggest that ENO1 can promote trophoblast invasion via an E2F8-dependent manner, highlighting a potential novel target for the physiological mechanisms of RM.

Analysis of the relationship between MYCN gene and serum NSE and urinary VMA levels and neuroblastoma pathological features and prognosis.

The purpose of this study was to explore the relationship between the MYCN gene, serum neuron-specific enolase (NSE), urinary vanillylmandelic acid (VMA) levels, and neuroblastoma pathological features and prognosis. Ninety-four children with neuroblastoma treated in the hospital were selected to compare the differences in MYCN gene amplification, serum NSE, and urinary VMA levels in children with different clinicopathological features and prognoses. The proportion of children with MYCN gene copy number ≥10 in INSS stage 3-4 was higher than that of children with INSS stage 1-2 (P < 0.05); the proportion of children with MYCN gene copy number ≥10 in high-risk children in the COG risk stratification was higher than that of children with intermediate and low risk (P < 0.05); the serum NSE of children aged >12 months higher than that of children aged ≤12 months (P < 0.05); serum NSE of children with tumors >500 cm3 higher than that of children with tumors ≤500 cm3 (P < 0.05); serum NSE and urinary VMA of children with INSS staging of stages 3-4 were higher than that of children with stages 1 to 2 (P < 0.05); serum NSE and urinary VMA in children with lymph node metastasis were higher than that of children without lymph node metastasis (P < 0.05); serum NSE of children with MYCN gene copy number ≥10 was higher than that of children without lymph node metastasis (P < 0.05); the proportion of children with MYCN gene copy number ≥10 who died, and the percentages of serum NSE and urinary VMA were higher than those of the surviving children (P < 0.05). MYCN gene amplification and serum NSE and urinary VMA levels were related to the age, tumor size, INSS stage, COG stage, lymph node metastasis, and prognosis of the children with neuroblastoma.

Glycolytic enzyme Enolase-1 regulates insulin gene expression in pancreatic ß-cell.

Enolase-1 (Eno1) plays a critical role in regulating glucose metabolism; however, its specific impact on pancreatic islet ß-cells remains elusive. This study aimed to provide a preliminary exploration of Eno1 function in pancreatic islet ß-cells. The findings revealed that the expression of ENO1 mRNA in type 2 diabetes donors was significantly increased and positively correlated with HbA1C and negatively correlated with insulin gene expression. A high level of Eno1 in human insulin-secreting rat INS-1832/13 cells with co-localization with intracellular insulin proteins was accordingly observed. Silencing of Eno1 using siRNA or inhibiting Eno1 protein activity with an Eno1 antagonist significantly reduced insulin secretion and insulin content in ß-cells, while the proinsulin/insulin content ratio remained unchanged. This reduction in ß-cells function was accompanied by a notable decrease in intracellular ATP and mitochondrial cytochrome C levels. Overall, our findings confirm that Eno1 regulates the insulin secretion process, particularly glucose metabolism and ATP production in the ß-cells. The mechanism primarily involves its influence on insulin production, suggesting that Eno1 represents a potential target for ß-cell protection and diabetes treatment.

Identification of host protein ENO1 (alpha-enolase) interacting with Cryptosporidium parvum sporozoite surface protein, Cpgp40.

BACKGROUND: Cryptosporidium parvum is an apicomplexan zoonotic parasite causing the diarrheal illness cryptosporidiosis in humans and animals. To invade the host intestinal epithelial cells, parasitic proteins expressed on the surface of sporozoites interact with host cells to facilitate the formation of parasitophorous vacuole for the parasite to reside and develop. The gp40 of C. parvum, named Cpgp40 and located on the surface of sporozoites, was proven to participate in the process of host cell invasion. METHODS: We utilized the purified Cpgp40 as a bait to obtain host cell proteins interacting with Cpgp40 through the glutathione S-transferase (GST) pull-down method. In vitro analysis, through bimolecular fluorescence complementation assay (BiFC) and coimmunoprecipitation (Co-IP), confirmed the solid interaction between Cpgp40 and ENO1. In addition, by using protein mutation and parasite infection rate analysis, it was demonstrated that ENO1 plays an important role in the C. parvum invasion of HCT-8 cells. RESULTS: To illustrate the functional activity of Cpgp40 interacting with host cells, we identified the alpha-enolase protein (ENO1) from HCT-8 cells, which showed direct interaction with Cpgp40. The mRNA level of ENO1 gene was significantly decreased at 3 and 24 h after C. parvum infection. Antibodies and siRNA specific to ENO1 showed the ability to neutralize C. parvum infection in vitro, which indicated the participation of ENO1 during the parasite invasion of HCT-8 cells. In addition, we further demonstrated that ENO1 protein was involved in the regulation of cytoplasmic matrix of HCT-8 cells during C. parvum invasion. Functional study of the protein mutation illustrated that ENO1 was also required for the endogenous development of C. parvum. CONCLUSIONS: In this study, we utilized the purified Cpgp40 as a bait to obtain host cell proteins ENO1 interacting with Cpgp40. Functional studies illustrated that the host cell protein ENO1 was involved in the regulation of tight junction and adherent junction proteins during C. parvum invasion and was required for endogenous development of C. parvum.

USP21 deubiquitinates and stabilizes HSP90 and ENO1 to promote aerobic glycolysis and proliferation in cholangiocarcinoma.

Deubiquitylating enzymes (DUBs) play an essential role in targeted protein degradation and represent an emerging therapeutic paradigm in cancer. However, their therapeutic potential in cholangiocarcinoma (CCA) has not been explored. Herein, based on The Cancer Genome Atlas (TCGA) and The Gene Expression Omnibus (GEO) databases, we found that ubiquitin-specific protease 21 (USP21) was upregulated in CCA, high USP21 level was associated with poor prognosis. In vivo and in vitro, we identified USP21 as a master regulator of CCA growth and maintenance, which directly interacted with deubiquitinates and stabilized the heat shock protein 90 (HSP90) through K48-linked deubiquitination, and in turn, this stabilization increased HIF1A expression, thus upregulating key glycolytic enzyme genes ENO2, ENO3, ALDOC, ACSS2, and then promoted aerobic glycolysis, which provided energy for CCA cell proliferation. In addition, USP21 could directly stabilize alpha-Enolase 1 (ENO1) to promote aerobic glycolysis. Furthermore, increased USP21 level enhanced chemotherapy resistance to the gemcitabine-based regimen. Taken together, we identify a USP21-regulated aerobic glycolysis mechanism that involves the USP21/HSP90/HIF1A axis and USP21/ENO1 axis in CCA tumorigenesis, which could serve as a potential target for the treatment of CCA.

Enolase of Streptococcus suis serotype 2 promotes biomolecular condensation of ribosomal protein SA for HBMECs apoptosis.

BACKGROUND: Ribosomal protein SA (RPSA) of human brain microvascular endothelial cells (HBMECs) can transfer from the cytosol to the cell surface and act as a receptor for some pathogens, including Streptococcus suis serotype 2 (SS2), a zoonotic pathogen causing meningitis in pigs and humans. We previously reported that SS2 virulence factor enolase (ENO) binds to RPSA on the cell surface of HBMECs and induces apoptosis. However, the mechanism that activates RPSA translocation to the cell surface and induces ENO-mediated HBMEC apoptosis is unclear. RESULTS: Here, we show that RPSA localization and condensation on the host cell surface depend on its internally disordered region (IDR). ENO binds to the IDR of RPSA and promotes its interaction with RPSA and vimentin (VIM), which is significantly suppressed after 1,6-Hexanediol (1,6-Hex, a widely used tool to disrupt phase separation) treatment, indicating that ENO incorporation and thus the concentration of RPSA/VIM complexes via co-condensation. Furthermore, increasing intracellular calcium ions (Ca2+) in response to SS2 infection further facilitates the liquid-like condensation of RPSA and aggravates ENO-induced HBMEC cell apoptosis. CONCLUSIONS: Together, our study provides a previously underappreciated molecular mechanism illuminating that ENO-induced RPSA condensation activates the migration of RPSA to the bacterial cell surface and stimulates SS2-infected HBMEC death and, potentially, disease progression. This study offers a fresh avenue for investigation into the mechanism by which other harmful bacteria infect hosts via cell surfaces' RPSA.

Multi-omics reveals the role of ENO1 in bladder cancer and constructs an epithelial-related prognostic model to predict prognosis and efficacy.

α-Enolase (ENO1) is a crucial molecular target for tumor therapy and has emerged as a research hotspot in recent decades. Here, we aimed to explore the role of ENO1 in bladder cancer (BLCA) and then construct a signature to predict the prognosis and treatment response of BLCA. Firstly, we found ENO1 was highly expressed in BLCA tissues, as verified by IHC, and was associated with poor prognosis. The analysis of the tumor immune microenvironment by bulk RNA-seq and scRNA-seq showed that ENO1 was associated with CD8+ T-cell exhaustion. Additionally, the results in vitro showed that ENO1 could promote the proliferation and invasion of BLCA cells. Then, the analysis of epithelial cells (ECs) revealed that ENO1 might promote BLCA progression by metabolism, the cell cycle and some carcinogenic pathways. A total of 249 hub genes were obtained from differentially expressed genes between ENO1-related ECs, and we used LASSO analysis to construct a novel signature that not only accurately predicted the prognosis of BLCA patients but also predicted the response to treatment for BLCA. Finally, we constructed a nomogram to better guide clinical application. In conclusion, through multi-omics analysis, we found that ENO1 was overexpressed in bladder cancer and associated with poor prognosis, CD8+ T-cell exhaustion and epithelial heterogeneity. Moreover, the prognosis and treatment of patients can be well predicted by constructing an epithelial-related prognostic signature.

Unveiling the functional significance of the 14.3.3 protein: A key player in Paracoccidioides brasiliensis biofilm formation.

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides spp. The interaction mediated by the presence of adhesins on the fungal surface and receptors in the extracellular matrix of the host, as well as the biofilm formation, is essential in its pathogenesis. Adhesins such as gp43, enolase, GAPDH (glyceraldehyde-3-phosphate dehydrogenase), and 14-3-3 have been demonstrated in the Paracoccidioides brasiliensis (Pb18) strain and recognized as necessary in the fungus-host interaction. The Pb 18 strain silenced to 14-3-3 showed changes in morphology, virulence, and adhesion capacity. The study aimed to evaluate the role of adhesin 14-3-3 in P. brasiliensis biofilm formation and the differential expression of genes related to adhesins, comparing planktonic and biofilm forms. The presence of biofilm was also verified in sutures in vitro and in vivo. The silenced strain (Pb14-3-3 aRNA) was compared with the wild type Pb18, determining the differential metabolic activity between the strains by the XTT reduction assay; the biomass by violet crystal and the polysaccharides by safranin, even as morphological differences by microscopic techniques. Differential gene expression for adhesins was also analyzed, comparing the relative expression of these in planktonic and biofilm forms at different times. The results suggested that the silencing of 14-3-3 protein altered the ability to form biofilm and its metabolism. The quantity of biomass was similar in both strains; however, the formation of exopolymeric substances and polysaccharide material was lower in the silenced strain. Our results showed increased expression of enolase, GAPDH, and 14-3-3 genes in the first periods of biofilm formation in the Pb18 strain. In contrast, the silenced strain showed a lower expression of these genes, indicating that gene silencing can influence the expression of other genes and be involved in the biofilm formation of P. brasiliensis. In vitro and in vivo assays using sutures confirmed this yeast's ability to form biofilm and may be implicated in the pathogenesis of paracoccidioidomycosis.

A variant in sperm-specific glycolytic enzyme enolase 4 (ENO4) causes human male infertility.

BACKGROUND: Although defects in sperm morphology and physiology lead to male infertility, in many instances, the exact disruption of molecular pathways in a given patient is often unknown. The glycolytic pathway is an essential process to supply energy in sperm cell motility. Enolase 4 (ENO4) is crucial for the glycolytic process, which provides the energy for sperm cells in motility. ENO4 is located in the sperm principal piece and is essential for the motility and organization of the sperm flagellum. In the present study, we characterized a family with asthenozoospermia and abnormal sperm morphology as a result of a variant in the enolase 4 (ENO4) gene. METHODS: Computer-assisted semen analysis, papanicolaou smear staining and scanning electron microscopy were used to examine sperm motility and morphology for semen analysis in patients. For genetic analysis, whole-exome sequencing followed by Sanger sequencing was performed. RESULTS: Two brothers in a consanguineous family were being clinically investigated for sperm motility and morphology issues. Genetic analysis by whole-exome sequencing revealed a homozygous variant [c.293A>G, p.(Lys98Arg)] in the ENO4 gene that segregated with infertility in the family, shared by affected but not controls. CONCLUSIONS: In view of the association of asthenozoospermia and abnormal sperm morphology in Eno4 knockout mice, we consider this to be the first report describing the involvement of ENO4 gene in human male infertility. We also explore the possible involvement of another variant in explaining other phenotypic features in this family.

A comprehensive study of the interactions in the B. subtilis degradosome with special emphasis on the role of the small proteins SR1P and SR7P.

Here, we employ coelution experiments and far-western blotting to identify stable interactions between the main components of the B. subtilis degradosome and the small proteins SR1P and SR7P. Our data indicate that B. subtilis has a degradosome comprising at least RNases Y and PnpA, enolase, phosphofructokinase, glycerol-3-phosphate dehydrogenase GapA, and helicase CshA that can be co-purified without cross-linking. All interactions were corroborated by far-western blotting with proteins purified from E. coli. Previously, we discovered that stress-induced SR7P binds enolase to enhance its interaction with and activity of enolase-bound RNase Y (RnY), while SR1P transcribed under gluconeogenic conditions interacts with GapA to stimulate its interaction with and the activity of RnjA (RnjA). We show that SR1P can directly bind RnjA, RnY, and PnpA independently of GapA, whereas SR7P only interacts with enolase. Northern blotting suggests that the degradation of individual RNAs in B. subtilis under gluconeogenic or stress conditions depends on either RnjA or RnY alone or on RnjA-SR1P, RnY-SR1P, or RnY-Eno. In vitro degradation assays with RnY or RnjA substrates corroborate the in vivo role of SR1P. Currently, it is unknown which substrate property is decisive for the utilization of one of the complexes.

Efficacy of recombinant enolase as a candidate vaccine against Haemaphysalis longicornis tick infestation in mice.

Tick infestation causes a significant threat to human and animal health, requiring effective immunological control methods. This study aimed to investigate the potential of recombinant Haemaphysalis longicornis enolase protein for tick vaccine development. The exact mechanism of the recently identified enolase protein from the H. longicornis Jeju strain remains poorly understood. Enolase plays a crucial role in glycolysis, the metabolic process that converts glucose into energy, and is essential for the motility, adhesion, invasion, growth, and differentiation of ticks. In this study, mice were immunized with recombinant enolase, and polyclonal antibodies were generated. Western blot analysis confirmed the specific recognition of enolase by the antiserum. The effects of immunization on tick feeding and attachment were assessed. Adult ticks attached to the recombinant enolase-immunized mice demonstrated longer attachment time, increased blood-sucking abilities, and lower engorgement weight than the controls. The nymphs and larvae had a reduced attachment rate and low engorgement rate compared to the controls. Mice immunized with recombinant enolase expressed in Escherichia coli displayed 90% efficacy in preventing tick infestation. The glycolytic nature of enolase and its involvement in crucial physiological processes makes it an attractive target for disrupting tick survival and disease transmission. Polyclonal antibodies recognize enolase and significantly reduce attachment rates, tick feeding, and engorgement. Our findings indicate that recombinant enolase may be a valuable vaccine candidate for H. longicornis infection in experimental murine model.

The Enolase of the Haemophilus influenzae Mediates Binding to Collagens: An Extracellular Matrix Component.

Enolase proteins play a significant role as moonlighting proteins. In their role as surface-associated enolase, they have multiple functions as they interact with extracellular matrix proteins. Type I and III collagens are the major constituents of this extracellular matrix, and collagen is one of the targets of interaction with the enolase of many pathogens, thereby helping the colonization process and promoting the subsequent invasion of the host. This work aimed to determine the participation of non-typeable H. influenzae enolase as a collagen-binding protein. In this study, through the use of in vitro tests it was demonstrated that recombinant enolase of non-typeable H. influenzae (rNTHiENO) strongly binds to type I collagen. Using molecular docking, the residues that could take part in the interaction of non-typeable H. influenzae enolase-type I collagen (NTHiENO-Cln I) and non-typeable H. influenzae enolase-type III collagen (NTHiENO-Cln III) were identified. However, in vitro assays show that NTHiENO has a better affinity to interact with Cln I, concerning type Cln III. The interaction of NTHiENO with collagen could play a significant role in the colonization process; this would allow H. influenzae to increase its virulence factors and strengthen its pathogenesis.

Characterization and Structural Analyses of Enolase from Shrimp (Litopenaeus vannamei).

Transcriptome analysis had recognized enolase from shrimp Litopenaeus vannamei (L. vannamei), which is termed LvEnolase, as one of the allergens, but its amino acid sequence and protein structure have been lacking. In this study, natural LvEnolase was isolated from L. vannamei and characterized for the first time. The full-length cDNA sequence of LvEnolase was effectively cloned, which encoded 434 amino acid residues. The crystal structure of LvEnolase was successfully determined at a resolution of 2.5 Å by X-ray crystallography (PDB: 8UEL). Notably, it was observed that near the active center, a loop exists in either an open or closed state, and the open loop was associated with the product release phase. Furthermore, enzyme activity assays were conducted to validate the catalytic capabilities of purified LvEnolase. These findings significantly enhance our comprehension of the enolase family and provide valuable support for delving into the functions and characteristics of LvEnolase.

N6-methyladenosine methyltransferase KIAA1429 promoted ovarian cancer aerobic glycolysis and progression through enhancing ENO1 expression.

BACKGROUND: Despite improvements in prognosis due to advances in treatment, including surgery, genetic screening, and molecular targeted therapy, the outcomes of ovarian cancer (OC) remain unsatisfactory. Internal mRNA modifications are extremely common in eukaryotes; N6-methyladenosine (m6A) alteration has significant effects on mRNA stability and translation, and it is involved in the pathophysiology of numerous diseases related to cancer. METHODS: Bioinformatics analysis, quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of vir-like m6A methyltransferase associated (KIAA1429) in OC tissues and cell lines. Several different cell models and animal models were established to determine the role of KIAA1429 in glucose metabolism reprogramming and the underlying molecular mechanism of OC. The mechanism of oncology functional assays, co-immunoprecipitation and a luciferase reporter gene was employed to ascertain how KIAA1429 interacts with important molecular targets. RESULTS: We reported that KIAA1429 was overexpressed in OC and predicted a poor prognosis. Functionally, KIAA1429 promoted cell growth by inducing proliferation and inhibiting necrosis. Mechanistically, KIAA1429 promoted tumor progression and glycolysis via stabilizing ENO1 mRNA in a way dependent on m6A. Furthermore, we investigated that the SPI1 transcription factor is the main transcription factor that regulates KIAA1429 transcription in OC. CONCLUSION: Our findings revealed that SPI1/KIAA1429/ENO1 signaling is a novel molecular axis and raises awareness of the vital functions of the changes in KIAA1429 and m6A changes in the metabolic reprogramming of OC. These results identified new potential biomarkers and treatment targets for OC.

Unrevealed roles of extracellular enolase­1 (ENO1) in promoting glycolysis and pro­cancer activities in multiple myeloma via hypoxia­inducible factor 1α.

The involvement of enolase­1 (ENO1), intracellularly or extracellularly, has been implicated in cancer development. Moreover, anticancer activities of an ENO1­targeting antibody has demonstrated the pathological roles of extracellular ENO1 (surface or secreted forms). However, although ENO1 was first identified as a glycolytic enzyme in the cytosol, to the best of our knowledge, extracellular ENO1 has not been implicated in glycolysis thus far. In the present study, the effects of extracellular ENO1 on glycolysis and other related pro­cancer activities were investigated in multiple myeloma (MM) cells in vitro and in vivo. Knockdown of ENO1 expression reduced lactate production, cell viability, cell migration and surface ENO1 expression in MM cells. Notably, addition of extracellular ENO1 protein in cancer cell culture enhanced glycolytic activity, hypoxia­inducible factor 1­α (HIF­1α) expression, glycolysis­related gene (GRG) expression and pro­cancer activities, such as cell migration, cell viability and tumor­promoting cytokine secretion. Consistently, these extracellular ENO1­induced cellular effects were inhibited by an ENO1­specific monoclonal antibody (mAb). In addition, extracellular ENO1­mediated glycolysis, GRG expression and pro­cancer activities were also reduced by HIF­1α silencing. Lastly, administration of an ENO1 mAb reduced tumor growth and serum lactate levels in an MM xenograft model. These results suggested that extracellular ENO1 (surface or secreted forms) enhanced a HIF­1α­mediated glycolytic pathway, in addition to its already identified roles. Therefore, the results of the present study highlighted the therapeutic potential of ENO1­specific antibodies in treating MM, possibly via glycolysis inhibition, and warrant further studies in other types of cancer.