Integrated full-length transcriptome and metabolome analysis reveals the defence response of melon to gummy stem blight.

Gummy stem blight (GSB), a widespread disease causing great loss to cucurbit production, has become a major threat to melon cultivation. However, the melon-GSB interaction remains largely unknown. Here, full-length transcriptome and widely targeted metabolome were used to investigate the defence responses of resistant (PI511089) and susceptible (Payzawat) melon accessions to GSB pathogen infection at 24 h. The biosynthesis of secondary metabolites and MAPK signalling pathway were specifically enriched for differentially expressed genes in PI511890, while carbohydrate metabolism and amino acid metabolism were specifically enriched in Payzawat. More than 1000 novel genes were identified and MAPK signalling pathway was specifically enriched for them in PI511890. There were 11 793 alternative splicing events involving in the defence response to GSB. Totally, 910 metabolites were identified in Payzawat and PI511890, and flavonoids were the dominant metabolites. Integrated full-length transcriptome and metabolome analysis showed eriodictyol and oxalic acid were the potential marker metabolites for GSB resistance in melon. Moreover, posttranscription regulation was widely involved in the defence response of melon to GSB pathogen infection. These results not only improve our understanding on the interaction between melon and GSB, but also facilitate the genetic improvement of melon with GSB resistance.

Somatic cell-derived BMPs induce premature meiosis in male germ cells during the embryonic stage by upregulating Dazl expression.

Although germ cell fate is believed to be determined by signaling factors from differentiated somatic cells, the molecular mechanism behind this process remains obscure. In this study, premature meiosis in male germ cells was observed during the embryonic stage by conditional activation of ß-catenin in Sertoli cells. Somatic and germ cell transcriptome results indicated that the BMP signaling pathway was enriched after ß-catenin activation. In addition, we observed a decreased DNA methylation within a reduction of DNMT3A in germ cells of ß-catenin activated testes and reversed increase after inhibiting BMP signaling pathway with LDN-193189. We also found that Dazl expression was increased in ß-catenin activated testes and decreased after LDN treatment. Taken together, this study demonstrates that male germ cells entered meiosis prematurely during the embryonic stage after ß-catenin activated in Sertoli cells. BMP signaling pathway involved in germ cell meiosis initiation by mediating DNA methylation to induce meiotic genes expression.

Modulating the Conduction Band of MOFs by Introducing Tiny TiO2 Nanoparticles for Enhanced Photocatalytic Performance: Importance of the Loading Position.

The preparation of TiO2 and metal-organic framework (MOF) into composite photocatalysts has been proven to be a mature and effective strategy to achieve stronger catalytic activity. In this work, we focus on exploring the significant effects and mechanisms of the relative positions of decorated titanium oxide nanoparticles and MOFs on the final catalytic activity. We first used a simple in situ method to encapsulate tiny TiO2 nanoparticles into a Zr-MOF (PCN-222), where Zr-Ti bonds were created at the interface of the two components. Thanks to the strong interfacial interaction forces, band bending occurred in TiO2@PCN-222 and a more negative conduction band (Δ = 0.26 V) with better electron transport properties was obtained. The results of photocatalytic CO2 reduction experiments under visible light showed a 78% increase (142 µmol g-1 h-1) in the production rate of HCOO-. Surprisingly, the loading of TiO2 nanoparticles on the MOF surface (TiO2@PCN-222) resulted in a significant decrease of 56% in the catalyst yield activity due to poor adsorption and electron transfer properties. This work demonstrates the possibility of tuning the band structure and catalytic activity of MOFs with the help of changing the position of the dopant and shows the importance of the rational design of MOF-based composites.

The beta subunit of AMP-activated protein kinase is critical for cell cycle progression and parasite development in Toxoplasma gondii.

Toxoplasma gondii is a widespread eukaryotic pathogen that causes life-threatening diseases in humans and diverse animals. It has a complex life cycle with multiple developmental stages, which are timely adjusted according to growth conditions. But the regulatory mechanisms are largely unknown. Here we show that the AMP-activated protein kinase (AMPK), a key regulator of energy homeostasis in eukaryotes, plays crucial roles in controlling the cell cycle progression and bradyzoite development in Toxoplasma. Deleting the ß regulatory subunit of AMPK in the type II strain ME49 caused massive DNA damage and increased spontaneous conversion to bradyzoites (parasites at chronic infection stage), leading to severe growth arrest and reduced virulence of the parasites. Under alkaline stress, all Δampkß mutants converted to a bradyzoite-like state but the cell division pattern was significantly impaired, resulting in compromised parasite viability. Moreover, we found that phosphorylation of the catalytic subunit AMPKα was greatly increased in alkaline stressed parasites, whereas AMPKß deletion mutants failed to do so. Phosphoproteomics found that many proteins with predicted roles in cell cycle and cell division regulation were differentially phosphorylated after AMPKß deletion, under both normal and alkaline stress conditions. Together, these results suggest that the parasite AMPK has critical roles in safeguarding cell cycle progression, and guiding the proper exist of the cell cycle to form mature bradyzoites when the parasites are stressed. Consistent with this model, growth of parasites was not significantly altered when AMPKß was deleted in a strain that was naturally reluctant to bradyzoite development.

Noninvasive Prediction of Ki-67 Expression in Hepatocellular Carcinoma Using Machine Learning-Based Ultrasomics: A Multicenter Study.

OBJECTIVES: To investigate the ability of ultrasomics to predict Ki-67 expression in hepatocellular carcinoma (HCC). METHODS: A total of 244 patients from three hospitals were retrospectively recruited (training dataset, n = 168; test dataset, n = 43; and validation dataset, n = 33). Lesion segmentation of the ultrasound images was performed manually by two radiologists. In total, 1409 ultrasomics features were extracted. Feature selection was conducted using the intra-class correlation coefficient, variance threshold, mutual information, and recursive feature elimination plus eXtreme Gradient Boosting. The support vector machine was combined with the learning curve and grid search parameter tuning to construct the clinical, ultrasomics, and combined models. The predictive performance of the models was assessed using the area under the receiver operating characteristic curve (AUC), sensitivity, specificity and accuracy. RESULTS: The ultrasomics model performed well on the training, test, and validation datasets. The AUC (95% confidence interval [CI]) for these datasets were 0.955 (0.912-0.981), 0.861 (0.721-0.947), and 0.665 (0.480-0.819), respectively. The combination of ultrasomics and clinical features significantly improved model performance on all three datasets. The AUC (95% CI), sensitivity, specificity, and accuracy were 0.986 (0.955-0.998), 0.973, 0.840, and 0.869 on the training dataset; 0.871 (0.734-0.954), 0.750, 0.829, and 0.814 on the test dataset; and 0.742 (0.560-0.878), 0.714, 0.808, and 0.788 on the validation dataset, respectively. CONCLUSIONS: Ultrasomics was proved to be a potential noninvasive method to predict Ki-67 expression in HCC.

The Green Synthesis of Reduced Graphene Oxide Using Ellagic Acid: Improving the Contrast-Enhancing Effect of Microbubbles in Ultrasound.

There is an urgent need to realize precise clinical ultrasound with ultrasound contrast agents that provide high echo intensity and mechanical index tolerance. Graphene derivatives possess exceptional characteristics, exhibiting great potential in fabricating ideal ultrasound contrast agents. Herein, we reported a facile and green approach to synthesizing reduced graphene oxide with ellagic acid (rGO-EA). To investigate the application of a graphene derivative in ultrasound contrast agents, rGO-EA was dispersed in saline solution and mixed with SonoVue (SV) to fabricate SV@rGO-EA microbubbles. To determine the properties of the product, analyses were performed, including ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectrum (XPS), X-ray diffraction analysis (XRD) and zeta potential analysis. Additionally, cell viability measurements and a hemolysis assay were conducted for a biosafety evaluation. SV@rGO-EA microbubbles were scanned at various mechanical index values to obtain the B-mode and contrast-enhanced ultrasound (CEUS) mode images in vitro. SV@rGO-EA microbubbles were administered to SD rats, and their livers and kidneys were imaged in CEUS and B-mode. The absorption of rGO-EA resulted in an enhanced echo intensity and mechanical index tolerance of SV@rGO-EA, surpassing the performance of SV microbubbles both in vitro and in vivo. This work exhibited the application potential of graphene derivatives in the field of ultrasound precision medicine.

WDR62 is involved in spindle assembly by interacting with CEP170 in spermatogenesis.

WDR62 is the second most common genetic alteration associated with microcephaly. It has been shown that Wdr62 is required for germ cell meiosis initiation in mice, and the majority of male germ cells are lost in the meiotic defect of first wave spermatogenesis in Wdr62 mutants. Strikingly, in this study, we found that the initiation of meiosis following spermatogenesis was not affected and the germ cells were gradually repopulated at later developmental stages. However, most germ cells were arrested at metaphase of meiosis I and no mature sperm were detected in epididymides. Further, this study demonstrated that metaphase I arrest of Wdr62-deficient spermatocytes was caused by asymmetric distribution of the centrosome and aberrant spindle assembly. Also, mechanistic studies demonstrated that WDR62 interacts with centrosome-associated protein CEP170, and deletion of Wdr62 causes downregulation of the CEP170 protein, which in turn leads to the aberrant spindle assembly. In summary, this study indicates that the meiosis of first wave spermatogenesis and the following spermatogenesis started from spermatogonium is probably regulated by different mechanisms. We also demonstrated a new function of WDR62 in germ cell meiosis, through its interaction with CEP170.

The specificity of the bilin lyase CpcS for chromophore attachment to allophycocyanin in the chlorophyll f-containing cyanobacterium Halomicronima hongdechloris.

Phycobilisomes are light-harvesting antenna complexes of cyanobacteria and red algae that are comprised of chromoproteins called phycobiliproteins. PBS core structures are made up of allophycocyanin subunits. Halomicronema hongdechloris (H. hongdechloris) is one of the cyanobacteria that produce chlorophyll f (Chl f) under far-red light and is regulated by the Far-Red Light Photoacclimation gene cluster. There are five genes encoding APC in this specific gene cluster, and they are responsible for assembling the red-shifted PBS in H. hongdechloris grown under far-red light. In this study, the five apc genes located in the FaRLiP gene cluster were heterologously expressed in an Escherichia coli reconstitution system. The canonical APC-encoding genes were also constructed in the same system for comparison. Additionally, five annotated phycobiliprotein lyase-encoding genes (cpcS) from the H. hongdechloris genome were phylogenetically classified and experimentally tested for their catalytic properties including their contribution to the shifted absorption of PBS. Through analysis of recombinant proteins, we determined that the heterodimer of CpcS-I and CpcU are able to ligate a chromophore to the APC-α/APC-ß subunits. We discuss some hypotheses towards understanding the roles of the specialised APC and contributions of PBP lyases.

Correction: Wdr62 is involved in female meiotic initiation via activating JNK signaling and associated with POI in humans.

[This corrects the article DOI: 10.1371/journal.pgen.1007463.].

Acquisition of exogenous fatty acids renders apicoplast-based biosynthesis dispensable in tachyzoites of Toxoplasma.

Toxoplasma gondii is a common protozoan parasite that infects a wide range of hosts, including livestock and humans. Previous studies have suggested that the type 2 fatty acid synthesis (FAS2) pathway, located in the apicoplast (a nonphotosynthetic plastid relict), is crucial for the parasite's survival. Here we examined the physiological relevance of fatty acid synthesis in T. gondii by focusing on the pyruvate dehydrogenase complex and malonyl-CoA-[acyl carrier protein] transacylase (FabD), which are located in the apicoplast to drive de novo fatty acid biosynthesis. Our results disclosed unexpected metabolic resilience of T. gondii tachyzoites, revealing that they can tolerate CRISPR/Cas9-assisted genetic deletions of three pyruvate dehydrogenase subunits or FabD. All mutants were fully viable in prolonged cultures, albeit with impaired growth and concurrent loss of the apicoplast. Even more surprisingly, these mutants displayed normal virulence in mice, suggesting an expendable role of the FAS2 pathway in vivo Metabolic labeling of the Δpdh-e1α mutant showed reduced incorporation of glucose-derived carbon into fatty acids with medium chain lengths (C14:0 and C16:0), revealing that FAS2 activity was indeed compromised. Moreover, supplementation of exogenous C14:0 or C16:0 significantly reversed the growth defect in the Δpdh-e1α mutant, indicating salvage of these fatty acids. Together, these results demonstrate that the FAS2 pathway is dispensable during the lytic cycle of Toxoplasma because of its remarkable flexibility in acquiring fatty acids. Our findings question the long-held assumption that targeting this pathway has significant therapeutic potential for managing Toxoplasma infections.

CHIR-99021 regulates mitochondrial remodelling via ß-catenin signalling and miRNA expression during endodermal differentiation.

Mitochondrial remodelling is a central feature of stem cell differentiation. However, little is known about the regulatory mechanisms during these processes. Previously, we found that a pharmacological inhibitor of glycogen synthase kinase-3α and -3ß, CHIR-99021, initiates human adipose stem cell differentiation into human definitive endodermal progenitor cells (hEPCs), which were directed to differentiate synchronously into hepatocyte-like cells after further treatment with combinations of soluble factors. In this study, we show that CHIR-99021 promotes mitochondrial biogenesis, the expression of PGC-1α (also known as PPARGC1A), TFAM and NRF1 (also known as NFE2L1), oxidative phosphorylation capacities, and the production of reactive oxygen species in hEPCs. Blocking mitochondrial dynamics using siRNA targeting DRP1 (also known as DNM1L) impaired definitive endodermal differentiation. Downregulation of ß-catenin (CTNNB1) expression weakened the effect of CHIR-99021 on the induction of mitochondrial remodelling and the expression of transcription factors for mitochondrial biogenesis. Moreover, CHIR-99021 decreased the expression of miR-19b-2-5p, miR-23a-3p, miR-23c, miR-130a-3p and miR-130a-5p in hEPCs, which target transcription factors for mitochondrial biogenesis. These data demonstrate that CHIR-99021 plays a role in mitochondrial structure and function remodelling via activation of the ß-catenin signalling pathway and inhibits the expression of miRNAs during definitive endodermal differentiation.This article has an associated First Person interview with the first author of the paper.

Prognostic effect of coexisting TP53 and ZFHX3 mutations in non-small cell lung cancer patients treated with immune checkpoint inhibitors.

In recent years, immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of patients with advanced-stage non-small cell lung cancer (NSCLC). The relationship between TP53 mutation and prognosis of non-small cell lung cancer (NSCLC) remains controversial. We aimed to identify advanced-stage NSCLC patients harboring TP53 mutation who would benefit from ICI treatment. Gene mutations and tumor mutational burden (TMB) data of NSCLC patients who received at least one dose of ICI therapy at the Memorial Sloan Kettering Cancer Center between 2013 and 2017 were extracted from the cBioPortal online platform. Gene clustering analyses were performed for patients with short and long overall survival (OS). The top ten significantly different mutated genes were identified. Furthermore, we analyzed the different OS of coexisting TP53 and other significantly different mutated genes to identify NSCLC patients with TP53 mutations who would benefit from immunotherapy. A total of 350 patients were enrolled in the study. Of these a total of 219 (62.6%) patients were found to harbor TP53 mutations, whereas 131 (37.4%) had wild-type TP53. There was no statistically significant difference in OS between TP53 mutated or wild-type NSCLC patients who underwent ICI treatment. However, coexisting TP53 and ZFHX3 mutations were independent prognostic factors. Higher somatic TMB (highest 20% in each histology) and combination of anti-CTLA-4 and anti-PD-1/PD-L1 therapy were also associated with longer OS in multivariate analysis. Coexisting TP53 and ZFHX3 mutations are independent prognostic factors for advanced-stage NSCLC patients undergoing ICI treatment. These findings could help identify patients harboring TP53 mutations that would benefit from ICI treatment.

An organophosphorus-mediated cross-Rauhut-Currier/Wittig domino reaction for the efficient synthesis of trisubstituted cyclopentenes.

An efficient organophosphorus-mediated cross-Rauhut-Currier/Wittig domino reaction of vinyl ketones with chalcones has been developed for the synthesis of trisubstituted cyclopentenes. The new synthetic method has the advantages of mild reaction conditions, high efficiency, environmental friendliness and satisfactory yields.

Proposal of diagnostic criteria for IgG4-related thyroid disease.

Patients with IgG4-related disease (IgG4-RD) are diagnosed in Japan by comprehensive or organ-specific diagnostic criteria. To date, organ-specific criteria have been established for several organs, but not for the thyroid. We attempted to establish diagnostic criteria for IgG4-related thyroid disease (IgG4-RTD) based on IgG4-RD research by The Research Program on Intractable Diseases from the Ministry of Health, Labour and Welfare of Japan. These criteria have been publicly reported to members of both the Japan Endocrine Society and the Japan Thyroid Association. Thyroid diseases associated with IgG4 include Hashimoto's thyroiditis, Graves' disease and Riedel's thyroiditis. As a comprehensive definition that includes both systematic and organ-specific forms, we use the broad term 'IgG4-related thyroid disease'. Diagnostic criteria for IgG4-RTD comprise the following five items: I) enlargement of the thyroid, II) hypoechoic lesions in the thyroid by ultrasonography, III) elevated serum IgG4 levels, IV) histopathological findings in the thyroid lesion (IgG4+ plasma cells >20/HPF and IgG4+/IgG+ plasma cell ratio >30%) and V) involvement of other organs. "Definitive" diagnosis of IgG4-RTD is made when I, II, III and IV are all fulfilled, while "probable" diagnosis of IgG4-RTD is when I, II, and IV or V are fulfilled. Patients who fulfill I, II and III criteria are considered as "possible" IgG4-RTD. We believe that the proposed diagnostic criteria contribute to more accurate diagnosis of IgG4-RTD as well as exclusion of mimicry. Furthermore, they may lead to better understanding of the clinical implications and underlying pathogenesis of IgG4-RTD.

How to identify indolent thyroid tumors unlikely to recur and cause cancer death immediately after surgery-Risk stratification of papillary thyroid carcinoma in young patients.

Current histopathological diagnosis methods cannot distinguish the two types of thyroid carcinoma: clinically significant carcinomas with a potential risk of recurrence, metastasis, and cancer death, and clinically insignificant carcinomas with a slow growth rate. Both thyroid tumors are diagnosed as "carcinoma" in current pathology practice. The clinician usually recommends surgery to the patient and the patient often accepts it because of cancer terminology. The treatment for these clinically insignificant carcinomas does not benefit the patient and negatively impacts society. The author proposed risk stratification of thyroid tumors using the growth rate (Ki-67 labeling index), which accurately differentiates four prognostically relevant risk groups based on the Ki-67 labeling index, ≥30%, ≥10 and <30%, >5 and <10%, and ≤5%. Indolent thyroid tumors with an excellent prognosis have the following four features: young age, early-stage (T1-2 M0), curatively treated, and low proliferation index (Ki-67 labeling index of ≤5%), and are unlikely to recur, metastasize, or cause cancer death. Accurate identification of these indolent tumors helps clinicians select more conservative treatments to avoid unnecessary aggressive (total thyroidectomy followed by radio-active iodine) treatments. Clinicians can alleviate the fears of patients by confirming these four features, including the low proliferation rate, in a pathology report immediately after surgery when patients are most concerned.

PHD finger protein 19 expression in multiple myeloma: Association with clinical features, induction therapy outcome, disease progression, and survival.

BACKGROUND: PHD finger protein 19 (PHF19), also known as polycomb-like protein 3 (PCL3), promotes the progression of multiple myeloma (MM) and drug resistance; however, its role in the management of MM remains unclear. Therefore, we aimed to elucidate the correlation between PHF19 expression and treatment response, disease progression, and survival of patients with MM. METHODS: Plasma cells derived from the bone marrow of 101 patients with de novo MM were collected prior to induction therapy, as were plasma cells derived from the bone marrow of 30 healthy donors. PHF19 expression in plasma cells was analyzed using quantitative reverse transcription polymerase chain reaction. Furthermore, the response to induction therapy, progression-free survival (PFS), and overall survival (OS) were assessed. RESULTS: PHF19 expression tends to be upregulated more often in MM patients than in healthy donors (p < 0.001) and can accurately predict MM risk (area under curve [AUC], 0.916; 95% confidence interval [CI], 0.869-0.962). Furthermore, elevated PHF19 expression was correlated with higher International Staging System (ISS) (p = 0.036) and revised ISS stages (p = 0.035). In addition, MM patients who achieved complete response (CR) exhibited reduced PHF19 compared to those who did not (p = 0.028). Moreover, increased PHF19 expression was correlated with unfavorable PFS (p = 0.006) and OS (p = 0.027) rates. Furthermore, the results of multivariate Cox analysis also revealed that PHF19 high expression was independently associated with a reduced PFS rate (hazard ratio: 2.025, p = 0.028). CONCLUSION: Increased PHF19 expression is correlated with poor induction therapy response and unfavorable long-term prognosis of MM.

Wdr62 is involved in female meiotic initiation via activating JNK signaling and associated with POI in humans.

Meiosis is a germ cell-specific division that is indispensable for the generation of haploid gametes. However, the regulatory mechanisms of meiotic initiation remain elusive. Here, we report that the Wdr62 (WD40-repeat protein 62) is involved in meiotic initiation as a permissive factor rather than an instructive factor. Knock-out of this gene in a mouse model resulted in female meiotic initiation defects. Further studies demonstrated that Wdr62 is required for RA-induced Stra8 expression via the activation of JNK signaling, and the defects in meiotic initiation from Wdr62-deficient female mice could be partially rescued by JNK1 overexpression in germ cells. More importantly, two novel mutations of the WDR62 gene were detected in patients with premature ovarian insufficiency (POI), and these mutations played dominant-negative roles in regulating Stra8 expression. Hence, this study revealed that Wdr62 is involved in female meiotic initiation via activating JNK signaling, which displays a novel mechanism for regulating meiotic initiation, and mutation of WDR62 is one of the potential etiologies of POI in humans.

Antitumor effects of a Toxoplasma mutant lacking lactate dehydrogenases.

"Bug as drug" is a concept recognized over a century ago and has gained significant research attention recently for fighting diseases such as immune disorders and others. Bacteria and viruses are constantly studied for this purpose, but the use of parasitic organisms is still rare. Recently, we found that Toxoplasma gondii mutants lacking two lactate dehydrogenases (ME49 Δldh1-Δldh2) were avirulent in mice but able to stimulate high levels of Th1 immunity. This outcome prompted us to determine whether Δldh mutants also displayed antitumor activities. Using a mouse melanoma model, we showed that intratumoral administration of Δldh1-Δldh2 repressed the growth of established tumors and helped to inhibit lethal tumor development in the mice. The sera of parasite-treated mice had high levels of TNF-α and INF-γ, which likely contributed to the tumor-repressing activity. We also found that chronic Toxoplasma infection, which is common in animals and humans, also led to antitumor activity. In addition, pre-existing chronic infections did not affect the antitumor efficiency of the Δldh1-Δldh2 mutant. Together, these results suggest that the attenuated T. gondii mutant Δldh1-Δldh2 has the potential to be a good antitumor therapy and provide new insights into the development of novel tumor therapeutics.

Arsenic removal in aqueous solutions using FeS2.

This study tested the technical feasibility of pyrite and/or persulfate oxidation system for arsenic (As) removal from aqueous solutions. The effects of persulfate on As removal by the pyrite in the integrated treatment were also investigated. Prior to the persulfate addition into the reaction system, the physico-chemical interactions between As and the pyrite alone in aqueous solutions were explored in batch studies. The adsorption mechanisms of As by the adsorbent were also presented. At the same As concentration of 5 mg/L, it was found that As(III) attained a longer equilibrium time (8 h) than As(V) (2 h), while the pyrite worked effectively at pH ranging from 6 to 11. At optimum conditions (0.25 g/L of pyrite, pH 8.0 and 5 mg/L of As(III) concentration), the addition of persulfate (0.5 mM) into the reaction promoted a complete removal of arsenic from the solutions. Consequently, this enabled the treated effluents to meet the arsenic maximum contaminant limit (MCL) of <10 µg/L according to the World Health Organization (WHO)'s requirements. The redox mechanisms, which involved electron transfer from the S22- of the pyrite to Fe3+, supply Fe2+ for persulfate decomposition, oxidizing As(III) to As(V). The sulfur species played roles in the redox cycle of the Fe3+/Fe2+ of the pyrite by giving its electrons, while the As(III) oxidation to As(V) was attributed to the pyrite. Overall, this work reveals the applicability of the pyrite as an adsorbent for water treatment and the importance of persulfate addition to promote a complete As removal from aqueous solutions.

FoxA2 inhibits the proliferation of hepatic progenitor cells by reducing PI3K/Akt/HK2-mediated glycolysis.

FoxA2 is an essential transcription factor for liver organogenesis and homeostasis. Although reduced expression of FoxA2 has been associated with chronic liver diseases, hepatic progenitor cells (HPCs) that are activated in these circumstances express FoxA2. However, the functional effects and underlying mechanism of FoxA2 in HPCs are still unknown. As revealed by immunostaining, HPCs expressed FoxA2 in human cirrhotic livers and in the livers of choline-deficient diet supplemented with ethionine (CDE) rats. Knocking down FoxA2 in HPCs isolated from CDE rats significantly increased cell proliferation and aerobic glycolysis. Moreover, gene transcription, protein expression, and the enzyme activities of hexokinase 2 (HK2) were upregulated, and blocking HK2 activities via 2-deoxyglucose markedly reduced cell proliferation and aerobic glycolysis. Kyoto Encyclopedia of Genes and Genomes analysis revealed that FoxA2 knockdown enhanced the transcription of genes involved in the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway and triggered downstream Akt phosphorylation. Blocking the PI3K/Akt pathway by Ly294002 inhibited HK2 activities, aerobic glycolysis, and cell proliferation in FoxA2-knockdown cells. Therefore, FoxA2 plays an important role in the proliferation and inhibition of HPCs by suppressing PI3K/Akt/HK2-regulated aerobic glycolysis.