TCR activation directly stimulates PYGB-dependent glycogenolysis to fuel the early recall response in CD8+ memory T cells.

Glycolysis facilitates the rapid recall response of CD8+ memory T (Tm) cells. However, it remains unclear whether Tm cells uptake exogenous glucose or mobilize endogenous sugar to fuel glycolysis. Here, we show that intracellular glycogen rather than extracellular glucose acts as the major carbon source for the early recall response. Following antigenic stimulation, Tm cells exhibit high glycogen phosphorylase (brain form, PYGB) activity, leading to glycogenolysis and release of glucose-6-phosphate (G6P). Elevated G6P mainly flows to glycolysis but is also partially channeled to the pentose phosphate pathway, which maintains the antioxidant capacity necessary for later recall stages. Mechanistically, TCR signaling directly induces phosphorylation of PYGB by LCK-ZAP70. Functionally, the glycogenolysis-fueled early recall response of CD8+ Tm cells accelerates the clearance of OVA-Listeria monocytogenes in an infected mouse model. Thus, we uncover a specific dependency on glycogen for the initial activation of memory T cells, which may have therapeutic implications for adaptive immunity.

Upregulation of CoQ shifts ferroptosis dependence from GPX4 to FSP1 in acquired radioresistance.

Acquired radioresistance is the primary contributor to treatment failure of radiotherapy, with ferroptosis is identified as a significant mechanism underlying cell death during radiotherapy. Although resistance to ferroptosis has been observed in both clinical samples of radioresistant cells and cell models, its mechanism remains unidentified. Herein, our investigation revealed that radioresistant cells exhibited greater tolerance to Glutathione Peroxidase 4 (GPX4) inhibitors and, conversely, increased sensitivity to ferroptosis suppressor protein 1 (FSP1) inhibitors compared to their sensitive counterparts. This observation suggested that FSP1 might play a dominant role in the development of radioresistance. Notably, the knockout of FSP1 demonstrated considerably superior efficacy in resensitizing cells to radiotherapy compared to the knockout of GPX4. To elucidate the driving force behind this functional shift, we conducted a metabolomic assay, which revealed an upregulation of Coenzyme Q (CoQ) synthesis and a downregulation of glutathione synthesis in the acquired radioresistance cells. Mechanistically, CoQ synthesis was found to be supported by aarF domain containing kinase 3-mediated phosphorylation of CoQ synthases, while the downregulation of Solute carrier family 7 member 11 led to decreased glutathione synthesis. Remarkably, our retrospective analysis of clinical response data further validated that the additional administration of statin during radiotherapy, which could impede CoQ production, effectively resensitized radioresistant cells to radiation. In summary, our findings demonstrate a dependency shift from GPX4 to FSP1 driven by altered metabolite synthesis during the acquisition of radioresistance. Moreover, we provide a promising therapeutic strategy for reversing radioresistance by inhibiting the FSP1-CoQ pathway.

Repurposing a human acetyl-CoA carboxylase inhibitor firsocostat to treat fungal candidiasis alone and in combination.

Opportunistic fungal infections, particularly caused by Candida albicans, remain a common cause of high morbidity and mortality in immunocompromised patients. The escalating prevalence of antifungal drug resistance necessitates the immediate exploration of alternative treatment strategies to combat these life-threatening fungal diseases. In this study, we investigated the antifungal efficacy of firsocostat, a human acetyl-CoA carboxylase (ACC) inhibitor, against C. albicans. Firsocostat alone displayed moderate antifungal activity, while combining it with voriconazole, itraconazole, or amphotericin B exhibited synergistic effects across almost all drug-sensitive and drug-resistant C. albicans strains tested. These observed synergies were further validated in two mouse models of oropharyngeal and systemic candidiasis, where the combination therapies demonstrated superior fungicidal effects compared to monotherapy. Moreover, firsocostat was shown to directly bind to C. albicans ACC and inhibit its enzymatic activity. Sequencing spontaneous firsocostat-resistant mutants revealed mutations mapping to C. albicans ACC, confirming that firsocostat has retained its target in C. albicans. Overall, our findings suggest that repurposing firsocostat, either alone or in combination with other antifungal agents, holds promising potential in the development of antifungal drugs and the treatment of candidiasis.

Loureirin A is a narrow-spectrum antimicrobial agent against Helicobacter pylori.

Currently, Helicobacter pylori eradication by antibiotic therapy faces various challenges, including antibiotic resistance, side effects on intestinal commensal bacteria, and patient compliance. In this study, loureirin A (LrA), a traditional Chinese medicine monomer extracted from Sanguis Draconis flavones, was found to possess specific antibacterial activity against H. pylori without the bacteria displaying a tendency to develop resistance in vitro. LrA demonstrated a synergistic or additive effect when combined with omeprazole (a proton pump inhibitor) against H. pylori. The combination of LrA and omeprazole showed promising anti-H. pylori potential, exhibiting notable in vivo efficacy comparable to standard triple therapy in mouse models infected with both drug-sensitive and drug-resistant H. pylori strains. Moreover, the narrow-spectrum antibacterial profile of LrA is reflected in its minimal effect on the diversity and composition of the mouse gut microbiota. The underlying mechanism of action of LrA against H. pylori involves the generation of bactericidal levels of reactive oxygen species, resulting in apoptosis-like cell death. These findings indicate that LrA is a promising lead compound targeting H. pylori without harming the commensal bacteria.

Clinical pathological significance and biological function of PLIN1 in hepatocellular carcinoma: bioinformatics analysis and in vitro experiments.

BACKGROUND & AIMS: Perilipin 1 (PLIN1) is an essential lipid droplet surface protein that participates in cell life activities by regulating energy balance and lipid metabolism. PLIN1 has been shown to be closely related to the development of numerous tumor types. The purpose of this work was to elucidate the clinicopathologic significance of PLIN1 in hepatocellular carcinoma (HCC), as well as its impact on the biological functions of HCC cells, and to investigate the underlying mechanisms involved. METHODS: Public high-throughput RNA microarray and RNA sequencing data were collected to examine PLIN1 levels and clinical significance in patients with HCC. Immunohistochemistry (IHC) and real-time quantitative reverse transcription polymerase chain reaction (RT‒qPCR) were conducted to assess the expression levels and the clinicopathological relevance of PLIN1 in HCC. Then, SK and Huh7 cells were transfected with a lentivirus overexpressing PLIN1. CCK8 assay, wound healing assay, transwell assay, and flow cytometric analysis were conducted to explore the effects of PLIN1 overexpression on HCC cell proliferation, migration, invasion, and cell cycle distribution. Ultimately, Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to investigate the underlying mechanisms of PLIN1 in HCC progression based on HCC differentially expressed genes and PLIN1 co-expressed genes. RESULTS: PLIN1 was markedly downregulated in HCC tissues, which correlated with a noticeably worse prognosis for HCC patients. Additionally, PLIN1 overexpression inhibited the proliferation, migration, and invasion of SK and Huh7 cells in vitro, as well as arresting the HCC cell cycle at the G0/G1 phase. More significantly, energy conversion-related biological processes, lipid metabolism, and cell cycle signalling pathways were the three most enriched molecular mechanisms. CONCLUSION: The present study revealed that PLIN1 downregulation is associated with poor prognosis in HCC patients and accelerated HCC progression by promoting cellular proliferation, migration, and metastasis, as well as the mechanisms underlying the regulation of lipid metabolism-related pathways in HCC.

Evaluating the potency of zoliflodacin against Helicobacter pylori: In vitro activity and conserved GyrB target.

BACKGROUND: The current standard treatment for Helicobacter pylori infection, which involves a combination of two broad-spectrum antibiotics, faces significant challenges due to its detrimental impact on the gut microbiota and the emergence of drug-resistant strains. This underscores the urgent requirement for the development of novel anti-H. pylori drugs. Zoliflodacin, a novel bacterial gyrase inhibitor, is currently undergoing global phase III clinical trials for treating uncomplicated Neisseria gonorrhoeae. However, there is no available data regarding its activity against H. pylori. MATERIALS AND METHODS: We evaluated the in vitro activity of zoliflodacin against H. pylori clinical isolates (n = 123) with diverse multidrug resistance. We performed DNA gyrase supercoiling and microscale thermophoresis assays to identify the target of zoliflodacin in H. pylori. We analyzed 2262 H. pylori whole genome sequences to identify Asp424Asn and Lys445Asn mutations in DNA gyrase subunit B (GyrB) that are associated with zoliflodacin resistance. RESULTS: Zoliflodacin exhibits potent activity against all tested isolates, with minimal inhibitory concentration (MIC) values ranging from 0.008 to 1 µg/mL (MIC50: 0.125 µg/mL; MIC90: 0.25 µg/mL). Importantly, there was no evidence of cross-resistance to any of the four first-line antibiotics commonly used against H. pylori. We identified GyrB as the primary target of zoliflodacin, with Asp424Asn or Lys445Asn substitutions conferring resistance. Screening of 2262 available H. pylori genomes for the two mutations revealed only one clinical isolate carrying Asp424Asn substitution. CONCLUSION: These findings support the potential of zoliflodacin as a promising candidate for H. pylori treatment, warranting further development and evaluation.

Screening of a potential probiotic Lactiplantibacillus plantarum NUC08 and its synergistic effects with yogurt starter.

This study aims to identify lactic acid bacteria (LAB) isolates possessing physiological characteristics suitable for use as probiotics in yogurt fermentation. Following acid and bile salt tolerance tests, Lactiplantibacillus plantarum (NUC08 and NUC101), Lacticaseibacillus rhamnosus (NUC55 and NUC201), and Lacticaseibacillus paracasei (NUC159, NUC216, and NUC351) were shortlisted based on intraspecies distribution for further evaluation. Their physiological probiotic properties, including transit tolerance, adhesion, autoaggregation, surface hydrophobicity, biofilm formation, and antibacterial activity, were assessed. Principal component analysis indicated that Lactiplantibacillus plantarum NUC08 was the preferred choice among the evaluated strains. Subsequent investigations revealed that co-culturing Lactiplantibacillus plantarum NUC08 with 2 yogurt starter strains resulted in a cooperative and synergistic effect, enhancing the growth of mixed strains and increasing their tolerance to simulated gastric and intestinal conditions. Additionally, when Vibrio harveyi bioluminescent reporter strain was used, the 3 cocultured strains cooperated to induce the activity of a quorum sensing (QS) molecule autoinducer-2 (AI-2), hinting a potential connection between phenotypic traits and QS in the cocultured strains. Importantly, LAB viable counts were significantly higher in yogurt co-fermented with Lactiplantibacillus plantarum NUC08, consistently throughout the storage period. In conclusion, the study demonstrates that the probiotic strain Lactiplantibacillus plantarum NUC08 can be employed in synergy with yogurt starter strains, affirming its potential for use in the development of functional fermented dairy products.

ORA47 is a transcriptional regulator of a general stress response hub.

Transcriptional regulators of the general stress response (GSR) reprogram the expression of selected genes to transduce informational signals into cellular events, ultimately manifested in a plant's ability to cope with environmental challenges. Identification of the core GSR regulatory proteins will uncover the principal modules and their mode of action in the establishment of adaptive responses. To define the GSR regulatory components, we employed a yeast-one-hybrid assay to identify the protein(s) binding to the previously established functional GSR motif, termed the rapid stress response element (RSRE). This led to the isolation of octadecanoid-responsive AP2/ERF-domain transcription factor 47 (ORA47), a methyl jasmonate inducible protein. Subsequently, ORA47 transcriptional activity was confirmed using the RSRE-driven luciferase (LUC) activity assay performed in the ORA47 loss- and gain-of-function lines introgressed into the 4xRSRE::Luc background. In addition, the prime contribution of CALMODULIN-BINDING TRANSCRIPTIONAL ACTIVATOR3 (CAMTA3) protein in the induction of RSRE was reaffirmed by genetic studies. Moreover, exogenous application of methyl jasmonate led to enhanced levels of ORA47 and CAMTA3 transcripts, as well as the induction of RSRE::LUC activity. Metabolic analyses illustrated the reciprocal functional inputs of ORA47 and CAMTA3 in increasing JA levels. Lastly, transient assays identified JASMONATE ZIM-domain1 (JAZ1) as a repressor of RSRE::LUC activity. Collectively, the present study provides fresh insight into the initial features of the mechanism that transduces informational signals into adaptive responses. This mechanism involves the functional interplay between the JA biosynthesis/signaling cascade and the transcriptional reprogramming that potentiates GSR. Furthermore, these findings offer a window into the role of intraorganellar communication in the establishment of adaptive responses.

Glycolysis induces Th2 cell infiltration and significantly affects prognosis and immunotherapy response to lung adenocarcinoma.

Glycolysis has a major role in cancer progression and can affect the tumor immune microenvironment, while its specific role in lung adenocarcinoma (LUAD) remains poorly studied. We obtained publicly available data from The Cancer Genome Atlas and Gene Expression Omnibus databases and used R software to analyze the specific role of glycolysis in LUAD. The Single Sample Gene Set Enrichment Analysis (ssGSEA) indicated a correlation between glycolysis and unfavorable clinical outcome, as well as a repression effect on the immunotherapy response of LUAD patients. Pathway enrichment analysis revealed a significant enrichment of MYC targets, epithelial-mesenchymal transition (EMT), hypoxia, G2M checkpoint, and mTORC1 signaling pathways in patients with higher activity of glycolysis. Immune infiltration analysis showed a higher infiltration of M0 and M1 macrophages in patients with elevated activity of glycolysis. Moreover, we developed a prognosis model based on six glycolysis-related genes, including DLGAP5, TOP2A, KIF20A, OIP5, HJURP, and ANLN. Both the training and validation cohorts demonstrated the high efficiency of prognostic prediction in this model, which identified that patients with high risk may have a poorer prognosis and lower sensitivity to immunotherapy. Additionally, we also found that Th2 cell infiltration may predict poorer survival and resistance to immunotherapy. The study indicated that glycolysis is significantly associated with poor prognosis in patients with LUAD and immunotherapy resistance, which might be partly dependent on the Th2 cell infiltration. Additionally, the signature comprised of six genes related to glycolysis showed promising predictive value for LUAD prognosis.

Translocation of vaginal and cervical low-abundance non-Lactobacillus bacteria notably associate with endometriosis: A pilot study.

The etiology remains to be understood for endometriosis (EMS) which affected health negatively for 10% of reproductive-age women globally. Emerging studies found the associations of EMS with genital microbiota dysbiosis. However, the role of vaginal and cervical microbiota is not fully understood for Chinese women. This study recruited forty Chinese women (21 healthy women and 19 EMS patients) to analyze vaginal and cervical microbiota using 16S rRNA amplicon sequencing method. For both sites, there were no significant differences for distribution of microbial samples between control and EMS group, which was concordant with dominated Lactobacillus in both groups. In contrast, we observed accumulation of several low-abundance genera in vaginal and cervical microbiota of EMS patients, such as Fannyhessea, Prevotella, Streptococcus, Bifidobacterium, Veillonella, Megasphaera and Sneathia. Random forest analysis found that translocation of these genera had the significant importance in differentiating EMS patients from controls. In addition, cervix/vagina ratio of these genera also associated with EMS severity. And these genera had notable associations with ascending infection-related functional pathways, including flagellar assembly, bacterial motility proteins, bacterial toxins and epithelial cell signaling in Helicobacter pylori infection. These findings suggest that translocation of specific genera between vaginal and cervical sites play a role in EMS.

The developmental relationship between nonsymbolic and symbolic fraction abilities.

A fundamental research question in quantitative cognition concerns the developmental relationship between nonsymbolic and symbolic quantitative abilities. This study examined this developmental relationship in abilities to process nonsymbolic and symbolic fractions. There were 99 6th graders (Mage = 11.86 years), 101 10th graders (Mage = 15.71 years), and 102 undergraduate and graduate students (Mage = 21.97 years) participating in this study, and their nonsymbolic and symbolic fraction abilities were measured with nonsymbolic and symbolic fraction comparison tasks, respectively. Nonsymbolic and symbolic fraction abilities were significantly correlated in all age groups even after controlling for the ability to process nonsymbolic absolute quantity and general cognitive abilities, including working memory and inhibitory control. Moreover, the strength of nonsymbolic-symbolic correlations was higher in 6th graders than in 10th graders and adults. These findings suggest a weakened association between nonsymbolic and symbolic fraction abilities during development, and this developmental pattern may be related with participants' increasing proficiency in symbolic fractions.

Identify GADD45G as a potential target of 4-methoxydalbergione in treatment of liver cancer: bioinformatics analysis and in vivo experiment.

BACKGROUND: The growth arrest and DNA damage-inducible gene gamma (GADD45G), an important member of GADD45 family, has been connected to the development of certain human cancers. Our previous studies have confirmed that GADD45G expression could be upregulated by 4-methoxydalbergione (4MOD) in liver cancer cells, but its potential pathological role in hepatocellular carcinoma (HCC) has not been fully understood. This study aimed to determine potential role of GADD45G in HCC, and the effects of 4-methoxydalbergione (4MOD) on the regulation of GADD45G expression in vivo were also analyzed. METHODS: Publicly available data and in-house immunohistochemistry (IHC) experiments were utilized to explore the expression profiles and clinical significance of GADD45G in HCC samples. Functional enrichment analysis based on GADD45G co-expression genes was used to excavate the molecular mechanism of GADD45G in HCC. We also conducted in vivo experiment on BALB/c nude mice to excavate the inhibitory effect of 4MOD on HCC and to evaluate the differences in the expression of GADD45G in xenograft tissues between the 4MOD-treated and untreated groups. RESULTS: GADD45G displayed significant low expression in HCC tissues. Downregulated expression of GADD45G was positively correlated with some high risk factors in HCC patients and predicted worse prognosis of HCC patients. There was a close association of GADD45G mRNA expression and immune cells, including neutrophils, NK cells, CD8 T cells, and macrophages. Co-expressed genes of GADD45G were involved in several pathways including cell cycle, carbon metabolism, and peroxisome. 4MOD could significantly suppress the growth of HCC in vivo, and this inhibitory effect was dependent on the upregulation of GADD45G expression. CONCLUSION: GADD45G expression can be used as a new clinical biomarker for HCC and GADD45G may be a potential target for the anti-cancer effect of 4MOD in liver cancer.

Arabidopsis TOE proteins convey a photoperiodic signal to antagonize CONSTANS and regulate flowering time.

Plants flower in an appropriate season to allow sufficient vegetative development and position flower development in favorable environments. In Arabidopsis, CONSTANS (CO) and FLAVIN-BINDING KELCH REPEAT F-BOX1 (FKF1) promote flowering by inducing FLOWER LOCUS T (FT) expression in the long-day afternoon. The CO protein is present in the morning but could not activate FT expression due to unknown negative mechanisms, which prevent premature flowering before the day length reaches a threshold. Here, we report that TARGET OF EAT1 (TOE1) and related proteins interact with the activation domain of CO and CO-like (COL) proteins and inhibit CO activity. TOE1 binds to the FT promoter near the CO-binding site, and reducing TOE function results in a morning peak of the FT mRNA. In addition, TOE1 interacts with the LOV domain of FKF1 and likely interferes with the FKF1-CO interaction, resulting in partial degradation of the CO protein in the afternoon to prevent premature flowering.

A plastidial retrograde signal potentiates biosynthesis of systemic stress response activators.

Plants employ an array of intricate and hierarchical signaling cascades to perceive and transduce informational cues to synchronize and tailor adaptive responses. Systemic stress response (SSR) is a recognized complex signaling and response network quintessential to plant's local and distal responses to environmental triggers; however, the identity of the initiating signals has remained fragmented. Here, we show that both biotic (aphids and viral pathogens) and abiotic (high light and wounding) stresses induce accumulation of the plastidial-retrograde-signaling metabolite methylerythritol cyclodiphosphate (MEcPP), leading to reduction of the phytohormone auxin and the subsequent decreased expression of the phosphatase PP2C.D1. This enables phosphorylation of mitogen-activated protein kinases 3/6 and the consequential induction of the downstream events ultimately, resulting in biosynthesis of the two SSR priming metabolites pipecolic acid and N-hydroxy-pipecolic acid. This work identifies plastids as a major initiation site, and the plastidial retrograde signal MEcPP as an initiator of a multicomponent signaling cascade potentiating the biosynthesis of SSR activators, in response to biotic and abiotic triggers.

The PROTEIN PHOSPHATASE4 Complex Promotes Transcription and Processing of Primary microRNAs in Arabidopsis.

PROTEIN PHOSPHATASE4 (PP4) is a highly conserved Ser/Thr protein phosphatase found in yeast, plants, and animals. The composition and functions of PP4 in plants are poorly understood. Here, we uncovered the complexity of PP4 composition and function in Arabidopsis (Arabidopsis thaliana) and identified the composition of one form of PP4 containing the regulatory subunit PP4R3A. We show that PP4R3A, together with one of two redundant catalytic subunit genes, PROTEIN PHOSPHATASE X (PPX)1 and PPX2, promotes the biogenesis of microRNAs (miRNAs). PP4R3A is a chromatin-associated protein that interacts with RNA polymerase II and recruits it to the promoters of miRNA-encoding (MIR) genes to promote their transcription. PP4R3A likely also promotes the cotranscriptional processing of miRNA precursors, because it recruits the microprocessor component HYPONASTIC LEAVES1 to MIR genes and to nuclear dicing bodies. Finally, we show that hundreds of introns exhibit splicing defects in pp4r3a mutants. Together, this study reveals roles for Arabidopsis PP4 in transcription and nuclear RNA metabolism.

Long-Term Environmental Enrichment Relieves Dysfunctional Cognition and Synaptic Protein Levels Induced by Prenatal Inflammation in Older CD-1 Mice.

A mounting body of evidence suggests that prenatal inflammation may enhance the rate of age-associated cognitive decline and may involve aberrant amounts of synaptic proteins in the hippocampus, including synaptotagmin-1 (Syt1) and activity-regulated cytoskeleton-associated protein (Arc). However, little is known about the specific impact of adolescent environmental enrichment (EE) on age-associated cognitive decline and the changes in synaptic proteins caused by prenatal inflammation. In this study, CD-1 mice in late pregnancy were given intraperitoneal doses of lipopolysaccharide (LPS, 50 µg/kg) or normal saline. Offspring arising from LPS dams were divided into a LPS group and a LPS plus EE (LPS-E) group. The LPS-E mice were exposed to EE from 2 months of age until the end of the experiment (3 or 15 months old). The Morris water maze (MWM) was used to assess the spatial learning and memory capacities of experimental mice, while western blotting and RNA-scope were used to determine the expression levels of Arc and Syt1 in the hippocampus at the protein and mRNA levels, respectively. Analysis revealed that at 15 months of age, the control mice experienced a reduction in cognitive ability and elevated expression levels of Arc and Syt1 genes when compared to control mice at 3 months of age. The LPS-E group exhibited better cognition and lower protein and mRNA levels of Arc and Syt1 than mice in the LPS group of the same age. However, the enriched environment mitigated but did not counteract, the effects of prenatal inflammation on cognitive and synaptic proteins when tested at either 3 or 15 months of age. Our findings revealed that long-term environmental enrichment improved the expression levels of synaptic proteins in CD-1 mice and that this effect was linked to the dysfunctional cognition caused by prenatal inflammation; this process may also be involved in the reduction of hippocampal Arc and Syt1 gene expression.

The eukaryotic MEP-pathway genes are evolutionarily conserved and originated from Chlaymidia and cyanobacteria.

BACKGROUND: Isoprenoids are the most ancient and essential class of metabolites produced in all organisms, either via mevalonate (MVA)-and/or methylerythritol phosphate (MEP)-pathways. The MEP-pathway is present in all plastid-bearing organisms and most eubacteria. However, no comprehensive study reveals the origination and evolutionary characteristics of MEP-pathway genes in eukaryotes. RESULTS: Here, detailed bioinformatics analyses of the MEP-pathway provide an in-depth understanding the evolutionary history of this indispensable biochemical route, and offer a basis for the co-existence of the cytosolic MVA- and plastidial MEP-pathway in plants given the established exchange of the end products between the two isoprenoid-biosynthesis pathways. Here, phylogenetic analyses establish the contributions of both cyanobacteria and Chlamydiae sequences to the plant's MEP-pathway genes. Moreover, Phylogenetic and inter-species syntenic block analyses demonstrate that six of the seven MEP-pathway genes have predominantly remained as single-copy in land plants in spite of multiple whole-genome duplication events (WGDs). Substitution rate and domain studies display the evolutionary conservation of these genes, reinforced by their high expression levels. Distinct phenotypic variation among plants with reduced expression levels of individual MEP-pathway genes confirm the indispensable function of each nuclear-encoded plastid-targeted MEP-pathway enzyme in plant growth and development. CONCLUSION: Collectively, these findings reveal the polyphyletic origin and restrict conservation of MEP-pathway genes, and reinforce the potential function of the individual enzymes beyond production of the isoprenoids intermediates.

Dihydrotanshinone I Is Effective against Drug-Resistant Helicobacter pylori In Vitro and In Vivo.

Helicobacter pylori is a major global pathogen and has been implicated in gastritis, peptic ulcer, and gastric carcinoma. The efficacy of the extensive therapy of H. pylori infection with antibiotics is compromised by the development of drug resistance and toxicity toward human gut microbiota, which urgently demands novel and selective antibacterial strategies. The present study was mainly performed to assess the in vitro and in vivo effects of a natural herbal compound, dihydrotanshinone I (DHT), against standard and clinical H. pylori strains. DHT demonstrated effective antibacterial activity against H. pyloriin vitro (MIC50/90, 0.25/0.5 µg/ml), with no development of resistance during continuous serial passaging. Time-kill curves showed strong time-dependent bactericidal activity for DHT. Also, DHT eliminated preformed biofilms and killed biofilm-encased H. pylori cells more efficiently than the conventional antibiotic metronidazole. In mouse models of multidrug-resistant H. pylori infection, dual therapy with DHT and omeprazole showed in vivo killing efficacy superior to that of the standard triple-therapy approach. Moreover, DHT treatment induces negligible toxicity against normal tissues and exhibits a relatively good safety index. These results suggest that DHT could be suitable for use as an anti-H. pylori agent in combination with a proton pump inhibitor to eradicate multidrug-resistant H. pylori.

Long-chain unsaturated fatty acids are involved in the viability and itraconazole susceptibility of Aspergillus fumigatus.

The prevalence of invasive aspergillosis with azole resistance is increasing, but the mechanisms underlying the development of resistance and treatment strategies are still limited. The present work is focused on finding a relationship between long-chain unsaturated fatty acids (LCUFAs), Aspergillus fumigatus development, and antifungal resistance. The effects of LCUFAs on antifungal agents in vitro were determined, and the stearic acid desaturase gene (sdeA) of A. fumigatus was characterized. In in vitro antifungal tests, LCUFAs antagonized the antifungal activity of itraconazole by extracting it from media, thereby preventing it from entering cells. The OA auxotrophic phenotype caused by an sdeA deletion confirmed that SdeA was required for OA biosynthesis in A. fumigatus. Furthermore, several low-level sdeA-overexpressing mutants with impaired vegetative growth phenotypes were successfully constructed. Additionally, an sdeA-overexpressing mutant, OEsdeA-5, showed lowered sensitivity levels to itraconazole. Moreover, RNA sequencing of OEsdeA-5 revealed that the altered gene-expression pattern. Through targeted metabolomics, decreased palmitic acid and stearic acid contents, accompanied by higher palmitoleic acid, margaroleic acid, and OA production levels, were found in OEsdeA-5. This study provides a novel insight of understanding of azole resistance and a potential target for drug development.

Retrograde Induction of phyB Orchestrates Ethylene-Auxin Hierarchy to Regulate Growth.

Exquisitely regulated plastid-to-nucleus communication by retrograde signaling pathways is essential for fine-tuning of responses to the prevailing environmental conditions. The plastidial retrograde signaling metabolite methylerythritol cyclodiphosphate (MEcPP) has emerged as a stress signal transduced into a diverse ensemble of response outputs. Here, we demonstrate enhanced phytochrome B protein abundance in red light-grown MEcPP-accumulating ceh1 mutant Arabidopsis (Arabidopsis thaliana) plants relative to wild-type seedlings. We further establish MEcPP-mediated coordination of phytochrome B with auxin and ethylene signaling pathways and uncover differential hypocotyl growth of red light-grown seedlings in response to these phytohormones. Genetic and pharmacological interference with ethylene and auxin pathways outlines the hierarchy of responses, placing ethylene epistatic to the auxin signaling pathway. Collectively, our findings establish a key role of a plastidial retrograde metabolite in orchestrating the transduction of a repertoire of signaling cascades. This work positions plastids at the zenith of relaying information coordinating external signals and internal regulatory circuitry to secure organismal integrity.