Tumor Cell Lysate-Based Multifunctional Nanoparticles Facilitate Enhanced mRNA Delivery and Immune Stimulation for Melanoma Gene Therapy.

Messenger ribonucleic acid (mRNA)-based gene therapy has great potential for cancer gene therapy. However, the effectiveness of mRNA in cancer therapy needs to be further improved, and the delivery efficiency and instability of mRNA limit the application of mRNA-based products. Both the delivery efficiency can be elevated by cell-penetrating peptide modification, and the immune response can be enhanced by tumor cell lysate stimulation, representing an advantageous strategy to expand the effectiveness of mRNA gene therapy. Therefore, it is vital to exploit a vector that can deliver high-efficiency mRNA with codelivery of tumor cell lysate to induce specific immune responses. We previously reported that DMP cationic nanoparticles, formed by the self-assembly of DOTAP and mPEG-PCL, can deliver different types of nucleic acids. DMP has been successfully applied in gene therapy research for various tumor types. Here, we encapsulated tumor cell lysates with DMP nanoparticles and then modified them with a fused cell-penetrating peptide (TAT-iRGD) to form an MLSV system. The MLSV system was loaded with encoded Bim mRNA, forming the MLSV/Bim complex. The average size of the synthesized MLSV was 191.4 nm, with a potential of 47.8 mV. The MLSV/mRNA complex promotes mRNA absorption through caveolin-mediated endocytosis, with a transfection rate of up to 68.6% in B16 cells. The MLSV system could also induce the maturation and activation of dendritic cells, obviously promoting the expression of CD80, CD86, and MHC-II both in vitro and in vivo. By loading the encoding Bim mRNA, the MLSV/Bim complex can inhibit cell proliferation and tumor growth, with inhibition rates of up to 87.3% in vitro. Similarly, the MLSV/Bim complex can inhibit tumor growth in vivo, with inhibition rates of up to 78.7% in the B16 subcutaneous tumor model and 63.3% in the B16 pulmonary metastatic tumor model. Our results suggest that the MLSV system is an advanced candidate for mRNA-based immunogene therapy.

Functionally and structurally distinct fusiform face area(s) in over 1000 participants.

The fusiform face area (FFA) is a widely studied region causally involved in face perception. Even though cognitive neuroscientists have been studying the FFA for over two decades, answers to foundational questions regarding the function, architecture, and connectivity of the FFA from a large (N>1000) group of participants are still lacking. To fill this gap in knowledge, we quantified these multimodal features of fusiform face-selective regions in 1053 participants in the Human Connectome Project. After manually defining over 4,000 fusiform face-selective regions, we report five main findings. First, 68.76% of hemispheres have two cortically separate regions (pFus-faces/FFA-1 and mFus-faces/FFA-2). Second, in 26.69% of hemispheres, pFus-faces/FFA-1 and mFus-faces/FFA-2 are spatially contiguous, yet are distinct based on functional, architectural, and connectivity metrics. Third, pFus-faces/FFA-1 is more face-selective than mFus-faces/FFA-2, and the two regions have distinct functional connectivity fingerprints. Fourth, pFus-faces/FFA-1 is cortically thinner and more heavily myelinated than mFus-faces/FFA-2. Fifth, face-selective patterns and functional connectivity fingerprints of each region are more similar in monozygotic than dizygotic twins and more so than architectural gradients. As we share our areal definitions with the field, future studies can explore how structural and functional features of these regions will inform theories regarding how visual categories are represented in the brain.

Diverse Secondary Metabolites from the Coral-Derived Fungus Aspergillus hiratsukae SCSIO 5Bn1003.

Three new metabolites, including a cyclic tetrapeptide asperhiratide (1), an ecdysteroid derivative asperhiratine (2), and a sesquiterpene lactone asperhiratone (3), were isolated and identified from the soft coral-derived fungus Aspergillus hiratsukae SCSIO 5Bn1003, together with 10 known compounds. Their structures were elucidated via spectroscopic analysis, X-ray diffraction analysis, and electronic circular dichroism calculations. In addition, the absolute configuration of 1 was determined by Marfey's technique and an analysis of the acid hydrolysates using a chiral phase HPLC column. Among all the compounds, 6 and 8 showed medium cytotoxic activities against four tumor cell lines (SF-268, HepG-2, MCF-7, and A549), with IC50 values ranging from 31.03 ± 3.04 to 50.25 ± 0.54 µM. Meanwhile, they strongly inhibited α-glucosidase activities, with IC50 values of 35.73 ± 3.94 and 22.00 ± 2.45 µM, which were close to and even stronger than the positive control acarbose (IC50 = 32.92 ± 1.03 µM). Compounds 6-8 showed significant antibacterial activities against Bacillus subtilis, with MIC values of 10.26 ± 0.76 µM, 17.00 ± 1.25 µM, and 5.30 ± 0.29 µM, respectively. Compounds 9 and 12 exhibited potent radical scavenging activities against DPPH, with IC50 values of 12.23 ± 0.78 µM and 7.38 ± 1.16 µM. In addition, asperhiratide (1) was evaluated for anti-angiogenic activities in the in vivo zebrafish model, which showed a weak inhibitory effect on intersegmental vessel (ISV) formation.

Chevalones H-M: Six New α-Pyrone Meroterpenoids from the Gorgonian Coral-Derived Fungus Aspergillus hiratsukae SCSIO 7S2001.

Six new α-pyrone meroterpenoid chevalones H-M (1-6), together with six known compounds (7-12), were isolated from the gorgonian coral-derived fungus Aspergillus hiratsukae SCSIO 7S2001 collected from Mischief Reef in the South China Sea. Their structures, including absolute configurations, were elucidated on the basis of spectroscopic analysis and X-ray diffraction data. Compounds 1-5 and 7 showed different degrees of antibacterial activity with MIC values of 6.25-100 µg/mL. Compound 8 exhibited potent cytotoxicity against SF-268, MCF-7, and A549 cell lines with IC50 values of 12.75, 9.29, and 20.11 µM, respectively.

Aging in Chinatowns: the Meaning of Place and Aging Experience for Older Immigrants.

The concept of "Aging in place" has not been fully validated among older immigrant groups living in diverse cultures. The study used a qualitative research approach and interviewed Chinese immigrant older adults across three Chinese enclave communities in New York City to identify whether Chinatowns are a place for Chinese immigrants to age and explore their experience of aging in Chinatowns. The findings showed that Chinese immigrants did consider Chinatown as the place, which conveyed practical, linguistic, social, emotional and cultural meaning. Aging in Chinatown, older adults sought independence, security, and autonomy through various social resources. However, older adults, especially newly arrived immigrants, have faced obstacles that undermine their aging experience. Older immigrants' unique aging experience has provided profound insight in understanding migration and AIP, which help develop proper policies and programs to support the AIP initiative.

Euroticins A and B, Two Pairs of Highly Constructed Salicylaldehyde Derivative Enantiomers from a Marine-Derived Fungus Eurotium sp. SCSIO F452.

Two pairs of salicylaldehyde derivative enantiomers, euroticins A and B (1 and 2), were isolated from a marine-derived fungus Eurotium sp. SCSIO F452. Compound 1 possesses a highly constructed 6/6/6/5/7 pentacyclic structure featuring an unprecedented 2,11-dioxatricyclo[5.3.1.04,8]undecane core. Compound 2 represents the first example of 6/6/6/6 tetracyclic salicylaldehyde derivative. Their structures were established by spectroscopic analyses, X-ray diffraction, and electronic circular dichroism (ECD) and 13C NMR calculations. Compounds (+)-2 and (-)-2 exhibited remarkable antioxidative activities.

A probabilistic atlas of the human motion complex built from large-scale functional localizer data.

Accurate motion perception is critical to dealing with the changing dynamics of our visual world. A cluster known as the human MT+ complex (hMT+) has been identified as a core region involved in motion perception. Several atlases defined based on cytoarchitecture, retinotopy, connectivity, and multimodal features include homologs of the hMT+. However, an hMT+ atlas defined directly based on this region's response for motion is still lacking. Here, we identified the hMT+ based on motion responses from functional magnetic resonance imaging (fMRI) localizer data in 509 participants and then built a probabilistic atlas of the hMT+. As a result, four main findings were revealed. First, the hMT+ showed large interindividual variability across participants. Second, the atlases stabilized when the number of participants used to build the atlas was more than 100. Third, the functional hMT+ showed good agreement with the hMT+ atlases built based on cytoarchitecture, retinotopy, and connectivity, suggesting a good structural-functional correspondence. Fourth, tests on multiple fMRI data sets acquired from independent participants, imaging parameters and paradigms revealed that the functional hMT+ showed higher sensitivity than all other atlases in ROI analysis except that connectivity and multimodal hMT+ atlases in the left hemisphere could infrequently attain comparable sensitivity to the functional atlas. Taken together, our findings reveal the benefit of using large-scale functional localizer data to build a reliable and representative hMT+ atlas. Our atlas is freely available for download; it can be used to localize the hMT+ in individual participants when functional localizer data are not available.

Amplitude of Low-Frequency Fluctuations During Resting State Differentially Predicts Authentic and Hubristic Pride.

OBJECTIVE: Pride is an important, self-conscious emotion composed of two distinct conceptual facets: arrogant, egotistic "hubristic pride," and pro-social, achievement-oriented "authentic pride." However, little is known about the neural basis of the two facets of pride. Here, we investigated the association between spontaneous brain activity and these two facets of pride in resting state. METHOD: We measured 276 participants on authentic and hubristic pride. The fractional amplitude of low-frequency fluctuations (fALFF) was used to identify pride-related regions. RESULTS: The results revealed individual differences in authentic pride were associated with the fALFF in the bilateral superior temporal gyrus (STG), which has been implicated in social processing. In contrast, individual differences in hubristic pride were associated with the fALFF in the left orbitofrontal cortex (OFC) and posterior cingulate cortex (PCC), which have been implicated in self-referential and reward processing. CONCLUSIONS: Together, our results provide initial evidence for the distinct neural substrates for authentic and hubristic pride.

Eurotiumins A⁻E, Five New Alkaloids from the Marine-Derived Fungus Eurotium sp. SCSIO F452.

Three new prenylated indole 2,5-diketopiperazine alkaloids (1⁻3) with nine known ones (5⁻13), one new indole alkaloid (4), and one new bis-benzyl pyrimidine derivative (14) were isolated and characterized from the marine-derived fungus Eurotium sp. SCSIO F452. 1 and 2, occurring as a pair of diastereomers, both presented a hexahydropyrrolo[2,3-b]indole skeleton. Their chemical structures, including absolute configurations, were elucidated by 1D and 2D NMR, HRESIMS, quantum chemical calculations of electronic circular dichroism, and single crystal X-ray diffraction experiments. Most isolated compounds were screened for antioxidative potency. Compounds 3, 5, 6, 7, 9, 10, and 12 showed significant radical scavenging activities against DPPH with IC50 values of 13, 19, 4, 3, 24, 13, and 18 µM, respectively. Five new compounds were evaluated for cytotoxic activities.

Theoretical study of the reaction of hydroxyl radicals with uridine: the influence of ribose and solvent.

The reaction of hydroxyl radicals (˙OH) with uridine has been investigated using density functional theory (DFT). The influence of the environment was investigated using water and benzene as models for polar and non-polar surroundings, in addition to gas phase calculations. In order to imitate a much more realistic situation to that found in RNA, the ribose of the uracil ring was considered. Different pathways for the reaction of ˙OH with uridine were considered, involving addition and hydrogen abstraction reactions, with contributions to the overall reaction being around 99.9% and 0.1% at 298 K, respectively. The cis- and trans-U5OH addition reactions contributed around 62.2% and 35.6% in the polar surroundings, and about 70.1% and 26.8% in the non-polar surroundings, respectively, to the overall reaction. The cis-U5OH adduct was found to be the major product of the title reaction for all of the modeled environments. The steric effects of the ribose on the uracil ring makes U6OH addition more difficult than U5OH addition. Theoretical study of the reaction of ˙OH with uridine could help us to better understand oxidative damage to DNA and RNA. The good agreement found between the calculated data and the available experimental data supports the methodology used in this work, as well as the data reported here for the first time.

Examining First and Second-Level Digital Divide at the Intersection of Race/Ethnicity, Gender, and Socioeconomic Status: An Analysis of the National Health and Aging Trends Study.

BACKGROUND AND OBJECTIVES: Significant societal and technological changes in the 2010s called for an up-to-date understanding of the digital divide among older adults in the United States (U.S.). This trend study aimed to examine the effects of race/ethnicity and the intersecting effects of race/ethnicity with other marginalized identities related to gender, income, education, and occupation on the first- and second-level digital divide. RESEARCH DESIGN AND METHODS: Utilizing a nationally representative sample of older community dwellers from the National Health and Aging Trends Study, we conducted weighted logistic regressions at three time points (2011/2013, 2015, and 2019). The first-level digital divide was measured by access to working phones or computers/laptops; the second-level divide was measured by seven activities in personal-task, social, and health-related Internet use. RESULTS: The first-level racial/ethnic digital divide became non-significant in 2019, whereas the disparities in all second-level measures persisted. The intersecting effects of race/ethnicity with low education and/or low income became non-significant in 2019 for personal-task use. However, the interactions with low education and/or low income became significant for social and health-related use in 2015 and/or 2019. DISCUSSION AND IMPLICATIONS: This study highlights the persistence of the second-level racial/ethnic digital divide among older community dwellers in the U.S., especially the exacerbated social and health-related digital divide for people of color with low socioeconomic status. By considering intersections of marginalized social identities, policymakers and stakeholders should develop targeted strategies to bridge the digital divide, promote health outcomes, and reduce health disparities.

Older adults' online activities and cognition: Investigating the psychological mechanisms and age and gender differences.

OBJECTIVES: This study aimed to investigate psychological mechanisms underlying the association between older adults' Internet use and cognition and examine potential age and gender group differences. METHODS: 2064 older participants were extracted from the Waves 2012, 2013, and 2016 Health and Retirement Study. Internet use was measured by two sets of variables: Internet access and different types of online activities (i.e., informational use, social use, online shopping, and online banking). Path analyses were applied to test the proposed mechanisms via three mediators (i.e., loneliness, depressive symptoms, and perceived control). Multi-group analyses were conducted to examine the potential group differences. RESULTS: Internet use was positively associated with cognition. Despite the large direct effect, small but significant indirect effects via depressive symptoms and perceived control were identified across all online activities. Multi-group analyses revealed age-group differences in the mechanisms: depressive symptoms mediated the effects of all online activities on cognition among young-old adults, while perceived control mediated all the effects among old-old adults. Gender group differences were also identified: depressive symptoms mediated the effects of all online activities on cognition among older women and most online activities among older men, whereas perceived control mediated the associations between informational and instrumental (i.e., online shopping and banking) use and cognition among older men. DISCUSSION: This study highlights the mediating effect of depressive symptoms and perceived control and age and gender differences regarding the Internet use-cognition association. Internet-based cognitive interventions should consider these psychological mediators and age and gender differences for the best results.

Bridging the Access Gap: A Decade of Narrowing the Digital Divide for Hispanic Older Adults in the United States.

Objectives: This study examines the digital divide between Hispanic and non-Hispanic White older adults in the United States from 2011 to 2021, using an intersectionality perspective. Methods: Eleven waves of data from the National Health and Aging Trend were analyzed through multilevel logistic regression, focusing on the intersection between race/ethnicity and time (measured by survey waves) within gender, education, and income subgroups. The digital divide was measured by Internet access. Results: Despite the enduring digital access gap, the longitudinal analysis revealed a narrowing digital divide between Hispanic and non-Hispanic White older adults, especially those with low education and income. Discussion: The observed trend signifies progress in digital inclusivity initiatives yet highlights ongoing challenges in fully bridging the divide for the Hispanic older adult community. Future efforts should not only focus on access but also on enhancing the effective usage of digital technologies to promote health equity and well-being.

Dual-mRNA Delivery Using Tumor Cell Lysate-Based Multifunctional Nanoparticles as an Efficient Colon Cancer Immunogene Therapy.

Background: Messenger RNA (mRNA)-based immunogene therapy holds significant promise as an emerging tumor therapy approach. However, the delivery efficiency of existing mRNA methods and their effectiveness in stimulating anti-tumor immune responses require further enhancement. Tumor cell lysates containing tumor-specific antigens and biomarkers can trigger a stronger immune response to tumors. In addition, strategies involving multiple gene therapies offer potential optimization paths for tumor gene treatments. Methods: Based on the previously developed ideal mRNA delivery system called DOTAP-mPEG-PCL (DMP), which was formed through the self-assembly of 1.2-dioleoyl-3-trimethylammonium-propane (DOTAP) and methoxypoly (ethylene glycol)-b-poly (ε-caprolactone) (mPEG-PCL), we introduced a fused cell-penetrating peptide (fCPP) into the framework and encapsulated tumor cell lysates to form a novel nanovector, termed CLSV system (CLS: CT26 tumor cell lysate, V: nanovector). This system served a dual purpose of facilitating the delivery of two mRNAs and enhancing tumor immunogene therapy through tumor cell lysates. Results: The synthesized CLSV system had an average size of 241.17 nm and a potential of 39.53 mV. The CLSV system could not only encapsulate tumor cell lysates, but also deliver two mRNAs to tumor cells simultaneously, with a transfection efficiency of up to 60%. The CLSV system effectively activated the immune system such as dendritic cells to mature and activate, leading to an anti-tumor immune response. By loading Bim-encoded mRNA and IL-23A-encoded mRNA, CLSV/Bim and CLSV/IL-23A complexes were formed, respectively, to further induce apoptosis and anti-tumor immunity. The prepared CLSV/dual-mRNA complex showed significant anti-cancer effects in multiple CT26 mouse models. Conclusion: Our results suggest that the prepared CLSV system is an ideal delivery system for dual-mRNA immunogene therapy.

Intra- and inter-rater reliability of muscle and fat thickness measurements obtained using portable ultrasonography in older adults.

BACKGROUND & AIMS: Ultrasonography (US) is a promising tool for assessing body composition, offering accuracy and accessibility. However, technician skills and equipment characteristics can impact measurement reliability. We aimed to evaluate the intra- and inter-rater reliability of two evaluators using A-mode Portable Ultrasound to measure muscle and fat thickness in Brazilian older adults. METHODS: Quantitative cross-sectional study carried out with 150 community-dwelling older adults of Campinas-SP-Brazil, recruited in a retirement preparation program and a geriatric outpatient care unit. Scans of nine anatomical points were performed using the portable ultrasound in A-mode (BodyMetrix Pro System BX2000; Livermore, CA), with 6 scans per location and 3 measurements taken by each evaluator. After the selection and analysis of the generated images, muscle and fat thickness were measured. Reliability estimates between measures of the same evaluator (intra-rater) and between evaluators (inter-rater) were assessed using intraclass correlation coefficients (ICC), and differences within and between technicians were assessed using one-way ANOVA. Analyses were carried out for the overall sample and stratified by sex and by nutritional status. RESULTS: Excellent ICC values (>0.90) were found for subcutaneous fat thickness in intra- and inter-rater reliability analyses. The lowest ICC values were observed for deep abdominal fat thickness measured by evaluator 1 (ICC = 0.90) and evaluator 2 (ICC = 0.87), as well as in the inter-rater analysis (ICC = 0.85). Muscle thickness measurements had satisfactory ICC values for triceps, biceps, anterior thigh, and calf, ranging from moderate to good (ICC 0.50-0.90). CONCLUSION: A portable A-mode ultrasound demonstrates excellent reliability among both intra- and inter-raters for assessing fat thickness but only moderate for muscle thickness in older adults. Hence, this could prompt inquiries regarding the sole reliance on this tool for quantifying muscle mass and examining sarcopenia in older adults. To our knowledge, this study represents the first assessment of reliability for a portable A-mode ultrasound device conducted with older adults.

Regulation of Burkholderia cenocepacia virulence by the fatty acyl-CoA ligase DsfR as a response regulator of quorum sensing signal.

Quorum sensing (QS) is a cell-to-cell communication mechanism mediated by small diffusible signaling molecules. Previous studies showed that RpfR controls Burkholderia cenocepacia virulence as a cis-2-dodecenoic acid (BDSF) QS signal receptor. Here, we report that the fatty acyl-CoA ligase DsfR (BCAM2136), which efficiently catalyzes in vitro synthesis of lauryl-CoA and oleoyl-CoA from lauric acid and oleic acid, respectively, acts as a global transcriptional regulator to control B. cenocepacia virulence by sensing BDSF. We show that BDSF binds to DsfR with high affinity and enhances the binding of DsfR to the promoter DNA regions of target genes. Furthermore, we demonstrate that the homolog of DsfR in B. lata, RS02960, binds to the target gene promoter, and perception of BDSF enhances the binding activity of RS02960. Together, these results provide insights into the evolved unusual functions of DsfR that control bacterial virulence as a response regulator of QS signal.

Doctors' recommendations and healthy lifestyle behaviors among individuals with hypertension in Brazil.

Little is known about whether doctors' recommendations encourage healthy behaviors among individuals with hypertension in Brazil. This study examined the biological, social, and health factors related to doctor's recommendations and the associations between doctor's recommendations and healthy behaviors. The sample consisted of individuals with hypertension (N = 18,260) from Brazil's 2019 National Health Survey. The outcomes examined included smoking, drinking, diet, salt intake, physical activity, and doctor visits. Study findings indicated that more than 80% of people with hypertension in Brazil received doctors' recommendations to adhere to medical care and engage in healthy behaviors. Those who received recommendations were more likely to practice healthy eating and exercise regularly but also to be obese/overweight, smoke, and drink excessively. Nonetheless, the findings concerning diet and exercise suggest the value of doctors' recommendations for individuals with hypertension in Brazil.

Elastic Fibre Prestressing Mechanics within a Polymeric Matrix Composite.

The elastic fibre prestressing (EFP) technique has been developed to balance the thermal residual stress generated during curing of a polymeric composite. The continuous fibre reinforcements are prestressed and then impregnated into a polymeric matrix, where the prestress load is only removed after the resin is fully cured in order to produce an elastically prestressed polymeric matrix composite (EPPMC). Although the EFP is active in improving the static mechanical performance of a composite, its mechanics on dynamic mechanical performance and viscoelasticity of a composite is still limited. Here, we established a theoretical model in order to decouple the EFP principle, aiming to better analyse the underlying mechanics. A bespoke fibre prestressing rig was then developed to apply tension on a unidirectional carbon-fibre-reinforced epoxy prepreg to produce EPPMC samples with various EFP levels. The effects of EFP were then investigated by carrying out both static and dynamic mechanical testing, as well as the viscoelastic creep performance. It was found that there is an optimal level of EFP in order to maximise the prestress benefits, whilst the EFP is detrimental to the fibre/matrix interface. The EFP mechanisms are then proposed based on these observations to reveal the in-plane stress evolutions within a polymeric composite.

A 4-Hydroxybenzoic Acid-Mediated Signaling System Controls the Physiology and Virulence of Shigella sonnei.

Many bacteria use small molecules, such as quorum sensing (QS) signals, to perform intraspecies signaling and interspecies or interkingdom communication. Previous studies demonstrated that some bacteria regulate their physiology and pathogenicity by employing 4-hydroxybenzoic acid (4-HBA). Here, we report that 4-HBA controls biological functions, virulence, and anthranilic acid production in Shigella sonnei. The biosynthesis of 4-HBA is performed by UbiC (SSON_4219), which is a chorismate pyruvate-lyase that catalyzes the conversion of chorismate to 4-HBA. Deletion of ubiC caused S. sonnei to exhibit impaired phenotypes, including impaired biofilm formation, extracellular polysaccharide (EPS) production, and virulence. In addition, we found that 4-HBA controls the physiology and virulence of S. sonnei through the response regulator AaeR (SSON_3385), which contains a helix-turn-helix (HTH) domain and a LysR substrate-binding (LysR_substrate) domain. The same biological functions are controlled by AaeR and the 4-HBA signal, and 4-HBA-deficient mutant phenotypes were rescued by in trans expression of AaeR. We found that 4-HBA binds to AaeR and then enhances the binding of AaeR to the promoter DNA regions in target genes. Moreover, we revealed that 4-HBA from S. sonnei reduces the competitive fitness of Candida albicans by interfering with morphological transition. Together, our results suggested that the 4-HBA signaling system plays crucial roles in bacterial physiology and interkingdom communication. IMPORTANCE Shigella sonnei is an important pathogen in human intestines. Following previous findings that some bacteria employ 4-HBA as a QS signal to regulate biological functions, we demonstrate that 4-HBA controls the physiology and virulence of S. sonnei. This study is significant because it identifies both the signal synthase UbiC and receptor AaeR and unveils the signaling pathway of 4-HBA in S. sonnei. In addition, this study also supports the important role of 4-HBA in microbial cross talk, as 4-HBA strongly inhibits hyphal formation by Candida albicans. Together, our findings describe the dual roles of 4-HBA in both intraspecies signaling and interkingdom communication.

Regulation of the physiology and virulence of Ralstonia solanacearum by the second messenger 2',3'-cyclic guanosine monophosphate.

Previous studies have demonstrated that bis-(3',5')-cyclic diguanosine monophosphate (bis-3',5'-c-di-GMP) is a ubiquitous second messenger employed by bacteria. Here, we report that 2',3'-cyclic guanosine monophosphate (2',3'-cGMP) controls the important biological functions, quorum sensing (QS) signaling systems and virulence in Ralstonia solanacearum through the transcriptional regulator RSp0980. This signal specifically binds to RSp0980 with high affinity and thus abolishes the interaction between RSp0980 and the promoters of target genes. In-frame deletion of RSp0334, which contains an evolved GGDEF domain with a LLARLGGDQF motif required to catalyze 2',3'-cGMP to (2',5')(3',5')-cyclic diguanosine monophosphate (2',3'-c-di-GMP), altered the abovementioned important phenotypes through increasing the intracellular 2',3'-cGMP levels. Furthermore, we found that 2',3'-cGMP, its receptor and the evolved GGDEF domain with a LLARLGGDEF motif also exist in the human pathogen Salmonella typhimurium. Together, our work provides insights into the unusual function of the GGDEF domain of RSp0334 and the special regulatory mechanism of 2',3'-cGMP signal in bacteria.