A bacterial virulence protein promotes pathogenicity by inhibiting the bacterium's own F1Fo ATP synthase.

Several intracellular pathogens, including Salmonella enterica and Mycobacterium tuberculosis, require the virulence protein MgtC to survive within macrophages and to cause a lethal infection in mice. We now report that, unlike secreted virulence factors that target the host vacuolar ATPase to withstand phagosomal acidity, the MgtC protein acts on Salmonella's own F1Fo ATP synthase. This complex couples proton translocation to ATP synthesis/hydrolysis and is required for virulence. We establish that MgtC interacts with the a subunit of the F1Fo ATP synthase, hindering ATP-driven proton translocation and NADH-driven ATP synthesis in inverted vesicles. An mgtC null mutant displays heightened ATP levels and an acidic cytoplasm, whereas mgtC overexpression decreases ATP levels. A single amino acid substitution in MgtC that prevents binding to the F1Fo ATP synthase abolishes control of ATP levels and attenuates pathogenicity. MgtC provides a singular example of a virulence protein that promotes pathogenicity by interfering with another virulence protein.

Brain decoding of spontaneous thought: Predictive modeling of self-relevance and valence using personal narratives.

The contents and dynamics of spontaneous thought are important factors for personality traits and mental health. However, assessing spontaneous thoughts is challenging due to their unconstrained nature, and directing participants' attention to report their thoughts may fundamentally alter them. Here, we aimed to decode two key content dimensions of spontaneous thought-self-relevance and valence-directly from brain activity. To train functional MRI-based predictive models, we used individually generated personal stories as stimuli in a story-reading task to mimic narrative-like spontaneous thoughts (n = 49). We then tested these models on multiple test datasets (total n = 199). The default mode, ventral attention, and frontoparietal networks played key roles in the predictions, with the anterior insula and midcingulate cortex contributing to self-relevance prediction and the left temporoparietal junction and dorsomedial prefrontal cortex contributing to valence prediction. Overall, this study presents brain models of internal thoughts and emotions, highlighting the potential for the brain decoding of spontaneous thought.

A bacterial mRNA leader that employs different mechanisms to sense disparate intracellular signals.

Bacterial mRNAs often contain leader sequences that respond to specific metabolites or ions by altering expression of the associated downstream protein-coding sequences. Here we report that the leader RNA of the Mg(2+) transporter gene mgtA of Salmonella enterica, which was previously known to function as a Mg(2+)-sensing riboswitch, harbors an 18 codon proline-rich open reading frame-termed mgtL-that permits intracellular proline to regulate mgtA expression. Interfering with mgtL translation by genetic, pharmacological, or environmental means was observed to increase the mRNA levels from the mgtA coding region. Substitution of the mgtL proline codons by other codons abolished the response to proline and to hyperosmotic stress but not to Mg(2+). Our findings show that mRNA leader sequences can consist of complex regulatory elements that utilize different mechanisms to sense separate signals and mediate an appropriate cellular response.

Lactobacillus crispatus Limits Bladder Uropathogenic E. coli Infection by Triggering a Host Type I Interferon Response.

Many urinary tract infections (UTIs) are recurrent because uropathogens persist within the bladder epithelial cells (BECs) for extended periods between bouts of infection. Because persistent uropathogens are intracellular, they are often refractive to antibiotic treatment. The recent discovery of endogenous Lactobacillus spp. in the bladders of healthy humans raised the question of whether these endogenous bacteria directly or indirectly impact intracellular bacterial burden in the bladder. Here, we report that in contrast to healthy women, female patients experiencing recurrent UTIs have a bladder population of Lactobacilli that is markedly reduced. Exposing infected human BECs to L. crispatus in vitro markedly reduced the intracellular uropathogenic Escherichia coli (UPEC) load. The adherence of Lactobacilli to BECs was found to result in increased type I interferon (IFN) production, which in turn enhanced the expression of cathepsin D within lysosomes harboring UPECs. This lysosomal cathepsin D-mediated UPEC killing was diminished in germ-free mice and type I IFN receptor-deficient mice. Secreted metabolites of L. crispatus seemed to be responsible for the increased expression of type I IFN in human BECs. Intravesicular administration of Lactobacilli into UPEC-infected murine bladders markedly reduced their intracellular bacterial load suggesting that components of the endogenous microflora can have therapeutic effects against UTIs.

Swd2/Cps35 determines H3K4 tri-methylation via interactions with Set1 and Rad6.

BACKGROUND: Histone H3K4 tri-methylation (H3K4me3) catalyzed by Set1/COMPASS, is a prominent epigenetic mark found in promoter-proximal regions of actively transcribed genes. H3K4me3 relies on prior monoubiquitination at the histone H2B (H2Bub) by Rad6 and Bre1. Swd2/Cps35, a Set1/COMPASS component, has been proposed as a key player in facilitating H2Bub-dependent H3K4me3. However, a more comprehensive investigation regarding the relationship among Rad6, Swd2, and Set1 is required to further understand the mechanisms and functions of the H3K4 methylation. RESULTS: We investigated the genome-wide occupancy patterns of Rad6, Swd2, and Set1 under various genetic conditions, aiming to clarify the roles of Set1 and Rad6 for occupancy of Swd2. Swd2 peaks appear on both the 5' region and 3' region of genes, which are overlapped with its tightly bound two complexes, Set1 and cleavage and polyadenylation factor (CPF), respectively. In the absence of Rad6/H2Bub, Set1 predominantly localized to the 5' region of genes, while Swd2 lost all the chromatin binding. However, in the absence of Set1, Swd2 occupancy near the 5' region was impaired and rather increased in the 3' region. CONCLUSIONS: This study highlights that the catalytic activity of Rad6 is essential for all the ways of Swd2's binding to the transcribed genes and Set1 redistributes the Swd2 to the 5' region for accomplishments of H3K4me3 in the genome-wide level.

Mitochondria and Endoplasmic Reticulum Stress in Retinal Organoids from Patients with Vision Loss.

Activating transcription factor 6 (ATF6), a key regulator of the unfolded protein response, plays a key role in endoplasmic reticulum function and protein homeostasis. Variants of ATF6 that abrogate transcriptional activity cause morphologic and molecular defects in cones, clinically manifesting as the human vision loss disease achromatopsia (ACHM). ATF6 is expressed in all retinal cells. However, the effect of disease-associated ATF6 variants on other retinal cell types remains unclear. Herein, this was investigated by analyzing bulk RNA-sequencing transcriptomes from retinal organoids generated from patients with ACHM, carrying homozygous loss-of-function ATF6 variants. Marked dysregulation in mitochondrial respiratory complex gene expression and disrupted mitochondrial morphology in ACHM retinal organoids were identified. This indicated that loss of ATF6 leads to previously unappreciated mitochondrial defects in the retina. Next, gene expression from control and ACHM retinal organoids were compared with transcriptome profiles of seven major retinal cell types generated from recent single-cell transcriptomic maps of nondiseased human retina. This indicated pronounced down-regulation of cone genes and up-regulation in Müller glia genes, with no significant effects on other retinal cells. Overall, the current analysis of ACHM patient retinal organoids identified new cellular and molecular phenotypes in addition to cone dysfunction: activation of Müller cells, increased endoplasmic reticulum stress, disrupted mitochondrial structure, and elevated respiratory chain activity gene expression.

Developing and Validating the Senior Meaning in Life Evaluation (SMiLE) Scale.

The Senior Meaning in Life Evaluation scale encompasses not only older adults' personal motivation and growth but also the meaning for them in society and in their relationships: With this scale, we aimed to present their voices. A three-phase process was followed: The scale's items were developed empirically from interviews of older adults; exploratory factor analysis (EFA) was conducted to test convergent and concurrent validity; and finally, confirmatory factor analysis (CFA) was performed. EFA resulted in 18 items grouped into 4 factors (i.e., proactive on life, overcoming emptiness, acceptance in life, and social contribution), which was supported by the CFA.

uORF-mediated riboregulation controls transcription of whiB7/wblC antibiotic resistance gene.

WhiB7/WblC is a transcriptional factor of actinomycetes conferring intrinsic resistance to multiple translation-inhibitory antibiotics. It positively autoregulates its own transcription in response to the same antibiotics. The presence of a uORF and a potential Rho-independent transcription terminator in the 5' leader region has suggested a possibility that the whiB7/wblC gene is regulated via a uORF-mediated transcription attenuation. However, experimental evidence for the molecular mechanism to explain how antibiotic stress suppresses the attenuator, if any, and induces transcription of the whiB7/wblC gene has been lacking. Here we report that the 5' leader sequences of the whiB7/wblC genes in sub-clades of actinomycetes include conserved antiterminator RNA structures. We confirmed that the putative antiterminator in the whiB7/wblC leader sequences of both Streptomyces and Mycobacterium indeed suppresses Rho-independent transcription terminator and facilitates transcription readthrough, which is required for WhiB7/WblC-mediated antibiotic resistance. The antibiotic-mediated suppression of the attenuator can be recapitulated by amino acid starvation, indicating that translational inhibition of uORF by multiple signals is a key to induce whiB7/wblC expression. Our findings of a mechanism leading to intrinsic antibiotic resistance could provide an alternative to treat drug-resistant mycobacteria.

Recovery of dopaminergic amacrine cells after strobe light stimulation in the developing rat retina.

Concerns regarding the impact of strobe light on human health and life have recently been raised. Sources of strobe light include visual display terminals, light-emitting diodes, and computer monitors. Strobe light exposure leads to visual discomfort, headaches, and poor visual performance and affects the number of dopaminergic amacrine cells (DACs) in the developing retina, as well as retinal dopamine levels in animals. DACs serve as the sole source of retinal dopamine, and dopamine release from the retina is activated by light exposure following a circadian rhythm. Using a Sprague-Dawley rat model, this study sought to determine whether changes in DACs caused by strobe light are recoverable after ceasing strobe light exposure during retinal development. From eye opening (postnatal 2 weeks), rats in the control group were reared under normal light (an unflickering 150 lux incandescent lamp with a 12 h light/dark cycle), whereas those in the experimental group (i.e., strobe-recovery group) were reared under strobe light (2 Hz for 12 h/day) exposure for 2 weeks. After postnatal week 4, normal light was provided to all animals to observe the reversibility of the effect of strobe light. Immunohistochemistry and immunoblot analysis for the rate limiting enzyme for dopamine synthesis, tyrosine hydroxylase (TH), as well as high-pressure liquid chromatography for measuring dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) were performed at postnatal weeks 4, 6, 8, and 10. The number of type I and type II TH-immunoreactive (TH-IR) cells across the entire retina was counted to evaluate whether changes in DACs induced by strobe light could recover after ceasing strobe light exposure. The number of type I TH-IR cells slightly decreased but remained at a constant level in the control group. In contrast, the number of type I TH-IR cells rapidly decreased up to postnatal week 6, but then increased after postnatal week 8 in the strobe-recovery group. Subsequently, the number of type I TH-IR cells eventually reached a number similar to that in the control group. In addition, the number of intermediate-sized TH-IR cells were increased at postnatal weeks 8 and 10 and the dopamine level was decreased at postnatal week 8 in the strobe-recovery group. However, the levels of DOPAC and TH proteins did not differ between the two groups. This suggests that changes in DACs caused by strobe light are reversible and that type II TH-IR cells may play a key role in this recovery.

Subgroups of self-neglect and effects on suicidal ideation among the older adults.

The issue of self-neglect among older adults is receiving attention in modern societies where aging is accelerating. To help expand our understanding of this phenomenon, this study identified its different types using latent profile analysis and verified the main variables that distinguish these types from each other. The three profiles that were identified are high self-neglect (HSN: 28.8%), low self-neglect (LSN: 35.6%), and poor personal hygiene (PPH: 35.6%). Interestingly, PPH showed a high rate and was identified as a noticeable type of elder self-neglect. Gender, age group, SES, support size, and suicidal ideation were significant in classifying the types of self-neglect. Men were more likely to be within the HSN group, and late elderly were more likely to be within the PPH group. The higher SES and social support, the higher the probability of being within the LSN group. The higher the suicidal ideation, the higher the possibility of falling under the HSN group. To reduce self-neglect among older adults, this study suggests to older adults vulnerable to self-neglect, expansion of the social support available to them, and provision of mental health services to this population.