Drosophila Histone Demethylase KDM5 Regulates Social Behavior through Immune Control and Gut Microbiota Maintenance

Vitamin B12 ameliorates gut epithelial injury via modulating the HIF-1 pathway and gut microbiota

Inflammatory bowel diseases (IBDs) are immune chronic diseases characterized by recurrent episodes, resulting in continuous intestinal barrier damage and intestinal microbiota dysbiosis. Safe strategies aimed at stabilizing and reducing IBDs recurrence have been vigorously pursued. Here, we constructed a recurrent intestinal injury Drosophila model and found that vitamin B12 (VB12), an essential co-factor for organism physiological functions, could effectively protect the intestine and reduce dextran sulfate sodium-induced intestinal barrier disruption. VB12 also alleviated microbial dysbiosis in the Drosophila model and inhibited the growth of gram-negative bacteria. We demonstrated that VB12 could mitigate intestinal damage by activating the hypoxia-inducible factor-1 signaling pathway in injured conditions, which was achieved by regulating the intestinal oxidation. In addition, we also validated the protective effect of VB12 in a murine acute colitis model. In summary, we offer new insights and implications for the potential supportive role of VB12 in the management of recurrent IBDs flare-ups.

Gut microbiota influences onset of foraging-related behavior but not physiological hallmarks of division of labor in honeybees

Gut microbes can impact cognition and behavior, but whether they regulate the division of labor in animal societies is unknown. We addressed this question using honeybees since they exhibit division of labor between nurses and foragers and because their gut microbiota can be manipulated. Using automated behavioral tracking and controlling for co-housing effects, we show that gut microbes influence the age at which bees start expressing foraging-like behaviors in the laboratory but have no effects on the time spent in a foraging arena and number of foraging trips. Moreover, the gut microbiota did not influence hallmarks of behavioral maturation such as body weight, cuticular hydrocarbon profile, hypopharyngeal gland size, gene expression, and the proportion of bees maturing into foragers. Overall, this study shows that the honeybee gut microbiota plays a role in controlling the onset of foraging-related behavior without permanent consequences on colony-level division of labor and several physiological hallmarks of behavioral maturation.

IMPORTANCE

The honeybee is emerging as a model system for studying gut microbiota-host interactions. Previous studies reported gut microbiota effects on multiple worker bee phenotypes, all of which change during behavioral maturation-the transition from nursing to foraging. We tested whether the documented effects may stem from an effect of the microbiota on behavioral maturation. The gut microbiota only subtly affected maturation: it accelerated the onset of foraging without affecting the overall proportion of foragers or their average output. We also found no effect of the microbiota on host weight, cuticular hydrocarbon (CHC) profile, hypopharyngeal gland size, and the expression of behavioral maturation-related genes. These results are inconsistent with previous studies reporting effects of the gut microbiota on bee weight and CHC profile. Our experiments revealed that co-housed bees tend to converge in behavior and physiology, suggesting that spurious associations may emerge when rearing environments are not replicated sufficiently or accounted for analytically.

Transcriptional programming mediated by the histone demethylase KDM5C regulates dendritic cell population heterogeneity and function

Functional and phenotypic heterogeneity of dendritic cells (DCs) play crucial roles in facilitating the development of diverse immune responses essential for host protection. Here, we report that KDM5C, a histone lysine demethylase, regulates conventional or classical DC (cDC) and plasmacytoid DC (pDC) population heterogeneity and function. Mice deficient in KDM5C in DCs have increased proportions of cDC2Bs and cDC1s, which is partly dependent on type I interferon (IFN) and pDCs. Loss of KDM5C results in an increase in Ly6C- pDCs, which, compared to Ly6C+ pDCs, have limited ability to produce type I IFN and more efficiently stimulate antigen-specific CD8 T cells. KDM5C-deficient DCs have increased expression of inflammatory genes, altered expression of lineage-specific genes, and decreased function. In response to Listeria infection, KDM5C-deficient mice mount reduced CD8 T cell responses due to decreased antigen presentation by cDC1s. Thus, KDM5C is a key regulator of DC heterogeneity and critical driver of the functional properties of DCs.

Early and long-term responses of intestinal microbiota and metabolites to 131I treatment in differentiated thyroid cancer patients

BACKGROUND

Multiple high doses of 131I therapy in patients with differentiated thyroid cancer (DTC) might disrupt the balance of gut microbiota and metabolites. This study aimed to investigate the alterations of intestinal bacteria and metabolism over two courses of 131I therapy, explore the interactions, and construct diagnostic models reflecting enteric microecology based on 131I therapy.

METHODS

A total of 81 patients were recruited for the first 131I therapy (131I-1st), among whom 16 received a second course (131I-2nd) after half a year. Fecal samples were collected 1 day before (Pre-131I-1st/2nd) and 3 days after (Post-131I-1st/2nd) 131I therapy for microbiome (16S rRNA gene sequencing) and metabolomic (LC-MS/MS) analyses.

RESULTS

A total of six microbial genera and 11 fecal metabolites enriched in three pathways were identified to show significant differences between Pre-131I-1st and other groups throughout the two courses of 131I treatment. In the Post-131I-1st group, the beneficial bacteria Bifidobacterium, Lachnoclostridium, uncultured_bacterium_f_Lachnospiraceae, and Lachnospiraceae_UCG004 were abundant and the radiation-sensitive pathways of linoleic acid (LA), arachidonic acid, and tryptophan metabolism were inhibited compared with the Pre-131I-1st group. Compared with the Pre-131I-1st group, the Pre-131I-2nd group exhibited a reduced diversity of flora and differentially expressed metabolites, with a low abundance of beneficial bacteria and dysregulated radiation-sensitive pathways. However, less significant differences in microbiota and metabolites were found between the Pre/Post-131I-2nd groups compared with those between the Pre/Post-131I-1st groups. A complex co-occurrence was observed between 6 genera and 11 metabolites, with Lachnoclostridium, Lachnospiraceae_UCG004, Escherichia-Shigella, and LA-related metabolites contributing the most. Furthermore, combined diagnostic models of charactered bacteria and metabolites answered well in the early, long-term, and dose-dependent responses for 131I therapy.

CONCLUSIONS

Different stages of 131I therapy exert various effects on gut microecology, which play an essential role in regulating radiotoxicity and predicting the therapeutic response.

Gut-brain axis: A cutting-edge approach to target neurological disorders and potential synbiotic application

The microbiota-gut-brain axis (MGBA) represents a sophisticated communication network between the brain and the gut, involving immunological, endocrinological, and neural mediators. This bidirectional interaction is facilitated through the vagus nerve, sympathetic and parasympathetic fibers, and is regulated by the hypothalamic-pituitary-adrenal (HPA) axis. Evidence shows that alterations in gut microbiota composition, or dysbiosis, significantly impact neurological disorders (NDs) like anxiety, depression, autism, Parkinson's disease (PD), and Alzheimer's disease (AD). Dysbiosis can affect the central nervous system (CNS) via neuroinflammation and microglial activation, highlighting the importance of the microbiota-gut-brain axis (MGBA) in disease pathogenesis. The microbiota influences the immune system by modulating chemokines and cytokines, impacting neuronal health. Synbiotics have shown promise in treating NDs by enhancing cognitive function and reducing inflammation. The gut microbiota's role in producing neurotransmitters and neuroactive compounds, such as short-chain fatty acids (SCFAs), is critical for CNS homeostasis. Therapeutic interventions targeting the MGBA, including dietary modulation and synbiotic supplementation, offer potential benefits for managing neurodegenerative disorders. However, more in-depth clinical studies are necessary to fully understand and harness the therapeutic potential of the MGBA in neurological health and disease.

Insect-microbe interactions and their influence on organisms and ecosystems

Microorganisms are important associates of insect and arthropod species. Insect-associated microbes, including bacteria, fungi, and viruses, can drastically impact host physiology, ecology, and fitness, while many microbes still have no known role. Over the past decade, we have increased our knowledge of the taxonomic composition and functional roles of insect-associated microbiomes and viromes. There has been a more recent shift toward examining the complexity of microbial communities, including how they vary in response to different factors (e.g., host genome, microbial strain, environment, and time), and the consequences of this variation for the host and the wider ecological community. We provide an overview of insect-microbe interactions, the variety of associated microbial functions, and the evolutionary ecology of these relationships. We explore the influence of the environment and the interactive effects of insects and their microbiomes across trophic levels. Additionally, we discuss the potential for subsequent synergistic and reciprocal impacts on the associated microbiomes, ecological interactions, and communities. Lastly, we discuss some potential avenues for the future of insect-microbe interactions that include the modification of existing microbial symbionts as well as the construction of synthetic microbial communities.

Stroke and Distal Organ Damage: Exploring Brain-Kidney Crosstalk

Stroke and kidney dysfunction represent significant public health challenges, yet the precise mechanisms connecting these conditions and their severe consequences remain unclear. Individuals experiencing chronic kidney disease (CKD) and acute kidney injury (AKI) are at heightened susceptibility to experiencing repeated strokes. Similarly, a reduced glomerular filtration rate is associated with an elevated risk of suffering a stroke. Prior strokes independently contribute to mortality, end-stage kidney disease, and cardiovascular complications, underscoring the pathological connection between the brain and the kidneys. In cases of AKI, various mechanisms, such as cytokine signaling, leukocyte infiltration, and oxidative stress, establish communication between the brain and the kidneys. The bidirectional relationship between stroke and kidney pathologies involves key factors such as uremic toxins, proteinuria, inflammatory responses, decreased glomerular filtration, impairment of the blood-brain barrier (BBB), oxidative stress, and metabolites produced by the gut microbiota. This review examines potential mechanisms of brain-kidney crosstalk underlying stroke and kidney diseases. It holds significance for comprehending multi-organ dysfunction associated with stroke and for formulating therapeutic strategies to address stroke-induced kidney dysfunction and the bidirectional pathological connection between the kidney and stroke.

Host-diet-microbiota interplay in intestinal nutrition and health

The intestine is populated by a complex and dynamic assortment of microbes, collectively called gut microbiota, that interact with the host and contribute to its metabolism and physiology. Diet is considered a key regulator of intestinal microbiota, as ingested nutrients interact with and shape the resident microbiota composition. Furthermore, recent studies underscore the interplay of dietary and microbiota-derived nutrients, which directly impinge on intestinal stem cells regulating their turnover to ensure a healthy gut barrier. Although advanced sequencing methodologies have allowed the characterization of the human gut microbiome, mechanistic studies assessing diet-microbiota-host interactions depend on the use of genetically tractable models, such as Drosophila melanogaster. In this review, we first discuss the similarities between the human and fly intestines and then we focus on the effects of diet and microbiota on nutrient-sensing signaling cascades controlling intestinal stem cell self-renewal and differentiation, as well as disease. Finally, we underline the use of the Drosophila model in assessing the role of microbiota in gut-related pathologies and in understanding the mechanisms that mediate different whole-body manifestations of gut dysfunction.

The Cellular Microbiome of Visceral Organs: An Inherent Inhabitant of Parenchymal Cells

The cell is the basic unit of life. It is composed of organelles and various organic and inorganic biomolecules. Recent 16S ribosomal ribonucleic acid (16S rRNA) gene sequencing studies have revealed the presence of tissue bacteria in both tumor and normal tissues. Recently, we found that the liver microbiome resided in hepatocytes. Here, we further report on the cellular microbiome in the parenchymal cells of visceral organs as inherent inhabitants. We performed 16S rRNA gene sequencing on visceral organs of male adult Sprague Dawley (SD) rats, pregnant rats, newborn rats, and fetuses and placentas; then, we performed fluorescence in situ hybridization and immunofluorescence in visceral organs. Furthermore, we performed Western blotting on nuclear and cytoplasmic extractions of visceral organs of SD rats and cell lines HepG2, Huh-7, Hepa1-6, and HSC-T6. A high abundance of 16S rRNA gene was detected in the visceral organs of male adult, pregnant, newborn, and fetal rats as well as their placentas. The number of operational taxonomic units (OTUs) of visceral bacteria was higher than that of the feces and ileum bacteria. Bacterial 16S rRNA, lipopolysaccharide (LPS), and lipoteichoic acid (LTA) were found in the parenchymal cells of visceral organs, as well as in HepG2, Huh-7, HSC-T6, and Hepa1-6 cells. LPS consistently appeared in the nucleus of cells, while LTA was mainly found in the cytoplasm. In conclusion, the cellular microbiome is an intrinsic component of cells. Gram-negative bacteria are located in the nucleus, and Gram-positive bacteria are located in the cytoplasm. This differs from the gut microbiome and may be inherited.

Wnt/β-catenin signaling within multiple cell types dependent upon kramer regulates Drosophila intestinal stem cell proliferation

The gut epithelium is subject to constant renewal, a process reliant upon intestinal stem cell (ISC) proliferation that is driven by Wnt/β-catenin signaling. Despite the importance of Wnt signaling within ISCs, the relevance of Wnt signaling within other gut cell types and the underlying mechanisms that modulate Wnt signaling in these contexts remain incompletely understood. Using challenge of the Drosophila midgut with a non-lethal enteric pathogen, we examine the cellular determinants of ISC proliferation, harnessing kramer, a recently identified regulator of Wnt signaling pathways, as a mechanistic tool. We find that Wnt signaling within Prospero-positive cells supports ISC proliferation and that kramer regulates Wnt signaling in this context by antagonizing kelch, a Cullin-3 E3 ligase adaptor that mediates Dishevelled polyubiquitination. This work establishes kramer as a physiological regulator of Wnt/β-catenin signaling in vivo and suggests enteroendocrine cells as a new cell type that regulates ISC proliferation via Wnt/β-catenin signaling.

Kismet/CHD7/CHD8 affects gut microbiota, mechanics, and the gut-brain axis in Drosophila melanogaster

The gut microbiome affects brain and neuronal development and may contribute to the pathophysiology of neurodevelopmental disorders. However, it is unclear how risk genes associated with such disorders affect gut physiology in a manner that could impact microbial colonization and how the mechanical properties of the gut tissue might play a role in gut-brain bidirectional communication. To address this, we used Drosophila melanogaster with a null mutation in the gene kismet, an ortholog of chromodomain helicase DNA-binding protein (CHD) family members CHD7 and CHD8. In humans, these are risk genes for neurodevelopmental disorders with co-occurring gastrointestinal symptoms. We found that kismet mutant flies have a significant increase in gastrointestinal transit time, indicating the functional homology of kismet with CHD7/CHD8 in vertebrates. Rheological characterization of dissected gut tissue revealed significant changes in the mechanics of kismet mutant gut elasticity, strain stiffening behavior, and tensile strength. Using 16S rRNA metagenomic sequencing, we also found that kismet mutants have reduced diversity and abundance of gut microbiota at every taxonomic level. To investigate the connection between the gut microbiome and behavior, we depleted gut microbiota in kismet mutant and control flies and quantified the flies' courtship behavior. Depletion of gut microbiota rescued courtship defects of kismet mutant flies, indicating a connection between gut microbiota and behavior. In striking contrast, depletion of the gut microbiome in the control strain reduced courtship activity, demonstrating that antibiotic treatment can have differential impacts on behavior and may depend on the status of microbial dysbiosis in the gut prior to depletion. We propose that Kismet influences multiple gastrointestinal phenotypes that contribute to the gut-microbiome-brain axis to influence behavior. We also suggest that gut tissue mechanics should be considered as an element in the gut-brain communication loop, both influenced by and potentially influencing the gut microbiome and neurodevelopment.

Unraveling host regulation of gut microbiota through the epigenome-microbiome axis

Recent studies of dynamic interactions between epigenetic modifications of a host organism and the composition or activity of its associated gut microbiota suggest an opportunity for the host to shape its microbiome through epigenetic alterations that lead to changes in gene expression and noncoding RNA activity. We use insights from microbiota-induced epigenetic changes to review the potential of the host to epigenetically regulate its gut microbiome, from which a bidirectional 'epigenome-microbiome axis' emerges. This axis embeds environmentally induced variation, which may influence the adaptive evolution of host-microbe interactions. We furthermore present our perspective on how the epigenome-microbiome axis can be understood and investigated within a holo-omic framework with potential applications in the applied health and food sciences.

Pinobanksin ameliorated DSS-induced acute colitis mainly through modulation of SLC7A11/glutathione-mediated intestinal epithelial ferroptosis

Inhibition of ferroptosis in intestinal epithelial cells serves as an attractive target for the development of therapeutic strategies for colitis. Pinobanksin, one of the main flavonoids derived from propolis, possesses significant anti-inflammatory effects and inhibits the cell death of several cell lines. Here, we evaluated whether pinobanksin influenced colitis by modulation of epithelial ferroptosis. Mice treated with 2.5% DSS dissolved in sterile distilled water were established for an acute colitis model. The mitochondrial morphology, colonic iron level, lipid peroxidation products MDA/4-HNE, and lipid reactive oxygen species levels were measured to assess ferroptosis in epithelial cells. RNA-seq and functional analyses were performed to reveal key genes mediating pinobanksin-exerted modulation of ferroptosis. We found that pinobanksin, at different doses, induced significant anti-colitis effects and inhibited the elevated ferroptosis in colonic epithelial cells isolated from DSS-treated mice largely by activating GPX4 (negative regulator of ferroptosis). Furthermore, RNA-seq assays indicated that pinobanksin significantly increased the cystine transporter SLC7A11 in colonic tissues from mice with colitis. Depletion of SLC7A11 largely blocked pinobanksin-induced promotion of cystine uptake/glutathione biosynthesis and suppression of ferroptosis in epithelial cells from mice with colitis or IEC-6 cells pretreated with RSL3. Altogether, pinobanksin alleviated DSS-induced colitis largely by inhibition of ferroptosis in epithelial cells. Activation of SLC7A11 by pinobanksin resulted in the promotion of cystine uptake and enhancement of glutathione biosynthesis. This work will provide novel guidance for the clinical use of pinobanksin to treat colitis through inhibition of epithelial ferroptosis.

Lactobacillus plantarum L168 improves hyperoxia-induced pulmonary inflammation and hypoalveolarization in a rat model of bronchopulmonary dysplasia

Alteration of gut microbiota can affect chronic lung diseases, such as asthma and chronic obstructive pulmonary disease, through abnormal immune and inflammatory responses. Previous studies have shown a feasible connection between gut microbiota and bronchopulmonary dysplasia (BPD) in preterm infants. However, whether BPD can be ameliorated by restoring the gut microbiota remains unclear. In preterm infants with BPD, we found variance in the diversity and structure of gut microbiota. Similarly, BPD rats showed gut dysbiosis, characterized by a deficiency of Lactobacillus, which was abundant in normal rats. We therefore explored the effect and potential mechanism of action of a probiotic strain, Lactobacillus plantarum L168, in improving BPD. The BPD rats were treated with L. plantarum L168 by gavage for 2 weeks, and the effect was evaluated by lung histopathology, lung function, and serum inflammatory markers. Subsequently, we observed reduced lung injury and improved lung development in BPD rats exposed to L. plantarum L168. Further evaluation revealed that L. plantarum L168 improved intestinal permeability in BPD rats. Serum metabolomics showed altered inflammation-associated metabolites following L. plantarum L168 intervention, notably a marked increase in anti-inflammatory metabolites. In agreement with the metabolites analysis, RNA-seq analysis of the intestine and lung showed that inflammation and immune-related genes were down-regulated. Based on the information from RNA-seq, we validated that L. plantarum L168 might improve BPD relating to down-regulation of TLR4 /NF-κB /CCL4 pathway. Together, our findings suggest the potential of L. plantarum L168 to provide probiotic-based therapeutic strategies for BPD.

Autism spectrum disorders and the gastrointestinal tract: insights into mechanisms and clinical relevance

Autism spectrum disorders (ASDs) are recognized as central neurodevelopmental disorders diagnosed by impairments in social interactions, communication and repetitive behaviours. The recognition of ASD as a central nervous system (CNS)-mediated neurobehavioural disorder has led most of the research in ASD to be focused on the CNS. However, gastrointestinal function is also likely to be affected owing to the neural mechanistic nature of ASD and the nervous system in the gastrointestinal tract (enteric nervous system). Thus, it is unsurprising that gastrointestinal disorders, particularly constipation, diarrhoea and abdominal pain, are highly comorbid in individuals with ASD. Gastrointestinal problems have also been repeatedly associated with increased severity of the core symptoms diagnostic of ASD and other centrally mediated comorbid conditions, including psychiatric issues, irritability, rigid-compulsive behaviours and aggression. Despite the high prevalence of gastrointestinal dysfunction in ASD and its associated behavioural comorbidities, the specific links between these two conditions have not been clearly delineated, and current data linking ASD to gastrointestinal dysfunction have not been extensively reviewed. This Review outlines the established and emerging clinical and preclinical evidence that emphasizes the gut as a novel mechanistic and potential therapeutic target for individuals with ASD.

A Gpr35-tuned gut microbe-brain metabolic axis regulates depressive-like behavior

Gene-environment interactions shape behavior and susceptibility to depression. However, little is known about the signaling pathways integrating genetic and environmental inputs to impact neurobehavioral outcomes. We report that gut G-protein-coupled receptor, Gpr35, engages a microbe-to-brain metabolic pathway to modulate neuronal plasticity and depressive behavior in mice. Psychological stress decreases intestinal epithelial Gpr35, genetic deletion of which induces depressive-like behavior in a microbiome-dependent manner. Gpr35-/- mice and individuals with depression have increased Parabacteroides distasonis, and its colonization to wild-type mice induces depression. Gpr35-/- and Parabacteroides distasonis-colonized mice show reduced indole-3-carboxaldehyde (IAld) and increased indole-3-lactate (ILA), which are produced from opposing branches along the bacterial catabolic pathway of tryptophan. IAld and ILA counteractively modulate neuroplasticity in the nucleus accumbens, a brain region linked to depression. IAld supplementation produces anti-depressant effects in mice with stress or gut epithelial Gpr35 deficiency. Together, these findings elucidate a gut microbe-brain signaling mechanism that underlies susceptibility to depression.

Larval microbiota primes the Drosophila adult gustatory response

The survival of animals depends, among other things, on their ability to identify threats in their surrounding environment. Senses such as olfaction, vision and taste play an essential role in sampling their living environment, including microorganisms, some of which are potentially pathogenic. This study focuses on the mechanisms of detection of bacteria by the Drosophila gustatory system. We demonstrate that the peptidoglycan (PGN) that forms the cell wall of bacteria triggers an immediate feeding aversive response when detected by the gustatory system of adult flies. Although we identify ppk23+ and Gr66a+ gustatory neurons as necessary to transduce fly response to PGN, we demonstrate that they play very different roles in the process. Time-controlled functional inactivation and in vivo calcium imaging demonstrate that while ppk23+ neurons are required in the adult flies to directly transduce PGN signal, Gr66a+ neurons must be functional in larvae to allow future adults to become PGN sensitive. Furthermore, the ability of adult flies to respond to bacterial PGN is lost when they hatch from larvae reared under axenic conditions. Recolonization of germ-free larvae, but not adults, with a single bacterial species, Lactobacillus brevis, is sufficient to restore the ability of adults to respond to PGN. Our data demonstrate that the genetic and environmental characteristics of the larvae are essential to make the future adults competent to respond to certain sensory stimuli such as PGN.

Inferior social hierarchy is vulnerable to anxiety-like behavior in chronic pain mice: Potential role of gut microbiota and metabolites

Social dominance is a universal phenomenon among grouped animals that profoundly affects survival, health, and reproductive success by determining access to resources, and exerting a powerful influence on subsequent behavior. However, the understanding of pain and anxiety comorbidities in dominant or subordinate animals suffering from chronic pain is not well-defined. Here, we provide evidence that subordinate mice are more susceptible to pain-induced anxiety compared to dominant mice. We propose that the gut microbiota may play a mediating role in this mechanism. Our findings demonstrate that transplantation of fecal microbiota from subordinate mice with chronic inflammatory pain, but not dominant mice, into antibiotics-treated pseudo-germ-free mice significantly amplifies anxiety-like phenotypes, highlighting the critical involvement of gut microbiota in this behavioral response. Using chronic inflammatory pain model, we carried out 16S rRNA sequencing and untargeted metabolomic analyses to explore the relationship between microbiota and metabolites in a stable social hierarchy of mice. Interestingly, anxiety-like behaviors were directly associated with some microbial genera and metabolites, especially bile acid metabolism. Overall, we have demonstrated a close relationship between social status and anxiety susceptibility, highlighting the contributions of gut microbiota and the associated metabolites in the high-anxiety state of subordinate mice with chronic inflammatory pain.

The many faces of microbiota-gut-brain axis in autism spectrum disorder

The gut-brain axis is gaining more attention in neurodevelopmental disorders, especially autism spectrum disorder (ASD). Many factors can influence microbiota in early life, including host genetics and perinatal events (infections, mode of birth/delivery, medications, nutritional supply, and environmental stressors). The gut microbiome can influence blood-brain barrier (BBB) permeability, drug bioavailability, and social behaviors. Developing microbiota-based interventions such as probiotics, gastrointestinal (GI) microbiota transplantation, or metabolite supplementation may offer an exciting approach to treating ASD. This review highlights that RNA sequencing, metabolomics, and transcriptomics data are needed to understand how microbial modulators can influence ASD pathophysiology. Due to the substantial clinical heterogeneity of ASD, medical caretakers may be unlikely to develop a broad and effective general gut microbiota modulator. However, dietary modulation followed by administration of microbiota modulators is a promising option for treating ASD-related behavioral and gastrointestinal symptoms. Future work should focus on the accuracy of biomarker tests and developing specific psychobiotic agents tailored towards the gut microbiota seen in ASD patients, which may include developing individualized treatment options.

Excess dietary sugar impairs Drosophila adult stem cells via elevated reactive oxygen species-induced JNK signaling

High-sugar diets (HSDs) often lead to obesity and type 2 diabetes, both metabolic syndromes associated with stem cell dysfunction. However, it is unclear whether excess dietary sugar affects stem cells. Here, we report that HSD impairs stem cell function in the intestine and ovaries of female Drosophila prior to the onset of insulin resistance, a hallmark of type 2 diabetes. Although 1 week of HSD leads to obesity, impaired oogenesis and altered lipid metabolism, insulin resistance does not occur. HSD increases glucose uptake by germline stem cells (GSCs) and triggers reactive oxygen species-induced JNK signaling, which reduces GSC proliferation. Removal of excess sugar from the diet reverses these HSD-induced phenomena. A similar phenomenon is found in intestinal stem cells (ISCs), except that HSD disrupts ISC maintenance and differentiation. Interestingly, tumor-like GSCs and ISCs are less responsive to HSD, which may be because of their dependence on glycolytic metabolism and high energy demand, respectively. This study suggests that excess dietary sugar induces oxidative stress and damages stem cells before insulin resistance develops, a mechanism that may also occur in higher organisms.

Epigenetic studies in insects and the valproic acid perspective

Abstract Valproic acid in association with sodium valproate (VPA) is an important anticonvulsant drug used for decades to treat neurological disorders. VPA also acts as an epigenetic modulator by inhibiting histone deacetylases, permitting histone acetylation, affecting the DNA and histone methylation status and gene expression, and inducing chromatin remodeling. Insects represent an important animal model for studies in several areas of science. Their high phenotypic plasticity makes them alternative models for epigenetic studies. This brief review emphasizes recent reports on insect epigenetics and the contribution of studies on the VPA action in insects, including effects on epigenetic markers, extending the pharmacological understanding of the potential of this drug, and demonstrating the usefulness of insects as an alternative animal model to drug studies.

Characterization of the bacterial microbiota of cattle ticks in northeastern Thailand through 16S rRNA amplicon sequencing

Ticks are vectors of a variety of pathogens that can infect humans and animals. Ticks also harbor non-pathogenic microbiota. This study characterized the microbiota of the ticks infesting beef cattle in Thailand. Two species of ticks; Rhipicephalus microplus (n = 15) and Haemaphysalis bispinosa (n = 5), were collected in seven provinces in northeastern Thailand. Microbial community profile of ticks was examined based on sequences of the V3-V4 region of 16S rRNA gene. Proteobacteria (Pseudomonadota) was the most abundant phylum, followed by Firmicutes (Bacillota), and Actinobacteriota. Coxiella-like endosymbiont was the most abundant bacterial taxon overall (49% of sequence reads), followed by Anaplasma (8.5%), Corynebacterium (5.5%), Ehrlichia (3.9%), and Castellaniella (3.4%). Co-infections of the pathogenic bacteria Ehrlichia and Anaplasma were detected in 19/20 (95%) female ticks. The tick with the lowest number of bacteria had the lowest abundance of the Coxiella-like endosymbiont, and the pathogenic bacteria Anaplasma and Ehrlichia were absent. This study provides baseline information of the microbiota of cattle ticks in northeastern Thailand, suggesting that ticks carry a few dominant bacterial taxa that are primarily non-pathogenic but can co-occur with pathogenic microorganisms. The information obtained is useful for monitoring disease outbreaks in the future and informing prevention and control strategies against cattle tick-borne diseases.

The microbiota-gut-brain axis and neurodevelopmental disorders

The gut microbiota has been found to interact with the brain through the microbiota-gut-brain axis, regulating various physiological processes. In recent years, the impacts of the gut microbiota on neurodevelopment through this axis have been increasingly appreciated. The gut microbiota is commonly considered to regulate neurodevelopment through three pathways, the immune pathway, the neuronal pathway, and the endocrine/systemic pathway, with overlaps and crosstalks in between. Accumulating studies have identified the role of the microbiota-gut-brain axis in neurodevelopmental disorders including autism spectrum disorder, attention deficit hyperactivity disorder, and Rett Syndrome. Numerous researchers have examined the physiological and pathophysiological mechanisms influenced by the gut microbiota in neurodevelopmental disorders (NDDs). This review aims to provide a comprehensive overview of advancements in research pertaining to the microbiota-gut-brain axis in NDDs. Furthermore, we analyzed both the current state of research progress and discuss future perspectives in this field.

DVT: a high-throughput analysis pipeline for locomotion and social behavior in adult Drosophila melanogaster

BACKGROUND

Drosophila melanogaster is excellent animal model for understanding the molecular basis of human neurological and motor disorders. The experimental conditions and chamber design varied between studies. Moreover, most previously established paradigms focus on fly trace detection algorithm development. A comprehensive understanding on how fly behaves in the chamber is still lacking.

RESULTS

In this report, we established 74 unique behavior metrics quantifying spatiotemporal characteristics of adult fly locomotion and social behaviors, of which 49 were newly proposed. By the aiding of the developed analysis pipeline, Drosophila video tracking (DVT), we identified siginificantly different patterns of fly behavior confronted with different chamber height, fly density, illumination and experimental time. Meanwhile, three fly strains which are widely used as control lines, Canton-S(CS), w1118 and Oregon-R (OR), were found to exhibit distinct motion explosiveness and exercise endurance.

CONCLUSIONS

We believe the proposed behavior metrics set and pipeline should help identify subtle spatial and temporal differences of drosophila behavior confronted with different environmental factors or gene variants.

Synthetic microbial consortia for the treatment of Clostridioides difficile infection in mice model

Clostridioides difficile infection (CDI) as of recent has become a great concern to the impact on human health due to its high hazardous risk and rate of recurrence. Live bacterial therapeutics is a promising method to treat or prevent CDI. Here, a synthetic microbial consortia (SMC) B10 was constructed using probiotic strains with antibacterial and anti-quorum sensing activities, and the therapeutic effect of SMC B10 against C. difficile infection was evaluated in vitro. Compared to the model group, the treatment of SMC B10 significantly increased the survival rate. The clinical signs of mice were significantly ameliorated, especially the cecum injury, while the secretion of pro-inflammatory associated cytokines such as IL-1α, IL-6, IL-17A and TNF-α was reduced, the expression of TLR4 was inhibited, which alleviated the inflammatory response, and the expression of the tight junction protein Claudin-1 was increased, ultimately promoting the recovery of host health. The treatment of B10 restored gut microbiota dysbiosis and led to a healthy intestinal microbiota structure, significantly improved alpha diversity, suppressing potentially harmful bacteria and restoring other core bacterial species. In conclusion, SMC B10 can effectively treat CDI through modulate gut microbiota and attenuate the inflammatory response.

Postpartum scarcity-adversity inflicts sex-specific cerebellar adaptations and reward behaviors in adolescence

Early life adversity in the form of poor postnatal care is a major developmental stressor impacting behavior later in life. Previous studies have shown the impact of early life stress on neurobehavioral abnormalities. Specifically, research has demonstrated how limited bedding and nesting (LBN) materials can cause behavioral deficits in adulthood. There is, however, a limited understanding of how LBN influences sex-specific neurobehavioral adaptation in adolescence, a developmental stage susceptible to psychiatric diseases including substance use disorder. LBN and stress-naive c57BL/6 adolescent male and female mouse offspring were tested for a battery of behaviors including open field, novel object recognition, elevated plus maze, social preference, and morphine-induced conditioned place preference. There was a significant sex-specific deficit in social preference in male mice exposed to LBN compared to stress-naïve counterparts and both LBN males and females had a higher preference towards the drug-paired chamber in the morphine-induced conditioned place preference test. These behavioral deficits were concomitant with sex-specific increases in the transcription factor, Klf9 in the deep cerebellar nuclei (DCN) of males. Further, mRNA levels of the circadian gene Bmal1, which is known to be transcriptionally regulated by Klf9, were decreased in the DCN. Since Bmal1 has recently been implicated in extracellular matrix modulation, we examined perineuronal nets (PNN) and observed depleted PNN in the DCN of males but not female LBN mice. Overall, we provide a novel understanding of how postpartum adversity impinges on the cerebellar extracellular matrix homeostasis, likely, through disruption of the circadian axis by Klf9 that might underlie sex-specific behavioral adaptations in adolescence.

Unveiling the role of gut-brain axis in regulating neurodegenerative diseases: A comprehensive review

Emerging evidence have shown the importance of gut microbiota in regulating brain functions. The diverse molecular mechanisms involved in cross-talk between gut and brain provide insight into importance of this communication in maintenance of brain homeostasis. It has also been observed that disturbed gut microbiota contributes to neurological diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and aging. Recently, gut microbiome-derived exosomes have also been reported to play an essential role in the development and progression of neurodegenerative diseases and could thereby act as a therapeutic target. Further, pharmacological interventions including antibiotics, prebiotics and probiotics can influence gut microbiome-mediated management of neurological diseases. However, extensive research is warranted to better comprehend this interconnection in maintenance of brain homeostasis and its implication in neurological diseases. Thus, the present review is aimed to provide a detailed understanding of gut-brain axis followed by possibilities to target the gut microbiome for improving neurological health.

Biglycan regulated colorectal cancer progress by modulating enteric neuron-derived IL-10 and abundance of Bacteroides thetaiotaomicron

Biglycan (BGN) is a proteoglycan with branch chains and highly expressed in enteric neurons in the tumor tissue of colorectal cancer (CRC), which is negatively associated with survival rates in patients with CRC. However, how the proteoglycan promotes the progress of CRC through interacting with bacteria and regulating the immune response of enteric neurons remains largely unknown. In the present study, we found that biglycan deficiency changed tumor distribution in a colitis-associated colon cancer model. Furthermore, we revealed that BGN deficiency inhibits tumor growth in an allograft tumor model and the migration of cancer cell by upregulating interleukin-10 expression in enteric neurons. Significantly, we demonstrated that biglycan deficiency enriched the abundance of Bacteroides thetaiotaomicron through competing with it for chondroitin sulfate to inhibit CRC progress. Our work provided new insights into the interaction between host proteoglycan and gut microbiota as well as the role of enteric neurons in the tumor microenvironment.

Sleep loss impairs intestinal stem cell function and gut homeostasis through the modulation of the GABA signalling pathway in Drosophila

Sleep is essential for maintaining health. Indeed, sleep loss is closely associated with multiple health problems, including gastrointestinal disorders. However, it is not yet clear whether sleep loss affects the function of intestinal stem cells (ISCs). Mechanical sleep deprivation and sss mutant flies were used to generate the sleep loss model. qRT-PCR was used to measure the relative mRNA expression. Gene knock-in flies were used to observe protein localization and expression patterns. Immunofluorescence staining was used to determine the intestinal phenotype. The shift in gut microbiota was observed using 16S rRNA sequencing and analysis. Sleep loss caused by mechanical sleep deprivation and sss mutants disturbs ISC proliferation and intestinal epithelial repair through the brain-gut axis. In addition, disruption of SSS causes gut microbiota dysbiosis in Drosophila. As regards the mechanism, gut microbiota and the GABA signalling pathway both partially played a role in the sss regulation of ISC proliferation and gut function. The research shows that sleep loss disturbed ISC proliferation, gut microbiota, and gut function. Therefore, our results offer a stem cell perspective on brain-gut communication, with details on the effect of the environment on ISCs.

Intake of caffeine containing sugar diet remodels gut microbiota and perturbs Drosophila melanogaster immunity and lifespan

The diet-microbiome-immunity axis is one among the many arms that draw up the "we are what we intake" proclamation. As such, studies on the effect of food and beverage intake on the gut environment and microbiome and on modulating immunological responses and the host's susceptibility to pathogens are on the rise. A typical accompaniment in different sustenance we consume on daily basis is the trimethylxanthine alkaloid caffeine. Being a chief component in our regular aliment, a better understanding of the effect of caffeine containing food and beverages on our gut-microbiome-immunity axis and henceforth on our health is much needed. In this study, we shed more light on the effect of oral consumption of caffeine supplemented sugar diet on the gut environment, specifically on the gut microbiota, innate immunity and host susceptibility to pathogens using the Drosophila melanogaster model organism. Our findings reveal that the oral intake of a dose-specific caffeine containing sucrose/agarose sugar diet causes a significant alteration within the fly gut milieu demarcated by microbial dysbiosis and an elevation in the production of reactive oxygen species and expression of immune-deficiency (Imd) pathway-dependent antimicrobial peptide genes. The oral intake of caffeine containing sucrose/agarose sugar diet also renders the flies more susceptible to bacterial infection and shortens their lifespan in both infection and non-infection settings. Our findings set forth additional insight into the potentiality of diet to alter the gut milieu and highlight the importance of dietary control on health.

Akkermansia muciniphila and Lactobacillus plantarum ameliorate systemic lupus erythematosus by possibly regulating immune response and remodeling gut microbiota

Systemic lupus erythematosus (SLE), characterized by persistent inflammation, is a complex autoimmune disorder that affects all organs, challenging clinical treatment. Dysbiosis of gut microbiota promotes autoimmune disorders that damage extraintestinal organs. Modulating the gut microbiome is proposed as a promising approach for fine-running parts of the immune system, relieving systematic inflammation in multiple diseases. This study demonstrated that the administration of Akkermansia muciniphila and Lactobacillus plantarum contributed to an anti-inflammatory environment by decreasing IL-6 and IL-17 and increasing IL-10 levels in the circulation. The treatment of A. muciniphila and L. plantarum restored the intestinal barrier integrity to a different extent. In addition, both strains reduced the deposit of IgG in the kidney and improved renal function significantly. Further studies revealed distinct remodeling roles of A. muciniphila and L. plantarum administration on the gut microbiome. This work demonstrated essential mechanisms of how A. muciniphila and L. plantarum remodel gut microbiota and regulate the immune responses in the SLE mice model. IMPORTANCE Several pieces of research have demonstrated that certain probiotic strains contribute to regulating excessive inflammation and restoring tolerances in the SLE animal model. More animal trials combined with clinical studies are urgently needed to further elucidate the mechanisms for the effect of specific probiotic bacteria in preventing SLE symptoms and developing novel therapeutic targets. In this study, we explored the role of A. muciniphila and L. plantarum in ameliorating the SLE disease activity. Both A. muciniphila and L. plantarum treatment relieved the systemic inflammation and improved renal function in the SLE mouse model. We demonstrated that A. muciniphila and L. plantarum contributed to an anti-inflammatory environment by regulating cytokine levels in the circulation, restoring the intestinal barrier integrity, and remodeling the gut microbiome, however, to a different extent.

New insights into irritable bowel syndrome pathophysiological mechanisms: contribution of epigenetics

Irritable bowel syndrome (IBS) is a complex multifactorial condition including alterations of the gut-brain axis, intestinal permeability, mucosal neuro-immune interactions, and microbiota imbalance. Recent advances proposed epigenetic factors as possible regulators of several mechanisms involved in IBS pathophysiology. These epigenetic factors include biomolecular mechanisms inducing chromosome-related and heritable changes in gene expression regardless of DNA coding sequence. Accordingly, altered gut microbiota may increase the production of metabolites such as sodium butyrate, a prominent inhibitor of histone deacetylases. Patients with IBS showed an increased amount of butyrate-producing microbial phila as well as an altered profile of methylated genes and micro-RNAs (miRNAs). Importantly, gene acetylation as well as specific miRNA profiles are involved in different IBS mechanisms and may be applied for future diagnostic purposes, especially to detect increased gut permeability and visceromotor dysfunctions. In this review, we summarize current knowledge of the role of epigenetics in IBS pathophysiology.

Glaucocalyxin A attenuates carbon tetrachloride-induced liver fibrosis and improves the associated gut microbiota imbalance

Liver fibrosis refers to the pathophysiological process of dysplasia on the connective tissue of the liver, caused by a variety of pathogenic factors. Glaucocalyxin A (GLA) has anticoagulation, antibacterial, anti-inflammation, antioxidant and antitumour properties. However, whether GLA ameliorates liver fibrosis or not is still unclear. In this study, a liver fibrosis model was established using male C57BL/6 mice. The mice were treated with 5 and 10 mg/kg GLA via intraperitoneal injection, respectively. The ones that were treated with 5 mg/kg OCA were used as the positive control group. The levels of liver function, liver fibrosis biomarkers and liver pathological changes were then evaluated. We also explored the effects of GLA on inflammatory response and liver cell apoptosis. In addition, we investigated the gut microbiota mechanisms of GLA on liver fibrosis. The results from this study that GLA could significantly decrease the level of liver function (AST, ALT, TBA) and liver fibrosis (HA, LN, PC-III, IV-C). On the other hand, a significant decrease in inflammation levels (IL-1β, TNF-α) were also noted. GLA also improves CCl4-induced pathological liver injuries and collagen deposition, in addition to decreasing apoptosis levels. In addition, an increase in the ratio of Bacteroidetes and Firmicutes in liver disease was also observed. GLA also improves the gut microbiota. In conclusion, GLA attenuates CCl4-induced liver fibrosis and improves the associated gut microbiota imbalance.

The ortholog of human ssDNA-binding protein SSBP3 influences neurodevelopment and autism-like behaviors in Drosophila melanogaster

1p32.3 microdeletion/duplication is implicated in many neurodevelopmental disorders-like phenotypes such as developmental delay, intellectual disability, autism, macro/microcephaly, and dysmorphic features. The 1p32.3 chromosomal region harbors several genes critical for development; however, their validation and characterization remain inadequate. One such gene is the single-stranded DNA-binding protein 3 (SSBP3) and its Drosophila melanogaster ortholog is called sequence-specific single-stranded DNA-binding protein (Ssdp). Here, we investigated consequences of Ssdp manipulations on neurodevelopment, gene expression, physiological function, and autism-associated behaviors using Drosophila models. We found that SSBP3 and Ssdp are expressed in excitatory neurons in the brain. Ssdp overexpression caused morphological alterations in Drosophila wing, mechanosensory bristles, and head. Ssdp manipulations also affected the neuropil brain volume and glial cell number in larvae and adult flies. Moreover, Ssdp overexpression led to differential changes in synaptic density in specific brain regions. We observed decreased levels of armadillo in the heads of Ssdp overexpressing flies, as well as a decrease in armadillo and wingless expression in the larval wing discs, implicating the involvement of the canonical Wnt signaling pathway in Ssdp functionality. RNA sequencing revealed perturbation of oxidative stress-related pathways in heads of Ssdp overexpressing flies. Furthermore, Ssdp overexpressing brains showed enhanced reactive oxygen species (ROS), altered neuronal mitochondrial morphology, and up-regulated fission and fusion genes. Flies with elevated levels of Ssdp exhibited heightened anxiety-like behavior, altered decisiveness, defective sensory perception and habituation, abnormal social interaction, and feeding defects, which were phenocopied in the pan-neuronal Ssdp knockdown flies, suggesting that Ssdp is dosage sensitive. Partial rescue of behavioral defects was observed upon normalization of Ssdp levels. Notably, Ssdp knockdown exclusively in adult flies did not produce behavioral and functional defects. Finally, we show that optogenetic manipulation of Ssdp-expressing neurons altered autism-associated behaviors. Collectively, our findings provide evidence that Ssdp, a dosage-sensitive gene in the 1p32.3 chromosomal region, is associated with various anatomical, physiological, and behavioral defects, which may be relevant to neurodevelopmental disorders like autism. Our study proposes SSBP3 as a critical gene in the 1p32.3 microdeletion/duplication genomic region and sheds light on the functional role of Ssdp in neurodevelopmental processes in Drosophila.

Multi-omics data reveals the disturbance of glycerophospholipid metabolism and linoleic acid metabolism caused by disordered gut microbiota in PM2.5 gastrointestinal exposed rats

The relationships between fine particulate matter (PM2.5) exposure and health effects are complex and incompletely understood. Evidence suggests that PM2.5 exposure alters gut microbiota composition and metabolites, but the connections between these changes remain unclear. The aim of our study was to investigate how gut microbiota are involved in the systemic metabolic changes following PM2.5 gastrointestinal exposure. We used multi-omics approaches, including 16S rRNA sequencing and serum metabolomics, to identify alterations in gut microbes and metabolites of PM2.5-exposed rats. We then explored correlations between perturbed gut microbiota and metabolic changes, and conducted pathway analyses to determine critical metabolic pathways impacted by PM2.5 exposure. To verify links between gut microbiome and metabolome disruptions, we performed fecal microbiota transplantation (FMT) experiment. A total of 30 differential gut microbe taxa were identified between PM2.5 and control groups, primarily in Firmicutes, Acidobacteria, and Proteobacteria phyla. We also identified 30 differential metabolites, including glycerophospholipids, fatty acyls, amino acids and others. Pathway analysis revealed disruptions in glycerophospholipid metabolism, steroid hormone biosynthesis, and linoleic acid metabolism. Through FMT, we confirmed PM2.5 altered phosphatidylcholine and linoleic acid metabolism by changing specific gut bacteria. Our results suggest that PM2.5 gastrointestinal exposure triggers systemic metabolic changes by disrupting the gut microbiome, especially glycerophospholipid and linoleic acid metabolism pathways.

Repression of Staphylococcus aureus and Escherichia coli by Lactiplantibacillus plantarum Strain AG10 in Drosophila melanogaster In Vivo Model

Probiotic bacteria exhibiting antagonistic activities against pathogenic bacteria are widely considered as potential options for the prevention and treatment of various infectious diseases and represent potential substitutes of antibiotics. Here we show that the L. plantarum AG10 strain represses the growth of Staphylococcus aureus and Escherichia coli in vitro and diminishes their negative effects in vivo in a Drosophila melanogaster model of survival on embryonic (larvae) and pupa stages. In an agar drop diffusion test, L. plantarum AG10 exhibited antagonistic properties against Escherichia coli, Staphylococcus aureus, Serratia marcescens and Pseudomonas aeruginosa, and repressed the growth of E. coli and S. aureus during milk fermentation. In a Drosophila melanogaster model, L. plantarum AG10 alone did not provide any significant effect, either during the embryonic stage or during further development of the flies. Despite this, it was able to restore the viability of groups infected with either E. coli and S. aureus, almost to the level of non-treated control at all stages of development (larvae, pupa and adult). Moreover, in the presence of L. plantarum AG10, pathogens-induced mutation rates and recombination events reduced 1.5-2-fold. The genome of L. plantarum AG10 was sequenced and deposited at NCBI under the accession number PRJNA953814 and consists of annotated genome and raw sequence data. It consists of 109 contigs and is 3,479,919 bp in length with a GC content of 44.5%. The analysis of the genome has revealed considerably few putative virulence factors and three genes responsible for the biosynthesis of putative antimicrobial peptides, with one of them exhibiting a high probability of antimicrobial properties. Taken together, these data allow the suggestion that the L. plantarum AG10 strain is promising for use in both dairy production and probiotics as a preservative from foodborne infections.

Lactobacillus plantarum-derived indole-3-lactic acid ameliorates colorectal tumorigenesis via epigenetic regulation of CD8+ T cell immunity

Previous studies have shown that Lactobacillus species play a role in ameliorating colorectal cancer (CRC) in a mouse model. However, the underlying mechanisms remain largely unknown. Here, we found that administration of a probiotic strain, Lactobacillus plantarumL168 and its metabolite, indole-3-lactic acid, ameliorated intestinal inflammation, tumor growth, and gut dysbiosis. Mechanistically, we indicated that indole-3-lactic acid accelerated IL12a production in dendritic cells by enhancing H3K27ac binding at the enhancer regions of IL12a that contributed to priming CD8⁺ T cell immunity against tumor growth. Furthermore, indole-3-lactic acid was found to transcriptionally inhibit Saa3 expression related to cholesterol metabolism of CD8⁺ T cells through changing chromatin accessibility and subsequent enhancing function of tumor-infiltrating CD8⁺ T cells. Together, our findings provide new insights into the epigenetic regulation of probiotics-mediated anti-tumor immunity and suggest the potential of L. plantarumL168 and indole-3-lactic acid to develop therapeutic strategies for patients with CRC.

Histone demethylase KDM5B licenses macrophage-mediated inflammatory responses by repressing Nfkbia transcription

Macrophages play a critical role in the immune homeostasis and host defense against invading pathogens. However, uncontrolled activation of inflammatory macrophages leads to tissue injury and even fuels autoimmunity. Hence the molecular mechanisms underlying macrophage activation need to be further elucidated. The effects of epigenetic modifications on the function of immune cells draw increasing attention. Here, we demonstrated that lysine-specific demethylase 5B (KDM5B), a classical transcriptional repressor in stem cell development and cancer, was required for the full activation of NF-κB signaling cascade and pro-inflammatory cytokine production in macrophages. KDM5B deficiency or inhibitor treatment protected mice from immunologic injury in both collagen-induced arthritis (CIA) model and endotoxin shock model. Genome-wide analysis of KDM5B-binding peaks identified that KDM5B was selectively recruited to the promoter of Nfkbia, the gene encoding IκBα, in activated macrophages. KDM5B mediated the H3K4me3 modification erasing and decreased chromatin accessibility of Nfkbia gene locus, coordinating the elaborate suppression of IκBα expression and the enhanced NF-κB-mediated macrophage activation. Our finding identifies the indispensable role of KDM5B in macrophage-mediated inflammatory responses and provides a candidate therapeutic target for autoimmune and inflammatory disorders.

Probiotics for Neurodegenerative Diseases: A Systemic Review

Neurodegenerative disorders (ND) are a group of conditions that affect the neurons in the brain and spinal cord, leading to their degeneration and eventually causing the loss of function in the affected areas. These disorders can be caused by a range of factors, including genetics, environmental factors, and lifestyle choices. Major pathological signs of these diseases are protein misfolding, proteosomal dysfunction, aggregation, inadequate degradation, oxidative stress, free radical formation, mitochondrial dysfunctions, impaired bioenergetics, DNA damage, fragmentation of Golgi apparatus neurons, disruption of axonal transport, dysfunction of neurotrophins (NTFs), neuroinflammatory or neuroimmune processes, and neurohumoral symptoms. According to recent studies, defects or imbalances in gut microbiota can directly lead to neurological disorders through the gut-brain axis. Probiotics in ND are recommended to prevent cognitive dysfunction, which is a major symptom of these diseases. Many in vivo and clinical trials have revealed that probiotics (Lactobacillus acidophilus, Bifidobacterium bifidum, and Lactobacillus casei, etc.) are effective candidates against the progression of ND. It has been proven that the inflammatory process and oxidative stress can be modulated by modifying the gut microbiota with the help of probiotics. As a result, this study provides an overview of the available data, bacterial variety, gut-brain axis defects, and probiotics' mode of action in averting ND. A literature search on particular sites, including PubMed, Nature, and Springer Link, has identified articles that might be pertinent to this subject. The search contains the following few groups of terms: (1) Neurodegenerative disorders and Probiotics OR (2) Probiotics and Neurodegenerative disorders. The outcomes of this study aid in elucidating the relationship between the effects of probiotics on different neurodegenerative disorders. This systematic review will assist in discovering new treatments in the future, as probiotics are generally safe and cause mild side effects in some cases in the human body.

Gut microbes and host behavior: The forgotten members of the gut-microbiome

The gut microbiota refers to an entire population of microorganisms that colonize the gut. This community includes viruses, prokaryotes (bacteria and archaea), and eukaryotes (fungi and parasites). Multiple studies in the last decades described the significant involvement of gut bacteria in gut-brain axis communication; however, the involvement of other members of the gut microbiota has been neglected. Recent studies found that these 'forgotten' members of the gut microbiota may also have a role in gut-brain communication, although it is still unclear whether they have a direct effect on the brain or if their effects are mediated by gut bacteria. Here, we provide concrete suggestions for future research to tease out mechanisms of the microbiota-gut-brain axis. This article is part of the Special Issue on "Microbiome & the Brain: Mechanisms & Maladies".

Axenic and gnotobiotic insect technologies in research on host-microbiota interactions

Insects are one of the most important animal life forms on earth. Symbiotic microbes are closely related to the growth and development of the host insects and can affect pathogen transmission. For decades, various axenic insect-rearing systems have been developed, allowing further manipulation of symbiotic microbiota composition. Here we review the historical development of axenic rearing systems and the latest progress in using axenic and gnotobiotic approaches to study insect-microbe interactions. We also discuss the challenges of these emerging technologies, possible solutions to address these challenges, and future research directions that can contribute to a more comprehensive understanding of insect-microbe interactions.

Exposure to cytarabine causes side effects on adult development and physiology and induces intestinal damage via apoptosis in Drosophila

Cytarabine (Ara-C) is a widely used drug in acute myeloid leukemia (AML). However, it faces serious challenges in clinical application due to serious side effects such as gastrointestinal disorders and neurologic toxicities. Until now, the mechanism of Ara-C-induced damage is not clear. Here, we used Drosophila melanogaster (fruit fly) as the in vivo model to explore the side effects and mechanism of Ara-C. Our results showed that Ara-C supplementation delayed larval development, reduced lifespan, impaired locomotor capacity, and increased susceptibility to stress response in adult flies. In addition, Ara-C led to the intestinal morphological damage and ROS accumulation in the guts. Moreover, administration of Ara-C promoted gene expressions of Toll pathway, IMD pathway, and apoptotic pathway in the guts. These findings raise the prospects of using Drosophila as in vivo model to rapidly assess chemotherapy-mediated toxicity and efficiently screen the protective drugs.

Wnt/β-catenin signaling within multiple cell types dependent upon kramer regulates Drosophila intestinal stem cell proliferation

The gut epithelium is subject to constant renewal, a process reliant upon intestinal stem cell (ISC) proliferation that is driven by Wnt/β-catenin signaling. Despite the importance of Wnt signaling within ISCs, the relevance of Wnt signaling within other gut cell types and the underlying mechanisms that modulate Wnt signaling in these contexts remain incompletely understood. Using challenge of the Drosophila midgut with a non-lethal enteric pathogen, we examine the cellular determinants of ISC proliferation, harnessing kramer, a recently identified regulator of Wnt signaling pathways, as a mechanistic tool. We find that Wnt signaling within Prospero-positive cells supports ISC proliferation and that kramer regulates Wnt signaling in this context by antagonizing kelch, a Cullin-3 E3 ligase adaptor that mediates Dishevelled polyubiquitination. This work establishes kramer as a physiological regulator of Wnt/β-catenin signaling in vivo and suggests enteroendocrine cells as a new cell type that regulates ISC proliferation via Wnt/β-catenin signaling.

Liver Microbiome in Healthy Rats: The Hidden Inhabitants of Hepatocytes

The tumor and tissue microbiota of human beings have recently been investigated. Gut permeability is known as a possible resource for the positive detection of tissue bacteria. Herein, we report that microbiota were detected in high abundance in the hepatocytes of healthy rats and that they were shared with the gut microbiota to an extent. We assessed male Sprague Dawley (SD) rats for the 16S ribosomal ribonucleic acid (rRNA) gene. After the rats were sacrificed by blood drainage from the portal vein, we extracted total deoxyribonucleic acid (DNA) from their ileal and colonic contents and liver tissues. The V3–V4 region of the 16S rRNA gene was amplified by polymerase chain reaction (PCR) and sequenced using an Illumina HiSeq 2500 platform. Sequences were assigned taxonomically by the SILVA database. We also detected bacterial lipopolysaccharide (LPS) and lipoteichoic acid (LTA) in situ using immunofluorescence (IF) and western blotting and the 16S rRNA gene using fluorescent in situ hybridization (FISH). In the livers of six rats, we detected $\mathrm{54,867.50}\pm 6450.03$ effective tags of the 16S rRNA gene and clustered them into 1003 kinds of operational taxonomic units (OTUs; $805.67\pm 70.14$ , 729–893). Rats showed conservation of bacterial richness, abundance, and evenness. LPS and the 16S rRNA gene were detected in the nuclei of hepatocytes. The main function composition of the genomes of annotated bacteria was correlated with metabolism ( $79.92\pm 0.24\%$ ). Gram negativity was about 1.6 times higher than gram positivity. The liver microbiome was shared with both the small and large intestines but showed significantly higher richness and evenness than the gut microbiome, and the β-diversity results showed that the liver microbiome exhibited significantly higher similarity than the small and large intestines ( $P<0.05$ ). Our results suggest that the bacteria in the liver microbiome are hidden intracellular inhabitants in healthy rat livers.

Processing Mechanism of Massa Medicata Fermentata Based on the Correlation Analysis of Strains, Chemical Compositions and Anti-Inflammatory Activity

The traditional Chinese medicine of fermented medicine may be under the involvement of multiple strains and the interaction between these microorganisms. Liu Shenqu (Massa Medicata Fermentata, MMF) is one of the most widely used fermented medicines, whose potential processing mechanism is still unclear. In this work, UPLC/MS and GNPS methods were employed to rapidly predict chemical compositions in MMF. Moreover, the dynamic changes of strains, chemical compositions and anti-inflammatory activity of MMF during fermentation process were investigated, and subsequently strains-chemical compositions-efficacy interactions were revealed by Pearson correlation analysis and partial least squares regression (PLSR) analysis. As a result, 24 components were identified, and the potential strains including Bacillus, Burkholderia_Caballeronia_Paraburkholderia, Enterobacter, Aspergillus heterocaryoticus, Rhizopus arrhizus, Kazachstania bulderi, which related to the production of anti-inflammatory active ingredients were exposed. These results demonstrated chemical compositions-strains-efficacy interactions during fermentation of MMF, and provide reference for the exploration of the processing mechanism of MMF.

The lipid-lowering effects of fenugreek gum, hawthorn pectin, and burdock inulin

Objective

The present study aimed to investigate the lipid-lowering effects and mechanisms of fenugreek gum (FG), hawthorn pectin (HP), and burdock inulin (BI) on high-fat diet (HFD)-induced hyperlipidemic rats.

Methods

In this study, high-fat diet (HFD) together with fat emulsion administration were used to establish hyperlipidemia model. The biochemical indices were assayed after administration of FG, HP, and BI. Their effects were evaluated by factor analysis. Alterations of gut microbiota and short chain fatty acids (SCFAs) in the cecal were assessed to illustrate the mechanism of lipid lowering.

Results

The supplementation of FG, HP, and BI on HFD-fed rats decreased the levels of serum lipid and reduced the HFD-related liver and testicle damage. In the scatter plot of factor analysis, HP and BI were closer to normal fat diet (NFD) group in restoring the severity of hyperlipidemia, while FG and HP enhanced the excretion of cholesterol and bile acids (BAs). The levels of total SCFAs, especially butyric acid reduced by HFD were increased by HP. The ratio of Firmicutes to Bacteroidetes increased by HFD was reduced by HP and BI. FG, HP, and BI enriched intestinal probiotics, which were related to bile acid excretion or lipid-lowering.

Conclusions

FG inhibited the absorption of cholesterol and enhanced the excretion of it, as well as increased the abundance of beneficial bacteria. While BI restored the imbalance of intestinal microbiota. HP enhanced the excretion of cholesterol and BAs, and restored the imbalance of intestinal microbiota. It was also utilized by intestinal microorganisms to yield SCFAs. This study suggested that FG, HP, and BI possessed the potential to be utilized as dietary supplements for obesity management.

The Effect of Limosilactobacillus reuteri on Social Behavior Is Independent of the Adaptive Immune System

Gut microbes can modulate almost all aspects of host physiology throughout life. As a result, specific microbial interventions are attracting considerable attention as potential therapeutic strategies for treating a variety of conditions. Nonetheless, little is known about the mechanisms through which many of these microbes work. Recently, we and others have found that the commensal bacterium Limosilactobacillus reuteri (formerly Lactobacillus reuteri) reverses social deficits in several mouse models (genetic, environmental, and idiopathic) for neurodevelopmental disorders in a vagus nerve-, oxytocin-, and biopterin-dependent manner. Given that gut microbes can signal to the brain through the immune system and L. reuteri promotes wound healing via the adaptive immune response, we sought to determine whether the prosocial effect mediated by L. reuteri also depends on adaptive immunity. Here, we found that the effects of L. reuteri on social behavior and related changes in synaptic function are independent of the mature adaptive immune system. Interestingly, these findings indicate that the same microbe (L. reuteri) can affect different host phenotypes through distinct mechanisms. IMPORTANCE Because preclinical animal studies support the idea that gut microbes could represent novel therapeutics for brain disorders, it is essential to fully understand the mechanisms by which gut microbes affect their host's physiology. Previously, we discovered that treatment with Limosilactobacillus reuteri selectively improves social behavior in different mouse models for autism spectrum disorder through the vagus nerve, oxytocin reward signaling in the brain, and biopterin metabolites (BH4) in the gut. However, given that (i) the immune system remains a key pathway for host-microbe interactions and that (ii) L. reuteri has been shown to facilitate wound healing through the adaptive immune system, we examined here whether the prosocial effects of L. reuteri require immune signaling. Unexpectedly, we found that the mature adaptive immune system (i.e., conventional B and T cells) is not required for L. reuteri to reverse social deficits and related changes in synaptic function. Overall, these findings add new insight into the mechanism through which L. reuteri modulates brain function and behavior. More importantly, they highlight that a given bacterial species can modulate different phenotypes (e.g., wound healing versus social behavior) through separate mechanisms.

Ruminococcaceae_UCG-013 Promotes Obesity Resistance in Mice

Alterations in the gut microbiome have been linked to obesity and type 2 diabetes, in epidemiologic studies and studies of fecal transfer effects in germ-free mice. Here, we aimed to identify the effects of specific gut microbes on the phenotype of mice fed a high-fat diet (HFD). After eight weeks of HFD feeding, male C57BL/6J mice in the HFD group ranking in the upper and lower quartiles for body weight gain were considered obese prone and obese resistant, respectively. 16S rRNA gene sequencing was used to determine the composition of the intestinal microbiota, and fecal transplantation (FMT) was conducted to determine whether the microbiota plays a causal role in phenotypic variation. Ruminococcaceae_UCG-013 was more abundant in the gut microbes of mice with a lean phenotype than in those with an obese phenotype. Ruminococcaceae_UCG-013 was identified as the most significant biomarker for alleviating obesity by random forest analysis. In a correlation analysis of serum parameters and body weight, Ruminococcaceae_UCG-013 was positively associated with serum HDL-C levels and negatively associated with serum TC, TG, and LDL-C levels. To conclude, Ruminococcaceae_UCG-013 was identified as a novel microbiome biomarker for obesity resistance, which may serve as a basis for understanding the critical gut microbes responsible for obesity resistance. Ruminococcaceae_UCG-013 may serve as a target for microbiome-based diagnoses and treatments in the future.

Thallium(I) exposure perturbs the gut microbiota and metabolic profile as well as the regional immune function of C57BL/6 J mice

Intestinal microbes regulate the development of diseases induced by environmental exposure. Thallium (Tl) is a highly toxic heavy metal, and its toxicity is rarely discussed in relation to gut microbes. Herein, we showed that Tl(I) exposure (10 ppm for 2 weeks) affected the alpha diversity of bacteria in the ileum, colon, and feces, but had little effect on the beta diversity of bacteria through 16S rRNA sequencing. LEfSe analysis revealed that Tl(I) exposure changed the abundance of intestinal microbiota along the digestive tract. Cecum metabolomic detection and analysis showed that Tl(I) exposure altered the abundance and composition of metabolites. In addition, the Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analysis revealed that Tl(I) exposure impaired amino acid, lipid, purine metabolism, and G protein-coupled receptor signalling pathways. A consistency test revealed a strong correlation, and a Pearson's correlation analysis showed an extensive interaction, between microorganisms and metabolites. Analysis of the intestinal immunity revealed that Tl(I) exposure suppressed the immune responses, which also had regional differences. These results identify the perturbation of the intestinal microenvironment by Tl exposure and provide a new explanation for Tl toxicity.

Molecular and cellular events linking variants in the histone demethylase KDM5C to the intellectual disability disorder Claes-Jensen syndrome

The widespread availability of genetic testing for those with neurodevelopmental disorders has highlighted the importance of many genes necessary for the proper development and function of the nervous system. One gene found to be genetically altered in the X-linked intellectual disability disorder Claes-Jensen syndrome is KDM5C, which encodes a histone demethylase that regulates transcription by altering chromatin. While the genetic link between KDM5C and cognitive (dys)function is clear, how KDM5C functions to control transcriptional programs within neurons to impact their growth and activity remains the subject of ongoing research. Here, we review our current knowledge of Claes-Jensen syndrome and discuss important new data using model organisms that have revealed the importance of KDM5C in regulating aspects of neuronal development and function. Continued research into the molecular and cellular activities regulated by KDM5C is expected to provide critical etiological insights into Claes-Jensen syndrome and highlight potential targets for developing therapies to improve the quality of life of those affected.