Inulin alleviates perinatal 2-ethylhexyl diphenyl phosphate (EHDPHP) exposure-induced intestinal toxicity by reshaping the gut microbiota and suppressing the enteric-origin LPS/TLR4/NF-κb pathway in dams and pups.

Organophosphorus flame retardants (OPFRs), such as 2-ethylhexyl diphenyl phosphate (EHDPHP), are ubiquitously used, leading to pervasive environmental contamination and human health risks. While associations between EHDPHP and health issues such as disruption of hormones, neurotoxic effects, and toxicity to reproduction have been recognized, exposure to EHDPHP during perinatal life and its implications for the intestinal health of dams and their pups have largely been unexplored. This study investigated the intestinal toxicity of EHDPHP and the potential for which inulin was effective. Dams were administered either an EHDPHP solution or a corn oil control from gestation day 7 (GD7) to postnatal day 21 (PND21), with inulin provided in their drinking water. Our results indicate that inulin supplementation mitigates damage to the intestinal epithelium caused by EHDPHP, restores mucus-secreting cells, suppresses intestinal hyperpermeability, and abates intestinal inflammation by curtailing lipopolysaccharide leakage through reshaping of the gut microbiota. A reduction in LPS levels concurrently inhibited the inflammation-associated TLR4/NF-κB pathway. In conclusion, inulin administration may ameliorate intestinal toxicity caused by EHDPHP in dams and pups by reshaping the gut microbiota and suppressing the LPS/TLR4/NF-κB pathway. These findings underscore the efficacy of inulin as a therapeutic agent for managing health risks linked to EHDPHP exposure.

Maternal inulin supplementation ameliorates prenatal methamphetamine exposure-induced hepatotoxicity and restores gut microbiota in mouse offspring.

Prenatal exposure to methamphetamine (METH) is an issue of global concern due to its adverse effects on offspring, particularly its impact on liver health, an area still not fully understood. Inulin, a recognized prebiotic, is thought to potentially ameliorate these developmental disorders and toxic injuries in progeny. To investigate the effects of prenatal METH exposure on the liver and the role of gut microbiota, we established a murine model, the subjects of which were exposed to METH prenatally and subsequently treated with inulin. Our findings indicate that prenatal METH exposure causes liver damage in offspring, as evidenced by a decreased liver index, histopathological changes, diminished glycogen synthesis, hepatic dysfunction, and alterations in mRNA profiles. Furthermore, it impairs the antioxidant system and induces oxidative stress, possibly due to changes in cecal microbiota and dysregulation of bile acid homeostasis. However, maternal inulin supplementation appears to restore the gut microbiota in offspring and mitigate the hepatotoxic effects induced by prenatal METH exposure. Our study provides definitive evidence of METH's transgenerational hepatotoxicity and suggests that maternal inulin supplementation could be an effective preventive strategy.

Multi-Omics Analysis Reveals the Role of Sigma-1 Receptor in a Takotsubo-like Cardiomyopathy Model.

Takotsubo syndrome (TTS) is a stress-induced cardiomyopathy that presents with sudden onset of chest pain and dyspneic and cardiac dysfunction as a result of extreme physical or emotional stress. The sigma-1 receptor (Sigmar1) is a ligand-dependent molecular chaperone that is postulated to be involved in various processes related to cardiovascular disease. However, the role of Sigmar1 in TTS remains unresolved. In this study, we established a mouse model of TTS using wild-type and Sigmar1 knockout mice to investigate the involvement of Sigmar1 in TTS development. Our results revealed that Sigmar1 knockout exacerbated cardiac dysfunction, with a noticeable decrease in ejection fraction (EF) and fractional shortening (FS) compared to the wild-type model. In terms of the gut microbiome, we observed regulation of Firmicutes and Bacteroidetes ratios; suppression of probiotic Lactobacillus growth; and a rise in pathogenic bacterial species, such as Colidextribacter. Metabolomic and transcriptomic analyses further suggested that Sigmar1 plays a role in regulating tryptophan metabolism and several signaling pathways, including MAPK, HIF-1, calcium signaling, and apoptosis pathways, which may be crucial in TTS pathogenesis. These findings offer valuable insight into the function of Sigmar1 in TTS, and this receptor may represent a promising therapeutic target for TTS.

Sigma-1 receptor knockout disturbs gut microbiota, remodels serum metabolome, and exacerbates isoprenaline-induced heart failure.

Introduction: Heart failure (HF) is usually the end stage of the continuum of various cardiovascular diseases. However, the mechanism underlying the progression and development of HF remains poorly understood. The sigma-1 receptor (Sigmar1) is a non-opioid transmembrane receptor implicated in many diseases, including HF. However, the role of Sigmar1 in HF has not been fully elucidated. Methods: In this study, we used isoproterenol (ISO) to induce HF in wild-type (WT) and Sigmar1 knockout (Sigmar1-/-) mice. Multi-omic analysis, including microbiomics, metabolomics and transcriptomics, was employed to comprehensively evaluate the role of Sigmar1 in HF. Results: Compared with the WT-ISO group, Sigmar1-/- aggravated ISO-induced HF, including left ventricular systolic dysfunction and ventricular remodeling. Moreover, Sigmar1-/- exacerbated ISO-induced gut microbiota dysbiosis, which was demonstrated by the lower abundance of probiotics g_Akkermansia and g_norank_f_Muribaculaceae, and higher abundance of pathogenic g_norank_f_Oscillospiraceae and Allobaculum. Furthermore, differential metabolites among WT-Control, WT-ISO and Sigmar-/--ISO groups were mainly enriched in bile secretion, tryptophan metabolism and phenylalanine metabolism, which presented a close association with microbial dysbiosis. Corresponding with the exacerbation of the microbiome, the inflammation-related NOD-like receptor signaling pathway, NF-kappa B signaling pathway and TNF signaling pathway were activated in the heart tissues. Conclusion: Taken together, this study provides evidence that a Sigmar1 knockout disturbs the gut microbiota and remodels the serum metabolome, which may exacerbate HF by stimulating heart inflammation.

Inulin alleviates neuroinflammation and oxidative stress induced by perinatal 2-ethylhexyl diphenyl phosphate (EHDPHP) exposure in female mice and offspring.

Organophosphorus flame retardants (OPFRs), including 2-ethylhexyl diphenyl phosphate (EHDPHP), are prevalent in everyday life due to their broad usage in fields such as healthcare, electronics, industry, and sports. These compounds, added to polymers through physical mixing, can leach into the environment, posing a risk to humans through direct contact or the food chain. Despite known associations with health issues like endocrine disruption, neurotoxicity, and reproductive toxicity, the implications of perinatal EHDPHP exposure on both mothers and offspring are still unclear. This study aimed to investigate the neuroinflammatory effects of EHDPHP and the potential mitigating role of inulin. Pregnant C57 mice were administered either a corn oil control or an EHDPHP solution (300 µg/kg bw/d) from gestation day 7 (GD7) to postnatal day 21 (PND21). Concurrently, mice were provided either regular drinking water or water supplemented with 1% inulin. We found that EHDPHP significantly increased the serum levels of IL-1ß, IL-6, and MDA, but decreased SOD levels in both mothers and pups. These effects were reversed by inulin supplementation. RNA-sequencing revealed that EHDPHP induced inflammation and oxidative stress through the TLR4/NF-κB pathway, which was mitigated by inulin. In conclusion, inulin ameliorated EHDPHP-induced neuroinflammation and oxidative stress in both mothers and offspring, highlighting its potential therapeutic role.

Epigallocatechin-3-gallate ameliorates polystyrene microplastics-induced anxiety-like behavior in mice by modulating gut microbe homeostasis.

Polystyrene microplastics (PS-MPs) have emerged as a concerning pollutant in modern society due to their widespread production and usage. Despite ongoing research efforts, the impact of PS-MPs on mammalian behavior and the mechanisms driving these effects remain incompletely elucidated. Consequently, effective strategies for prevention have yet to be developed. To fill these gaps, C57BL/6 mice were orally administered with 5 µm PS-MPs for 28 consecutive days in this study. The open-field test and the elevated plus-maze test were performed to evaluate the anxiety-like behavior, 16S rRNA sequencing and untargeted metabolomics analysis were used to detect the changes of gut microbiota and serum metabolites. Our results indicated that PS-MPs exposure activated hippocampal inflammation and induced anxiety-like behavior in mice. Meanwhile, PS-MPs disturbed the gut microbiota, impaired the intestinal barrier, and aroused peripheral inflammation. Specifically, PS-MPs increased the abundance of pathogenic microbiota Tuzzerella, while lowered the abundance of probiotics Faecalibaculum and Akkermansia. Interestingly, eliminating the gut microbiota protected against the deleterious effects of PS-MPs on intestinal barrier integrity, reduced the levels of peripheral inflammatory cytokines, and ameliorated anxiety-like behavior. Additionally, green tea's primary bioactive constituent, epigallocatechin-3-gallate (EGCG), optimized gut microbial composition, improved intestinal barrier function, reduced peripheral inflammation, and exerted anti-anxiety effects by inhibiting the hippocampal TLR4/MyD88/NF-κB signaling cascade. EGCG also remodeled serum metabolism, especially modulated purine metabolism. These findings suggested that gut microbiota participates in PS-MPs-induced anxiety-like behavior by modulating the gut-brain axis, and that EGCG could serve as a potential preventive strategy.

Microbial community succession in the intestine of mice with deep partial-thickness burns.

Introduction: Burn injury has been shown to lead to changes in the composition of the gut microbiome and cause other damage in patients. However, little is known about how the gut microbial community evolves in individuals who have recovered from burn injury. Methods: In this study, we established a model of deep partial-thickness burn in mice and collected fecal samples at eight time points (pre-burn, 1, 3, 5, 7, 14, 21, and 28 days post-burn) for 16S rRNA amplification and high-throughput sequencing. Results: The results of the sequencing were analyzed using measures of alpha diversity, and beta diversity and taxonomy. We observed that the richness of the gut microbiome declined from day 7 post-burn and that the principal component and microbial community structure varied over time. On day 28 after the burn, the microbiome composition largely returned to the pre-burn level, although day 5 was a turning point for change. Some probiotics, such as the Lachnospiraceae_NK4A136_group, decreased in composition after the burn but were restored in the later recovery period. In contrast, Proteobacteria showed an opposite trend, which is known to include potential pathogenic bacteria. Conclusion: These findings demonstrate gut microbial dysbiosis after burn injury and provide new insights into the burn-related dysbiosis of the gut microbiome and strategies for improving the treatment of burn injury from the perspective of the microbiota.

Gut microbiota contribute to Methamphetamine-induced cardiotoxicity in mouse model.

Methamphetamine (METH) is a psychotropic drug known to cause cardiotoxicity. The gut-heart axis is emerging as an important pathway linking gut microbiota to cardiovascular disease, but the precise association between METH-induced cardiotoxicity and gut microbiota has yet to be elucidated. In this study, we established an escalating dose-multiple METH administration model in male BALB/c mice, examined cardiac injury and gut microbiota, and investigated the contribution of gut microbiota to cardiotoxicity induced by METH. Additionally, we treated mice with antibiotics and fecal microbiota transplantation (FMT) to assess the impact of gut microbiota on cardiotoxicity. Our results showed that METH exposure altered the p53 and PI3K/Akt signaling pathways and modulated the apoptosis pathway in heart tissue, accompanied by elevated levels of Bax/BCL-2 expression and cleaved caspase-3 proteins. METH exposure increased the diversity and richness of gut microbiota, and significantly changed the microbial community composition, accompanied by elevated abundance of Lactobacillus, Bifidobacterium, and decreased abundance of Bacteroides, norank_f_Muribaculaceae and Alistipes. Eliminating gut microbiota by antibiotics treatment alleviated METH-induced cardiotoxicity, while FMT treatment transferred similar cardiac injury manifestations from METH-exposed mice to healthy recipient mice. Our study unveils the crucial involvement of gut microbiota in the development of cardiotoxicity induced by METH and provides potential strategies for treating cardiac complications caused by METH.

Gut microbiota from sigma-1 receptor knockout mice induces depression-like behaviors and modulates the cAMP/CREB/BDNF signaling pathway.

Introduction: Depression is a common mental disorder that affects approximately 350 million people worldwide. Much remains unknown about the molecular mechanisms underlying this complex disorder. Sigma-1 receptor (Sig-1R) is expressed at high levels in the central nervous system. Increasing evidence has demonstrated a close association between the Sig-1R and depression. Recently, research has suggested that the gut microbiota may play a crucial role in the development of depression. Methods: Male Sig-1R knockout (Sig-1R KO) and wild-type (WT) mice were used for this study. All transgenic mice were of a pure C57BL/6J background. Mice received a daily gavage of vancomycin (100 mg/kg), neomycin sulfate (200 mg/kg), metronidazole (200 mg/kg), and ampicillin (200 mg/kg) for one week to deplete gut microbiota. Fecal microbiota transplantation (FMT) was conducted to assess the effects of gut microbiota. Depression-like behaviors was evaluated by tail suspension test (TST), forced swimming test (FST) and sucrose preference test (SPT). Gut microbiota was analyzed by 16s rRNA and hippocampal transcriptome changes were assessed by RNA-seq. Results: We found that Sig-1R knockout induced depression-like behaviors in mice, including a significant reduction in immobility time and an increase in latency to immobility in the FST and TST, which was reversed upon clearance of gut microbiota with antibiotic treatment. Sig-1R knockout significantly altered the composition of the gut microbiota. At the genus level, the abundance of Alistipes, Alloprevotella, and Lleibacterium decreased significantly. Gut microbiota dysfunction and depression-like phenotypes in Sig-1R knockout mice could be reproduced through FMT experiments. Additionally, hippocampal RNA sequencing identified multiple KEGG pathways that are associated with depression. We also discovered that the cAMP/CREB/BDNF signaling pathway is inhibited in the Sig-1R KO group along with lower expression of neurotrophic factors including CTNF, TGF-α and NGF. Fecal bacteria transplantation from Sig-1R KO mice also inhibited cAMP/CREB/BDNF signaling pathway. Discussion: In our study, we found that the gut-brain axis may be a potential mechanism through which Sig-1R regulates depression-like behaviors. Our study provides new insights into the mechanisms by which Sig-1R regulates depression and further supports the concept of the gut-brain axis.

Obeticholic acid protects against methamphetamine-induced anxiety-like behavior by ameliorating microbiota-mediated intestinal barrier impairment.

Methamphetamine (Meth) abuse can cause severe anxiety disorder and interfere with gut homeostasis. Obeticholic acid (OCA) has emerged as a protective agent against diet-related anxiety that improves gut homeostasis. The potential for OCA to ameliorate Meth-induced anxiety, and the microbial mechanisms involved, remain obscure. Here, C57/BL6 mice were intraperitoneally injected with Meth (15 mg/kg) to induce anxiety-like behavior. 16 S rRNA sequence analysis and fecal microbiome transplantation (FMT) were used to profile the gut microbiome and evaluate its effects, respectively. Orally administered OCA was investigated for protection against Meth-induced anxiety. Results indicated that Meth mediated anxiety-like behavior, aroused hippocampal neuroinflammation through activation of the TLR4/MyD88/NF-κB pathway, weakened intestinal barrier and disturbed the gut microbiome. Specifically, abundance of anxiety-related Rikenella was increased. FMT from Meth-administrated mice also weakened intestinal barrier and elevated serum LPS, inducing hippocampal neuroinflammation and anxiety-like behavior in recipient mice. Finally, OCA pretreatment ameliorated Meth-induced impairment of gut homeostasis by reshaping the microbial composition and improving the intestinal barrier. Meth-induced anxiety-like behavior and hippocampal neuroinflammation were also ameliorated by OCA pretreatment. These preliminary findings reveal the crucial role of gut microbiota in Meth-induced anxiety-like behavior and neuroinflammation, highlighting OCA as a potential candidate for the prevention of Meth-induced anxiety.

Gut microbiota mediates methamphetamine-induced hepatic inflammation via the impairment of bile acid homeostasis.

Methamphetamine (Meth), an addictive psychostimulant of abuse worldwide, has been a common cause of acute toxic hepatitis in adults. Gut microbiota has emerged as a modulator of host immunity via metabolic pathways. However, the microbial mechanism of Meth-induced hepatic inflammation and effective therapeutic strategies remain unknown. Here, mice were intraperitoneally (i.p.) injected with Meth to induce hepatotoxicity. Cecal microbiome and bile acids (BAs) composition were analyzed after Meth administration. Fecal microbiota transplantation (FMT) technology was utilized to investigate the role of microbiota. Additionally, the protective effects of obeticholic acid (OCA), an agonist of farnesoid X receptor (FXR), were evaluated. Results indicated that Meth administration induced hepatic cholestasis, dysfunction and aroused hepatic inflammation by stimulating the TLR4/MyD88/NF-κB pathway in mice. Meanwhile, Meth disturbed the cecal microbiome and impaired the homeostasis of BAs. Interestingly, FMT from Meth administered mice resulted in serum and hepatic BA accumulation and transferred similar phenotypic changes into the healthy recipient mice. Finally, OCA normalized Meth-induced BA accumulation in both serum and the liver, and effectively protected against Meth-induced hepatic dysfunction and inflammation by suppressing the TLR4/MyD88/NF-κB pathway. This study established the importance of microbial mechanism and its inhibition as a potential therapeutic target to treat Meth-related hepatotoxicity.

Methamphetamine Disturbs Gut Homeostasis and Reshapes Serum Metabolome, Inducing Neurotoxicity and Abnormal Behaviors in Mice.

As an illicit psychostimulant, repeated methamphetamine (MA) exposure results in addiction and causes severe neurotoxicity. Studies have revealed complex interactions among gut homeostasis, metabolism, and the central nervous system (CNS). To investigate the disturbance of gut homeostasis and metabolism in MA-induced neurotoxicity, 2 mg/kg MA or equal volume saline was intraperitoneally (i.p.) injected into C57BL/6 mice. Behavioral tests and western blotting were used to evaluate neurotoxicity. To determine alterations of colonic dysbiosis, 16s rRNA gene sequencing was performed to analyze the status of gut microbiota, while RNA-sequencing (RNA-seq) and Western Blot analysis were performed to detect colonic damage. Serum metabolome was profiled by LC-MS analysis. We found that MA induced locomotor sensitization, depression-, and anxiety-like behaviors in mice, along with dysfunction of the dopaminergic system and stimulation of autophagy as well as apoptosis in the striatum. Notably, MA significantly decreased microbial diversity and altered the component of microbiota. Moreover, findings from RNA-seq implied stimulation of the inflammation-related pathway after MA treatment. Western blotting confirmed that MA mediated colonic inflammation by activating the TLR4-MyD88-NF-κB pathway and impaired colonic barrier. In addition, serum metabolome was reshaped after MA treatment. Specifically, bacteroides-derived sphingolipids and serotonin were obviously altered, which were closely correlated with locomotor sensitization, depression-, and anxiety-like behaviors. These findings suggest that MA disrupts gut homeostasis by altering its microbiome and arousing inflammation, and reshapes serum metabolome, which provide new insights into understanding the interactions between gut homeostasis and MA-induced neurotoxicity.

mRNA microarray analysis for the identification of potential biomarkers for vital reaction in burned skin: a preliminary pilot study.

The identification of ante- and post-mortem burns is challenging in forensic pathology. In this study, microarray analysis was used to detect the mRNA expression profiles in the skin of an experimental burn mouse model; the results were validated using RT-qPCR. Differentially expressed mRNAs (DE-mRNAs) were assessed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Our results revealed that mRNA expression of 501 genes was significantly different, of which 273 were upregulated and 228 were downregulated in ante-mortem burned mice skin. The expression levels of eight random mRNAs were consistent when measured using the microarray assay-based method and RT-qPCR. Genes from different functional categories and signalling pathways were enriched, including interleukin-20 binding, type IV hypersensitivity, negative regulation of acute inflammatory response, sensory organ development, endocytosis, neuroactive ligand-receptor interaction, and Jak-STAT signalling pathway. Only five of the eight mRNAs exhibited consistent changes in expression between burned skin samples of mice and human autopsy specimens. Our findings showed that DE-mRNAs revealed using microarray are potential biomarkers of ante-mortem burns. However, DE-mRNAs identified from experimental animal models cannot be directly extended to autopsy specimens without careful validation.

Hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound in the treatment of a rabbit liver trauma model.

The aim of our study was to investigate the hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound treatment of liver trauma. Thirty rabbits with liver trauma were randomly divided into three groups-the microbubble-enhanced ultrasound (MEUS; further subdivided based on exposure intensity into MEUS1 [0.11 W/cm2], MEUS2 [0.55 W/cm2], and MEUS3 [1.1 W/cm2]), ultrasound without microbubbles (US), and microbubbles without ultrasound (MB) groups. The pre- and post-treatment bleeding weight and visual bleeding scores were evaluated. The serum liver enzyme concentrations as well as the blood perfusion level represented by mean peak contrast intensity (PI) ratio in the treatment area were analyzed. The hemostatic mechanism was evaluated by histological and transmission electron microscopic examination of liver tissue samples. The MEUS subgroups 1-3 (grade 0-1, grade 0-2, and grade 1-2, respectively) exhibited significantly lower post-treatment visual bleeding scores than the US and MB groups (both, grade 3-4; all, P < 0.05). Subgroups MEUS1 (0.346 ± 0.345 g) and MEUS2 (2.232 ± 2.256 g) exhibited significantly lower post-treatment bleeding weight than the US and MB groups (5.698 ± 1.938 and 5.688 ± 2.317 g, respectively; all, P < 0.05). Additionally, MEUS subgroups 1-3 exhibited significantly lower post-treatment blood perfusion levels (PI ratios, 0.64 ± 0.085, 0.73 ± 0.045, and 0.84 ± 0.034, respectively) than the US and MB groups (PI ratios, 1.00 ± 0.005 and 0.99 ± 0.005, respectively; all, P < 0.05). In the MEUS group, hepatic cells became edematous and compressed the hepatic sinus and associated blood vessels. However, the serum liver enzyme levels were not significantly altered. Microbubble-enhanced non-focused ultrasound does not significantly affect blood perfusion and liver function and can be used to induce rapid hemostasis in case of liver trauma.

Therapeutic effect of gene-therapy in combination with local X-irradiation in a mouse malignant melanoma model.

Plasmid containing mIL-18 and B7.1 genes downstream of Egr-1 promoter was constructed and used in gene-radiotherapy on malignant melanoma in C57BL/6J mice implanted with B16 cells followed by exploration of the immunologic mechanism of the therapeutic effect. The treatment with plasmid pEgr-IL-18-B7.1 plus local X-irradiation showed more effective suppression of tumor growth than the treatment with radiation alone, pEgr-IL-18-B7.1 alone, or single gene pEgr-IL-18 (or pEgr-B7.1) combined with local X-irradiation. Anticancer immunity was found to be significantly upregulated in tumor-bearing mice treated with pEgr-IL-18-B7.1 plus local X-irradiation. IL-18 showed no direct killing effect on malignant melanoma cells in vitro, and the mechanism of the combined therapy with pEgr-IL-18-B7.1 and local X-irradiation was apparently related with the stimulation of host anticancer immunity by increased secretion of IL-18 and upregulated immunogenicity of the tumor cells by increased expression of B7.1 on their surface in addition to the direct effect of local X-irradiation on the tumor cells.