The FASEB Journal最新文献

This study aimed to investigate the effects of electroacupuncture (EA) at specific acupoints (DU20 and ST36) and different frequencies (2 and 100 Hz) on brain regions associated with trigeminal neuralgia, anxiety, and depression. Chronic trigeminal neuralgia was induced by the chronic constriction of the infraorbital nerve (CION). Anxiety and depression were assessed through behavioral tests. The effects of high-frequency (100 Hz) and low-frequency (2 Hz) EA at DU20 and ST36 were compared using immunofluorescence staining to evaluate their impact on pain, anxiety, depression, and brain activity. CION induced prominent trigeminal neuralgia in mice, accompanied by anxiety- and depression-like behaviors. Two weeks post-CION surgery increased neural activity was observed in the Prl, Cg1, CeA, BLA, TRN, CA3, CA1, vlPAG, PC5, and LPB brain regions, while reduced activity was noted in the PVN, VTA, and LDTgv regions. EA at 100 Hz applied to DU20 and ST36 rapidly alleviated pain and specifically reduced despair behavior, a depressive-like phenotype. In contrast, 2 Hz EA at the same acupoints addressed both anxiety- and depression-like behaviors, modulating a broader range of brain regions, including the PrL, BLA, PVN, VTA, vlPAG, and LDTgv, compared to 100 Hz EA. Repeated 2 Hz EA exclusively at DU20 was sufficient for analgesia and improvement of anxiety and depression, demonstrating a more extensive modulation of brain activity, particularly in the VTA and LDTgv, than EA at ST36. The study reveals that CION induces significant trigeminal neuralgia, accompanied by anxiety and depression, characterized by distinct neural activity patterns. EA at 2 Hz exhibits greater effectiveness in alleviating anxiety and depression, exerting broad modulation across various brain regions. Notably, EA at DU20 demonstrates superior modulation of brain activity and enhanced antidepressant and analgesic effects compared to ST36. These findings provide valuable insights into the nuanced therapeutic effects of EA on the interplay between chronic pain and affective disorders, suggesting potential clinical strategies for intervention.

Ghrelin is a gastric peptide that modulates various biological functions, including potential anti-inflammatory and antifibrotic properties. Increasingly evidence have demonstrated that exosomes derived from injured hepatocytes (IHC-Exo) can accelerate the activation of hepatic stellate cells (HSCs) and liver fibrosis. Ferroptosis, a type of novel programmed cell death, regulates diverse pathological processes, including liver fibrosis. However, it remains unclear whether ghrelin exerts its antifibrotic effect through mechanisms involving exosomes and ferroptosis. To explore the mechanism, IHC-Exo were isolated from supernatant of injured mouse primary hepatocytes (HCs) treated with palmitic acid (PA). Mouse primary HSCs and a bile duct ligation (BDL)-induced liver fibrosis murine model were then treated with IHC-Exo or exosomes derived from ghrelin-pretreated injured hepatocytes (GHR-IHC-Exo). The expression of α-SMA, Collagen I and long noncoding (lnc) RNA MALAT1 in HSCs were then detected. The ferroptosis of HSCs was evaluated by assessing the level of CCK8, MDA, GSH, and GPX4 expression. Mouse serum and liver biopsy samples were used to determine whether ferroptosis is involved in the progression of liver fibrosis. Nanoparticle tracking analysis and electron microscopy characterized the features of IHC-Exo. As the results suggested, compared with IHC-Exo, GHR-IHC-Exo treatment significantly promoted ferroptosis of HSCs, inhibited their activation, and consequently alleviated liver fibrosis progression in BDL mice. The inhibitory effect of GHR-IHC-Exo on activation of HSCs was partially reversed by treatment with the ferroptosis inhibitor Ferrostatin-1. The expression of lncMALAT1 was significantly down-regulated in GHR-IHC-Exo as compared to IHC-Exo. Serum exosome levels of MALAT1 were significantly higher in patients with severe liver fibrosis compared to those with mild liver fibrosis. Additionally, the expression of ferroptosis suppressor protein GPX4 was elevated as liver fibrosis progression, indicating decreased ferroptosis of HSCs in patients with severe liver fibrosis. In conclusion, Ghrelin reduced the pro-fibrotic effect of IHC-Exo in liver fibrosis by regulating lncMALAT1/GPX4 pathway mediated HSCs ferroptosis. Triggering HSCs ferroptosis via GHR-IHC-Exo may become a novel strategy to alleviate the progression of liver fibrosis.

Milk is a multifaceted biofluid that is essential for infant nutrition and development, yet its cellular and bioactive components, particularly maternal milk cells, remain understudied. Early research on milk cells indicated that they cross the infant's intestinal barrier and accumulate within systemic organs. However, due to the absence of modern analytical techniques, these studies were limited in scope and mechanistic analysis. To overcome this knowledge gap, we have investigated the transintestinal transport of milk cells and components in pups over a 21-day period. Studies employed a mT/mG foster nursing model in which milk cells express a membrane-bound fluorophore, tdTomato. Using flow cytometry, we tracked the transport of milk cell-derived components across local and systemic tissues, including the intestines, blood, thymus, mesenteric lymph nodes, and liver. These experiments identified milk-derived fluorescent signals in intestinal epithelial and immune cells as well as liver macrophages in 7-day-old pups. However, the minute numbers of macrophages in mouse milk suggest that maternal cells are not systemically accumulating in the infant; instead, pup macrophages are consuming milk cell membrane components, such as apoptotic bodies or extracellular vesicles (EVs). Ex vivo experiments using primary macrophages support this hypothesis, showing that immune cells preferentially consumed EVs over milk cells. Together, these data suggest a more complex interplay between milk cells and the infant's immune and digestive systems than previously recognized and highlight the need for future research on the role of milk cells in infant health.

Sarcopenia is an age-related muscle atrophy syndrome characterized by the loss of muscle strength and mass. Although many agents have been used to treat sarcopenia, there are no successful treatments to date. In this study, we identified Danshensu sodium salt (DSS) as a substantial suppressive agent of muscle atrophy. We used a D-galactose (DG)-induced aging-acceleration model, both in vivo and in vitro, to confirm the effect of DSS on sarcopenia. DSS inhibits the expression of muscle atrophy-related factors (MuRF1, MAFbx, myostatin, and FoxO3a) in DG-induced mouse C2C12 and human skeletal muscle cells. Additionally, DSS restored the diameter of reduced C2C12 myotubes. Next, we demonstrated that DSS stimulates AMPK and PGC1α through CaMKII. DSS inhibits the translocation of FoxO3a into the nucleus, thus inhibiting muscle atrophy in a calcium-dependent manner. DSS initiated the protein–protein interaction between FoxO3a and PGC1α. The reduction of the PGC1α-FoxO3a interaction by DG was restored by DSS. Also, DSS suppressed increased intracellular reactive oxygen species (ROS) by DG. In animal models, DSS administration improved mouse muscle mass and physical performance (grip strength and hanging test) under DG-induced accelerated aging conditions. These findings demonstrated that DSS attenuates muscle atrophy by inhibiting the expression of muscle atrophy-related factors. Therefore, DSS may be a potential therapeutic agent for the treatment of sarcopenia.

The kinases AMPK, and mTOR as part of either mTORC1 or mTORC2, are major orchestrators of cellular growth and metabolism. Phosphorylation of mTOR Ser1261 is reportedly stimulated by both insulin and AMPK activation and a regulator of both mTORC1 and mTORC2 activity. Intrigued by the possibilities that Ser1261 might be a convergence point between insulin and AMPK signaling in skeletal muscle, we investigated the regulation and function of this site using a combination of human exercise, transgenic mouse, and cell culture models. Ser1261 phosphorylation on mTOR did not respond to insulin in any of our tested models, but instead responded acutely to contractile activity in human and mouse muscle in an AMPK activity-dependent manner. Contraction-stimulated mTOR Ser1261 phosphorylation in mice was decreased by Raptor muscle knockout (mKO) and increased by Raptor muscle overexpression, yet was not affected by Rictor mKO, suggesting most of Ser1261 phosphorylation occurs within mTORC1 in skeletal muscle. In accordance, HEK293 cells mTOR Ser1261Ala mutation strongly impaired phosphorylation of mTORC1 substrates but not mTORC2 substrates. However, neither mTORC1 nor mTORC2-dependent phosphorylations were affected in muscle-specific kinase-dead AMPK mice with no detectable mTOR Ser1261 phosphorylation in skeletal muscle. Thus, mTOR Ser1261 is an exercise but not insulin-responsive AMPK-dependent phosphosite in human and murine skeletal muscle, playing an unclear role in mTORC1 regulation but clearly not required for mTORC2 activity.

Macrophage infiltration and activation is a key factor in the progression of diabetic nephropathy (DN). However, aerobic glycolysis induced by m6A methylation modification plays a key role in M1-type activation of macrophages, but the specific mechanism remains unclear in DN. In this study, the expression of m6A demethylase Fto in bone marrow derived macrophages and primary kidney macrophages from db/db mice. Loss and gain-of-function analysis of Fto were performed to assess the role of Fto in DN. Transcriptome and MeRIP-seq association analysis was performed to identified the target gene was Npas2. In this study, we found that demethylase Fto exhibits low expression in type 2 DN m6A modification of Npas2 mediated by Fto regulates macrophages M1-type activation and glucose metabolism reprogramming to participate in the process of DN. Furthermore, Fto reduces the m6A modification level of Npas2 in macrophages through a Prrc2a-dependent mechanism, and decreasing its stability. This process mediates inflammation and glycolysis in M1 macrophages by regulating the Hif-1α signaling pathway. Fto may act as a suppressor of M1 macrophages inflammation and glycolysis in DN through the m6A/Npas2/Hif-1α axis. This findings providing a new basis for the prevention and treatment of DN.

Neuropathic pain, caused by nerve damage, greatly affects quality of life. Recent research proposes modulating brain activity, particularly through electrical stimulation of the insular cortex (IC), as a treatment option. This study aimed to understand how IC stimulation (ICS) affects pain modulation. In a rat neuropathy model, researchers used optogenetic and ICS techniques to evaluate changes in mechanical allodynia and synaptic changes, focusing on glutamate receptors (AMPAR, NR2A, NR2B). Optogenetic inhibition of IC neurons relieved pain without altering synaptic plasticity. However, repetitive ICS combined with optogenetic activation diminished the pain-relieving effects of ICS and increased AMPAR and NR2B receptor levels. Additionally, activating inhibitory neurons also reduced pain, while repetitive activation of excitatory neurons lessened the effectiveness of ICS and was associated with heightened receptor expression. These findings suggest that inhibiting excitatory neurons or activating inhibitory neurons in the IC could help modulate pain in neuropathic conditions, shedding light on how ICS can influence pain management through changes in synaptic plasticity.

Skeletal muscle function gradually declines with aging, presenting substantial health and societal challenges. Comparative analysis of how aging affects fast- and slow-twitch muscles remains lacking. We utilized 20-month-old mice to reveal the aging effects on muscle structure and fiber composition, followed by bulk RNA sequencing for fast- and slow-twitch muscles and integration with human single-cell RNA sequencing dataset providing a comparative analysis across species. In mouse slow-twitch muscles, aging induced a switch from fast to slow fibers and distinctively altered lipid metabolism in ceramide and triglyceride, with the upregulation of regulatory genes Gk and Ppargc1a also observed in human slow fibers. Additionally, both types of muscles exhibited common collagen deposition and fibrosis, possibly due to the imbalance between collagen synthesis and degradation. The extracellular matrix gene changes substantially overlapped between mice and humans in aging, yet also highlighted clear differences. This integrative analysis provides further understanding of aged fast- and slow-twitch muscles and offers new insights into the molecular changes in aging.

DFNA1 (deafness, nonsyndromic autosomal dominant 1), initially identified as nonsyndromic sensorineural hearing loss, has been associated with an additional symptom: macrothrombocytopenia. However, the timing of the onset of hearing loss (HL) and thrombocytopenia has not been investigated, leaving it unclear which occurs earlier. Here, we generated a knock-in (KI) DFNA1 mouse model, diaphanous-related formin 1 (DIA1)^{KIΔv3/KIΔv3}, in which Aequorea coerulescens green fluorescent protein (AcGFP)-tagged human DIA1(p.R1213X) was knocked into the ATG site of Dia1. Additionally, the exon 7 of Dia1 was deleted using genome editing to knock out (KO) Dia1-v3, a specific variant of Dia1. AcGFP-DIA1(p.R1213X) expression and endogenous DIA1 KO were confirmed in cochleae and platelets. Hearing function in DIA1^{KIΔv3/KIΔv3}, but not DIA1^KIΔv3/+ mice, evaluated by auditory brainstem response, was significantly worse at low frequencies compared to wild-type (WT) mice starting at 3 months of age (3M), with progressive deterioration. Using confocal microscopy and scanning electron microscopy, various stereociliary deformities were identified in the cochleae of DIA1^{KIΔv3/KIΔv3} mice. Platelet counts in DIA1^{KIΔv3/KIΔv3}, but not DIA1^KIΔv3/+ mice, were significantly lower than those in WT mice at 12M, but not at 6M. Furthermore, in a cohort of eight patients with DFNA1 harboring the p.R1213X mutation, HL preceded thrombocytopenia in three individuals. Thus, in both mice and humans, though HL and thrombocytopenia are progressive, HL manifests earlier than thrombocytopenia. Unlike myosin heavy chain 9 (MYH9)-related diseases, thrombocytopenia cannot be a predictive marker for HL in DFNA1. Nevertheless, monitoring platelet counts could provide insights into the progression of the hearing impairments in patients with DFNA1.

Aerobic exercise (AE) has been shown to offer significant benefits for Alzheimer's disease (AD), potentially influencing the gut microbiota. However, the impact of changes in intestinal flora in early Alzheimer's disease induced by aerobic exercise on metabolic pathways and metabolites is not well understood. In this study, 3-month-old APP/PS1 and C57BL/6 mice were divided into two groups each: a control group (ADC for APP/PS1 and WTC for C57BL/6) and an aerobic exercise group (ADE for APP/PS1 and WTE for C57BL/6). The exercise groups underwent a 20-week aerobic training program on a motorized treadmill before the behavioral test (both the Morris water maze experiment (MWM) and the eight-arm maze test). Fecal samples were collected to analyze gut microbiota profiles via 16S rRNA gene sequencing. At the same time, the metabolic pathway analysis and the detection of metabolites were carried out. At the phylum level, the ADE group exhibited a significant reduced in the relative abundance of Bacteroidetes compared to the ADC group. At the genus level, both Ileibacterium and Faecalibaculum were found to be more abundant in the ADE group than in the ADC group. Additionally, PICRUSt analysis revealed that lipid metabolism and bile acid metabolism pathways were significantly enriched in the cecal microbiota of mice in the ADE group. The metabolites detected further confirmed the changes in the metabolic pathways mentioned above. Aerobic exercise may modify gut microbiota profiles and metabolites in APP/PS1 mice, thereby potentially playing a beneficial role in delaying cognitive impairment associated with early-stage Alzheimer's disease.