TOR Signaling in Growth and Metabolism

mTOR pathway: A key player in diabetic nephropathy progression and therapeutic targets

Diabetic nephropathy is a prevalent complication of diabetes and stands as the primary contributor to end-stage renal disease. The global prevalence of diabetic nephropathy is on the rise, however, due to its intricate pathogenesis, there is currently an absence of efficacious treatments to enhance renal prognosis in affected patients. The mammalian target of rapamycin (mTOR), a serine/threonine protease, assumes a pivotal role in cellular division, survival, apoptosis delay, and angiogenesis. It is implicated in diverse signaling pathways and has been observed to partake in the progression of diabetic nephropathy by inhibiting autophagy, promoting inflammation, and increasing oxidative stress. In this academic review, we have consolidated the understanding of the pathological mechanisms associated with four distinct resident renal cell types (podocytes, glomerular mesangial cells, renal tubular epithelial cells, and glomerular endothelial cells), as well as macrophages and T lymphocytes, within a diabetic environment. Additionally, we highlight the research progress in the treatment of diabetic nephropathy with drugs and various molecules interfering with the mTOR signaling pathway, providing a theoretical reference for the treatment and prevention of diabetic nephropathy.

Beyond a ferroptosis inducer: erastin can suppress nutrient deprivation induced cell death in the intervertebral disc

BACKGROUND

Erastin has been found to induce ferroptosis; however, whether erastin may have roles other than ferroptosis inducer in cells is unknown. Nutrient deficiency is one of the major causes of many diseases including intervertebral disc (IVD) degeneration.

PURPOSE

The current study investigates the effect of erastin in nucleus pulposus cells under nutrient deprivation condition.

STUDY DESIGN

Experiment in vitro and ex vivo.

METHODS

The effect of erastin on the cell survival of nucleus pulposus cells was evaluated in fetal bovine serum (FBS) and glucose deprivation condition. RSL3 and ferrostatin-1 were applied to illustrate whether the effect of erastin is ferroptosis dependent. The involvement of solute carrier family 7, membrane 11(SLC7A11), autophagy as well as mechanistic target of rapamycin kinase complex 1(mTORC1) and transcription factor EB (TFEB) were assessed to demonstrate the working mechanism of erastin.

RESULTS

Erastin may induce cell death at the concentration of ≥ 5μM; however, it may protect nucleus pulposus cells against nutrient deprivation induced cell death at lower concentration (0.25-1μM) and the effect of erastin is ferroptosis independent. The mechanism study showed that the effect of erastin may relate to its SCL7A11 regulation, as SCL7A11 knock-down may have the similar effect as erastin. Furthermore, it was also demonstrated that mTORC1-TFEB mediated autophagy was involved in protective effect of erastin.

CONCLUSIONS

Low dose erastin may promote cell survival under nutrient deprivation condition, and its effect is ferroptosis independent; erastin may exert its protective effect through mTORC1-TFEB mediated autophagy regulation.

CLINICAL SIGNIFICANCE

Nutrient deprivation is a major contributor to intervertebral disc degeneration. Our in vitro and ex vivo study showed that low dose of erastin may suppress nutrient deprivation induced cell death in IVD degeneration. Although it was not validated in vivo model due to lack of in vivo nutrient deprivation induced IVD degeneration model currently, this study may still provide a potential therapeutic option for IVD degeneration, which of cause need further validation.

Increasing cellular NAD+ protects hepatocytes against palmitate-induced lipotoxicity by preventing PARP-1 inhibition and the mTORC1-p300 pathway activation

Hepatic lipotoxicity, resulting from excessive lipid accumulation in hepatocytes, plays a central role in the pathogenesis of various metabolic liver diseases. Despite recent progress, the precise mechanisms remain incompletely understood. Using excessive exposure to palmitate in hepatocytes as our primary experimental model and mice studies, we aimed to uncover the mechanisms behind hepatic lipotoxicity, thereby developing potential treatments. Our data reveal for the first time that exposure to palmitate leads to downregulated expression of poly (ADP-ribose) polymerase 1 (PARP-1) in hepatocytes, inhibiting its enzymatic activity. Whereas inhibiting PARP-1 worsens palmitate-induced hepatotoxicity, preventing PARP-1 suppression, using nicotinamide adenine dinucleotide (NAD+) precursors, nicotinamide N-methyltransferase (NNMT) inhibitors, or a poly(ADP-ribose) glycohydrolase (PARG) inhibitor, prevents it. Moreover, we uncover that PARP-1 suppression contributes to palmitate-triggered mechanistic target of rapamycin complex 1 (mTORC1) activation, which has been previously reported by us to contribute to palmitate-induced hepatocyte cell death. Furthermore, our results identify p300 as a downstream target of mTORC1 activation upon palmitate exposure. Importantly, p300 inhibition via either pharmacological or genetic approaches protects against palmitate hepatotoxicity. In addition, we provide evidence that the toll-like receptor 4 (TLR4)-nuclear factor κB (NF-κB) pathway activation in response to palmitate plays a mechanistic role in mediating palmitate-induced PARP-1 downregulation in that both TLR4 antagonist and NF-κB inhibitors prevent palmitate-induced PARP-1 reduction and protect against hepatocyte cell death. In conclusion, our study presents new evidence that the PARP-1-mTORC1-p300 pathway serves as a novel molecular mechanism underlying palmitate-induced hepatic lipotoxicity. Targeting the PARP-1 pathway by increasing cellular NAD+ availability either through its precursor supplementation or by inhibiting its degradation represents a promising therapeutic approach for treating hepatic lipotoxicity.NEW & NOTEWORTHY This study explores the mechanisms of palmitate-induced hepatotoxicity, highlighting the role of PARP-1 downregulation in triggering the mTORC1-p300 pathway and resultant hepatocyte cell death. It further reveals that enhancing cellular NAD+ levels through either precursor supplementation or NNMT inhibitors prevents lipotoxicity by restoring PARP-1 activity. Finally, the study identifies that the TLR4-NF-κB activation mediates palmitate-induced PARP-1 suppression and offers potential therapeutic insights for metabolic liver diseases caused by lipotoxicity.

Tsc1 deletion in Purkinje neurons disrupts the axon initial segment, impairing excitability and cerebellar function

Loss-of-function mutations in tuberous sclerosis 1 (TSC1) are prevalent monogenic causes of autism spectrum disorder (ASD). Selective deletion of Tsc1 from mouse cerebellar Purkinje neurons has been shown to cause several ASD-linked behavioral impairments, which are linked to reduced Purkinje neuron repetitive firing rates. We used electrophysiology methods to investigate why Purkinje neuron-specific Tsc1 deletion (Tsc1mut/mut) impairs Purkinje neuron firing. These studies revealed a depolarized shift in action potential threshold voltage, an effect that we link to reduced expression of the fast-transient voltage-gated sodium (Nav) current in Tsc1mut/mut Purkinje neurons. The reduced Nav currents in these cells was associated with diminished secondary immunofluorescence from anti-pan Nav channel labeling at Purkinje neuron axon initial segments (AIS). Anti-ankyrinG immunofluorescence was also found to be significantly reduced at the AIS of Tsc1mut/mut Purkinje neurons, suggesting Tsc1 is necessary for the organization and functioning of the Purkinje neuron AIS. An analysis of the 1st and 2nd derivative of the action potential voltage-waveform supported this hypothesis, revealing spike initiation and propagation from the AIS of Tsc1mut/mut Purkinje neurons is impaired compared to age-matched control Purkinje neurons. Heterozygous Tsc1 deletion resulted in no significant changes in the firing properties of adult Purkinje neurons, and slight reductions in anti-pan Nav and anti-ankyrinG labeling at the Purkinje neuron AIS, revealing deficits in Purkinje neuron firing due to Tsc1 haploinsufficiency are delayed compared to age-matched Tsc1mut/mut Purkinje neurons. Together, these data reveal that the loss of Tsc1 impairs Purkinje neuron firing and membrane excitability through the dysregulation of proteins essential for AIS organization and function.

Eucommia ulmoides leaf extracts combined with Astragalus polysaccharides: Effects on growth, antioxidant capacity, and intestinal inflammation in juvenile large yellow croaker (Larimichthys crocea)

Eucommia ulmoides leaf extract (ELE) and Astragalus polysaccharides (APS) have been widely used as immunopotentiators in aquaculture. Our prior research on large yellow croaker (Larimichthys crocea) demonstrated that dietary 1 g/kg APS bolstered fish immunity and antioxidant defense. However, the combined effect of ELE and APS in juvenile large yellow croaker remains unknown. Hence, this study aimed to investigate the synergistic effect of ELE and APS on the growth, antioxidant capacity, and intestinal inflammation in large yellow croaker. A total of 1200 fish were divided into five groups and fed diets with 1 g/kg APS and varying ELE levels: 0 g/kg (ELE0), 0.25 g/kg (ELE0.25), 0.5 g/kg (ELE0.5), 1 g/kg (ELE1), and 2 g/kg (ELE2). After an 8-week feeding period, the ELE0.5 and ELE1 groups showed superior weight gain rate, specific growth rate, and feed efficiency compared to other groups. The ELE1 group also had elevated trypsin and lipase activities in the intestine, whereas α-amylase activity was not influenced by ELE addition. Antioxidant enzyme activities, such as hepatopancreas superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the ELE1 group were significantly enhanced, while malondialdehyde (MDA) levels decreased with increasing ELE. Intestinal morphology revealed the highest villi height in proximal and distal intestines of ELE1 group, with no significant change in mucosal thickness. In terms of cytokines, the ELE1 group showed significant down-regulation of pro-inflammatory (tnf-α, il-1β and il-6) and up-regulation of anti-inflammatory (il-4/13a, il-10 and tgf-β) markers, modulated by MAPK and mTOR signaling. In conclusion, this study indicates that supplementing diets with 1 g/kg ELE alongside 1 g/kg APS in juvenile large yellow croaker offers the best synergistic effect on fish immunity, including enhanced growth, antioxidant capacity, and relieved intestinal inflammation through MAPK and mTOR signaling.

From sensory organs to internal pathways: A comprehensive review of amino acid sensing in Drosophila

Organisms require various nutrients to provide energy, support growth, and maintain metabolic balance. Amino acid is among the most basic nutrients, serving as fundamental building blocks for protein synthesis while playing vital roles in growth, development, and reproduction. Understanding the mechanisms by which organisms perceive amino acids is key to unraveling how they select appropriate food sources and adapt to environmental challenges. The fruit fly, Drosophila melanogaster, serves as a powerful model for understanding fundamental genetic and physiological processes. This review focuses on recent advances in amino acid sensing mechanisms in Drosophila melanogaster and their relevance to feeding behavior, nutrient homeostasis, and adaptive responses, and integrates insights into peripheral sensory systems, such as the legs and proboscis, as well as internal regulatory mechanisms within the gut, fat body, and brain. It highlights key molecular players, including ionotropic receptors, gut-derived hormones, neuropeptides, and the microbiome-gut-brain axis. Additionally, the manuscript identifies knowledge gaps and proposes directions for future research, providing a comprehensive overview of this dynamic field.

Non-dikarya fungi share the TORC1 pathway with animals, not with Saccharomyces cerevisiae

Target of rapamycin (TOR), discovered in Saccharomyces cerevisiae, is a highly conserved serine/threonine kinase acting as a regulatory hub between the cell and its environment. Like mammals, in fungi, the TOR complex 1 (TORC1) pathway is essential for coordinating cell growth in response to nutrient availability. The activation of TORC1 is similar in yeast and mammals, while its inhibition is more complex in mammals. This divergence of TORC1 regulation opens the question of how common are the yeast and mammalian variants in the fungal kingdom. In this work, we trace the evolutionary history of TORC1 components throughout the fungal kingdom. Our findings show that these fungi contain the mammalian-specific KICSTOR complex for TORC1 inhibition. They also possess orthologs of serine, arginine and methionine sensors of TORC1 pathway that orchestrate the response to nutrient starvation in mammals. The Rheb-TSC mediated activation of mammalian TORC1 that was lost in Saccharomycotina was also conserved in non-Dikarya. These findings indicate that the TORC1 pathway in non-Dikarya fungi resembles mammalian TORC1. Saccharomycotina lost many of the inhibitory components and evolved alternate regulatory mechanisms. Furthermore, our work highlights the limitations of using S. cerevisiae as a fungal model while putting forward other fungi as possible research models.

Exploring the therapeutic potential of Chinese herbs on comorbid type 2 diabetes mellitus and Parkinson's disease: A mechanistic study

ETHNOPHARMACOLOGICAL RELEVANCE

Type 2 diabetes mellitus (T2DM) and Parkinson's disease (PD) are chronic conditions that affect the aging population, with increasing prevalence globally. The rising prevalence of comorbidity between these conditions, driven by demographic shifts, severely impacts the quality of life of patients, posing a significant burden on healthcare resources. Chinese herbal medicine has been used to treat T2DM and PD for millennia. Pharmacological studies have demonstrated that medicinal herbs effectively lower blood glucose levels and exert neuroprotective effects, suggesting their potential as adjunctive therapy for concurrent management of T2DM and PD.

AIM OF THE STUDY

To elucidate the shared mechanisms underlying T2DM and PD, particularly focusing on the potential mechanisms by which medicinal herbs (including herbal formulas, single herbs, and active compounds) may treat these diseases, to provide valuable insights for developing therapeutics targeting comorbid T2DM and PD.

MATERIALS AND METHODS

Studies exploring the mechanisms underlying T2DM and PD, as well as the treatment of these conditions with medicinal herbs, were extracted from several electronic databases, including PubMed, Web of Science, Google Scholar, and China National Knowledge Infrastructure (CNKI).

RESULTS

Numerous studies have shown that inflammation, oxidative stress, insulin resistance, impaired autophagy, gut microbiota dysbiosis, and ferroptosis are shared mechanisms underlying T2DM and PD mediated through the NLRP3 inflammasome, NF-κB, MAPK, Keap1/Nrf2/ARE, PI3K/AKT, AMPK/SIRT1, and System XC--GSH-GPX4 signaling pathways. Thirty-four medicinal herbs, including 2 herbal formulas, 4 single herbs, and 28 active compounds, have been reported to potentially exert anti-T2DM and anti-PD effects by targeting these shared mechanisms.

CONCLUSIONS

Traditional Chinese medicine effectively combats T2DM and PD through shared pathological mechanisms, highlighting their potential for application in treating these comorbid conditions.

The mTOR Signaling Pathway: Key Regulator and Therapeutic Target for Heart Disease

Heart disease, including myocardial infarction, heart failure, cardiac hypertrophy, and cardiomyopathy, remains a leading cause of mortality worldwide. The mammalian target of rapamycin (mTOR) is a centrally regulated kinase that governs key cellular processes, including growth, proliferation, metabolism, and survival. Notably, mTOR plays a pivotal role in cardiovascular health and disease, particularly in the onset and progression of cardiac conditions. In this review, we discuss mTOR's structure and function as well as the regulatory mechanisms of its associated signaling pathways. We focus on the molecular mechanisms by which mTOR signaling regulates cardiac diseases and the potential of mTOR inhibitors and related regulatory drugs in preventing these conditions. We conclude that the mTOR signaling pathway is a promising therapeutic target for heart disease.

The Role of Gut Microbiota-Derived Trimethylamine N-Oxide in the Pathogenesis and Treatment of Mild Cognitive Impairment

Mild cognitive impairment (MCI) represents a transitional stage between normal aging and dementia, often considered critical for dementia prevention. Despite its significance, no effective clinical treatment for MCI has yet been established. Emerging evidence has demonstrated a strong association between trimethylamine-N-oxide (TMAO), a prominent metabolite derived from the gut microbiota, and MCI, highlighting its potential as a biomarker and therapeutic target. TMAO has been implicated in increasing MCI risk through its influence on factors such as hypertension, cardiovascular disease, depression, diabetes, and stroke. Moreover, it contributes to MCI by promoting oxidative stress, disrupting the blood-brain barrier, impairing synaptic plasticity, inducing inflammation, causing mitochondrial metabolic disturbances, and facilitating abnormal protein aggregation. This review further explores therapeutic strategies targeting TMAO to mitigate MCI progression.

The natural polyphenol fisetin in atherosclerosis prevention: a mechanistic review

The incidence and mortality rate of atherosclerotic cardiovascular disease (ASCVD) is increasing yearly worldwide. Recently, a growing body of evidence has unveiled the anti-atherosclerotic properties of fisetin, a natural polyphenol compound. In this article, we reviewed the pharmacologic actions of fisetin on experimental atherosclerosis and its protective effects on disease-relevant cell types such as endothelial cells, macrophages, vascular smooth muscle cells, and platelets. Based on its profound cardiovascular actions, fisetin holds potential for clinical translation and could be developed as a potential therapeutic option for atherosclerosis and its related complications. Large-scale randomized clinical trials are warranted to ascertain the safety and efficacy of fisetin in patients with or high risk for ASCVD.

Time Restricted Eating: A Valuable Alternative to Calorie Restriction for Addressing Obesity?

PURPOSE OF REVIEW

In this review, we summarize the molecular effects of time-restricted eating (TRE) and its possible role in appetite regulation. We also discuss the potential clinical benefits of TRE in obesity.

RECENT FINDINGS

TRE is an emerging dietary approach consisting in limiting food intake to a specific window of time each day. The rationale behind this strategy is to restore the circadian misalignment, commonly seen in obesity. Preclinical studies have shown that restricting food intake only during the active phase of the day can positively influence several cellular functions including senescence, mitochondrial activity, inflammation, autophagy and nutrients' sensing pathways. Furthermore, TRE may play a role by modulating appetite and satiety hormones, though further research is needed to clarify its exact mechanisms. Clinical trials involving patients with obesity or type 2 diabetes suggest that TRE can be effective for weight loss, but its broader effects on improving other clinical outcomes, such as cardiovascular risk factors, remain less certain. The epidemic proportions of obesity cause urgency to find dietary, pharmacological and surgical interventions that can be effective in the medium and long term. According to its molecular effects, TRE can be an interesting alternative to caloric restriction in the treatment of obesity, but the considerable variability across clinical trials regarding population, intervention, and follow-up duration makes it difficult to reach definitive conclusions.

The integrated stress response drives MET oncogene overexpression in cancers

Cancer cells rely on invasive growth to survive in a hostile microenvironment; this growth is characterised by interconnected processes such as epithelial-to-mesenchymal transition and migration. A master regulator of these events is the MET oncogene, which is overexpressed in the majority of cancers; however, since mutations in the MET oncogene are seen only rarely in cancers and are relatively infrequent, the mechanisms that cause this widespread MET overexpression remain obscure. Here, we show that the 5' untranslated region (5'UTR) of MET mRNA harbours two functional stress-responsive elements, conferring translational regulation by the integrated stress response (ISR), regulated by phosphorylation of eukaryotic translation initiation factor 2 alpha (eIF2α) at serine 52. ISR activation by serum starvation, leucine deprivation, hypoxia, irradiation, thapsigargin or gemcitabine is followed by MET protein overexpression. We mechanistically link MET translation to the ISR by (i) mutation of the two uORFs within the MET 5'UTR, (ii) CRISPR/Cas9-mediated mutation of eIF2α (S52A), or (iii) the application of ISR pathway inhibitors. All of these interventions reduce stress-induced MET overexpression. Finally, we show that blocking stress-induced MET translation blunts MET-dependent invasive growth. These findings indicate that upregulation of the MET oncogene is a functional requirement linking integrated stress response to cancer progression.

Comparative transcriptomic and metabolomics analysis of ovary in Nilaparvata lugens after trehalase inhibition

The fecundity of Nilaparvata lugens (brown planthopper) is influenced by trehalase (TRE). To investigate the mechanism by which trehalose affects the reproduction of N. lugens, we conducted a comparative transcriptomic and metabolomic analysis of the ovaries of N. lugens following injection with dsTREs and validamycin (a TRE inhibitor). The results revealed that 844 differentially expressed genes (DEGs) were identified between the dsGFP and dsTREs injection groups, with 317 up-regulated genes and 527 down-regulated genes. Additionally, 1451 DEGs were identified between the water and validamycin injection groups, with 637 up-regulated genes and 814 down-regulated genes. The total number of DEGs identified between the two comparison groups was 236. The overlapping DEGs were implicated in various biological processes, including protein metabolism, fatty acid metabolism, AMPK signaling, mTOR signaling, insulin/insulin-like growth factor signaling (IIS), the tricarboxylic acid (TCA) cycle, oxidative phosphorylation, and the cellular process of meiosis in oocytes. These results suggest that the inhibition of TRE expression may lead to alterations in ovarian nutrient and energy metabolism by modulating glucose transport and affecting amino acid metabolic pathways. These alterations may influence the reproduction of N. lugens by modulating reproductive regulatory signals. These findings provide robust evidence supporting the mechanism through which trehalase inhibition reduces the reproductive capacity of N. lugens.

Hematopoietic stem cell metabolism within the bone marrow niche - insights and opportunities

Hematopoiesis unfolds within the bone marrow niche where hematopoietic stem cells (HSCs) play a central role in continually replenishing blood cells. The hypoxic bone marrow environment imparts peculiar metabolic characteristics to hematopoietic processes. Here, we discuss the internal metabolism of HSCs and describe external influences exerted on HSC metabolism by the bone marrow niche environment. Importantly, we suggest that the metabolic environment and metabolic cues are intertwined with HSC cell fate, and are crucial for hematopoietic processes. Metabolic dysregulation within the bone marrow niche during acute stress, inflammation, and chronic inflammatory conditions can lead to reduced HSC vitality. Additionally, we raise questions regarding metabolic stresses imposed on HSCs during implementation of stem cell protocols such as allo-SCT and gene therapy, and the potential ramifications. Enhancing our comprehension of metabolic influences on HSCs will expand our understanding of pathophysiology in the bone marrow and improve the application of stem cell therapies.

Tsc1 Deletion in Purkinje Neurons Disrupts the Axon Initial Segment, Impairing Excitability and Cerebellar Function

Loss-of-function mutations in tuberous sclerosis 1 (TSC1) are prevalent monogenic causes of autism spectrum disorder (ASD). Selective deletion of Tsc1 from mouse cerebellar Purkinje neurons has been shown to cause several ASD-linked behavioral impairments, which are linked to reduced Purkinje neuron repetitive firing rates. We used electrophysiology methods to investigate why Purkinje neuron-specific Tsc1 deletion (Tsc1 mut/mut ) impairs Purkinje neuron firing. These studies revealed a depolarized shift in action potential threshold voltage, an effect that we link to reduced expression of the fast-transient voltage-gated sodium (Nav) current in Tsc1 mut/mut Purkinje neurons. The reduced Nav currents in these cells was associated with diminished secondary immunofluorescence from anti-pan Nav channel labeling at Purkinje neuron axon initial segments (AIS). Interestingly, anti-ankyrinG immunofluorescence was also found to be significantly reduced at the AIS of Tsc1 mut/mut Purkinje neurons, suggesting Tsc1 is necessary for the organization and functioning of the Purkinje neuron AIS. An analysis of the 1st and 2nd derivative of the action potential voltage-waveform supported this hypothesis, revealing spike initiation and propagation from the AIS of Tsc1 mut/mut Purkinje neurons is impaired compared to age-matched control Purkinje neurons. Heterozygous Tsc1 deletion resulted in no significant changes in the firing properties of adult Purkinje neurons, and slight reductions in anti-pan Nav and anti-ankyrinG labeling at the Purkinje neuron AIS, revealing deficits in Purkinje neuron firing due to Tsc1 haploinsufficiency are delayed compared to age-matched Tsc1 mut/mut Purkinje neurons. Together, these data reveal the loss of Tsc1 impairs Purkinje neuron firing and membrane excitability through the dysregulation of proteins necessary for AIS organization and function.

OsFKBP12 transduces the sucrose signal from OsNIN8 to the OsTOR pathway in a loosely binding manner for cell division

Previously, OsNIN8 initiated a sucrose signal for cell division in radicle and seed development in rice. Here, a set of genes was induced in starved sprouts after sucrose treatment, and 14 genes were screened between ZH11 and nin8 as reporters of sucrose signal. Expressions of reporter depended on levels of OsNIN8 in overexpression and RNAi lines. Further, OsNIN8 interacted with OsFKBP12, a regulator of TOR signal for cell division, and OsFKBP12 interacted with OsTOR (OsTORKD). However, interactions of OsFKBP12 with OsNIN8 or OsTORKD were a loose binding depending on the hydrophobicity of OsFKBP12 C-terminus in Y2H. In addition, OsFKBP12 associating with OsNIN8 was endothermic but with OsNIN8m was exothermic. Knockout OsFKBP12 reappeared nin8 phenotypes and the complementation of the knockout with C-termini of OsFKBP12 worsened the phenotypes. Treatment with TOR inhibitors caused short radicle and OsTOR RNAi repeated low seed-setting of the phenotypes. So, OsFKBP12 transduced sucrose signal from OsNIN8 to the TOR pathway.

Interplay of epilepsy and long-term potentiation: implications for memory

The interplay between long-term potentiation (LTP) and epilepsy represents a crucial facet in understanding synaptic plasticity and memory within neuroscience. LTP, a phenomenon characterized by a sustained increase in synaptic strength, is pivotal in learning and memory processes, particularly in the hippocampus. This review delves into the intricate relationship between LTP and epilepsy, exploring how alterations in synaptic plasticity mechanisms akin to those seen in LTP contribute to the hyperexcitable state of epilepsy. This state is conceptualized as a dysregulation between LTP and LTD (Long-term depression), leading to pathologically enhanced synaptic efficacy. Additionally, the role of neuroinflammation in both LTP and epilepsy is examined, highlighting how inflammatory mediators can influence synaptic plasticity. The dual role of neuroinflammatory pathways, enhancing or inhibiting LTP, is a focal area of ongoing research. The significance of various signaling pathways, including the MAPK, mTOR, and WNT/β-catenin pathways, in the modulation of synaptic plasticity and their relevance in both LTP and epilepsy. These pathways are instrumental in memory formation, consolidation, and epileptogenesis, illustrating a complex interaction between cellular mechanisms in the nervous system. Lastly, the role of calcium signaling in the relationship between LTP and epilepsy is scrutinized. Aberrant calcium signaling in epilepsy leads to an enhanced, yet pathologically altered, LTP. This dysregulation disrupts normal neural pathways, potentially leading to cognitive dysfunction, particularly in memory encoding and retrieval. The review emphasizes the need for targeted interventions in epilepsy that address cognitive functions alongside seizure control.

SNRK modulates mTOR-autophagy pathway for liver lipid homeostasis in MAFLD

Metabolism-related fatty liver disease (MAFLD) is associated with abnormal fat accumulation in the liver. The exact mechanism underlying the occurrence and development of MAFLD remains to be elucidated. Here, we discovered that the expression of sucrose non-fermenting-related kinase (SNRK) is elevated in the liver of the MAFLD population. Mice deficient in SNRK exhibited damage to fatty acid oxidation and persistent accumulation of lipids in the liver. Pharmacological inhibition of the mTOR pathway in SNRK-deficient mice restored autophagy and improved lipid accumulation. In terms of mechanism, we observed that SNRK binds to the raptor component of mTOR complex 1, promoting fatty acid oxidation in the liver by activating autophagy. Overexpression of SNRK in high-fat diet-induced obese mice restored autophagy and ameliorated lipid accumulation. Notably, we also demonstrated that overexpression of SNRK significantly enhanced fatty acid oxidation in the mouse liver. We further confirmed that SNRK is essential for the liver to regulate autophagy and fatty acid oxidation. These findings underscore the importance of the potential of SNRK in the treatment of MAFLD.

tRNA thiolation optimizes appressorium-mediated infection by enhancing codon-specific translation in Magnaporthe oryzae

Thiolation, a post-transcriptional modification catalyzed by Uba4-Urm1-Ncs2/Ncs6 pathway in three specific transfer RNAs (tRNAs), is conserved from yeast to humans and plays an important role in enhancing codon-anticodon interaction and translation efficiency. Yet, except for affecting effector secretion, its roles in plant pathogenic fungi are not fully understood. Here, we used Magnaporthe oryzae as a model system to illustrate the vital role of s2U34 modification on the appressorium-mediated virulence. The absence of tRNA thiolation leads to diminished translation elongation at AAA/CAA/GAA but not their synonymous codons, resulting in reduced levels of key proteins enriched in these codons, which are critical for appressorium development and function. Importantly, overexpressing these proteins can partially mitigate the defects resulting from NCS2 deletion. Our study sheds light on the s2U34 modification's role in plant pathogenic fungi, enhancing our understanding of translational control beyond effector secretion.

Dietary cinnamon promotes longevity and extends healthspan via mTORC1 and autophagy signaling

Cinnamon, renowned for its aromatic flavor, represents one of the most widely used spices worldwide. Cinnamon is also considered beneficial to human health with therapeutic potential for treating various diseases, ranging from diabetes and cancer to neurodegenerative diseases. However, the mechanisms underlying cinnamon's health benefits remain elusive. It is also unclear whether cinnamon has any role in aging. Using C. elegans as a model, here we show that feeding worms cinnamaldehyde (CA), the active ingredient in cinnamon oil, prolongs longevity. CA also promotes stress resistance and reduces β-Amyloid toxicity in a C. elegans model of Alzheimer's disease. Mechanistically, CA exerts its beneficial effects through mTORC1 and autophagy signaling. Interestingly, CA promotes longevity by inducing a dietary restriction-like state without affecting food intake, suggesting CA as a dietary restriction mimetic. In human cells, CA exerts a similar effect on mTORC1 and autophagy signaling, suggesting a conserved mechanism. Our results demonstrate that dietary cinnamon promotes both lifespan and healthspan and does so by regulating mTORC1 and autophagy signaling.

Toosendanin alleviates acute lung injury by reducing pulmonary vascular barrier dysfunction mediated by endoplasmic reticulum stress through mTOR

BACKGROUND

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe clinical conditions with limited treatment options. Toosendanin (TSN), a triterpenoid compound with anti-inflammatory effects, has unclear efficacy in ALI.

PURPOSE

This study aimed to evaluate TSN's protective effects on ALI and the related mechanisms.

METHODS

Lipopolysaccharide (LPS)-induced ALI models were developed in vivo and in vitro. Endothelial permeability was measured using Evans Blue dye; lipid reactive oxygen species (ROS) and apoptosis were assessed using flow cytometry. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined, and cell viability was measured. mRNA and protein expression were quantified using qRT-PCR and Western blotting. Network pharmacology and surface plasmon resonance were used to identify and validate TSN's targets.

RESULTS

TSN reduced endothelial permeability and LPS-induced ALI. It lowered ROS levels, lipid peroxidation, endoplasmic reticulum (ER) stress, and apoptosis, both in vitro and in vivo. Network pharmacology identified mTOR as a key target of TSN, and surface plasmon resonance analysis confirmed TSN's direct binding to mTOR, underscoring mTOR's role in TSN's protective effects against ALI. Western blotting showed that TSN inhibits mTOR and its phosphorylation. In vitro, the mTOR activator MHY1485 reversed TSN's protective effects, increasing ER stress, apoptosis, and endothelial permeability. In vivo, TSN and rapamycin synergistically protected against ALI.

CONCLUSION

This study is the first to demonstrate that TSN protects against ALI by targeting the mTOR pathway, regulating ER stress and apoptosis and mitigating endothelial damage. These findings suggest a novel approach for ALI treatment and underscore TSN's potential clinical value.

RICTOR variants are associated with neurodevelopmental disorders

RICTOR is a key component of the mTORC2 signaling complex which is involved in the regulation of cell growth, proliferation and survival. RICTOR is highly expressed in neurons and is necessary for brain development. Here, we report eight unrelated patients presenting with intellectual disability and/or development delay and carrying variants in the RICTOR gene. The phenotypic presentation is diverse with associated features including growth failure, feeding difficulties, abnormal behavior, seizure, hypertonia, brain anomalies and various other congenital organ and skeletal malformations. All patients carried de novo or heterozygous variants inherited from one affected parent, including three missense variants, four loss-of-function variants and one 3 kb deletion encompassing RICTOR. The mTORC2 pathway was hyperactivated in a patient's fibroblasts carrying a missense variant, while the expression of RICTOR remained unchanged, indicating a gain-of-function mechanism. RNA sequencing on RICTOR knock-out mouse embryonic fibroblasts confirmed the potential role of RICTOR in neuronal cell development.

Oscillatory autophagy induction is enabled by an updated AMPK-ULK1 regulatory wiring

Autophagy-dependent survival relies on a crucial oscillatory response during cellular stress. Although oscillatory behaviour is typically associated with processes like the cell cycle or circadian rhythm, emerging experimental and theoretical evidence suggests that such periodic dynamics may explain conflicting experimental results in autophagy research. In this study, we demonstrate that oscillatory behaviour in the regulation of the non-selective, stress-induced macroautophagy arises from a series of interlinked negative and positive feedback loops within the mTORC1-AMPK-ULK1 regulatory triangle. While many of these interactions have been known for decades, recent discoveries have revealed how mTORC1, AMPK, and ULK1 are truly interconnected. Although these new findings initially appeared contradictory to established models, additional experiments and our systems biology analysis clarify the updated regulatory structure. Through computational modelling of the autophagy oscillatory response, we show how this regulatory network governs autophagy induction. Our results not only reconcile previous conflicting experimental observations but also offer insights for refining autophagy regulation and advancing understanding of its mechanisms of action.

Selective deletion of Tsc1 from mouse cerebellar Purkinje neurons drives sex-specific behavioral impairments linked to autism

There is a striking sex bias in the prevalence and severity of autism spectrum disorder (ASD) with 80% of diagnoses occurring in males. Because the molecular etiology of ASD is likely combinatorial, including interactions across multiple genetic and environmental factors, it is difficult to investigate the physiological mechanisms driving sex-specific differences. Loss of function mutations in TSC1 result in dysregulated mTORC1 signaling and underlie a multi-system disorder known as tuberous sclerosis (TSC). Interestingly, more than 50% of individuals diagnosed with TSC are also diagnosed with ASD, making TSC mutations one of the most prevalent monogenic causes of ASD. Mice harboring targeted deletion of Tsc1 selectively in cerebellar Purkinje neurons, referred to here as Tsc1mut/mut , have multiple ASD-linked behavioral impairments, including deficits in social interactions, motor coordination, and vocalizations. However, these ASD-linked behavioral deficits have only been investigated using male Tsc1mut/mut animals. Here, we used cohorts of male and female Tsc1mut/mut animals to determine if behavioral impairments, previously identified in this model, are similar across sex. Specifically, we measured balance and motor coordination and social interaction behaviors in two age groups across sex. We determined balance and motor coordination deficits are similar in male and female Tsc1mut/mut mice, and that deficits in the firing of Tsc1mut/mut Purkinje neurons located in the cerebellar vermis are also similar across sex. However, impairments in social approach behavior were found to be significantly more severe in Tsc1mut/mut males compared to females. These results indicate the selective deletion of Tsc1 in Purkinje neurons differentially impairs cerebellar circuits based on sex.

Casein kinase 1 controls components of a TORC2 signaling network in budding yeast

Tor kinases play diverse and essential roles in control of nutrient signaling and cell growth. These kinases are assembled into two multiprotein complexes known as TORC1 and TORC2. In budding yeast, TORC2 relays nutrient-dependent signals that strongly influence growth rate and cell size. However, the mechanisms that control TORC2 signaling are poorly understood. Activation of TORC2 requires Mss4, a phosphatidylinositol 4-phosphate 5-kinase that recruits and activates downstream targets of TORC2. Localization of Mss4 to the plasma membrane is thought to be controlled by phosphorylation, and previous work has suggested that yeast homologs of casein kinase 1, Yck1 and Yck2 (referred to here collectively as Yck1/2), Control phosphorylation of Mss4. Here, we generated a new analog-sensitive allele of YCK2 and used it to test whether Yck1/2 influence localization of Mss4 or signaling in the TORC2 network. We found that Yck1/2 strongly influence Mss4 phosphorylation and localization, as well as influencing regulation of multiple components of the TORC2 network. However, inhibition of Yck1/2 causes mild effects on the best-characterized signaling axis in the TORC2 pathway, suggesting that Yck1/2 might play a larger role in influencing less well-understood aspects of TORC2 signaling.

NgLst8 Coactivates TOR Signaling to Activate Photosynthetic Growth in Nannochloropsis gaditana

The target of rapamycin (TOR) serves as a central regulator of cell growth, coordinating anabolic and catabolic processes in response to nutrient availability, growth factors, and energy supply. Activation of TOR has been shown to promote photosynthesis, growth, and development in yeast, animals, and plants. In this study, the complete cDNA sequence of the Lst8 gene was obtained from Nannochloropsis gaditana. The structure of N. gaditana LST8 comprises a typical WD40 repeat sequence, exhibiting high sequence similarity to several known LST8 proteins. By overexpressing the Lst8 gene in N. gaditana, we constructed the NgLst8 transgenic algal strain and measured its photosynthetic activity and growth. We observed that an increase in LST8 abundance promotes the expression of TOR-related kinase, thereby enhancing photosynthetic growth. Transcriptome analysis further elucidated the response mechanism of elevated Lst8 abundance in relation to photosynthesis. Our findings indicate that increased Lst8 expression activates ABC transporter proteins and the MAPK signaling pathway, which regulate the transmembrane transport of sugars and other metabolites, integrate photosynthesis, sugar metabolism, and energy signaling, and modulate energy metabolism in algal cells through interactions with the TOR signaling pathway.

Barbatula nuda: an economically valuable freshwater fish that accepts phytoplankton as first food

Barbatula nuda is considered a promising emerging species to diversify small cold-water fish aquaculture worldwide due to its rapid growth and delicious flesh. However, limited information on larval development and nutrition is available. In this study, 7-day feeding experiments were performed to evaluate three different initial diets (zooplankton, phytoplankton, and artificial microdiet) in the zoo group, algae group, and AD group on growth, development, and digestion of larvae B. nuda. The results showed that there was no significant difference in survival rate among the three groups (p > 0.05). The algae group exhibited the highest feed intake success rate and body weight (p < 0.05), the best intestinal development with the protruded intestinal mucosa, and visible intestinal microvillus. Pepsase and trypsin enzyme activities in the algae group larvae were significantly higher than those in the other two groups (p < 0.05). Transcriptome data showed that the mechanistic target of rapamycin pathway of B. nuda fed with phytoplankton was activated, and the metabolisms of carbohydrate were significantly more active than those in the other two groups. As omnivorous fish, B. nuda could accept zooplankton, phytoplankton, and microdiet as initial diets with its survival unaffected, but B. nuda fed with phytoplankton exhibited better growth status and digestive tract development and higher digestive enzyme activities than those fed with other two diets. Therefore, phytoplankton was a suitable initial diet for B. nuda. Our findings provide guidance for the artificial breeding of B. nuda and a theoretical basis for research on fish initial diet.

Effects of tire particles and associated-chemicals on the Pacific oyster (Magallana gigas) physiology, reproduction and next-generation

By 2040, tire particles (TP) are expected to dominate marine plastic contamination, raising concerns about their effects on marine animals. This study employed a multidisciplinary and multigenerational approach on the Pacific oyster Magallana gigas to investigate the effects of TP and their leachates (LEA). Effects were analyzed at the individual scale, from cellular, molecular, and microbiota changes to reproductive outputs and offspring performance. Microbiota characterization revealed potential dysbiosis in oysters treated with high concentration of both TP and LEA. RNA-seq analyses highlighted the activation of energy metabolism and stress responses in the LEA treatment. Additionally, transcriptional changes in oocytes and the reduction of motile spermatozoa suggested potential effects on gamete quality. Notably, possible oyster resilience was pointed out by the lack of significant ecophysiological modifications in adults and impacts on the growth and reproductive outputs of the offspring. Overall, the implications of the observed oyster resilience under our experimental setting are discussed in relation to available toxicity data and within a comprehensive view of coastal ecosystems, where a higher diversity of plastic/rubber materials and harsher environmental conditions occur.

Senescence-Associated Sugar Transporter1 affects developmental master regulators and controls senescence in Arabidopsis

Sugar transport across membranes is critical for plant development and yield. However, an analysis of the role of intracellular sugar transporters in senescence is lacking. Here, we characterized the role of Senescence-Associated Sugar Transporter1 (SAST1) during senescence in Arabidopsis (Arabidopsis thaliana). SAST1 expression was induced in leaves during senescence and after the application of abscisic acid (ABA). SAST1 is a vacuolar protein that pumps glucose out of the cytosol. sast1 mutants exhibited a stay-green phenotype during developmental senescence, after the darkening of single leaves, and after ABA feeding. To explain the stay-green phenotype of sast1 mutants, we analyzed the activity of the glucose-induced master regulator TOR (target of rapamycin), which is responsible for maintaining a high anabolic state. TOR activity was higher in sast1 mutants during senescence compared to wild types, whereas the activity of its antagonist, SNF1-related protein kinase 1 (SnRK1), was reduced in sast1 mutants under senescent conditions. This deregulation of TOR and SnRK1 activities correlated with high cytosolic glucose levels under senescent conditions in sast1 mutants. Although sast1 mutants displayed a functional stay-green phenotype, their seed yield was reduced. These analyses place the activity of SAST1 in the last phase of a leaf's existence in the molecular program required to complete its life cycle.

Rheb1 deficiency elicits mitochondrial dysfunction and accelerates podocyte senescence through promoting Atp5f1c acetylation

Podocyte senescence can cause persistent podocyte injury and albuminuria in diabetic kidney disease (DKD), but the mechanism remains obscure. In this study, podocyte senescence was confirmed by immunohistochemical staining in podocytes from patients and mice with DKD. Rheb1 knockout in podocytes aggravated podocyte senescence and injury in diabetic mice, but mitigated podocyte injury in mice with podocyte-specific mTORC1 activation induced by Tsc1 deletion. In cultured podocytes, Rheb1 knockdown remarkably accelerated podocyte senescence, independent of mTORC1. Mechanistically, PDH phosphorylation in podocyte was correlated with podocyte senescence in DKD patients. Rheb1 deficiency decreased ATP, mitochondrial membrane potential and partial components of respiratory chain complex, and enhanced ROS production and PDH phosphorylation, which indicates mitochondrial dysfunction, both in vitro and in vivo. Furthermore, Rheb1 interacted with Atp5f1c, and regulated its acetylation under a high-glucose condition. Together, Rheb1 deficiency elicits mitochondrial dysfunction and accelerates podocyte senescence through promoting Atp5f1c acetylation, in an mTORC1-independent manner, which provides experimental basis for the treatment of DKD.

A loss of primary cilia by a reduction in mTOR signaling correlates with age-related deteriorations in condylar cartilage

Age-related deterioration of condylar cartilage is an etiological factor in temporomandibular joint-osteoarthritis (TMJ-OA). However, its underlying mechanism remains unknown. Therefore, we examined age-related changes and the relationship between mTOR signaling and primary cilia in condylar cartilage to determine the intrinsic mechanisms of age-related TMJ-OA. Age-related morphological changes were analyzed using micro-computed tomography and safranin O-stained histological samples of the mandibular condyle of C57BL/6J mice (up to 78 weeks old). Immunohistochemistry was used to assess the activity of mTOR signaling, primary cilia frequency, and Golgi size of condylar chondrocytes. Four-week-old mice receiving an 11-week series of intraperitoneal injections of rapamycin, a potent mTOR signaling inhibitor, were used for the histological evaluation of the condylar cartilage. The condylar cartilage demonstrated an age-related reduction in cartilage area, including chondrocyte size, cell density, and cell size distribution. The Golgi size, primary cilia frequency, and mTOR signaling also decreased with age. Rapamycin injections resulted in both diminished cartilage area and cell size, resembling the phenotypes observed in aged mice. Rapamycin-injected mice also exhibited a smaller Golgi size and lower primary cilia frequency in condylar cartilage. We demonstrated that a loss of primary cilia due to a decline in mTOR signaling was correlated with age-related deteriorations in condylar cartilage. Our findings provide new insights into the tissue homeostasis of condylar cartilage, contributing to understanding the etiology of age-related TMJ-OA.

LdAMPKα2 knockdown accelerated the growth but depressed the chitin biosynthesis in Lymantria dispar larvae

AMPK (AMP-activated protein kinase) is a crucial cellular energy sensor across all eukaryotic species. Its multiple roles in maintaining energy homeostasis, regulating cellular metabolic processes have been widely investigated in mammals. In contrast, the function of AMPK in insects has been less reported. Here, we successfully identified three AMPK subunits from Lymantria dispar (L. dispar), a Lepidoptera pest in forestry. Based on that, in particular, the role of AMPK signaling in regulating larval development, as well as chitin biosynthesis was investigated by the application of RNAi-mediated LdAMPKα2 knockdown. The results indicated that knockdown of LdAMPKα2 significantly increased the body weight of L. dispar larvae, and dramatically upregulated the expression of LdmTOR, LdS6K and LdSREBP1, the key genes in mTOR (mammalian target of rapamycin) signaling pathway. While, it significantly reduced the expression of Ld4EBP, a critical repressor of mTOR pathway. Besides, the glucose level was increased and trehalose level was decreased in L. dispar after LdAMPKα2 silencing. Furthermore, we found that the chitin content in the epidermis, as well as the expressions of four key genes in the chitin biosynthesis pathway, LdGFAT, LdPAGM, LdUAP and LdCHSA, were significantly decreased after LdAMPKα2 knockdown. Taken together, these results revealed that AMPK signaling played a pivotal role in regulating the growth and development, as well as carbohydrate metabolism and chitin biosynthesis in L. dispar larvae. The findings expand our understanding of the comprehensive regulatory role of AMPK signaling in insects.

Fission yeast Pib2 localizes to vacuolar membranes and regulates TOR complex 1 through evolutionarily conserved domains

TOR complex 1 (TORC1) is a multi-protein kinase complex that coordinates cellular growth with environmental cues. Recent studies have identified Pib2 as a critical activator of TORC1 in budding yeast. Here, we show that loss of Pib2 causes severe growth defects in fission yeast cells, particularly when basal TORC1 activity is diminished by hypomorphic mutations in tor2, the gene encoding the catalytic subunit of TORC1. Consistently, TORC1 activity is significantly compromised in the tor2 hypomorphic mutants lacking Pib2. Moreover, as in budding yeast, fission yeast Pib2 localizes to vacuolar membranes via its FYVE domain, with its tail motif indispensable for TORC1 activation. These results strongly suggest that Pib2-mediated positive regulation of TORC1 is evolutionarily conserved between the two yeast species.

Role of PIM Kinase Inhibitor in the Treatment of Alzheimer's Disease

Alzheimer's disease (AD), a neurodegenerative disorder, is the most prevalent form of senile dementia, causing progressive deterioration of cognition, behavior, and rational skills. Neuropathologically, AD is characterized by two hallmark proteinaceous aggregates: amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) formed of hyperphosphorylated tau. A significant study has been done to understand how Aβ and/or tau accumulation can alter signaling pathways that affect neuronal function. A conserved protein kinase known as the mammalian target of rapamycin (mTOR) is essential for maintaining the proper balance between protein synthesis and degradation. Overwhelming evidence shows mTOR signaling's primary role in age-dependent cognitive decline and the pathogenesis of AD. Postmortem human AD brains consistently show an upregulation of mTOR signaling. Confocal microscopy findings demonstrated a direct connection between mTOR and intraneuronal Aβ42 through molecular processes of PRAS40 phosphorylation. By attaching to the mTORC1 complex, PRAS40 inhibits the activity of mTOR. Furthermore, inhibiting PRAS40 phosphorylation can stop the Aβ-mediated increase in mTOR activity, indicating that the accumulation of Aβ may aid in PRAS40 phosphorylation. Physiologically, PRAS40 is phosphorylated by PIM1 which is a serine/threonine kinase of proto-oncogene PIM kinase family. Pharmacological inhibition of PIM1 activity prevents the Aβ-induced mTOR hyperactivity in vivo by blocking PRAS40 phosphorylation and restores cognitive impairments by enhancing proteasome function. Recently identified small-molecule PIM1 inhibitors have been developed as potential therapeutic to reduce AD-neuropathology. This comprehensive study aims to address the activity of PIM1 inhibitor that has been tested for the treatment of AD, in addition to the pharmacological and structural aspects of PIM1.

Effect of Zinc on Blood Biochemical and mTOR Gene Expression in Rats with Polycystic Ovarian

Zinc (Zn) is a significant element of the reproductive system and is associated with several enzymes that regulate different metabolic pathways. Organic Zn can significantly affect polycystic ovarian syndrome (PCOS) pathogenesis. Insulin resistance (IR) is a common complication of PCOS. Mammalian target of rapamycin (mTOR), which controls crucial cell functions, is regulated by insulin and nutrients. It has two complexes, namely, mTORC1 and mTORC2. mTOR associates with its binding partner's regulatory associated protein of mTOR (Raptor) and rapamycin-insensitive companion of mTOR (Rictor), which form these distinct complexes, respectively, and is activated in PCOS. This research aimed to evaluate the effect of Zn on the expression of mTOR signaling genes (Raptor and Rictor) and IR in PCOS model rats. Different Zn supplements, including standard diet (SD): (control - or + , SD without supplementation), Zn25, Zn75, and Zn175 (daily given three levels of 25, 75, and 175 mg Zn methionine (ZnMet)/kg for 6 weeks, respectively), were applied to the control and PCOS groups. Fasting glucose (FG), fasting insulin (FI), IR indices, and Raptor and Rictor expression levels were measured in both groups. The results showed that PCOS induction dramatically increased FG, FI, IR indices, and mTOR-related gene expression; however, different Zn supplementation concentrations, especially at 75 mg/kg, reduced the effects of PCOS induction. Organic Zn collectively exerted positive effects on Estradiol Valerate (EV)-induced PCOS rats by reducing IR and mTOR signaling gene (i.e., Raptor and Rictor) expression. Moreover, this study revealed a correlation between Zn and IR. Therefore, Zn supplementation could be a valuable therapeutic method for treating PCOS.

The transcription factor FgSfp1 orchestrates mycotoxin deoxynivalenol biosynthesis in Fusarium graminearum

Fusarium graminearum (F. graminearum) and its derivative mycotoxin deoxynivalenol (DON) are highly concerned with food safety and sustainability worldwide. Although several transcription factors (TFs) had been elucidated, molecular mechanism participates in DON biosynthesis regulation remains largely unrevealed. Here, we first characterized a zinc finger-contained TF in F. graminearum, FgSfp1, which is indispensable for DON production since its depletion resulting in a 95.4% DON yielding reduction. Interestingly, contrast to previous knowledge, all TRI-cluster genes were abnormally upregulated in ΔFgSfp1 while Tri proteins abundance rationally decreased simultaneously. Further evidence show FgSfp1 could coordinate genetic translation pace by manipulating ribosomal biogenesis process. Specifically, FgSfp1-depletion leads to ribosome biogenesis assembly factor (RiBi) expression attenuation along with DON precursor acetyl-CoA synthase reduction since FgSfp1 actively interacts with RNA 2'-O-methylation enzyme FgNop1 revealed by Bi-FC. It subsequently influences mRNA translation pace. In conclusion, we elucidated that the FgSfp1 orchestrates DON biosynthesis via participating RNA posttranscriptional modification for ribosomal RNA maturation, offering insights into the DON biosynthesis regulation. Ultimately, this TF might be a key regulator for DON contamination control in the whole food chain.

Skin-Resident γδ T Cells Mediate Potent and Selective Antitumor Cytotoxicity through Directed Chemotactic Migration and Mobilization of Cytotoxic Granules

Dendritic epidermal T cells (DETCs) are a unique subset of γδ T cells that reside predominantly in mouse epidermis; yet, their antitumor functions remain enigmatic. In this study, we report that DETCs mediate potent and exquisitely selective cytotoxicity against diverse tumor types while sparing healthy cells. In vitro, DETCs induced apoptosis in melanoma, hepatoma, colon carcinoma, and lymphoma lines in a dose- and time-dependent manner that required direct cell-cell contact. In vivo, adoptive DETC transfer significantly suppressed melanoma growth and metastasis while prolonging survival. Mechanistically, DETCs upregulated perforin/granzyme B expression upon tumor recognition, and inhibition of this pathway ablated cytotoxicity. DETCs selectively homed to and formed intimate contacts with tumor cells in vivo through directed chemotaxis and aggregation. Tumor engagement triggered proinflammatory DETC activation while dampening immunosuppressive factors in the microenvironment. Notably, mTOR signaling coupled tumor recognition to DETC trafficking, cytotoxicity, and inflammatory programs because rapamycin treatment impaired effector functions and therapeutic efficacy. Collectively, these findings establish DETCs as multidimensional antitumor effectors and provide insights for harnessing their unique biology for cancer immunotherapy.

TOR2 plays the central role in rapamycin-induced lifespan extension in budding yeast

The target of rapamycin (TOR) protein, renowned for its highly conserved nature across species, plays a pivotal role in modulating signaling pathways via its multiprotein complexes, TORC1 and TORC2. The relationship between TOR and its inhibitor, rapamycin, especially in the context of lifespan extension, has earned significant attention. Unlike mammals, which have a single TOR gene, the budding yeast Saccharomyces cerevisiae features two TOR paralogs: TOR1 and TOR2. Non-essential TOR1 gene has been the focus of extensive research, whereas the essential TOR2 gene has received relatively little attention in lifespan studies. In our research, we engineered a point mutation (Ser-1975-Ile) within the FKBP12-rapamycin-binding (FRB) domain of Tor2p to block rapamycin binding. Remarkably, this mutation negated the lifespan-extending benefits of rapamycin, irrespective of the TOR1 gene status. Our findings indicate that the TOR2 gene likely serves as the primary mammalian ortholog, playing a crucial role in mediating the effects of rapamycin on lifespan extension. This discovery opens a new avenue for the development of innovative anti-aging agents targeting the TOR. complex.

Thermal modulation of energy allocation during sex determination in the European sea bass (Dicentrarchus labrax)

Water temperature governs physiological functions such as growth, energy allocation, and sex determination in ectothermic species. The European sea bass (Dicentrarchus labrax) is a major species in European aquaculture, exhibiting early dimorphic growth favoring females. The species has a polygenic sex determination system that interacts with water temperature to determine an individual's sex, with two periods during development that are sensitive to temperature. The current study investigated the influence of water temperature on energy allocation and sex-biased genes during sex determination and differentiation periods. RNA-Sequencing and qPCR analyses were conducted in two separate experiments, of either constant water temperatures typical of aquaculture conditions or natural seasonal thermal regimes, respectively. We focused on eight key genes associated with energy allocation, growth regulation, and sex determination and differentiation. In Experiment 1, cold and warm temperature treatments favored female and male proportions, respectively. The RNA-seq analysis highlighted sex-dependent energy allocation transcripts, with higher levels of nucb1 and pomc1 in future females, and increased levels of egfra and spry1 in future males. In Experiment 2, a warm thermal regime favored females, while a cold regime favored males. qPCR analysis in Experiment 2 revealed that ghrelin and nucb1 were down-regulated by warm temperatures. A significant sex-temperature interaction was observed for pank1a with higher and lower expression for males in the cold and warm regimes respectively, compared to females. Notably, spry1 displayed increased expression in future males at the all-fins stage and in males undergoing molecular sex differentiation in both experimental conditions, indicating that it provides a novel, robust, and consistent marker for masculinization. Overall, our findings emphasize the complex interplay of genes involved in feeding, energy allocation, growth, and sex determination in response to temperature variations in the European sea bass.

High-density lipoprotein protects normotensive and hypertensive rats against ischemia-reperfusion injury through differential regulation of mTORC1 and mTORC2 signaling

Background

High-density lipoprotein (HDL) protects against myocardial ischemia-reperfusion (I/R) injury. Mammalian target of rapamycin complexes 1 and 2 (mTORC1 and mTORC2) play opposing roles in protecting against I/R injury, whereby mTORC1 appears to be detrimental while mTORC2 is protective. However, the role of HDL and mTORC signaling in protecting against I/R in hypertensive rodents is not clearly understood. In this study, we investigated the involvement of mTORC1 and mTORC2 in HDL-mediated protection against myocardial I/R injury in normotensive Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SHR).

Methods

Hearts from WKY and SHR were subjected to I/R injury using a modified Langendorff system. Hemodynamics data were collected, and infarct size was measured. Rapamycin and JR-AB2-011 were used to test the role of mTORC1 and mTORC2, respectively. MK-2206 was used to test the role of Akt in HDL-mediated cardiac protection. The expression levels and the activation states of mediators of mTORC1 and mTORC2 signaling and myocardial apoptosis were measured by immunoblotting and/or enzyme-linked immunosorbent assay (ELISA).

Results

HDL protected hearts from WKY and SHR against I/R injury as indicated by significant improvements in cardiac hemodynamics and reduction in infarct size. HDL induced greater protection in WKY compared to SHR. HDL treatment attenuated mTORC1 signaling in WKY by reducing the phosphorylation of P70S6K (mTORC1 substrate). In SHR however, HDL attenuated mTORC1 signaling by reducing the levels of phospho-mTORC1, Rag C (mTORC1 activator), and phospho-PRAS40 (mTORC1 inhibitor). HDL increased the phosphorylation of mTORC2 substrate Akt, specifically the Akt2 isoform in SHR and to a greater extent in WKY. HDL-induced protection was abolished in the presence of Akt antagonist and involved attenuation of GSK, caspases 7 and 8 activation, and cytochrome C release.

Conclusion

HDL mediates cardiac protection via attenuation of mTORC1, activation of mTORC2-Akt2, and inhibition of myocardial apoptosis. HDL regulates mTORC1 and mTORC2 signaling via distinct mechanisms in normotensive and hypertensive rats. HDL attenuation of mTORC1 and activation of mTORC2-Akt2 signaling could be a mechanism by which HDL protects against myocardial I/R injury in hypertension.

TORC1 Regulates Thermotolerance via Modulating Metabolic Rate and Antioxidant Capacity in Scallop Argopecten irradians irradians

Target of rapamycin complex 1 (TORC1) is a key regulator of metabolism in eukaryotes across multiple pathways. Although TORC1 has been extensively studied in vertebrates and some invertebrates, research on this complex in scallops is limited. In this study, we identified the genes encoding TORC1 complex subunits in the scallop Argopecten irradians irradians through genome-wide in silico scanning. Five genes, including TOR, RAPTOR, LST8, DEPTOR, and PRAS40, that encode the subunits of TORC1 complex were identified in the bay scallop. We then conducted structural characterization and phylogenetic analysis of the A. i. irradians TORC1 (AiTORC1) subunits to determine their structural features and evolutionary relationships. Next, we analyzed the spatiotemporal expressions of AiTORC1-coding genes during various embryo/larvae developmental stages and across different tissues in healthy adult scallops. The results revealed stage- and tissue-specific expression patterns, suggesting diverse roles in development and growth. Furthermore, the regulation of AiTORC1-coding genes was examined in temperature-sensitive tissues (the mantle, gill, hemocyte, and heart) of bay scallops exposed to high-temperature (32 °C) stress over different durations (0 h, 6 h, 12 h, 24 h, 3 d, 6 d, and 10 d). The expression of AiTORC1-coding genes was predominantly suppressed in the hemocyte but was generally activated in the mantle, gill, and heart, indicating a tissue-specific response to heat stress. Finally, functional validation was performed using the TOR inhibitor rapamycin to suppress AiTORC1, leading to an enhanced catabolism, a decreased antioxidant capacity, and a significant reduction in thermotolerance in bay scallops. Collectively, this study elucidates the presence, structural features, evolutional relationships, expression profiles, and roles in antioxidant capacity and metabolism regulation of AiTORC1 in the bay scallop, providing a preliminary understanding of its versatile functions in response to high-temperature challenges in marine mollusks.

The Research Progress of Metformin Regulation of Metabolic Reprogramming in Malignant Tumors

BACKGROUND

Metabolism reprogramming is a crucial hallmark of malignant tumors. Tumor cells demonstrate enhanced metabolic efficiency, converting nutrient inputs into glucose, amino acids, and lipids essential for their malignant proliferation and progression. Metformin, a commonly prescribed medication for type 2 diabetes mellitus, has garnered attention for its potential anticancer effects beyond its established hypoglycemic benefits.

METHODS

This review adopts a comprehensive approach to delineate the mechanisms underlying metabolite abnormalities within the primary metabolic processes of malignant tumors.

RESULTS

This review examines the abnormal activation of G protein-coupled receptors (GPCRs) in these metabolic pathways, encompassing aerobic glycolysis with increased lactate production in glucose metabolism, heightened lipid synthesis and cholesterol accumulation in lipid metabolism, and glutamine activation alongside abnormal protein post-translational modifications in amino acid and protein metabolism. Furthermore, the intricate metabolic pathways and molecular mechanisms through which metformin exerts its anticancer effects are synthesized and analyzed, particularly its impacts on AMP-activated protein kinase activation and the mTOR pathway. The analysis reveals a multifaceted understanding of how metformin can modulate tumor metabolism, targeting key nodes in metabolic reprogramming essential for tumor growth and progression. The review compiles evidence that supports metformin's potential as an adjuvant therapy for malignant tumors, highlighting its capacity to interfere with critical metabolic pathways.

CONCLUSION

In conclusion, this review offers a comprehensive overview of the plausible mechanisms mediating metformin's influence on tumor metabolism, fostering a deeper comprehension of its anticancer mechanisms. By expanding the clinical horizons of metformin and providing insight into metabolism-targeted tumor therapies, this review lays the groundwork for future research endeavors aimed at refining and advancing metabolic intervention strategies for cancer treatment.

Hydrogen peroxide modulates the expression of the target of rapamycin (TOR) and cell division in Arabidopsis thaliana

Hydrogen peroxide (H2O2) is naturally produced by plant cells during normal development and serves as a messenger that regulates cell metabolism. Despite its importance, the relationship between hydrogen peroxide and the target of rapamycin (TOR) pathway, as well as its impact on cell division, has been poorly analyzed. In this study, we explore the interaction of H2O2 with TOR, a serine/threonine protein kinase that plays a central role in controlling cell growth, size, and metabolism in Arabidopsis thaliana. By applying two concentrations of H2O2 exogenously (0.5 and 1 mM), we could correlate developmental traits, such as primary root growth, lateral root formation, and fresh weight, with the expression of the cell cycle gene CYCB1;1, as well as TOR expression. When assessing the expression of the ribosome biogenesis-related gene RPS27B, an increase of 94.34% was noted following exposure to 1 mM H2O2 treatment. This increase was suppressed by the TOR inhibitor torin 2. The elimination of H2O2 accumulation with ascorbic acid (AA) resulted in decreased cell division as well as TOR expression. The potential molecular mechanisms associated with the effects of H2O2 on the cell cycle and TOR expression in roots are discussed in the context of the results.

Hyperglycemia-driven signaling bridges between diabetes and cancer

Growing epidemiological evidence indicates an association between obesity, type 2 diabetes, and certain cancers, suggesting the existence of common underlying mechanisms in these diseases. Frequent hyperglycemias in type 2 diabetes promote pro-inflammatory responses and stimulate intracellular metabolic flux which rewires signaling pathways and influences the onset and advancement of different types of cancers. Here, we review the provocative impact of hyperglycemia on a subset of interconnected signalling pathways that regulate (i) cell growth and survival, (ii) metabolism adjustments, (iii) protein function modulation in response to nutrient availability (iv) and cell fate and proliferation and which are driven respectively by PI3K (Phosphoinositide 3-kinase), AMPK (AMP-activated protein kinase), O-GlcNAc (O-linked N-acetylglucosamine) and Wnt/β-catenin. Specifically, we will elaborate on their involvement in glucose metabolism, inflammation, and cell proliferation, highlighting their interplay in the pathogenesis of diabetes and cancer. Furthermore, the influence of antineoplastic and antidiabetic drugs on the unbridled cellular pathways will be examined. This review aims to inspire the next molecular studies to understand how type 2 diabetes may lead to certain cancers. This will contribute to personalized medicine and direct better prevention strategies.

The dynamics and functional impact of tRNA repertoires during early embryogenesis in zebrafish

Embryogenesis entails dramatic shifts in mRNA translation and turnover that reprogram gene expression during cellular proliferation and differentiation. Codon identity modulates mRNA stability during early vertebrate embryogenesis, but how the composition of tRNA pools is matched to translational demand is unknown. By quantitative profiling of tRNA repertoires in zebrafish embryos during the maternal-to-zygotic transition, we show that zygotic tRNA repertoires are established after the onset of gastrulation, succeeding the major wave of zygotic mRNA transcription. Maternal and zygotic tRNA pools are distinct, but their reprogramming does not result in a better match to the codon content of the zygotic transcriptome. Instead, we find that an increase in global translation at gastrulation sensitizes decoding rates to tRNA supply, thus destabilizing maternal mRNAs enriched in slowly translated codons. Translational activation and zygotic tRNA expression temporally coincide with an increase of TORC1 activity at gastrulation, which phosphorylates and inactivates the RNA polymerase III repressor Maf1a/b. Our data indicate that a switch in global translation, rather than tRNA reprogramming, determines the onset of codon-dependent maternal mRNA decay during zebrafish embryogenesis.

Characterization and analysis of extracellular vesicle-derived miRNAs from different adipose tissues in mice

Adipose tissue is traditionally classified into two main types based on their functions: brown adipose tissue (BAT) and white adipose tissue (WAT). Each type plays a distinct role in the body's energy metabolism. Additionally, a third type, beige adipose tissue, can develop within subcutaneous WAT (including inguinal WAT, iWAT) in response to specific stimuli and exhibits characteristics of both BAT and WAT. Extracellular vesicles (EVs) are crucial for intercellular communication, carrying a diverse array of biomolecules such as proteins, lipids, and nucleic acids. While the functional diversity and endocrine roles of adipose tissues are well-documented, a comparative analysis of the functions of EVs released by different adipose tissues from mice housed at room temperature has not been thoroughly explored. MicroRNAs (miRNAs), which are highly enriched in small extracellular vesicles (sEVs), offer a promising avenue for investigating the complex functions and unique roles of various adipose tissues. In this study, we isolated sEVs from different adipose tissues under basal conditions and performed a comprehensive analysis of their miRNA content. By comparing miRNA profiles across different adipose tissues, we aim to elucidate the potential roles of sEV-derived miRNAs in mediating intercellular communication and the distinct physiological functions of adipose tissues. Understanding the molecular features of miRNAs in adipose tissue EVs could reveal new aspects of adipose tissue biology and lay the groundwork for further research into their physiological significance.

Research Progress on Using Nanoparticles to Enhance the Efficacy of Drug Therapy for Chronic Mountain Sickness

Chronic mountain sickness (CMS) poses a significant health risk to individuals who rapidly ascend to high altitudes, potentially endangering their lives. Nanoparticles (NPs) offer an effective means of transporting and delivering drugs, protecting nucleic acids from nuclease degradation, and mediating the expression of target genes in specific cells. These NPs are almost non-toxic and easy to prepare and store, possess a large surface area, exhibit good biocompatibility and degradability, and maintain good stability. They can be utilized in the treatment of CMS to enhance the therapeutic efficacy of drugs. This paper provides an overview of the impact of NPs on CMS, discussing their roles as nanocarriers and their potential in CMS treatment. It aims to present novel therapeutic strategies for the clinical management of CMS and summarizes the relevant pathways through which NPs contribute to plateau disease treatment, providing a theoretical foundation for future clinical research.

Impact of SARS-CoV-2 infection on immune cell cuproptosis in patients with lung adenocarcinoma via glutamine regulation

OBJECTIVE

Lung adenocarcinoma (LA), the most prevalent type of lung cancer, is associated with a high mortality rate, especially among patients with cancer previously infected with coronavirus disease (COVID-19). Therefore, this study aimed to explore the mechanisms by which COVID-19 exacerbates LA progression in a clinical setting.

METHODS

The experiment involved collecting serum samples from three groups: a healthy control group (Con, n = 20), a lung adenocarcinoma group (LA, n = 30), and a group of lung adenocarcinoma patients with first-time COVID-19 infection (C-LA, n = 58). Metabolites were analyzed using liquid chromatography-mass spectrometry, and differentially expressed metabolites were identified through bioinformatics analysis. The concentrations of glutathione (GSH), reactive oxygen species (ROS), and copper ions (Cu2+) in the serum of patients in the Con and C-LA groups were measured. Mitochondrial morphological changes in monocytes and lymphocytes were observed using electron microscopy.

RESULTS

Metabolomic analysis revealed 142 distinct metabolites, among which glutamine (Gln) expression was significantly decreased in the C-LA group. Compared to the Con group, the C-LA group showed a significant decrease in GSH and a notable increase in ROS and Cu2+. Further research revealed that the mitochondria of monocytes and lymphocytes in the C-LA group exhibited corresponding alterations indicative of cuproptosis.

CONCLUSIONS

SARS-CoV-2 infection may reduce Gln levels, leading to reduced GSH levels, copper overload, and increased death of immune cells, which may further exacerbate rapid tumor development. Thus, glutamine regulation plays an important role in LA progression in patients with COVID-19 and represents a potential therapeutic target.