Cell Metabolism Research Articles

Epicatechin and β-Glucan from Whole Highland Barley Grain Synergistic Benefit on Attenuating Hyperglycemia via Improving Hepatic Glucose Metabolism in Diabetic C57BL/6J Mice.

Our previous study proved that epicatechin (EC) and β-glucan (BG) from whole-grain highland barley synergistically modulate glucose metabolism in insulin-resistant HepG2 cells. However, the main target and the mechanism underlying the modulation of glucose metabolism in vivo remain largely unknown. In this study, cell transfection assay and microscale thermophoresis analysis revealed that EC and BG could directly bind to the insulin receptor (IR) and mammalian receptor for rapamycin (mTOR), respectively. Molecular dynamic analysis indicated that the key amino acids of binding sites were Asp, Met, Val, Lys, Ser, and Tys. EC supplementation upregulated the IRS-1/PI3K/Akt pathway, while BG upregulated the mTOR/Akt pathway. Notably, supplementation with EC + BG significantly increased Akt and glucose transporter type 4 (GLUT4) protein expressions, while decreasing glycogen synthase kinase 3β (GSK-3β) expression in liver cells as compared to the individual effects of EC and BG, indicating their synergistic effect on improving hepatic glucose uptake and glycogen synthesis. Consistently, supplementation with EC + BG significantly decreased blood glucose levels and improved oral glucose tolerance compared to EC and BG. Therefore, combined supplementation with EC and BG may bind to corresponding receptors, targeting synergistic activation of Akt expression, leading to the improvement of hepatic glucose metabolism and thereby ameliorating hyperglycemia in vivo.

Metabolic homeostasis in fungal infections from the perspective of pathogens, immune cells, and whole-body systems.

SUMMARYThe ability to overcome metabolic stress is a major determinant of outcomes during infections. Pathogens face nutrient and oxygen deprivation in host niches and during their encounter with immune cells. Immune cells require metabolic adaptations for producing antimicrobial compounds and mounting antifungal inflammation. Infection also triggers systemic changes in organ metabolism and energy expenditure that range from an enhanced metabolism to produce energy for a robust immune response to reduced metabolism as infection progresses, which coincides with immune and organ dysfunction. Competition for energy and nutrients between hosts and pathogens means that successful survival and recovery from an infection require a balance between elimination of the pathogen by the immune systems (resistance), and doing so with minimal damage to host tissues and organs (tolerance). Here, we discuss our current knowledge of pathogen, immune cell and systemic metabolism in fungal infections, and the impact of metabolic disorders, such as obesity and diabetes. We put forward the idea that, while our knowledge of the use of metabolic regulation for fungal proliferation and antifungal immune responses (i.e., resistance) has been growing over the years, we also need to study the metabolic mechanisms that control tolerance of fungal pathogens. A comprehensive understanding of how to balance resistance and tolerance by metabolic interventions may provide insights into therapeutic strategies that could be used adjunctly with antifungal drugs to improve patient outcomes.

Microsporidia secretory effectors and their roles in pathogenesis.

Microsporidia, a group of unicellular eukaryotic parasites, rely intensely on secretory effectors for successful invasion and proliferation within host cells. This review focuses on the identification, characterization, and functional roles of effectors, including secretory proteins and microRNAs. The adhesion proteins like the Ricin-B-lectin facilitate initial invasion, which binds to the host cell surface. Once inside, microsporidia deploy a range of effectors to modulate host immune responses, such as serpin proteins, and redirect host cell metabolism to meet the parasite's nutritional needs through hexokinase. Some effectors such as microRNAs, alter the host gene expression to create a more favorable intracellular parasitic environment. In conclusion, the secretory effectors of microsporidia play a pivotal role spanning from host cell invasion to intracellular establishment. In the future, more effectors secreted by microsporidia will be studied, which will not only help to elucidate the molecular mechanism of pathogenic manipulation of the host but also help to provide the potential targets for anti-parasitic treatments.

Identification of potential NUDT5 inhibitors from marine bacterial natural compounds via molecular dynamics and free energy landscape analysis.

NUDIX hydrolase 5 (NUDT5) is an enzyme involved in the hydrolysis of nucleoside diphosphates linked to other moieties, such as ADP-ribose. This cofactor is vital in redox reactions and is essential for the activity of sirtuins and poly(ADP-ribose) polymerases, which are involved in DNA repair and genomic stability. It has been shown that NUDT5 activity can also influence NAD+ homeostasis, thereby affecting cancer cell metabolism and survival. In this regard, the discovery of NUDT5 inhibitors has emerged as a potential therapeutic approach in cancer treatment. In this study, we conducted a high-throughput virtual screening of marine bacterial compounds against the NUDT5 enzyme and four molecules were selected based on their docking scores. These compounds established strong interactions within the NUDT5 active site, with molecular analysis highlighting the key role of Trp28A and Trp46B residues. Molecular dynamics simulations over 200 ns indicated a stable behavior, in association with root mean square deviation values always below 3 Å, suggesting conformational stability. Free energy landscape analysis further supported their potential as NUDT5 inhibitors, offering avenues for novel therapeutic strategies against NUDT5-associated breast cancer.

Peculiarities of the Ontogenesis of Bacilli During Development from a Vegetative Cell to a Spore

Understanding the development processes of bacteria, in particular spore-forming ones, has both fundamental and applied importance, since at various stages of this process, the cells of microorganisms perform certain functions that can be regulated by influencing certain factors depending on the tasks. Literature data and the results of our research on the influence of the composition of the nutrient medium, pH, temperature, and aeration on sporulation are analyzed in the article. It isshown that the direction of bacterial cells’ development in certain ways is determined by signals that come from the surrounding environment, affect their genome, and determine the ways of cell development – growth or sporulation. Sporogenesis can also be induced by metabolites formed during microorganism development. It is emphasized that the environmental factors that influence the sporulation of bacteria have been studied in sufficient detail. However, the mechanisms of their action remain debatable. Morphological, genetic, and biochemical changes of spore-forming bacteria under the conditions of macrocyclic and microcyclic ways of their development are also highlighted, which makes it possible to correctly understand the functioning of regulatory mechanisms in the ontogenesis of microbial cells. In particular, the data of our research on the dynamics of morphological changes in the ontogenesis of a specific individual bacterial cell are presented. In addition, factors, including specific terminal products of cell metabolism, such as antibiotics, and genetic mechanisms of sporogenesis regulation of various genera and species of bacteria are described in detail. The nature of the vast majority of "sporogenes" has not been clarified, and there are only a few hypotheses regarding the mechanism of their action. However, most of the biological regulators of sporogenesis were found in the culture liquid, which indicates the cellular nature of their action. Therefore, to obtain more convincing data on the regulation of sporogenesis, studies at the cellular level are needed.

Hyaluronic Acid Influences Amino Acid Metabolism via Differential L‐Type Amino Acid Transporter 1 Expression in the U87‐Malignant Glioma Cell Line

The glioblastoma (GBM) tumor microenvironment is heterogeneous, complex, and being increasingly understood as a significant contributor to tumor progression. In brain tumors, the extracellular matrix contains a large concentration of hyaluronic acid (HA) that makes it important to study its role in cancer progression. In particular, abnormal accumulation of HA is observed in gliomas and is often associated with poor prognosis. In addition, HA is a polymer and its molecular weight (MW) distribution may influence tumor cell activity. Herein, the influence of the MW of HA on tumor cell metabolism is evaluated. A 2D cell culture approach is used to expose the U87‐MG (medium glucose [MG]) cell line to different HA MWs (10, 60, and 500 kDa) and glucose concentrations (0, 5.5, and 25 mm). Notably, it is found that HA influences GBM amino acid metabolism via reduction in LAT1 transporter protein expression. Also an influence on mitochondrial respiration levels and a difference in the accumulation of some key products of cell metabolic activity (lactic acid, glutamic acid, and succinic acid) are reported. Overall, in these results, it is indicated that HA MW can influence GBM metabolic state, with implications for cell invasion and tumor progression.

Unraveling the Mystery of Energy-Sensing Enzymes and Signaling Pathways in Tumorigenesis and Their Potential as Therapeutic Targets for Cancer

Cancer research has advanced tremendously with the identification of causative genes, proteins, and signaling pathways. Numerous antitumor drugs have been designed and screened for cancer therapeutics; however, designing target-specific drugs for malignant cells with minimal side effects is challenging. Recently, energy-sensing- and homeostasis-associated molecules and signaling pathways playing a role in proliferation, apoptosis, autophagy, and angiogenesis have received increasing attention. Energy-metabolism-based studies have shown the contribution of energetics to cancer development, where tumor cells show increased glycolytic activity and decreased oxidative phosphorylation (the Warburg effect) in order to obtain the required additional energy for rapid division. The role of energy homeostasis in the survival of normal as well as malignant cells is critical; therefore, fuel intake and expenditure must be balanced within acceptable limits. Thus, energy-sensing enzymes detecting the disruption of glycolysis, AMP, ATP, or GTP levels are promising anticancer therapeutic targets. Here, we review the common energy mediators and energy sensors and their metabolic properties, mechanisms, and associated signaling pathways involved in carcinogenesis, and explore the possibility of identifying drugs for inhibiting the energy metabolism of tumor cells. Furthermore, to corroborate our hypothesis, we performed meta-analysis based on transcriptomic profiling to search for energy-associated biomarkers and canonical pathways.

Tryptophan 2,3-dioxygenase-positive matrix fibroblasts fuel breast cancer lung metastasis via kynurenine-mediated ferroptosis resistance of metastatic cells and T cell dysfunction.

Tumor metastasis is a major threat to cancer patient survival. The organ-specific niche plays a pivotal role in tumor organotropic metastasis. Fibroblasts serve as a vital component of the metastatic microenvironment, but how heterogeneous metastasis-associated fibroblasts (MAFs) promote organotropic metastasis is poorly characterized. Here, we aimed to decipher the heterogeneity of MAFs and elucidate the distinct roles of these fibroblasts in pulmonary metastasis formation in breast cancer. Mouse models of breast cancer pulmonary metastasis were established using an in vivo selection method of repeated injections of metastatic cells purified from the mouse lung. Single-cell RNA-sequencing (scRNA-seq) was employed to investigate the heterogeneity of MAFs. Transgenic mice were used to examine the contribution of tryptophan 2,3-dioxygenase-positive matrix fibroblasts (TDO2+ MFs) in lung metastasis. We uncovered 3 subtypes of MAFs in the lung metastatic microenvironment, and their transcriptome profiles changed dynamically as lung metastasis evolved. As the predominant subtype, MFs were exclusively marked by platelet-derived growth factor receptor alpha (PDGFRA) and mainly located on the edge of the metastasis, and T cells were enriched around MFs. Notably, high MF signatures were significantly associated with poor survival in breast cancer patients. Lung metastases were markedly diminished, and the suppression of T cells was dramatically attenuated in MF-depleted experimental metastatic mouse models. We found that TDO2+ MFs controlled pulmonary metastasis by producing kynurenine (KYN), which upregulated ferritin heavy chain 1 (FTH1) level in disseminated tumor cells (DTCs), enabling DTCs to resist ferroptosis. Moreover, TDO2+ MF-secreted chemokines C-C motif chemokine ligand 8 (CCL8) and C-C motif chemokine ligand 11 (CCL11) recruited T cells. TDO2+ MF-derived KYN induced T cell dysfunction. Conditional knockout of Tdo2 in MFs diminished lung metastasis and enhanced immune activation. Our study reveals crucial roles of TDO2+ MFs in promoting lung metastasis and DTCs' immune evasion in the metastatic niche. It suggests that targeting the metabolism of lung-specific stromal cells may be an effective treatment strategy for breast cancer patients with lung metastasis.

Modulatory effects of miRNAs in doxorubicin resistance: A mechanistic view.

MicroRNAs (miRNAs) are a group of small non-coding RNAs and play an important role in controlling vital biological processes, including cell cycle control, apoptosis, metabolism, and development and differentiation, which lead to various diseases such as neurological, metabolic disorders, and cancer. Chemotherapy consider as gold treatment approaches for cancer patients. However, chemotherapeutic is one of the main challenges in cancer management. Doxorubicin (DOX) is an anti-cancer drug that interferes with the growth and spread of cancer cells. DOX is used to treat various types of cancer, including breast, nervous tissue, bladder, stomach, ovary, thyroid, lung, bone, muscle, joint and soft tissue cancers. Also recently, miRNAs have been identified as master regulators of specific genes responsible for the mechanisms that initiate chemical resistance. miRNAs have a regulatory effect on chemotherapy resistance through the regulation of apoptosis process. Also, the effect of miRNAs p53 gene as a key tumor suppressor was confirmed via studies. miRNAs can affect main biological pathways include PI3K pathway. This review aimed to present the current understanding of the mechanisms and effects of miRNAs on apoptosis, p53 and PTEN/PI3K/Akt signaling pathway related to DOX resistance.

Multi-Omics Reveals the Role of Arachidonic Acid Metabolism in the Gut–Follicle Axis for the Antral Follicular Development of Holstein Cows

In vitro embryonic technology is crucial for improving farm animal reproduction but is hampered by the poor quality of oocytes and insufficient development potential. This study investigated the relationships among changes in the gut microbiota and metabolism, serum features, and the follicular fluid metabolome atlas. Correlation network maps were constructed to reveal how the metabolites affect follicular development by regulating gene expression in granulosa cells. The superovulation synchronization results showed that the number of follicle diameters from 4 to 8 mm, qualified oocyte number, cleavage, and blastocyst rates were improved in the dairy heifers (DH) compared with the non-lactating multiparous dairy cows (NDC) groups. The gut microbiota was decreased in Rikenellaceae_RC9_gut_group, Alistipes, and Bifidobacterium, but increased in Firmicutes, Cyanobacteria, Fibrobacterota, Desulfobacterota, and Verrucomicrobiota in the NDC group, which was highly associated with phospholipid-related metabolites of gut microbiota and serum. Metabolomic profiling of the gut microbiota, serum, and follicular fluid further demonstrated that the co-metabolites were phosphocholine and linoleic acid. Moreover, the expression of genes related to arachidonic acid metabolism in granulosa cells was significantly correlated with phosphocholine and linoleic acid. The results in granulosa cells showed that the levels of PLCB1 and COX2, participating in arachidonic acid metabolism, were increased in the DH group, which improved the concentrations of PGD2 and PGF2α in the follicular fluid. Finally, the expression levels of apoptosis-related proteins, cytokines, and steroidogenesis-related genes in granulosa cells and the concentrations of steroid hormones in follicular fluid were determinants of follicular development. According to our results, gut microbiota-related phosphocholine and linoleic acid participate in arachidonic acid metabolism in granulosa cells through the gut–follicle axis, which regulates follicular development. These findings hold promise for enhancing follicular development and optimizing oocyte quality in subfertile dairy cows.

See the power in kidney cells with ATP biosensor

Yamamoto etal. developed an exciting technical advance to examine intracellular adenosine triphosphate levels with single-cell resolution in intact living kidney tissue, including in tubular and vascular segments that lie deep under the kidney surface. The work is a significant advance on prior invivo biosensor studies, and it allows for mechanistic investigation of alterations in cell metabolism, kidney disease pathobiology, and the effects of drug treatments on energy sources in different kidney cell types.

Evaluation of cadmium effects on the glucose metabolism on insulin resistance HepG2 cells

Cadmium (Cd) is an environmental endocrine disruptor. Despite increasing research about the metabolic effects of Cd on HepG2 cells, information about the metabolic effects of Cd on insulin resistance HepG2 (IR-HepG2) cells is limited. Currently, most individuals with diabetes are exposed to Cd due to pollution. Previously, we reported that Cd exposure resulted in decreased blood glucose levels in diabetic mice, the underlying mechanism deserves further study. Therefore, we used palmitic acid (0.25mM) to treat HepG2 cells to establish IR-HepG2 model. IR-HepG2 cells were exposed to CdCl2 (1 μM and 2 μM). Commercial kits were used to measure glucose production, glucose consumption, ROS and mitochondrial membrane potential. Western blot and qRT-PCR were used to measure the proteins and genes of glucose metabolism. In the current study setting, we found no significant changes in glucose metabolism in Cd-exposed HepG2 cells, but Cd enhanced glucose uptake, inhibited gluconeogenesis and activated the insulin signaling pathway in IR-HepG2 cells. Meanwhile, we observed that Cd caused oxidative stress and increased the intracellular calcium concentration and inhibited mitochondrial membrane potential in IR-HepG2 cells. Cd compensatingly increased glycolysis in IR-HepG2 cells. Collectively, we found Cd ameliorated glucose metabolism disorders in IR-HepG2 cells. Furthermore, Cd exacerbated mitochondrial damage and compensatory increased glycolysis in IR-HepG2 cells. These findings will provide novel insights for Cd exposure in insulin resistant individuals.

Changes in bioenergetic characteristics of the murine lymphoma cells under the action of a thiazole derivative in complex with polymeric nanoparticles

Background. Mitochondria can influence cancer cells both indirectly via reactive oxygen species mediation and directly through mitochondrial biogenesis. Energy production in mitochondria is crucial as it facilitates the synthesis of essential molecules needed for cellular biosynthesis, growth, and proliferation. The development of new anticancer drugs that target the energy metabolism of tumor cells shows promise in cancer treatment. Our study aimed to investigate how the thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide (BF1), the polymeric nanoparticles based on the polyethylene glycol (PEG-PN, Th5), and their complex with BF1 (Th6) affect respiration and mitochondrial membrane potential in murine NK/Ly tumor cells. Materials and Methods. The study was performed on white wild-type male mice with grafted NK/Ly lymphoma. The test substances were added to the cell suspension at a final concentration of 10 μM and incubated for 15 min at 37 °C. Oxygen uptake rates in NK/Ly cells were measured using a polarographic method with Clark electrode. Changes in mitochondrial membrane potential were assessed using the tetramethylrhodamine methyl ester fluorescence dye. The fluorescence intensity was evaluated using the ImageJ computer program. Results. After incubating NK/Ly cells with BF1 (10 µM), Th5, or the BF1 + PEG-PN complex (Th6) for 15 min, no changes were observed in glucose-fueled basal respiration. However, the Th6 complex significantly activated FCCP-stimulated respiratory processes in NK/Ly lymphoma cells. Fluorescent microscopy data indicated that BF1 or Th5 alone did not affect mitochondrial membrane potential values. However, the Th6 complex significantly decreased mitochondrial membrane potential, suggesting a reduction in NK/Ly cell viability. Conclusions The investigated complex of thiazole derivative BF1 with PEG-based polymeric nanoparticles may realize its cytotoxic effect by depolarization of mitochondrial membrane in NK/Ly lymphoma cells.

In silico modeling the potential clinical effect of growth factor treatment on the metabolism of human nucleus pulposus cells.

While growth factors have the potential to halt degeneration and decrease inflammation in animal models, the literature investigating the effect of dosage on human cells is lacking. Moreover, despite the completion of clinical trials using growth differentiation factor-5 (GDF-5), no results have been publicly released. The overall objective was to quantitatively assess the effect of three clinically relevant concentrations of GDF-5 (0.25, 1, and 2 mg) as a therapeutic for disc regeneration. Firstly, this work experimentally determined the effects of GDF-5 concentration on the metabolic and matrix synthesis rates of human nucleus pulposus (NP) cells. Secondly, in silico modeling was employed to predict the subsequent regenerative effect of different GDF-5 treatments (± cells). This study suggests a trend of increased matrix synthesis with 0.25 and 1 mg of GDF-5. However, 2 mg of GDF-5 significantly upregulates oxygen consumption. Despite this, in silico models highlight the potential of growth factors in promoting matrix synthesis compared to cell-only treatments, without significantly perturbing the nutrient microenvironment. This work elucidates the potential of GDF-5 on human NP cells. Although the results did not reveal statistical differences across all doses, the variability and response among donors is an interesting finding. It highlights the complexity of human response to biological treatments and reinforces the need for further human research and personalized approaches. Furthermore, this study raises a crucial question about whether these potential biologics are more regenerative in nature or better suited as prophylactic therapies for younger patient groups. Biological agents exhibit unique characteristics and features, demanding tailored development strategies and individualized assessments rather than a one-size-fits-all approach. Therefore, the journey to realizing the full potential of biological therapies is long and costly. Nonetheless, it holds the promise of revolutionizing spinal healthcare and improving the quality of life for patients suffering from discogenic back pain.

CD36-mediated accumulation of MDSCs exerts abscopal immunosuppressive responses in hepatocellular carcinoma after insufficient microwave ablation

The immune landscape of distant unablated tumors following insufficient microwave ablation (iMWA) in hepatocellular carcinoma (HCC) remains to be clarified. The objective of this study is to define the abscopal immune landscape in distant unablated tumor before and after iMWA for HCC. Two treatment-naive patients were recruited for tumor tissue sampling, of each with two HCC lesions. Tumor samples were obtained at before and after microwave ablation in distant unablated sites for single-cell RNA sequencing (scRNA-seq). Mouse model with bilateral hepatoma tumors were developed, and distant unablated tumors were analyzed using multicolor immunofluorescence, RNA sequencing and flow cytometry. The scRNA-seq revealed that a reduced proportion of CD8+ T cells and an increased proportion of myeloid-derived suppressor cells (MDSCs) were observed in the distant unablated tumor microenvironment (TME). A notable disruption was observed in the lipid metabolism of tumor-associated immune cells, accompanied by an upregulated expression of CD36 in tumor-infiltrating immune cells in distant unablated tumor. The administration of a CD36 inhibitor has been demonstrated to ameliorate the adverse effects induced by iMWA, primarily by reinstating the anti-tumor responses of T cells in distant unablated tumor. These findings explain the recurrence and progression of tumors after iMWA and provide a new target of immunotherapy for HCC.

P01-28 The effects of chlorinated paraffins on thyroid hormone metabolism in human HepaRG cells

P01-28 The effects of chlorinated paraffins on thyroid hormone metabolism in human HepaRG cells

P11-01 BPS and BPF by acting as mitochondrial disrupting chemicals cause changes in energy metabolism in human ovarian granulosa cells

P11-01 BPS and BPF by acting as mitochondrial disrupting chemicals cause changes in energy metabolism in human ovarian granulosa cells

Oxyphylla A exerts antiparkinsonian effects by ameliorating 6-OHDA-induced mitochondrial dysfunction and dyskinesia in vitro and in vivo

Parkinson's disease (PD) poses a formidable challenge in neurology, marked by progressive neuronal loss in the substantia nigra. Despite extensive investigations, understanding PD's pathophysiology remains elusive, with no effective therapeutic intervention identified to alter its course. Oxyphylla A (OPA), a natural compound extracted from Alpinia oxyphylla, exhibits promise in experimental models of various neurodegenerative disorders (ND), notably through novel mechanisms like α-synuclein degradation. The purpose of this investigation was to explore the neuroprotective potential of OPA on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in PD models, with a focus on mitochondrial functions. Additionally, potential OPA targets for neuroprotection were explored. PC12 cells and C57BL/6 mice were lesioned with 6-OHDA as PD models. Impaired mitochondrial membrane potential (Δψm) was assessed using JC-1 staining. The oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were also detected to evaluate mitochondrial function and glucose metabolism in PC12 cells. Behavioral analysis and immunohistochemistry were performed to evaluate pathological lesions in the mouse brain. Moreover, bioinformatics tools predicted OPA targets.OPA restored cellular energy metabolism and mitochondrial biogenesis, preserving Δψm in 6-OHDA-induced neuronal damage. Pre-treatment mitigated loss of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra and striatal dopaminergic fibers, restoring dopamine levels and ameliorating motor deficits in PD mice. Mechanistically, OPA may activate PKA/Akt/GSK-3β and CREB/PGC-1α/NRF-1/TFAM signaling cascades. Bioinformatics analysis identified potential OPA targets, including CTNNB1, ESR1, MAPK1, MAPK14, and SRC. OPA, derived from Alpinia oxyphylla, exhibited promising neuroprotective activity against PD through addressing mitochondrial dysfunction, suggesting its potential as a multi-targeted therapeutic for PD.

Targeted Inhibition of the PI3K/Akt/mTOR Signaling Axis: Potential for Sarcoma Therapy.

Sarcoma is a heterogeneous group of malignancies often resistant to conventional chemotherapy and radiation therapy. The phosphatidylinositol-3-kinase/ protein kinase B /mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway has emerged as a critical cancer target due to its central role in regulating key cellular processes such as cell growth, proliferation, survival, and metabolism. Dysregulation of this pathway has been implicated in the development and progression of bone sarcomas (BS) and soft tissue sarcomas (STS). PI3K/Akt/mTOR inhibitors have shown promising preclinical and clinical activity in various cancers. These agents can inhibit the activation of PI3K, Akt, and mTOR, thereby reducing the downstream signaling events that promote tumor growth and survival. In addition, PI3K/Akt/mTOR inhibitors have been shown to enhance the efficacy of other anticancer therapies, such as chemotherapy and radiation therapy. The different types of PI3K/Akt/mTOR inhibitors vary in their specificity, potency, and side effect profiles and may be effective depending on the specific sarcoma type and stage. The molecular targeting of PI3K/Akt/mToR pathway using drugs, phytochemicals, nanomaterials (NMs), and microbe-derived molecules as Pan-PI3K inhibitors, selective PI3K inhibitors, and dual PI3K/mTOR inhibitors have been delineated. While there are still challenges to be addressed, the preclinical and clinical evidence suggests that these inhibitors may significantly improve patient outcomes. Further research is needed to understand the potential of these inhibitors as sarcoma therapeutics and to continue developing more selective and effective agents to meet the clinical needs of sarcoma patients.

The ion channel TRPM8 is a direct target of the immunosuppressant rapamycin in primary sensory neurons.

The mechanistic target of rapamycin (mTOR) signalling pathway is a key regulator of cell growth and metabolism. Its deregulation is implicated in several diseases. The macrolide rapamycin, a specific inhibitor of mTOR, has immunosuppressive, anti-inflammatory and antiproliferative properties. Recently, we identified tacrolimus, another macrolide immunosuppressant, as a novel activator of TRPM8 ion channels, involved in cold temperature sensing, thermoregulation, tearing and cold pain. We hypothesized that rapamycin may also have agonist activity on TRPM8 channels. Using calcium imaging and electrophysiology in transfected HEK293 cells and wildtype or Trpm8 KO mouse DRG neurons, we characterized rapamycin's effects on TRPM8 channels. We also examined the effects of rapamycin on tearing in mice. Micromolar concentrations of rapamycin activated rat and mouse TRPM8 channels directly and potentiated cold-evoked responses, effects also observed in human TRPM8 channels. In cultured mouse DRG neurons, rapamycin increased intracellular calcium levels almost exclusively in cold-sensitive neurons. Responses were markedly decreased in Trpm8 KO mice or by TRPM8 channel antagonists. Cutaneous cold thermoreceptor endings were also activated by rapamycin. Topical application of rapamycin to the eye surface evokes tearing in mice by a TRPM8-dependent mechanism. These results identify TRPM8 cationic channels in sensory neurons as novel molecular targets of the immunosuppressant rapamycin. These findings may help explain some of its therapeutic effects after topical application to the skin and the eye surface. Moreover, rapamycin could be used as an experimental tool in the clinic to explore cold thermoreceptors.