International Journal of Molecular Sciences最新文献

The FLT3-ITD mutation is a critical prognostic marker in acute myeloid leukemia (AML) and recent clinical trials demonstrate that FLT3-based measurable residual disease (MRD) is both prognostic and predictive, guiding therapeutic interventions in intensive and post-transplant settings. Conventional detection methods lack the sensitivity required for effective MRD monitoring. We developed a patient-specific droplet digital PCR (ddPCR) approach achieving analytical sensitivity of 10^-5 (0.001%) for FLT3-ITD quantification. In our cohort, ddPCR enabled longitudinal monitoring of clonal dynamics, allowing the detection of re-emerging FLT3-ITD clones months before hematologic relapse and earlier than standard capillary electrophoresis. Notably, 25% of patients who relapsed as FLT3-ITD positive despite being classified as FLT3-negative at diagnosis harbored detectable microclones when retrospectively analyzed by ddPCR, suggesting that FLT3-ITD-positive relapse frequently originates from pre-existing subclones below conventional detection thresholds. These findings challenge current diagnostic classification and may influence risk stratification and treatment decisions, particularly regarding FLT3 inhibitor eligibility. While ddPCR is limited to tracking known dominant clones, it represents a practical, cost-effective solution for high-sensitivity MRD surveillance. In the era of targeted FLT3 therapies, integrating sensitive molecular monitoring into routine AML management may enable timely therapeutic adjustments and improve patient outcomes.

Adipocytes produce the hormone leptin, a hormone that links energy availability to reproductive function by permitting activation of the hypothalamic-pituitary-gonadal (HPG) axis. Loss-of-function mutations in the long leptin receptor isoform (LEPRb) disrupt intracellular signaling pathways, including the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3), phosphoinositide 3-kinase (PI3K), and mitogen-activated protein kinase (MAPK) pathways, resulting in central leptin resistance and impaired neuroendocrine control of reproduction. Evidence from human monogenic obesity syndromes, animal models, and neuroendocrine studies indicates that LEPRb mutations disrupt hypothalamic circuitry upstream of gonadotropin-releasing hormone (GnRH) neurons, impairing GnRH pulsatility and leading to hypogonadotropic hypogonadism (HH) and infertility. This review synthesizes molecular, translational, and clinical data highlighting the central role of kisspeptin-mediated signaling in leptin-dependent reproductive regulation. Current therapeutic limitations are discussed alongside emerging approaches, including kisspeptin-based therapies and receptor-targeted strategies. Elucidating how LEPRb dysfunction disrupts metabolic-reproductive integration may provide insights into both rare monogenic conditions and common obesity-associated reproductive dysfunction.

Natural compounds are increasingly recognized as valuable sources of pharmacologically active agents for cancer therapy. Among them, plant-derived triterpenoids attract attention due to their structural diversity and broad biological activity. Roburic acid (RA), a tetracyclic triterpenoid, has previously been shown to exert antiproliferative effects in colorectal cancer (CRC) cells with limited cytotoxicity. In the present study, we investigated the cellular mechanisms underlying RA activity in CRC cells, focusing on cell cycle regulation, mitochondrial function, apoptosis, oxidative stress, and DNA integrity. RA treatment markedly suppressed CRC cell proliferation, resulting in G₀/G₁ cell cycle arrest and downregulation of key proliferation markers. Mitochondrial analysis revealed an early reduction in mitochondrial membrane potential (MMP) following RA exposure, indicating mitochondrial dysfunction. Importantly, these effects occurred in the absence of intracellular reactive oxygen species (ROS) generation and without induction of DNA strand breaks, demonstrating a non-pro-oxidant and non-genotoxic profile of RA. Apoptotic features were observed mainly at higher concentrations and after prolonged exposure and were strongly dependent on cell line and assay type. Overall, RA limits CRC cell growth predominantly through cytostatic mechanisms, including cell cycle arrest and mitochondrial modulation, while apoptosis is a secondary, context-dependent response. The lack of oxidative stress and genotoxicity distinguishes RA from many conventional cytotoxic agents and supports its further investigation as a non-genotoxic anticancer compound.

The role of adenylate kinase in regulating the glycolysis rate and the potential contribution of the adenylate kinase reaction to ATP production were examined using mathematical models of energy metabolism in human erythrocytes and resting anaerobic mammalian skeletal muscle. The adenylate kinase reaction was shown to play a critical role in the regulation of cellular energy metabolism. Through the action of adenylate kinase, small changes in intracellular [ATP] give rise to large changes in [AMP], a potent activator of glycolytic flux via the activation of phosphofructokinase (PFK). This mechanism ensures an increase in the glycolytic rate as [ATP] decreases within the physiological range of ATP concentrations. As a result, negative feedback regulation of glycolysis by [ATP] is established, allowing the rate of ATP production to adjust to the energy demands of the cell and thereby stabilizing [ATP] under varying rates of ATP consumption. Importantly, allosteric inhibition of PFK by ATP alone was insufficient to provide negative feedback regulation of glycolysis via [ATP]. The contribution of the adenylate kinase reaction to ATP production appears to be negligible. Also, due to the presence of adenylate kinase in cells, energy metabolism is regulated not by the absolute concentration of ATP, but by the energy charge or the ratio of [ATP] to the sum of [ATP], [ADP], and [AMP].

The long asymptomatic period of clear cell renal cell carcinoma, which leads to delayed diagnosis and poorer prognosis, poses a global challenge. Chemokines play a pivotal role in immune regulation and tumor progression, making them promising biomarker candidates. This study aimed to evaluate the usefulness of the C-C motif chemokine ligand 3 (CCL3) and C-C motif chemokine ligand 7 (CCL7) by assessing their serum concentrations in 40 patients with stage G1 + G2 and stage G3 + G4 renal cancer, as well as in 58 healthy volunteers. Chemokine concentrations were measured using a multiplex Luminex assay and analyzed statistically, including receiver operating characteristic (ROC) analysis. Serum CCL3 concentrations were significantly elevated in ccRCC patients compared to controls and increased with tumor grade, with the highest levels observed in patients with advanced disease (G3+G4). In contrast, serum CCL7 levels were significantly lower in ccRCC patients than in healthy individuals, with no significant differences between tumor grade subgroups. ROC analysis revealed comparable diagnostic performance of CCL3 and CCL7, with CCL3 showing a slightly higher area under the curve. CCL3 showed high sensitivity, whereas CCL7 exhibited higher specificity than sensitivity, and a relatively high positive predictive value, consistent with its inverse regulation in ccRCC. These findings suggest that serum CCL3 and CCL7 are oppositely regulated in ccRCC and may serve as complementary non-invasive biomarkers for renal cancer detection.

Respiratory syncytial virus (RSV) poses a substantial global health burden, particularly in infants and the elderly. The fusion (F) protein is a key therapeutic target for inhibiting RSV entry. In this study, we performed a structure-based virtual screening of the Comprehensive Marine Natural Products Database (CMNPD) to discover novel anti-RSV agents targeting the prefusion F protein trimer. Screening of 31,561 compounds via molecular docking, followed by stringent ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiling and MM/GBSA (Molecular Mechanics/Generalized Born Surface Area) binding free energy calculations, identified 11 promising candidates. Among these, manzamine alkaloids exhibited the most favorable docking scores (as low as -13.3 kcal/mol) and promising Ligand Efficiency (LE) values. These molecules primarily interact with conserved hydrophobic residues (Phe140, Phe488) through hydrophobic interactions, π-stacking, and electrostatic forces. Our study highlights marine natural products, especially manzamine alkaloids, as promising leads for the development of novel, orally bioavailable RSV fusion inhibitors, potentially offering avenues to overcome existing drug resistance. However, these computational findings require in vitro validation to confirm efficacy.

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. During the last few years, remarkable advances have been made in the treatment of DN. Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) consistently prevent or delay albuminuria and renal failure in patients with DN. Prior research from our group highlights the Janus kinase/signal transducers and activators of transcription axis as a critical target in DN. Specifically, the administration of suppression of cytokine signaling 1 (SOCS1) mimetic peptides (MiS1) modulates aberrant signaling, resulting in profound beneficial effects on renal function and structural integrity in experimental DN. The aim of this study was to evaluate the effect of empagliflozin and MiS1 on kidney damage and its associated inflammatory, oxidative stress and lipotoxic mechanisms in an advanced type 2 DN mouse model BTBR ob/ob. Mice were treated for 7 weeks with empagliflozin and MiS1, alone or in combination, and monitored for glycemia, body weight, albuminuria, histopathological damage, podocyte loss, and gene expression related to inflammation, redox balance, and lipid metabolism. Empagliflozin or MiS1 monotherapies significantly reduced albuminuria and structural renal injury, preserved podocyte number, and downregulated genes involved in inflammatory, oxidative, and mitochondrial-lipid metabolic dysregulation, with empagliflozin additionally improving metabolic parameters. Notably, the combined therapy achieved the greatest reduction in albuminuria and histological damage with enhanced suppression of pathogenic inflammatory and metabolic pathways, resulting in superior renoprotection compared with monotherapy. These findings suggested that add-on therapy with SOCS1 peptidomimetics and SGLT2i may help mitigate residual albuminuria and renal damage in type 2 DN.

Lipopolysaccharides (LPSs) are key components of the bacterial outer envelope, determining its structural integrity, barrier properties, and interactions with the surrounding environment. This review analyzes the relationship between the molecular architecture of LPSs and their physicochemical properties. Particular attention is being paid to the organization of LPS-containing supramolecular assemblies, including bacterial outer membranes, bilayers, micelles, and LPS brushes. The review further focuses on theoretical frameworks employed to describe LPS layers and discusses the physical meaning of the parameters involved in these models. The simulations involve a wide range of approaches starting from all-atom molecular treatment and up to polymer and colloidal approaches. When considering these models, we focus on the relationships between parameters that are addressed at each level of modeling. It is shown that biological functions such as membrane stability and bacterial adhesion are largely governed by the molecular organization of LPS. This structure-property relationship provides a basis for predicting the performance of anti-adhesive biomaterials, antimicrobial strategies, and bactericidal agents.

Diabetic nephropathy (DN) is a serious complication in diabetic patients, leading to kidney dysfunction and ultimately end-stage renal disease. Although several pharmacological agents have been developed, treating DN remains challenging due to its complex and multifaceted pathogenesis. Endoplasmic reticulum (ER) stress plays a crucial role in DN pathology; however, the molecular mechanisms underlying reduced ER stress remain poorly understood. This study investigated the protective effects of 4-phenylbutyrate (4-PBA), an ER stress inhibitor, on DN and the related regulatory molecules through gene expression network analysis. A C57BL/6 mouse model of DN was used in combination with a high-fat diet and streptozotocin after unilateral nephrectomy and treated with 4-PBA by intraperitoneal injection for 6 weeks. The 4-PBA treatment effectively improves DN-induced renal structural and functional abnormalities by reducing albuminuria, podocyte loss, glomerular and tubular injury, and renal inflammation and cell death. These changes induced by 4-PBA were associated with decreased expression of ER stress markers and increased autophagy activities in diabetic kidneys. Importantly, 4-PBA reduced components of the complement C1q pathway, the NADPH oxidase complex, and chemokines, thereby attenuating chronic renal dysfunction. Conclusively, inhibition of ER stress is a promising pharmacological target for treating patients with DN.

Delayed effects of acute radiation exposure (DEARE), including radiation pneumonitis (lung-DEARE), develop weeks to months after radiation exposure. Pathway-targeted biomarkers that capture early oxidative stress and cell death could improve risk stratification and provide objective measures of mitigator efficacy. The objective was to test whether molecular lung imaging predicts long-term survival and mitigator response after irradiation. Rats received 13.5 Gy leg-out partial-body irradiation with a subset treated with the radiation-injury mitigator lisinopril. Rats underwent lung imaging at weeks 2 and 4 post-irradiation with ^99mTc-duramycin (cell death) and ^99mTc-HMPAO (oxidative stress). Plasma mitochondrial damage-associated molecular patterns (mtDAMPs) were also measured. Irradiation reduced survival with animals evidencing significant pleural effusion as an indication of radiation pneumonitis, which was mitigated with lisinopril as previously shown. Lung uptake of both imaging biomarkers increased in irradiated rats between weeks 2 and 4, consistent with worsening cell death and oxidative stress. Rats that succumbed by day 120 exhibited significantly larger increases in both biomarkers than the survivors. A predictive test was developed that predicted death by day 120 with ~70% sensitivity and specificity. Plasma mtDAMPs (ND1/2 and ATPase 6/8) increased following irradiation, and the D-loop increase from week 2 to 3 separated outcomes (increase in nonsurvivors versus decrease in survivors). Both imaging and mtDAMPs data from lisinopril-treated animals showed blunted responses. Early dual-tracer molecular lung imaging predicted long-term survival after radiation exposure and tracked mitigation with lisinopril. Circulating mtDAMPs may provide complementary systemic information to further strengthen early risk stratification after radiation exposure.