Optimal first-line treatment for EGFR-mutated NSCLC: a comparative analysis of osimertinib and second-generation EGFR-TKIs.

BACKGROUND: Osimertinib is an irreversible third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). It is the preferred first-line treatment for EGFR-mutated non-small cell lung cancer (NSCLC) compared to first-generation EGFR-TKIs. However, limited research has compared its clinical effectiveness with second-generation (2nd G) EGFR-TKIs. MATERIALS AND METHODS: This study recruited patients diagnosed with stage IIIb-IV EGFR-mutated NSCLC who received first-line treatment with either 2nd G EGFR-TKIs (afatinib and dacomitinib) or osimertinib between April 2020 and April 2023. RESULTS: The final analysis included 168 patients, of whom 113 received 2nd G EGFR-TKIs (afatinib or dacomitinib) and 55 received osimertinib. The median progression-free survival (PFS) did not differ significantly between 2nd G EGFR-TKIs and osimertinib (del 19: 17.6 months; L858R: 20.0 months vs. 28.3 months, p = 0.081). In patients with the EGFR exon 19 deletion, osimertinib conferred a longer median PFS (28.3 vs. 17.6 months, p = 0.118) and time to treatment failure (30.2 vs. 22.7 months, p = 0.722) than 2nd G EGFR-TKIs. However, the differences were not statistically significant. In patients with with the EGFR exon 19 deletion and central nervous system metastasis, the median PFS did not differ significantly between those treated with osimertinib (14.3 months) and those treated with 2nd G EGFR-TKIs (17.6 months; p = 0.881). Multivariate regression analysis revealed that the NSCLC stage was the only independent negative predictor of PFS. The treatment patterns in the second line also differed significantly between groups (p = 0.008). CONCLUSIONS: This study found comparable effectiveness between osimertinib and 2nd G EGFR-TKIs as first-line treatment for advanced EGFR-mutated NSCLC, with only the NSCLC stage identified as a negative predictor of PFS. However, whether the different second-line treatments affect overall survival should be examined.

Alterations of striatal phosphodiesterase 10 A and their association with recurrence rate in bipolar I disorder.

Phosphodiesterase 10 A (PDE10A), a pivotal element of the second messenger signaling downstream of the dopamine receptor stimulation, is conceived to be crucially involved in the mood instability of bipolar I disorder (BD-I) as a primary causal factor or in response to dysregulated dopaminergic tone. We aimed to determine whether striatal PDE10A availability is altered in patients with BD-I and assessed its relationship with the clinical characteristics of BD-I. This case-control study used positron emission tomography (PET) with 2-(2-(3-(4-(2-[18F]fluoroethoxy)phenyl)-7-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)ethyl)-4-isopropoxyisoindoline-1,3-dione ([18F]MNI-659), a radioligand that binds to PDE10A, to examine the alterations of the striatal PDE10A availability in the living brains of individuals with BD-I and their association with the clinical characteristics of BD-I. [18F]MNI-659 PET data were acquired from 25 patients with BD-I and 27 age- and sex-matched healthy controls. Patients with BD-I had significantly lower PDE10A availability than controls in the executive (F = 8.86; P = 0.005) and sensorimotor (F = 6.13; P = 0.017) subregions of the striatum. Lower PDE10A availability in the executive subregion was significantly associated with a higher frequency of mood episodes in patients with BD-I (r = -0.546; P = 0.007). This study provides the first evidence of altered PDE10A availability in patients with BD-I. Lower PDE10A availability in the executive subregion of the striatum is associated with an increased recurrence risk, suggesting that PDE10A may prevent BD-I relapse. Further studies are required to elucidate the role of PDE10A in BD-I pathophysiology and explore its potential as a treatment target.

Post-hoc safety/efficacy analyses from pediatric delgocitinib atopic dermatitis trials.

BACKGROUND: Delgocitinib ointment is usually recommended for use in children at a concentration of 0.25%. However, there are no clear criteria for dosing, except that a 0.5% formulation may also be used, depending on symptom severity. Treatment of atopic dermatitis is based on combinations of topical corticosteroids, tacrolimus ointment, and delgocitinib ointment, but there are no reports on the safety of delgocitinib ointment when used in combination with other drugs. METHODS: This is a post-hoc analysis of data from two delgocitinib ointment trials with pediatric atopic dermatitis patients. The efficacy and safety of the 0.25% and 0.5% formulations were compared. Efficacy and safety were evaluated after up to 4 and 56 weeks of treatment, respectively. The safety of delgocitinib ointment when used in combination with topical corticosteroids and/or tacrolimus ointment was investigated. RESULTS: The dose-response relationship was examined according to baseline disease severity. The proportions of subjects with mild disease who achieved cumulative investigator's global assessment of 0 (clear) or 1 (almost clear) were 46.2% (0.25% ointment), 71.4% (0.5% ointment), and 7.7% (vehicle). For subjects with moderate to severe disease, the corresponding proportions were 19.0%, 20.0%, and 0.0%, respectively. No overall differences were seen in the safety profiles of the 0.25% and 0.5% delgocitinib ointment doses, or in the safety profiles of the two doses relating to disease severity or to concomitant use of topical corticosteroids and/or tacrolimus ointment. CONCLUSIONS: These analyses indicate that after up to 4 weeks of treatment, delgocitinib 0.5% ointment may be more effective than the 0.25% dose for mild atopic dermatitis, and that after up to 56 weeks of treatment, delgocitinib is well tolerated in a pediatric trial population when used as prescribed in combination with topical corticosteroids and/or tacrolimus ointment.

Novel quinazolin-4-one based derivatives bearing 1,2,3-triazole and glycoside moieties as potential cytotoxic agents through dual EGFR and VEGFR-2 inhibitory activity.

The toxicity that was caused by the developed medications for anticancer treatment is, unfortunately, an earnest problem stemming from the various involved targets, and accordingly, intense research for overcoming such a phenomenon remains indispensable. In the current inquiry, an innovative category of substituted quinazoline-based glycosides incorporating a core of 1,2,3-triazole and attached to distinct acetylated likewise deprotected sugar segments are created and produced synthetically. The resulted 1,2,3-triazolyl-glycosides products were investigated for their ability to cause cytotoxicity to several human cancer cell lines. The quinazoline based glycosyl-1,2,3-triazoles 10-13 with free hydroxy sugar moiety revealed excellent potency against (IC50 range = 5.70-8.10 µM, IC50 Doxorubicin = 5.6 ± 0.30 µM, IC50 Erlotinib = 4.3 ± 0.1 µM). against MCF-7 cancer cell line. In addition, the derived glycosides incorporating quinazolinone and triazole core 6-13 with acetylated and deprotected sugar parts showed excellent and superior potency against HCT-116 (IC50 range = 2.90-6.40 µM). The potent products were revealed as safe cytotoxic agents as indicated by their studied safety profiles. Additional research of promising candidates inhibitory analysis performed against EGFR and VEGFR-2. The hydroxylated glycosides incorporating triazole and quinazoline system 11 and 13 with N-methyl substitution of quinazolinone, gave excellent potency against EGFR (IC50 = 0.35 ± 0.11 and 0.31 ± 0.06 µM, correspondingly) since glycoside 13 revealed comparable IC50 (3.20 ± 0.15 µM) to sorafenib against VEGFR-2. For more understanding of its action mode, it was analyzed how the 1,2,3-triazolyl glycoside 13 made an effect on the apoptosis induction and the arrest of the cell cycle. It was revealed that it had the ability to stop HCT-116 cells in their cell cycle's G1 stage. Moreover, the influence of quinazolinone-1,2,3-triazole-glycoside 13 upon p53, Bax, and Bcl-2 levels in HCT-116 units was also studied for future approaches toward its behavior. Additionally, the latter derivative may trigger apoptosis, as indicated by a significant increase in apoptotic cells. Furthermore, molecular docking was simulated to make an obvious validation and comprehension acquirement of the binding's characteristics also attractions among the most forceful compounds side by side with their aimed enzymes.

Mitochondrial modulation treating postoperative cognitive dysfunction neuroprotection via DRP1 inhibition by Mdivi1.

This study investigated the role of mitochondrial dynamics in postoperative cognitive dysfunction (POCD) and assessed the therapeutic potential of mitochondrial modulation, particularly through the inhibition of dynamin-related protein 1 (DRP1) with Mdivi-1. Our findings indicated that DRP1 inhibition substantially mitigated neuroinflammation mediated by microglial cells, contributing to improved cognitive function in POCD models. The administration of Mdivi-1 led to a notable decrease in mitochondrial fission, reduced reactive oxygen species (ROS) production, and stabilization of mitochondrial membrane potential, all of which correlate with diminished neuroinflammation, as evidenced by lower NOD-like receptor family pyrin domain containing 3 (NLRP3)/ interleukin-1ß (IL-1ß) expression in microglial cells. Importantly, Mdivi-1 treatment was also found to enhance synaptic plasticity, increasing synaptic spine density in the hippocampal region of POCD mice. This improvement in mitochondrial health and synaptic integrity was paralleled by enhanced cognitive performance, as demonstrated in Y-maze tests. These results underscored the critical role of mitochondrial dynamics in the pathophysiology of POCD and suggested that targeting mitochondrial dysfunction, specifically through DRP1 inhibition, could be an effective approach for POCD treatment.

High-Speed Countercurrent Chromatography Isolation of Active Components from Evodia Rutaecarpa and Affinity Ultrafiltration Screening for Their Acetylcholinesterase Inhibitor Activity.

Acetylcholinesterase inhibitors from Evodia rutaecarpa were screened, prepared, and evaluated. To screen the lipophilic alkaloid active constituents in E. rutaecarpa, we improved and optimized an ultrafiltration system. Three acetylcholinesterase (AChE) inhibitors, dehydroevodiamine, evodiamine, and rutecarpine, were screened. Addressing the limitations of the traditional response surface methodology (RSM) for multiobjective screening, we integrated RSM with the Non-dominated Sorting Genetic Algorithm III to achieve the optimal extraction of these active ingredients. High-speed countercurrent chromatography was used to isolate the active components using a two-phase solvent system: n-hexane/ethyl acetate/methanol/water (3.0:2.5:3.5:2.0, v/v/v/v) and ethyl acetate/methanol/water (3.0:1.0:4.0, v/v/v). The nuclear magnetic resonance spectroscopy confirmed the structures of the compounds, and molecular docking and dynamics simulations assessed the inhibitory effects of the chemical components on AChE, which were consistent with the findings of the ultrafiltration experiments. We also confirmed the neuroprotective properties of these compounds against glutamate-induced apoptosis in PC12 cells. Overall, we achieved the systematic optimization of multitarget compound extraction and lipophilic alkaloid ultrafiltration screening, as well as preparation and activity validation, laying the groundwork for the development of AChE inhibitors from lipophilic alkaloids.

Pharmacophore Establishment and Optimization of Saturated 1,6-Naphthyridine-Fused Quinazolinones that Inhibit Meningoencephalitis-Causing Naegleria fowleri.

Primary amoebic meningoencephalitis (PAM) is a human brain infection caused by Naegleria fowleri with a 97% mortality rate. Quinazolinones resulting from a Mannich-coupled domino rearrangement were recently identified as inhibitors of the amoeba. Herein, we resolved the effective concentrations for 25 pilot compounds and then, using the Mannich protocol and a key late-stage, N-demethylation/functionalization, we synthesized 53 additional analogs to improve potency, solubility and microsomal stability. We established an antiamoebic quinazolinone pharmacophore, culminating in (±)-trans-57b which featured the best combination of potency, selectivity index, solubility, and microsomal stability. Enantiomeric separation afforded (4aS,13bR)-57b (BDGR-20237) with a 41-fold potency advantage over its enantiomer. ADME and mouse pharmacokinetic profiling for BDGR-20237 revealed high brain penetrance but a limited half-life which did not statistically enhance the mouse survival in a pilot efficacy study. The pharmacophoric model, supported by 88 quinazolinones, several of which exhibit subnanomolar potency, will guide further scaffold optimization.

Modulating mitochondrial dynamics ameliorates left ventricular dysfunction by suppressing diverse cell death pathways after diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM) triggers a detrimental shift in mitochondrial dynamics, characterized by increased fission and decreased fusion, contributing to cardiomyocyte apoptosis and cardiac dysfunction. This study investigated the impact of modulating mitochondrial dynamics on DCM outcomes and underlying mechanisms in a mouse model. DCM induction led to upregulation of fission genes (Drp1, Mff, Fis1) and downregulation of fusion genes (Mfn1, Mfn2, Opa1). Inhibiting fission with Mdivi-1 or promoting fusion with Ginsenoside Rg1 preserved cardiac function, as evidenced by improved left ventricular ejection fraction (LVEF), fractional shortening (FS), and E/A ratio. Both treatments also reduced infarct size and attenuated cardiomyocyte apoptosis, indicated by decreased caspase-3 activity. Mechanistically, Mdivi-1 enhanced mitochondrial function by improving mitochondrial membrane potential, reducing reactive oxygen species (ROS) production, and increasing ATP generation. Ginsenoside Rg1 also preserved mitochondrial integrity and function under hypoxic conditions in HL-1 cardiomyocytes. These findings suggest that restoring the balance of mitochondrial dynamics through pharmacological interventions targeting either fission or fusion may offer a promising therapeutic strategy for mitigating MI-induced cardiac injury and improving patient outcomes.

DNA-PKcs modulates mouse lung homeostasis via the regulation of mitochondrial fission.

BACKGROUND: The role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is multifaceted, paradoxically promoting both cell survival and cell death across multiple organs. However, its impact on lung homeostasis remains elusive. Here, we investigate the function of DNA-PKcs in mouse lungs, aiming to elucidate its role for lung abnormalities associated with DNA-PKcs deficiency. MATERIALS AND METHODS: Histological assessment and immunohistochemistry were used to reveal the pathological changes of the lungs in DNA-PKcs-deficient mice. Transcriptomic analysis identified differentially expressed genes and pathways in DNA-PKcs-deficient lungs. Furthermore, mitochondrial dysfunction induced by DNA-PKcs deficiency was investigated by qPCR and immunoblotting. Mouse primary lung fibroblasts were used to evaluate the potential therapeutic effect of inhibiting mitochondrial fission with Mdivi-1. KEY FINDINGS: In DNA-PKcs-deficient mouse lungs, we observed pathological changes including alveolar septal thickening, capillary congestion and hemorrhage, along with lung cell proliferation. Transcriptome analysis revealed an upregulation of the reactive oxygen species (ROS) biosynthesis process and the apoptotic signaling pathway caused by DNA-PKcs deficiency. Further investigations demonstrated that DNA-PKcs deficiency led to mitochondrial dysfunction and increased oxidative stress, along with increased cell apoptosis in the mouse lungs. Notably, we detected enhanced phosphorylation of the mitochondrial fission protein DRP1 in DNA-PKcs-deficient mouse lungs. Intriguingly, inhibiting mitochondrial fission using Mdivi-1 suppressed cell death in primary mouse lung fibroblasts with siRNA-mediated DNA-PKcs knockdown. SIGNIFICANCE: Our study provides insights into the crucial role of DNA-PKcs in sustaining lung homeostasis via the maintenance of mitochondrial functionality and provides a therapeutic strategy targeting mitochondrial fission against DNA-PKcs deficiency-associated lung diseases.

Reciprocal regulation of oxidative stress and mitochondrial fission augments parvalbumin downregulation through CDK5-DRP1- and GPx1-NF-κB signaling pathways.

Loss of parvalbumin (PV) expressing neurons (PV neurons) is relevant to the underlying mechanisms of the pathogenesis of neurological and psychiatric diseases associated with the dysregulation of neuronal excitatory networks and brain metabolism. Although PV modulates mitochondrial morphology, volume and dynamics, it is largely unknown whether mitochondrial dynamics affect PV expression and what the molecular events are responsible for PV neuronal degeneration. In the present study, L-buthionine sulfoximine (BSO, an inhibitor of glutathione synthesis) did not degenerate PV neurons under physiological condition. However, BSO-induced oxidative stress decreased PV expression and facilitated cyclin-dependent kinase 5 (CDK5) tyrosine (Y) 15 phosphorylation, dynamin-related protein 1 (DRP1)-mediated mitochondrial fission and glutathione peroxidase-1 (GPx1) downregulation in PV neurons. Co-treatment of roscovitine (a CDK5 inhibitor) or mitochondrial division inhibitor-1 (Mdivi-1, an inhibitor of mitochondrial fission) attenuated BSO-induced PV downregulation. WY14643 (an inducer of mitochondrial fission) reduced PV expression without affecting CDK5 Y15 phosphorylation. Following status epilepticus (SE), CDK5 Y15 phosphorylation and mitochondrial fission were augmented in PV neurons. These were accompanied by reduced GPx1-mediated inhibition of NF-κB p65 serine (S) 536 phosphorylation. N-acetylcysteine (NAC), roscovitine and Mdivi-1 ameliorated SE-induced PV neuronal degeneration by mitigating CDK5 Y15 hyperphosphorylation, aberrant mitochondrial fragmentation and reduced GPx1-mediated NF-κB inhibition. Furthermore, SN50 (a NF-κB inhibitor) alleviated SE-induced PV neuronal degeneration, independent of dysregulation of mitochondrial fission, CDK5 hyperactivation and GPx1 downregulation. These findings provide an evidence that oxidative stress may activate CDK5-DRP1- and GPx1-NF-κB-mediated signaling pathways, which would be possible therapeutic targets for preservation of PV neurons in various diseases.

ATH434, a promising iron-targeting compound for treating iron regulation disorders.

Cytotoxic accumulation of loosely bound mitochondrial Fe2+ is a hallmark of Friedreich's Ataxia (FA), a rare and fatal neuromuscular disorder with limited therapeutic options. There are no clinically approved medications targeting excess Fe2+ associated with FA or the neurological disorders Parkinson's disease and Multiple System Atrophy. Traditional iron-chelating drugs clinically approved for systemic iron overload that target ferritin-stored Fe3+ for urinary excretion demonstrated limited efficacy in FA and exacerbated ataxia. Poor treatment outcomes reflect inadequate binding to excess toxic Fe2+ or exceptionally high affinities (i.e. ≤10-31) for non-pathologic Fe3+ that disrupts intrinsic iron homeostasis. To understand previous treatment failures and identify beneficial factors for Fe2+-targeted therapeutics, we compared traditional Fe3+ chelators deferiprone (DFP) and deferasirox (DFX) with additional iron-binding compounds including ATH434, DMOG, and IOX3. ATH434 and DFX had moderate Fe2+ binding affinities (Kd's of 1-4  µM), similar to endogenous iron chaperones, while the remaining had weaker divalent metal interactions. These compounds had low/moderate affinities for Fe3+(0.46-9.59 µM) relative to DFX and DFP. While all compounds coordinated iron using molecular oxygen and/or nitrogen ligands, thermodynamic analyses suggest ATH434 completes Fe2+ coordination using H2O. ATH434 significantly stabilized bound Fe2+ from ligand-induced autooxidation, reducing reactive oxygen species (ROS) production, whereas DFP and DFX promoted production. The comparable affinity of ATH434 for Fe2+ and Fe3+ position it to sequester excess Fe2+ and facilitate drug-to-protein iron metal exchange, mimicking natural endogenous iron binding proteins, at a reduced risk of autooxidation-induced ROS generation or perturbation of cellular iron stores.

Design, Synthesis, and Preclinical Evaluation of a High-Affinity 18F-Labeled Radioligand for Myocardial Growth Hormone Secretagogue Receptor Before and After Myocardial Infarction.

The peptide hormone ghrelin is produced in cardiomyocytes and acts through the myocardial growth hormone secretagogue receptor (GHSR) to promote cardiomyocyte survival. Administration of ghrelin may have therapeutic effects on post-myocardial infarction (MI) outcomes. Therefore, there is a need to develop molecular imaging probes that can track the dynamics of GHSR in health and disease to better predict the effectiveness of ghrelin-based therapeutics. We designed a high-affinity GHSR ligand labeled with 18F for imaging by PET and characterized its in vivo properties in a canine model of MI. Methods: We rationally designed and radiolabeled with 18F a quinazolinone derivative ([18F]LCE470) with subnanomolar binding affinity to GHSR. We determined the sensitivity and in vivo and ex vivo specificity of [18F]LCE470 in a canine model of surgically induced MI using PET/MRI, which allowed for anatomic localization of tracer uptake and simultaneous determination of global cardiac function. Uptake of [18F]LCE470 was determined by time-activity curve and SUV analysis in 3 regions of the left ventricle-area of infarct, territory served by the left circumflex coronary artery, and remote myocardium-over a period of 1.5 y. Changes in cardiac perfusion were tracked by [13N]NH3 PET. Results: The receptor binding affinity of LCE470 was measured at 0.33 nM, the highest known receptor binding affinity for a radiolabeled GHSR ligand. In vivo blocking studies in healthy hounds and ex vivo blocking studies in myocardial tissue showed the specificity of [18F]LCE470, and sensitivity was demonstrated by a positive correlation between tracer uptake and GHSR abundance. Post-MI changes in [18F]LCE470 uptake occurred independently of perfusion tracer distributions and changes in global cardiac function. We found that the regional distribution of [18F]LCE470 within the left ventricle diverged significantly within 1 d after MI and remained that way throughout the 1.5-y duration of the study. Conclusion: [18F]LCE470 is a high-affinity PET tracer that can detect changes in the regional distribution of myocardial GHSR after MI. In vivo PET molecular imaging of the global dynamics of GHSR may lead to improved GHSR-based therapeutics in the treatment of post-MI remodeling.

Quinazolinone-Hydrazine Cyanoacetamide Hybrids as Potent Multitarget-Directed Druggable Therapeutics against Alzheimer's Disease: Design, Synthesis, and Biochemical, In Silico, and Mechanistic Analyses.

The discovery of effective multitarget-directed ligands (MTDLs) against multifactorial Alzheimer's disease (AD) remnants has been focused in an incessant drug discovery pursuit. In this perception, the current study explores the rational design, synthesis, and evaluation of 26 quinazolinone-hydrazine cyanoacetamide hybrids 7(a-j), 8(a-j), and 9(a-f) as MTDLs against AD. These new compounds were synthesized in four-step processes using simple phthalimide as the starting material without any major workup procedures and were characterized by different spectroscopic techniques. In Ellman's assay, the most potent analogues 7i, 8j, and 9d were identified as selective and mixed-type inhibitors of hAChE. Furthermore, biophysical and computational assessments revealed that the analogues 7i, 8j, and 9d were bound to both the catalytic active site and peripheral anionic site of hAChE with high affinity. The molecular dynamics simulation analysis highlighted the conformational changes of hAChE upon binding of 7i, 8j, and 9d and also the stability of resulting biomolecular systems all over 100 ns simulations. In addition to antioxidant activity, the most active congeners were found to protect substantially SK-N-SH cells from oxidative damage. Decisively, the most active analogues 7i, 8j, and 9d were assessed as potent Aß1-42 fibril modulators and protective agents against Aß1-42-induced toxicity in SH-SY5Y cells. Additionally, glioblastoma C6 cell-based assays also demonstrated the use of the most active congeners 7i, 8j, and 9d as protective agents against Aß1-42-induced toxicity. Overall, this multifunctional capacity of quinazolinone-hydrazine cyanoacetamide hybrids demonstrated the noteworthy potential of these hybrids to develop as effectual MTDLs against AD. However, further pharmacokinetics, toxicology, and behavioral studies are warranted.

ERK1/2 Regulates Epileptic Seizures by Modulating the DRP1-Mediated Mitochondrial Dynamic.

After seizures, the hyperactivation of extracellular signal-regulated kinases (ERK1/2) causes mitochondrial dysfunction. Through the guidance of dynamin-related protein 1 (DRP1), ERK1/2 plays a role in the pathogenesis of several illnesses. Herein, we speculate that ERK1/2 affects mitochondrial division and participates in the pathogenesis of epilepsy by regulating the activity of DRP1. LiCl-Pilocarpine was injected intraperitoneally to establish a rat model of status epilepticus (SE) for this study. Before SE induction, PD98059 and Mdivi-1 were injected intraperitoneally. The number of seizures and the latency period before the onset of the first seizure were then monitored. The analysis of Western blot was also used to measure the phosphorylated and total ERK1/2 and DRP1 protein expression levels in the rat hippocampus. In addition, immunohistochemistry revealed the distribution of ERK1/2 and DRP1 in neurons of hippocampal CA1 and CA3. Both PD98059 and Mdivi-1 reduced the susceptibility of rats to epileptic seizures, according to behavioral findings. By inhibiting ERK1/2 phosphorylation, the Western blot revealed that PD98059 indirectly reduced the phosphorylation of DRP1 at Ser616 (p-DRP1-Ser616). Eventually, the ERK1/2 and DRP1 were distributed in the cytoplasm of neurons by immunohistochemistry. Inhibition of ERK1/2 signaling pathways downregulates p-DRP1-Ser616 expression, which could inhibit DRP1-mediated excessive mitochondrial fission and then regulate the pathogenesis of epilepsy.

Mitochondrial dynamics as a potential therapeutic target in acute myeloid leukemia.

Acute myeloid leukemia (AML) cells are highly dependent on oxidative phosphorylation and the mitochondrial dynamics regulated by fusion-related genes MFN1, MFN2, and OPA1 and fission-related genes DNM1L and MFF. An analysis of previously published gene expression datasets showed that high expression of MFF was significantly associated with poor prognosis in patients with AML. Based on this finding, we investigated the impact of mitochondrial dynamics in AML. Transduction of shRNA against fission-related genes, DNM1L and MFF, inhibited growth and increased the mitochondrial area in AML cell lines. Extracellular flux analysis showed that deletion of mitochondrial dynamic regulators reduced mitochondrial respiration without significantly affecting glycolysis, except in shDNM1L-transfected cells. Immunodeficient NOG mice transplanted with DNM1L- or MFF-knockdown AML cells survived significantly longer than controls. Treatment of AML cell lines with Mdivi-1, which inhibits the DRP1 encoded by DNM1L, inhibited cell proliferation and oxidative phosphorylation. Our results show that mitochondrial dynamics play an important role in AML, and provide novel biological insights. The inhibition of mitochondrial dynamics induces unique mitochondrial alterations, which may be explored as a potential therapeutic target in AML.

Inhibition of histone methyltransferase promotes cognition and mitochondrial function in vascular dementia model.

Vascular dementia (VD) is one of the most common forms of dementia worldwide, characterized by problems with reasoning, planning, judgment, and memory. This study investigated the effect of a histone methyltransferase inhibitor on cognition and mitochondrial function in a rat model of VD, as well as its impact on H2O2-induced neurotoxicity in hippocampal neuronal cultures. In the in vivo experiments, VD was induced by bilateral occlusion of the common carotid artery (CCA) for one month. The histone methyltransferase inhibitor, BIX01294, was administered intracerebroventricularly for one month (22.5 µg.kg-1 three times/week). On day 30, behavioral tests, including the novel object recognition test and elevated plus maze test, were conducted. Mitochondrial enzyme activities, including aconitase, α-ketoglutarate dehydrogenase (α-KG), complex I, and complex IV, were evaluated in the hippocampus of rats following CCA ligation. In the in vitro experiments, the effect of BIX01294 (50-600 µM) on H2O2 (400 µM)-induced cytotoxicity in hippocampal neuronal cells was assessed using the MTT assay. Flow cytometry was performed to evaluate apoptosis. Our findings revealed that BIX01294 effectively improved memory function, Krebs cycle enzyme activity, and mitochondrial function in the rat model of VD. Moreover, in vitro results showed that BIX01294 at a concentration of 100 µM significantly reversed the cytotoxicity and apoptosis induced by H2O2 in neuronal cells. These findings suggest that BIX01294 may have the potential to improve VD complications by reducing oxidative stress and inhibiting histone methylation.

Targeting TGR5 to mitigate liver fibrosis: Inhibition of hepatic stellate cell activation through modulation of mitochondrial fission.

Chronic hepatitis B virus (HBV) infection continues to be a prominent cause of liver fibrosis and end-stage liver disease in China, necessitating the development of effective therapeutic strategies. This study investigated the potential of targeting TGR5 to alleviate liver fibrosis by impeding the activation of hepatic stellate cells (HSCs), which play a pivotal role in fibrotic progression. Using the human hepatic stellate cell line LX-2 overexpressing hepatitis B virus X protein (HBX), this study revealed that TGR5 activation through INT-777 inhibits HBX-induced LX-2 cell activation, thereby ameliorating liver fibrosis, which is associated with the attenuation of mitochondrial fission and introduces a novel regulatory pathway in liver fibrosis. Additional experiments with mitochondrial fission inducers and inhibitors confirm the crucial role of mitochondrial dynamics in TGR5-mediated effects. In vivo studies using TGR5 knockout mice substantiate these findings, demonstrating exacerbated fibrosis in the absence of TGR5 and its alleviation with the mitochondrial fission inhibitor Mdivi-1. Overall, this study provides insights into TGR5-mediated regulation of liver fibrosis through the modulation of mitochondrial fission in HSCs, suggesting potential therapeutic strategies for liver fibrosis intervention.

Role of Excessive Mitochondrial Fission in Seawater Immersion Aggravated Hemorrhagic Shock-Induced Cardiac Dysfunction and the Protective Effect of Mitochondrial Division Inhibitor-1.

Aims: Seawater immersion significantly aggravated organ dysfunction following hemorrhagic shock, leading to higher mortality rate. However, the effective treatment is still unavailable in clinic. Mitochondria were involved in the onset and development of multiple organ function disorders; whether mitochondria participate in the cardiac dysfunction following seawater immersion combined with hemorrhagic shock remains poorly understood. Hence, we investigated the role and possible mechanism of mitochondria in seawater immersion combined with hemorrhage shock-induced cardiac dysfunction. Results: Mitochondrial fission protein dynamin-related protein 1 (Drp1) was activated and translocated from the cytoplasm to mitochondria in the heart following seawater immersion combined with hemorrhagic shock, leading to excessive mitochondrial fission. Excessive mitochondrial fission disrupted mitochondrial function and structure and activated mitophagy and apoptosis. At the same time, excessive mitochondrial fission resulted in disturbance of myocardial structure and hemodynamic disorders and ultimately provoked multiple organ dysfunction and high mortality. Further studies showed that the mitochondrial division inhibitor mitochondrial division inhibitor-1 can significantly reverse Drp1 mitochondrial translocation and inhibit mitochondrial fragmentation, reactive oxygen species (ROS) accumulation, mitophagy, and apoptosis and then protect circulation and vital organ functions, prolonging animal survival. Innovation: Our findings indicate that Drp1-mediated mitochondrial fission could be a novel therapeutic targets for the treatment of seawater immersion combined with hemorrhagic shock. Conclusion: Drp1 mitochondrial translocation played an important role in the cardiac dysfunction after seawater immersion combined with hemorrhage shock. Drp1-mediated excessive mitochondrial fission leads to cardiac dysfunction due to the mitochondrial structure and bioenergetics impairment.

Integrated stress response activator halofuginone protects mice from diabetes-like phenotypes.

The integrated stress response (ISR) is a vital signaling pathway initiated by four kinases, PERK, GCN2, HRI and PKR, that ensure cellular resilience and protect cells from challenges. Here, we investigated whether increasing ISR signaling could rescue diabetes-like phenotypes in a mouse model of diet-induced obesity (DIO). We show that the orally available and clinically approved GCN2 activator halofuginone (HF) can activate the ISR in mouse tissues. We found that daily oral administration of HF increases glucose tolerance whilst reducing weight gain, insulin resistance, and serum insulin in DIO mice. Conversely, the ISR inhibitor GSK2656157, used at low doses to optimize its selectivity, aggravates glucose intolerance in DIO mice. Whilst loss of function mutations in mice and humans have revealed that PERK is the essential ISR kinase that protects from diabetes, our work demonstrates the therapeutic value of increasing ISR signaling by activating the related kinase GCN2 to reduce diabetes phenotypes in a DIO mouse model.

PINK1 insufficiency can be exploited as a specific target for drug combinations inducing mitochondrial pathology-mediated cell death in gastric adenocarcinoma.

There exist very limited non-hazardous therapeutic strategies except for surgical resection and lymphadenectomy against gastric cancer (GC) despite being the third leading cause of cancer deaths worldwide. This study proposes an innovative treatment approach against GC using a drug combination strategy that manipulates mitochondrial dynamics in conjunction with the induction of mitochondrial pathology-mediated cell death. Comparative analysis was done with gastric adenocarcinoma and normal cells by qPCR, western blot, microscopic immunocytochemistry, and live cell imaging. In this study, impairment of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission by Mdivi-1 created an imbalance in mitochondrial structural dynamics in indomethacin-treated AGS cells in which mitophagy-regulator protein PINK1 is downregulated. These drug combinations with the individual sub-lethal doses ultimately led to the activation of cell death machinery upregulating pro-apoptotic proteins like Bax, Puma, and Noxa. Interestingly, this combinatorial therapy did not affect normal gastric epithelial cells significantly and also no significant upregulation of death markers was observed. Moreover, the drug combination strategy also retarded cell migration and reduced stemness in GC cells. In summary, this study offers a pioneering specific therapeutic strategy for GC treatment, sparing normal cells providing opportunities for minimal drug-mediated toxicity utilizing mitochondria as a viable and specific target for anti-cancer therapy in gastric cancer.