Search Results (164)

Background and Objectives: Cutaneous melanoma (CM) is widely regarded as the most aggressive form of skin cancer worldwide, showing a rising global incidence. It develops from the uncontrolled transformation of pigment-producing melanocytes. The aim of this study is to characterize the cytotoxic and anti-proliferative properties of two 1-(2-aryl-adamantyl)piperazine derivatives, 6 and 7, with a specific emphasis on their impact on melanoma cells. Both compounds are synthesized based on the adamantane core structure which increases drug-like properties of the lead compound phencyclidine I, without increasing toxicity. Materials and Methods: This study describes concentration-dependent effects on cell viability and clonogenicity. Results: SRB assays, clonogenic (long-term) assays, and scratch assays reveal a significant anticancer activity of these two agents at low μΜ levels with a selective activity against melanoma cells. Furthermore, Western blot experiments indicate that both 6 and 7 induce LC3 accumulation, procaspase 3 decrease, and PARP cleavage, suggesting the implication of multiple death pathways in their anticancer mechanism of action. Conclusions: This study sheds light on the in vitro anticancer potential of two novel 1-(2-aryl-2-adamantyl)piperazine derivatives. It highlights their differential activity against melanoma and emphasizes their potential as lead candidates for further therapeutic exploration. Full article

Dehydroepiandrosterone (DHEA) and its sulfate ester form DHEAS, are multifunctional steroid hormones primarily produced in the adrenal cortex, with additional synthesis in peripheral tissues. DHEA/DHEAS serve as precursors to sex steroids and exhibit neuroprotective, anti-inflammatory, and immune-modulating effects. DHEA levels decline significantly with age, a phenomenon termed “adrenopause”, prompting interest in supplementation to mitigate age-related symptoms. Particularly in postmenopausal women, DHEA has shown potential benefits in treating genitourinary syndrome of menopause (GSM), including improved vaginal health, lubrication, and sexual function. While intravaginal DHEA appears effective and safer than systemic estrogen therapy, especially for women with estrogen sensitivity, results remain mixed for oral administration. DHEA and DHEAS exhibit diverse neuroactive properties through modulation of GABA-A, NMDA, and sigma-1 receptors. These neurosteroids contribute to neuroprotection, synaptic plasticity, and mood regulation. Altered DHEA/DHEAS levels have been implicated in neurodegenerative disorders and depression, with emerging evidence supporting their potential therapeutic value. In addition, DHEA plays a multifaceted role in aging-related physiological changes. It supports muscle anabolism, bone density maintenance, cardiovascular protection, and immune regulation. Though supplementation shows potential benefits, especially in conjunction with resistance training, results remain discrepant. Current evidence has revealed that the therapeutic effects of DHEA supplementation are inconsistent in different human systems among different studies. The diversity of results is mainly due to heterogeneous receptor distribution, various action pathways, and distinct tissue responses in different systems. Further research is needed to define its efficacy and dosage across various systems. Full article

Central nervous system (CNS) disorders such as neurodegenerative diseases, multiple sclerosis, or even brain ischemia represent major therapeutic challenges with limited effective treatments. The sigma-1 receptor (S1R), a unique ligand-operated molecular chaperone enriched at mitochondria-associated membranes, has emerged as a promising drug target due to its role in neuroprotection and neuroinflammation. Building upon our previously identified S1R ligand (compound 1), we designed and synthesized six novel benzamide derivatives through pharmacomodulation to optimize affinity, selectivity, and safety profiles. Among these, compound 2 demonstrated superior S1R affinity, improved selectivity over the sigma-2 receptor (S2R), and favorable ADME properties, including enhanced permeability and markedly reduced in vitro cardiac toxicity compared to the lead compound. Functional assays confirmed the agonist activity of key derivatives, while safety evaluations revealed low cytotoxicity and minimal off-target receptor interactions. Collectively, these findings support compound 2 as a promising candidate for further preclinical development in S1R-related CNS disorders. Full article

Protein tyrosine phosphatase receptor sigma (PTPRS) regulates cellular signals involved in hematopoietic stem cell development, synaptic plasticity, and synovium differentiation. The soluble extracellular Ig-like domains of PTPRS have therapeutic potential by binding to a ligand, inhibiting the ligand-binding of endogenous PTPRS. However, the wild-type Ig-like domains have poor solubility, which limits their therapeutic use. In this study, we identified solvent-exposed hydrophobic residues on the surface of PTPRS and mutated the residues to hydrophilic residues for solubility-enhancing engineering. The mutagenesis screening increased its solubility up to five-fold. In addition, the expression yields were also increased by up to 14-fold. The biochemical and functional analysis of the engineered PTPRS showed that the mutant protein had comparable properties to the wild type. Thus, the engineered PTPRS has potential for therapeutic applications where modulation of PTPRS is critical. Full article

Indolethylamine N-methyltransferase (INMT) is a Class 1 methyltransferase responsible for N-methylation of various endogenous and exogenous compounds, including tryptamine, serotonin, and dopamine. This review aims to provide a comprehensive overview of the biological and therapeutic relevance of INMT, emphasizing the human isoform (hINMT), highlighting its structural characteristics, disease association, and recent advances in analytical strategies. Dysregulation of INMT activity has been linked to a range of pathological conditions, including neuropsychiatric disorders, neurodegeneration, and several forms of cancer. These associations are addressed by integrating current findings across disease pathophysiology, enzyme inhibition, and analytical methodologies, including both radiolabeled and non-radiolabeled in vitro assays, for measuring INMT activity. We further explored the chemical diversity of INMT inhibitors, both natural and synthetic, and highlighted key compounds with therapeutic relevance. Additionally, recent commercial assays for quantifying INMT activity are emphasized. By integrating emerging evidence from structural biology and disease pathology with inhibitor profiling and analytical technologies, this review highlights the underexplored therapeutic potential of targeting INMT and underscores its value as a promising target for drug development and therapeutic applications. Full article

Age-related macular degeneration (AMD) is a common eye disease that significantly affects daily activities and impedes the quality of life in aging adults, yet effective treatments to halt or reverse disease progression are currently lacking. Ongoing research aims at understanding the complex mechanisms underlying AMD pathophysiology involving retinal pigment epithelium (RPE) dysfunction, drusen formation, inflammation, neovascularization, and RPE/photoreceptor degeneration. Sigma 2 receptor/transmembrane protein 97 (σ₂R/TMEM97) is a multifunctional protein implicated in cellular processes including cholesterol homeostasis, lysosome-dependent autophagy, calcium homeostasis, and integrated stress response (ISR). Recent genome-wide association studies (GWASs) have identified σ₂R/TMEM97 as a novel genetic risk factor strongly associated with AMD development. In this review, we summarize recent research progress on σ₂R/TMEM97 in age-related neurodegenerative diseases, highlighting its implication as a molecular target in AMD via regulating oxidative stress, inflammation, lipid uptake, drusen formation, and epithelial–mesenchymal transition (EMT). We also discuss the potential of modulating σ₂R/TMEM97 function with novel small-molecule drugs as a promising treatment for dry AMD and the unresolved questions in understanding the mechanistic basis of their actions. Full article

Choline has been recognized as an essential nutrient involved in various physiological functions critical to human health. Adequate daily intake of choline has been established by the US National Academy of Medicine in 1998, considering choline requirements for different ages, sex differences and physiological states (e.g., pregnancy). By serving as a precursor for acetylcholine and phospholipids, choline is important for cholinergic transmission and the structural integrity of cell membranes. In addition, choline is involved in lipid and cholesterol transport and serves as a methyl donor after oxidation to betaine. Extracellular choline is transported across the cell membrane via various transport systems (high-affinity and low-affinity choline transporters) with distinct features and roles. An adequate dietary intake of choline during pregnancy supports proper fetal development, and throughout life supports brain, liver, and muscle functions, while choline deficiency is linked to disease states like fatty liver. Choline has important roles in neurodevelopment, cognition, liver function, lipid metabolism, and cardiovascular health. While its signaling role has been considered mostly indirect via acetylcholine and phosphatidylcholine which are synthesized from choline, emerging evidence supports a role for choline as an intracellular messenger acting on Sigma-1R, a non-opioid intracellular receptor. These new findings expand the cell signaling repertoire and increase the current understanding of the role of choline while warranting more research to uncover the molecular mechanisms and significance in the context of GPCR signaling, the relevance for physiology and disease states. Full article

Sigma1 receptor (S1R) and some aquaporins (AQPs) are involved in controlling oxidative stress, but only recently has their possible interaction emerged. S1R acts by interacting with proteins in the plasma membrane and organelles and AQPs by favoring the hydrogen peroxide (H₂O₂) cell removal. To date, the possible regulation of peroxiporins by S1R has not been explored. Using H₂O₂ HyPer7 biosensors and knockdown techniques, we investigated (1) the AQPs and S1R functional involvement in H₂O₂ diffusion through the plasma membrane and in the outer and inner mitochondrial membranes, and (2) the possible interaction between S1R and AQPs. Our data showed the functional involvement of different AQPs in the diffusion of H₂O₂: AQP3, AQP6, and AQP8 in the plasma membrane; AQP6 in the outer mitochondrial membrane; and AQP6 and AQP8 in the inner mitochondrial membrane. The knockdown of S1R demonstrated its involvement in the overall diffusion of H₂O₂ across the three compartments. The double knockdown of S1R and a single AQP indicated that AQP8 and AQP6 could be regulated by S1R. These findings demonstrate the coordinated role of AQPs in the mitochondria and the plasma membranes and that S1R modulates the AQP-facilitated H₂O₂ cell removal, thus controlling the oxidative status and, most likely, the oxidative stress. Full article

Neurosteroids pregnenolone, progesterone, allopregnanolone, and dehydroepiandrosterone have been actively studied in the last years as candidates for the treatment of neurodegenerative diseases and postinjury rehabilitation. The neuroprotective mechanisms of these neurosteroids have been shown in clinical studies of depression, epilepsy, status epilepticus, traumatic brain injury, fragile X syndrome, and chemical neurotoxicity. However, only the allopregnanolone analogs brexanolone and zuranolone have been recently approved by the FDA for the treatment of depression. The aim of this review was to evaluate whether the endogenous neurosteroids can be used in clinical practice as neuroprotectors. Neurosteroids are multitarget compounds with strong anti-inflammatory, immunomodulatory, and cytoprotective action; they stimulate the synthesis and release of BDNF and increase remyelination and regeneration. In addition to nuclear and membrane steroid hormone receptors, such as PR, mPR, PGRMC1,2, ER, AR, CAR, and PXR, they can bind to GABAA receptors, NMDA receptors, Sigma-1 and -2 receptors (σ1-R/σ2-R). Among these, mPRs, PGRMC1,2, sigma receptors, and mitochondrial proteins attract comprehensive attention because of strong binding with the P4 and DHEA, but subsequent signaling is poorly studied. Other plasma membrane and mitochondrial proteins are involved in the rapid nongenomic neuroprotective action of neurosteroids. P-glycoprotein, BCL-2 proteins, and the components of the mitochondrial permeability transition pore (mPTP) play a significant role in the defense against the injuries of the brain and the peripheral nervous system. The role of these proteins in the molecular mechanisms of action in neuroprotection and neuroinflammation has not yet been clearly established. The aspects of their participation in these pathological processes are discussed. New formulations, such as lipophilic emulsions, nanogels, and microneedle array patches, are attractive strategies to overcome the low bioavailability of these neurosteroids for the amelioration and treatment of various nervous disorders. Full article

Originally identified as a potential receptor for opioids, the sigma-1 receptor is now recognized as an intracellular chaperone protein associated with mitochondria-associated membranes at the endoplasmic reticulum (ER). Over the past two decades, extensive research has revealed that the sigma-1 receptor regulates many cellular processes, such as calcium homeostasis, oxidative stress responses, protein folding, and mitochondrial function. The various functions of the sigma-1 receptor highlight its role as a central modulator of neuronal health and may be a promising pharmacological target across multiple neurodegenerative conditions. Herein, we provide an overview of the current pharmacological understanding of the sigma-1 receptor with an emphasis on the signaling mechanisms involved. We examine its pathological implications in common neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, Huntington’s disease, and multiple sclerosis. We then highlight how sigma-1 receptor modulation may influence disease progression as well as potential pharmacological mechanisms to alter disease outcomes. The translational potential of sigma-1 receptor therapies is discussed, as well as the most up-to-date results of ongoing clinical trials. This review aims to clarify the therapeutic potential of the sigma-1 receptor in neurodegeneration and guide future research in these diseases. Full article

Neurodegenerative disorders, such as Alzheimer’s, Parkinson’s, and Huntington’s disease, due to their multifaced and complicated nature, remain uncurable and impose substantial financial and human burdens on society. Therefore, developing new innovative therapeutic strategies is vital. In this context, drug repurposing has emerged as a promising avenue to expedite the development of treatments for these challenging conditions. One particularly compelling target in this regard is the chaperone protein sigma-1 receptor (S1R), which has garnered significant attention for its neuroprotective properties. Interestingly, several medications, including fluvoxamine (an antidepressant), dextromethorphan (a cough suppressant), and amantadine (an antiviral), which were initially developed for unrelated indications, have shown encouraging results in neurodegenerative therapy through S1R activation. These findings suggest that existing drugs in pharmacopeias can play an essential role in alleviating neurodegenerative symptoms by modulating S1R, thereby offering a faster route and cost-effective path to clinical applications compared to the de novo development of entirely new compounds. Furthermore, as a synergistic benefit, combining S1R-targeting drugs with other therapeutic agents may also improve treatment efficacy. In this review, we highlight key repurposed drugs targeting S1R and explore their mechanisms of action, shedding light on their emerging therapeutic potential in the fight against neurodegeneration. Full article

Alzheimer’s disease (AD) is a neurodegenerative disease marked by the accumulation of toxic amyloid-beta (Aβ) oligomers. These oligomers are thought to cause synaptic dysfunction and contribute to neurodegeneration. CT1812 is a small-molecule sigma-2 receptor antagonist that is currently being investigated and tested as a potential disease-modifying treatment for AD. CT1812 acts by displacing Aβ oligomers into the cerebrospinal fluid and preventing their interaction with receptors on neurons. Preclinical studies and early clinical trials of CT1812 show promising results and provide evidence for its potential to slow AD progression. This review outlines the role of Aβ oligomers in AD, CT1812’s mechanism of action, and the effectiveness and limitations of CT1812 based on preclinical and clinical studies. Full article

Background/Objectives: The available treatment for attention deficit is drug therapy, but the drugs show poor adverse effect profiles and individual variability in response, especially in adults. Hypidone hydrochloride (YL-0919) is a selective sigma-1 receptor agonist that demonstrated a faster onset antidepressant effect in our previous studies. Current studies aim to study the attention-enhancing effect and mechanism of YL-0919. Methods: We used the five-choice serial reaction time task (5-CSRTT) to measure the attention-improving effect of YL-0919 in SD rats under a physiological state and exogenous corticosterone (CORT)-exposed state. The depression/anxiety-like behavioral experiments were used in the CORT-exposed rats. Immunofluorescence staining, western blotting, and Golgi–Cox staining were used to investigate the attention-improving mechanism of YL-0919. Results: The studies found that intragastric administration of 2.5 and 5 mg/kg YL-0919 for 6 days significantly improved the attention of SD rats under a physiological state. CORT exposure caused depression/anxiety-like behaviors and attention deficit in the rats. Intragastric administration of 3 mg/kg SA4503 or 2.5 and 5 mg/kg YL-0919 for 6 days significantly alleviated attention deficit in SD rats under an exogenous CORT-exposed state. In addition, YL-0919 administration obviously increased the expression of BDNF, PSD95, and synapsin1 and improved the dendritic complexity and the dendritic spine density in the medial prefrontal cortex (mPFC). Conclusions: These results reveal that YL-0919 as a selective sigma-1 receptor agonist can significantly improve the attention of SD rats under a physiological state and exogenous CORT-exposed state. Improving the level of BDNF and dendritic complexity in the mPFC may be the important mechanisms of YL-0919 to improve attention. The study also provides a potential novel target for the drug therapy of attention deficit. Full article

Marine cyanobacteria have gained momentum in recent years as a source of novel bioactive small molecules. This paper describes the structure elucidation and pharmacological evaluation of two new (veraguamide O (1) and veraguamide P (2)) and one known (veraguamide C (3)) analogs isolated from a cyanobacterial collection made in the Las Perlas Archipelago of Panama. We hypothesized that these compounds would be cytotoxic in cancer cell lines. The compounds were screened against HEK-293, estrogen receptor positive (MCF-7), and triple-negative breast cancer (MDA-MB-231) cells as well as against a broad panel of membrane-bound receptors. The planar structures were determined based on NMR and MS data along with a comparison to previously isolated veraguamide analogs. Phylogenetic analysis of the collection suggests it to be an Okeania sp., a similar species to the cyanobacterium reported to produce other veraguamides. Veraguamide O shows no cytotoxicity (greater than 100 μM) against ER-positive cells (MCF-7) with 13 μM IC₅₀ against MDA-MB-231 TNBC cells. Interestingly, these compounds show affinity for the sigma2/TMEM-97 receptor, making them potential leads for the development of non-toxic sigma 2 targeting ligands. Full article

Sigma receptors (σRs) represent very attractive biological targets for the development of potential agents for the treatment of several neurological disorders. In the search for new small molecule drugs against neuropathic pain, we identified 2-{[2-(1-benzylpiperidin-4-yl)ethyl]amino}-6-[methyl(prop-2-yn-1-yl)amino]pyridine-3,5-dicarbonitrile (5) as a polyfunctionalized small pyridine with potent dual-target activities against acetylcholinesterase (AChE) (IC₅₀ = 13 nM) and butyrylcholinesterase (BuChE) (IC₅₀ = 3.1 µM), exhibiting high σ₁R affinity (K_i(hσ₁R) = 1.45 nM) and 290-fold selectivity over the σ₂R subtype. These results are in good agreement with those found in the molecular modeling of compound 5. This is possibly due to the preferred combination in this molecule of a linker n = 2 connecting the N-Bn-piperidine motif to the C2 pyridine, without a phenyl group at C4, and a N-Me-substituted propargyl amine in the chain located at C6. Full article