Multifaceted role of mTOR (mammalian target of rapamycin) signaling pathway in human health and disease.

The mammalian target of rapamycin (mTOR) is a protein kinase that controls cellular metabolism, catabolism, immune responses, autophagy, survival, proliferation, and migration, to maintain cellular homeostasis. The mTOR signaling cascade consists of two distinct multi-subunit complexes named mTOR complex 1/2 (mTORC1/2). mTOR catalyzes the phosphorylation of several critical proteins like AKT, protein kinase C, insulin growth factor receptor (IGF-1R), 4E binding protein 1 (4E-BP1), ribosomal protein S6 kinase (S6K), transcription factor EB (TFEB), sterol-responsive element-binding proteins (SREBPs), Lipin-1, and Unc-51-like autophagy-activating kinases. mTOR signaling plays a central role in regulating translation, lipid synthesis, nucleotide synthesis, biogenesis of lysosomes, nutrient sensing, and growth factor signaling. The emerging pieces of evidence have revealed that the constitutive activation of the mTOR pathway due to mutations/amplification/deletion in either mTOR and its complexes (mTORC1 and mTORC2) or upstream targets is responsible for aging, neurological diseases, and human malignancies. Here, we provide the detailed structure of mTOR, its complexes, and the comprehensive role of upstream regulators, as well as downstream effectors of mTOR signaling cascades in the metabolism, biogenesis of biomolecules, immune responses, and autophagy. Additionally, we summarize the potential of long noncoding RNAs (lncRNAs) as an important modulator of mTOR signaling. Importantly, we have highlighted the potential of mTOR signaling in aging, neurological disorders, human cancers, cancer stem cells, and drug resistance. Here, we discuss the developments for the therapeutic targeting of mTOR signaling with improved anticancer efficacy for the benefit of cancer patients in clinics.

Preparation and characterization of amoxapine- and naringin-loaded solid lipid nanoparticles: drug-release and molecular-docking studies.

Aim: Amoxapine (AMX) has been reported to be metabolized by CYP3A4 and CYP2D6. Naringin (NG) has been reported to inhibit CYP enzymes. Therefore, the current work was designed to develop AMX solid lipid nanoparticles (AMX-SLNs) and NG-SLNs for better therapeutic performance. Materials & methods: AMX-SLNs and NG-SLNs were prepared and characterized. AMX and NG interactions with CYP450s were studied with molecular docking to rationalize the effectiveness of the combination. Results: AMX-SLNs and NG-SLNs showed nanometric size with a sustained in vitro drug-release profile. NG showed a higher predicted binding affinity for CYP3A4 and CYP2D6, suggesting the potential for inhibition. Conclusion: The developed formulations were thoroughly characterized along with molecular docking data indicating promising AMX and NG combinations that may show good therapeutic activity.