Cellular model system to dissect the isoform-selectivity of Akt inhibitors

PSAT1 regulated by STAT4 enhances the proliferation, invasion and migration of ovarian cancer cells via the PI3K/AKT pathway

Epithelial ovarian cancer, the most prevalent form of ovarian cancer, is a health concern worldwide. Phosphoserine aminotransferase 1 (PSAT1), as the rate‑limiting enzyme in serine synthesis, is key in the conversion of 3‑phosphoglycerate to serine. The present study explored the role of PSAT1 expression in epithelial ovarian tumors. Gene Expression Profiling Interactive Analysis was used for gene expression and survival analyses. The effects of PSAT1 overexpression and knockdown on invasion, migration, proliferation and cell cycle progression of ovarian cancer cell lines were investigated both in vitro and in vivo. Western blotting was conducted to assess alterations in PI3K/AKT signalling pathway proteins. Database and tissue sample data confirmed that PSAT1 was significantly upregulated in ovarian cancer. Preliminary functional investigations indicated that PSAT1 was involved in modulation of invasion and migration, demonstrating the capacity of PSAT1 to enhance expression of the PI3K/AKT signalling pathway. These findings suggested that PSAT1 served a critical role in the onset and progression of ovarian cancer, thereby offering a theoretical basis for early detection and therapeutic strategies.

Synthesis, X-ray diffraction, and computational studies of acyclovir and HBG analogs derived from Triazolyl-1,4-benzothiazine and their oxidized forms for breast cancer and SARS-CoV-2

This study presents a simple and efficient synthetic method for preparing a new series of acyclonucleosides derived from 1,4-benzothiazine and 1,4-benzothiazine-1,1-dioxide. These compounds feature the introduction of a 1,2,3-triazole-4-ylmethyl ring as a spacer between the heterocyclic bases and the pseudosugars of acyclovir (ACV) and hydroxybutylguanine (HBG). The acyclonucleosides were synthesized through copper-catalyzed 1,3-dipolar cycloaddition reactions between azides 8a and 8b and the N4-propargyl base 7. Following this, the deprotection of the acyclic chains and the oxidation of the sulfur to sulfone afforded the acyclonucleosides 9a,b-12a,b in satisfactory yields. The synthesized acyclonucleosides were characterized using 1H and 13C NMR spectroscopy. Moreover, the structure of 9b was confirmed by single-crystal X-ray diffraction analysis. The synthesized acyclonucleosides were evaluated through in silico studies, including network pharmacology for bioactivity, toxicity prediction, physicochemical properties, and ADMET analysis. Molecular docking studies revealed significant interactions, highlighting compound 11b's favorable binding with the target protein AKT1, achieving a binding energy of -6.43 kcal/mol, which is close to the Capivasertib standard. Similarly, compound 12b showed interactions akin to hydroxychloroquine, with a binding energy of -6.29 kcal/mol for the SARS-CoV-2 target protein. Molecular dynamics simulations further validated the stability of the ligand-protein complexes during 200 ns, as evidenced by acceptable RMSD and RMSF and Rg values. The post-dynamic, MMGBSA, PCA, FEL, PDF, and DCCM analyses of the AKT and SARS-CoV-2 protein-ligand complexes have provided comprehensive insights into their interactions with standard drugs, binding affinities, conformational dynamics, and structural stability. These studies are crucial for understanding the molecular mechanisms underlying drug efficacy and resistance, thereby informing the rational design of new inhibitors targeting AKT and SARS-CoV-2 proteins. Finally, the two most promising compounds, 11b and 12b, selected from the docking results, were analyzed using Density Functional Theory (DFT). These analyses revealed significant variations in their electronic properties, providing valuable insights into their reactivity, stability, and polarity.

Pharmacodynamic components and molecular mechanism of Gastrodia elata Blume in treating hypertension: Absorbed components, network pharmacology analysis, molecular docking and in vivo experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizome of Gastrodia elata Blume (RGE) is a valuable traditional Chinese Medicine (TCM) in the clinical practice. The Compendium of Materia Medica records that RGE has the effect of flatting liver wind out. It has sedative, analgesic, hypnotic, anticonvulsant, anti-hypertensive, anti-myocardial ischemia, anti-arrhythmic and anti-platelet aggregation effects. RGE is often used to relieve and treat vertigo, headache, hypertension, convulsions, and epilepsy in TCM clinic for thousands of years. Accumulated evidences have suggested that hypertension disease is related to the renin-angiotensin-aldosterone system (RAAS) disturbance. However, the potential pharmacodynamic components and anti-hypertensive mechanisms of RGE are unclear now.

AIM OF THE STUDY

The active component and mechanism of RGE in treating hypertension were elucidated to strengthen the quality control and development of anti-hypertensive drugs.

MATERIALS AND METHODS

The anti-hypertensive active components of RGE were analyzed by multi-dimensional qualitative analysis method including ethanol extract, in-vitro intestinal absorption, in-vivo plasma. The ultra high performance liquid chromatography-mass spectrometry (UPLC-Q-Exactive MS/MS) analysis technology was adopted to identify these components. Network pharmacology was applied to predicted anti-hypertensive active components, target proteins and pathways. Molecular docking was used to evaluate the potential molecular binding modes between 68 components and nine proteins. Spontaneously hypertensive rats (SHR) model was adopted to evaluate the activity of reducing systolic and diastolic blood pressure (SBP and DBP). Levels of renin, angiotcnsin II (Ang II) and aldosterone (ALD) in serum were determined by Elisa kit. Immunohistochemical were adopted to compare the changes of Ang II receptor 1 (AT1R) protein levels in SHR model and RGE groups.

RESULTS

The multi-dimensional components qualitative analysis method of RGE was established. The results showed that 79, 70 and 30 components were identified in RGE ethanol extract, in-vitro intestinal absorption and in-vivo plasma, respectively. These components were mainly parishins, nucleosides, amino acids, phenolic acids, flavonoids, organic acids et al. Network pharmacology results showed that anti-hypertensive active components were nucleosides and organic acids. It was speculated that RGE could exert its anti-hypertensive effect by regulating aldosterone-regulated sodium reabsorption, renin-angiotensin system pathways and related target proteins. Molecular docking results showed that 21 components including parishins, nucleosides and phenolic acids were potential active components of anti-hypertensive. Taking together, parishin A, B, E, C, D, adenosine, N6-(4-hydroxybenzyl) adenosine, guanosine, ferulic acid were the main anti-hypertensive active components of RGE. Pharmacodynamic results showed that RGE (0.7 g·kg-1) at low dosage could reduce SBP and DBP of SHR in vivo. Meanwhile, RGE (1.4 g·kg-1) markedly reduced the contents of renin, angiotcnsin II and ALD (p < 0.05) of SHR. Immunohistochemical data demonstrated that RGE (0.7 g·kg-1) could downregulate the protein expression of AT1R. In general, RGE can significantly reduce blood pressure of SHR by regulating RAAS.

CONCLUSION

The multi-dimensional components qualitative analysis combining network pharmacology and molecular docking technology provide a new perspective for discovering potential anti-hypertensive components of RGE. RGE possess anti-hypertensive activity by regulating multiple targets of RAAS. Thus, it has the potential to develop into the novel raw material of anti-hypertensive drugs.

Structural requirements of isoform-specific inhibitors of Akt: Implications in the development of effective cancer treatment strategies

Akt, also known as protein kinase-B, is an important therapeutic target in the treatment of cancer due to its pivotal roles in the signaling pathways that regulate various hall-mark features of cancer cells such as cell growth, survival, migration, differentiation, and metabolism. The three closely related isoforms of Akt viz., Akt1, Akt2, and Akt3 exhibit distinct physiological roles that affect cellular behavior and tumor development, making isoform selectivity a crucial driving factor in the design and development of inhibitors. This review outlines key amino acids and their structural traits in Akt isoforms, potentially dictating isoform selectivity. We present an analysis of existing structure-activity relationship data of covalent-allosteric Akt inhibitors to shed light on isoform selectivity. Additionally, a brief review of potential predictive biomarkers in enhancing the therapeutic efficacy of Akt inhibitors is presented. Identifying biomarkers that can reliably predict patient response to treatment is crucial for personalizing cancer therapies and improving overall treatment outcomes. By integrating predictive biomarker identification with the ongoing development of isoform-selective Akt inhibitors, it is plausible to establish a foundation for more precise and efficacious interventions in cancer therapy.

Circular RNAs and host genes act synergistically in regulating cellular processes and functions in skeletal myogenesis

Circular RNAs (circRNAs) are post-transcriptional regulators generated from backsplicing of pre-mRNAs of host genes. A major circRNA regulatory mechanism involves microRNA (miRNA) sequestering, relieving miRNA-blocked mRNAs for translation and functions. To investigate possible circRNA-host gene relationship, skeletal myogenesis is chosen as a study model for its developmental importance and for readily available muscle tissues from farm animals for studies at different myogenic stages. This review aims to provide an integrated interpretations on methodologies, regulatory mechanisms and possible host gene-circRNA synergistic functional relationships in skeletal myogenesis, focusing on myoblast differentiation and proliferation, core drivers of muscle formation in myogenesis, while other myogenic processes that play supportive roles in the structure, maintenance and function of muscle tissues are also briefly discussed. On literature review,thirty-two circRNAs derived from thirty-one host genes involved in various myogenic stages are identified; twenty-two (68.6 %) of these circRNAs regulate myogenesis by sequestering miRNAs to engage PI3K/AKT and other signaling pathways while four (12.5 %) are translated into proteins for functions. In circRNA-host gene relationship,ten (32.3 %) host genes are shown to regulate myogenesis,nine (29.0 %) are specific to skeletal muscle functions,and twelve (38.8 %) are linked to skeletal muscle disorders.Our analysis of skeletal myogenesis suggests that circRNAs and host genes act synergistically to regulate cellular functions. Such circRNA-host gene functional synergism may also be found in other major cellular processes. CircRNAs may have evolved later than miRNAs to counteract the suppressive effects of miRNAs and to augment host gene functions to further fine-tune gene regulation.

Preparation of ethynylsulfonamides and study of their reactivity with nucleophilic amino acids

The development of covalent drugs, particularly those utilizing Michael acceptors, has garnered significant attention in recent pharmaceutical research due to the ability of such molecules to irreversibly inhibit protein function. This study focusses on the synthesis and evaluation of ethynylsulfonamides, which are predicted to have superior covalent binding ability, metabolic stability, and water solubility compared to traditional amides. We developed a straightforward synthesis method for ethynylsulfonamides and comprehensively evaluated the covalent binding abilities of these compounds using NMR with various nucleophilic amino acids in different solvents. Our results revealed that ethynylsulfonamides exhibit rapid and selective reactivity with cysteine residues, particularly in phosphate-buffered saline (PBS), where the reaction progressed quantitatively within five minutes. Notably, propynylsulfonamide demonstrated high reactivity and selectivity toward cysteine, suggestive of the significant potential of this molecule for applications in antibody-drug conjugates (ADCs) and other therapeutic areas where metabolic stability, water solubility, and selective reactivity are crucial.

Machine learning discovery of novel antihypertensive peptides from highland barley protein inhibiting angiotensin I-converting enzyme (ACE)

Hypertension is a major global health concern, and there is a need for new antihypertensive agents derived from natural sources. This study aims to identify novel angiotensin I-converting enzyme (ACE) inhibitors from bioactive peptides derived from food sources, particularly highland barley proteins, addressing the gap in effective natural ACE inhibitors. This research employs a machine learning-based pipeline combined with peptidomics to screen for ACE-inhibitory peptides, Gradient Boosted Decision Trees (GBDT) with the best performance among four tested models was used to predict the ACE-inhibitory capacity of peptides derived from papain-hydrolyzed highland barley protein. The selected peptides were validated through computer simulations and in vitro experiments, with FPRPFL identified as the most potent ACE-inhibitor (IC50 = 1.18 μM). Enzyme inhibition kinetics and digestion stability simulations were used to investigate its inhibition mode and stability. The binding mode and mechanism of action of FPRPFL with ACE were further analyzed using circular dichroism, molecular docking and molecular dynamics simulations. Network pharmacology revealed its multi-target and multi-pathway antihypertensive properties. The integration of machine learning and in vitro experiments enables accurate bioactive peptides identification and comprehensive their functionality analysis, establishing a valuable pipeline for elucidating peptide mechanisms and laying a solid foundation for industrial-scale production of natural ACE-inhibitors.

AKT and the Hallmarks of Cancer

Nearly a quarter century ago, Hanahan and Weinberg conceived six unifying principles explaining how normal cells transform into malignant tumors. Their provisional set of biological capabilities acquired during tumor development-cancer hallmarks-would evolve to 14 tenets as knowledge of cancer genomes, molecular mechanisms, and the tumor microenvironment expanded, most recently adding four emerging enabling characteristics: phenotypic plasticity, epigenetic reprogramming, polymorphic microbiomes, and senescent cells. AKT kinases are critical signaling molecules that regulate cellular physiology upon receptor tyrosine kinases and PI3K activation. The complex branching of the AKT signaling network involves several critical downstream nodes that significantly magnify its functional impact, such that nearly every organ system and cell in the body may be affected by AKT activity. Conversely, tumor-intrinsic dysregulation of AKT can have numerous adverse cellular and pathologic ramifications, particularly in oncogenesis, as multiple tumor suppressors and oncogenic proteins regulate AKT signaling. Herein, we review the mounting evidence implicating the AKT pathway in the aggregate of currently recognized hallmarks of cancer underlying the complexities of human malignant diseases. The challenges, recent successes, and likely areas for exciting future advances in targeting this complex pathway are also discussed.

The evolution of small-molecule Akt inhibitors from hit to clinical candidate

Akt, a key regulator of cell survival, proliferation, and metabolism, has become a prominent target for treatment of cancer and inflammatory diseases. The journey of small-molecule Akt inhibitors from discovery to the clinic has faced numerous challenges, with a significant emphasis on optimization throughout the development process. Early discovery efforts identified various classes of inhibitors, including ATP-competitive and allosteric modulators. However, during preclinical and clinical development, several issues arose, including poor specificity, limited bioavailability, and toxicity. Optimization efforts have been central to overcoming these hurdles. Researchers focused on enhancing the selectivity of inhibitors to target Akt isoforms more precisely, reducing off-target effects, and improving pharmacokinetic properties to ensure better bioavailability and distribution. Structural modifications and the design of prodrugs have played a crucial role in refining the efficacy and safety profile of these inhibitors. Additionally, efforts have been made to optimize the therapeutic window, balancing effective dosing with minimal adverse effects. The review highlights how these optimization strategies have been key in advancing small-molecule Akt inhibitors toward clinical success and underscores the importance of continued refinement in their development.

Improving compound-protein interaction prediction by focusing on intra-modality and inter-modality dynamics with a multimodal tensor fusion strategy

Identifying novel compound-protein interactions (CPIs) plays a pivotal role in target identification and drug discovery. Although the recent multimodal methods have achieved outstanding advances in CPI prediction, they fail to effectively learn both intra-modality and inter-modality dynamics, which limits their prediction performance. To address the limitation, we propose a novel multimodal tensor fusion CPI prediction framework, named MMTF-CPI, which contains three unimodal learning modules for structure, heterogeneous network and transcriptional profiling modalities, a tensor fusion module and a prediction module. MMTF-CPI is capable of focusing on both intra-modality and inter-modality dynamics with the tensor fusion module. We demonstrated that MMTF-CPI is superior to multiple state-of-the-art multimodal methods across seven datasets. The prediction performance of MMTF-CPI is significantly improved with the tensor fusion module compared to other fusion methods. Moreover, our case studies confirmed the practical value of MMTF-CPI in target identification. Via MMTF-CPI, we also discovered several candidate compounds for the therapy of breast cancer and non-small cell lung cancer.

AKT kinases as therapeutic targets

AKT, or protein kinase B, is a central node of the PI3K signaling pathway that is pivotal for a range of normal cellular physiologies that also underlie several pathological conditions, including inflammatory and autoimmune diseases, overgrowth syndromes, and neoplastic transformation. These pathologies, notably cancer, arise if either the activity of AKT or its positive or negative upstream or downstream regulators or effectors goes unchecked, superimposed on by its intersection with a slew of other pathways. Targeting the PI3K/AKT pathway is, therefore, a prudent countermeasure. AKT inhibitors have been tested in many clinical trials, primarily in combination with other drugs. While some have recently garnered attention for their favorable profile, concern over resistance and off-target effects have continued to hinder their widespread adoption in the clinic, mandating a discussion on alternative modes of targeting. In this review, we discuss isoform-centric targeting that may be more effective and less toxic than traditional pan-AKT inhibitors and its significance for disease prevention and treatment, including immunotherapy. We also touch on the emerging mutant- or allele-selective covalent allosteric AKT inhibitors (CAAIs), as well as indirect, novel AKT-targeting approaches, and end with a briefing on the ongoing quest for more reliable biomarkers predicting sensitivity and response to AKT inhibitors, and their current state of affairs.

Unusual norcucurbitacin glycosides from the roots of Siraitia grosvenorii

Siraitia grosvenorii Swingle is one of the first approved medicine food homology species in China, and it has been used as a natural sweetener in the food industry and as a traditional medicine to relieve cough and reduce phlegm. However, many S. grosvenorii roots are discarded yearly, which results in a great waste of resources. Twelve undescribed norcucurbitacin-type triterpenoid glycosides, siraitiaosides A-L (1-12), and six known analogs (13-18) were isolated from the roots of S. grosvenorii. The structures of isolated norcucurbitacin glycosides were elucidated by comprehensive data analyses, including HRESIMS, UV, IR, NMR, ECD calculations, and X-ray crystallography analysis. Siraitiaosides A-E (1-5) featured an unusual 19,29-norcucurbitacin framework while siraitiaosides F-L (6-12) featured a rare 29-norcucurbitacin framework. Notably, compound 4 displayed moderate anti-acetylcholinesterase (AChE) activity with an IC50 of 21.0 μM, meanwhile, compounds 16 and 18 exhibited pronounced cytotoxic activities against MCF-7, CNE-1, and HeLa cancer cell lines with IC50 values of 2.1-15.2 μM. In silico studies showed that compound 4 bound closely to AChE with a binding energy of -5.04 kcal/mol, and compound 18 could tightly bind to PI3K, AKT1, ERK2, and MMP9 proteins that related to autophagy, apoptosis, migration/invasion, and growth/proliferation. In summary, the roots of Siraitia grosvenorii have potential medicinal values due to the multiple bioactive components.

Bioinformatics and computational studies of chabamide F and chabamide G for breast cancer and their probable mechanisms of action

Globally, the prevalence of breast cancer (BC) is increasing at an alarming level, despite early detection and technological improvements. Alkaloids are diverse chemical groups, and many within this class have been reported as potential anticancer compounds. Chabamide F (F) and chabamide G (G) are two dimeric amide alkaloids found in a traditional medicinal plant, Piper chaba, and possess significant cytotoxic effects. However, their scientific rationalization in BC remains unknown. Here, we aimed to investigate their potential and molecular mechanisms for BC through in silico approaches. From network pharmacology, we identified 64 BC-related genes as targets. GO and KEGG studies showed that they were involved in various biological processes and mostly expressed in BC-related pathways such as RAS, PI3K-AKT, estrogen, MAPK, and FoxO pathways. However, PPI analysis revealed SRC and AKT1 as hub genes, which play key roles in BC tumorigenesis and metastasis. Molecular docking revealed the strong binding affinity of F (- 10.7 kcal/mol) and G (- 9.4 and - 11.7 kcal/mol) for SRC and AKT1, respectively, as well as the acquisition of vital residues to inhibit them. Their long-term stability was evaluated using 200 ns molecular dynamics simulation. The RMSD, RMSF, Rg, and SASA analyses showed that the G-SRC and G-AKT1 complexes were excellently stable compared to the control, dasatinib, and capivasertib, respectively. Additionally, the PCA and DCCM analyses revealed a significant reduction in the residual correlation and motions. By contrast, the stability of the F-SRC complex was greater than that of the control, whereas it was moderately stable in complex with AKT1. The MMPBSA analysis demonstrated higher binding energies for both compounds than the controls. In particular, the binding energy of G for SRC and AKT1 was - 120.671 ± 16.997 and - 130.437 ± 19.111 kJ/mol, respectively, which was approximately twice as high as the control molecules. Van der Waal and polar solvation energies significantly contributed to this energy. Furthermore, both of them exhibited significant interactions with the binding site residues of both proteins. In summary, this study indicates that these two molecules could be a potential ATP-competitive inhibitor of SRC and an allosteric inhibitor of AKT1.

Molecular insights into the regulatory landscape of PKC-related kinase-2 (PRK2/PKN2) using targeted small compounds

The PKC-related kinases (PRKs, also termed PKNs) are important in cell migration, cancer, hepatitis C infection, and nutrient sensing. They belong to a group of protein kinases called AGC kinases that share common features like a C-terminal extension to the catalytic domain comprising a hydrophobic motif. PRKs are regulated by N-terminal domains, a pseudosubstrate sequence, Rho-binding domains, and a C2 domain involved in inhibition and dimerization, while Rho and lipids are activators. We investigated the allosteric regulation of PRK2 and its interaction with its upstream kinase PDK1 using a chemical biology approach. We confirmed the phosphoinositide-dependent protein kinase 1 (PDK1)-interacting fragment (PIF)-mediated docking interaction of PRK2 with PDK1 and showed that this interaction can be modulated allosterically. We showed that the polypeptide PIFtide and a small compound binding to the PIF-pocket of PRK2 were allosteric activators, by displacing the pseudosubstrate PKL region from the active site. In addition, a small compound binding to the PIF-pocket allosterically inhibited the catalytic activity of PRK2. Together, we confirmed the docking interaction and allostery between PRK2 and PDK1 and described an allosteric communication between the PIF-pocket and the active site of PRK2, both modulating the conformation of the ATP-binding site and the pseudosubstrate PKL-binding site. Our study highlights the allosteric modulation of the activity and the conformation of PRK2 in addition to the existence of at least two different complexes between PRK2 and its upstream kinase PDK1. Finally, the study highlights the potential for developing allosteric drugs to modulate PRK2 kinase conformations and catalytic activity.

Identification of an Alepterolic Acid Derivative as a Potent Anti-Breast-Cancer Agent via Inhibition of the Akt/p70S6K Signaling Pathway

Alepterolic acid is a diterpene occurring in the fern Aleuritopteris argentea with potential biological activity that warrants further structural modification. In the present work, sixteen alepterolic acid derivatives were synthesized and evaluated for their anticancer activities. Among them, N-[m-(trifluoromethoxy)phenyl] alepterolamide displayed comparable activity (IC50=4.20±0.21 μM) in MCF-7 cells. Moreover, mechanistic investigations indicated this compound was significantly capable of diminishing cell proliferation and viability of MCF-7 cells. After treatment with N-[m-(trifluoromethoxy)phenyl] alepterolamide, a significant increase in cleaved caspase-9, cleaved caspase-3, cleaved poly (ADP-ribose) polymerase (PARP) and Bax/Bcl2 ratio were observed in MCF-7 cells, leading to caspase-dependent apoptotic pathways. Further studies showed this compound promoted cellular apoptosis and inhibited migration in MCF-7 cells via modulation of the Akt/p70S6K signaling pathway. All these results revealed the potential of N-[m-(trifluoromethoxy)phenyl] alepterolamide as an appealing therapeutic drug candidate for breast cancer.

Akt Inhibitor Advancements: From Capivasertib Approval to Covalent-Allosteric Promises

Akt kinase is vital in cell growth, survival, metabolism, and migration. Dysregulation of Akt signaling is implicated in cancer and metabolic disorders. In the context of cancer, overactive Akt promotes cell survival and proliferation. This has spurred extensive research into developing Akt inhibitors as potential therapeutic agents to disrupt aberrant Akt signaling. Akt inhibitors are classified into three main types: ATP-competitive, allosteric, and covalent-allosteric inhibitors (CAAIs). ATP-competitive inhibitors compete with ATP for binding to Akt, allosteric inhibitors interact with the Pleckstrin homology (PH) domain, and covalent-allosteric inhibitors form covalent bonds, making them more potent and selective. Notably, capivasertib (AZD5363), a potent ATP-competitive Akt inhibitor, received FDA approval in November 2023 for use in combination with the estrogen receptor degrader fulvestrant to treat breast cancer. Challenges remain, including improving selectivity, identifying biomarkers to tailor treatments, and enhancing therapeutic efficacy while minimizing adverse effects. Particularly covalent-allosteric inhibitors hold promise for future more effective and personalized treatments.

CircAKT3 alleviates postoperative cognitive dysfunction by stabilizing the feedback cycle of miR-106a-5p/HDAC4/MEF2C axis in hippocampi of aged mice

Circular RNAs (circRNAs) have garnered significant attention in the field of neurodegenerative diseases including Alzheimer's diseases due to their covalently closed loop structure. However, the involvement of circRNAs in postoperative cognitive dysfunction (POCD) is still largely unexplored. To identify the genes differentially expressed between non-POCD (NPOCD) and POCD mice, we conducted the whole transcriptome sequencing initially in this study. According to the expression profiles, we observed that circAKT3 was associated with hippocampal neuronal apoptosis in POCD mice. Moreover, we found that circAKT3 overexpression reduced apoptosis of hippocampal neurons and alleviated POCD. Subsequently, through bioinformatics analysis, our data showed that circAKT3 overexpression in vitro and in vivo elevated the abundance of miR-106a-5p significantly, resulting in a decrease of HDAC4 protein and an increase of MEF2C protein. Additionally, this effect of circAKT3 was blocked by miR-106a-5p inhibitor. Interestingly, MEF2C could activate the transcription of miR-106a-5p promoter and form a positive feedback loop. Therefore, our findings revealed more potential modulation ways between circRNA-miRNA and miRNA-mRNA, providing different directions and targets for preclinical studies of POCD.

Nobiletin alleviates atherosclerosis by inhibiting lipid uptake via the PPARG/CD36 pathway

BACKGROUND

Atherosclerosis (AS) is a persistent inflammatory condition triggered and exacerbated by several factors including lipid accumulation, endothelial dysfunction and macrophages infiltration. Nobiletin (NOB) has been reported to alleviate atherosclerosis; however, the underlying mechanism remains incompletely understood.

METHODS

This study involved comprehensive bioinformatic analysis, including multidatabase target prediction; GO and KEGG enrichment analyses for function and pathway exploration; DeepSite and AutoDock for drug binding site prediction; and CIBERSORT for immune cell involvement. In addition, target intervention was verified via cell scratch assays, oil red O staining, ELISA, flow cytometry, qRT‒PCR and Western blotting. In addition, by establishing a mouse model of AS, it was demonstrated that NOB attenuated lipid accumulation and the extent of atherosclerotic lesions.

RESULTS

(1) Altogether, 141 potentially targetable genes were identified through which NOB could intervene in atherosclerosis. (2) Lipid and atherosclerosis, fluid shear stress and atherosclerosis may be the dominant pathways and potential mechanisms. (3) ALB, AKT1, CASP3 and 7 other genes were identified as the top 10 target genes. (4) Six genes, including PPARG, MMP9, SRC and 3 other genes, were related to the M0 fraction. (5) CD36 and PPARG were upregulated in atherosclerosis samples compared to the normal control. (6) By inhibiting lipid uptake in RAW264.7 cells, NOB prevents the formation of foam cell. (7) In RAW264.7 cells, the inhibitory effect of oxidized low-density lipoprotein on foam cells formation and lipid accumulation was closely associated with the PPARG signaling pathway. (8) In vivo validation showed that NOB significantly attenuated intra-arterial lipid accumulation and macrophage infiltration and reduced CD36 expression.

CONCLUSIONS

Nobiletin alleviates atherosclerosis by inhibiting lipid uptake via the PPARG/CD36 pathway.

Selectivity Studies and Free Energy Calculations of AKT Inhibitors

Protein kinase B (PKB) or AKT protein is an important target for cancer treatment. Significant advances have been made in developing ATP-competitive inhibitors and allosteric binders targeting AKT1. However, adverse effects or toxicities have been found, and the cutaneous toxicity was found to be linked to the inhibition of AKT2. Thus, selective inhibition of AKT inhibitors is of significance. Our work, using the Schrödinger Covalent Dock (CovDock) program and the Movable Type (MT)-based free energy calculation (ΔG), yielded small mean errors for the experimentally derived binding free energy (ΔG). The docking data suggested that AKT1 binding may require residues Asn54, Trp80, Tyr272, Asp274, and Asp292, whereas AKT2 binding would expect residues Phe163 and Glu279, and AKT3 binding would favor residues Glu17, Trp79, Phe306, and Glu295. These findings may help guide AKT1-selective or AKT3-selective molecular design while sparing the inhibition of AKT2 to minimize the cutaneous toxicity.

Computer-Aided Identification of Kinase-Targeted Small Molecules for Cancer: A Review on AKT Protein

AKT (also known as PKB) is a serine/threonine kinase that plays a pivotal regulatory role in the PI3K/AKT/mTOR signaling pathway. Dysregulation of AKT activity, especially its hyperactivation, is closely associated with the development of various human cancers and resistance to chemotherapy. Over the years, a wide array of AKT inhibitors has been discovered through experimental and computational approaches. In this regard, herein we present a comprehensive overview of AKT inhibitors identified using computer-assisted drug design methodologies (including docking-based and pharmacophore-based virtual screening, machine learning, and quantitative structure-activity relationships) and successfully validated small molecules endowed with anticancer activity. Thus, this review provides valuable insights to support scientists focused on AKT inhibition for cancer treatment and suggests untapped directions for future computer-aided drug discovery efforts.

Expanding the Chemistry of Dihaloacetamides as Tunable Electrophiles for Reversible Covalent Targeting of Cysteines

The choice of an appropriate electrophile is crucial in the design of targeted covalent inhibitors (TCIs). In this report, we systematically investigated the glutathione (GSH) reactivity of various haloacetamides and the aqueous stability of their thiol adducts. Our findings revealed that dihaloacetamides cover a broad range of GSH reactivity depending on the combination of the halogen atoms and the structure of the amine scaffold. Among the dihaloacetamides, dichloroacetamide (DCA) exhibited slightly lower GSH reactivity than chlorofluoroacetamide (CFA). The DCA-thiol adduct is readily hydrolyzed under aqueous conditions, but it can stably exist in the solvent-sequestered binding pocket of the protein. These reactivity profiles of DCA were successfully exploited in the design of TCIs targeting noncatalytic cysteines of KRAS^G12C and EGFR^L858R/T790M. These inhibitors exhibited strong antiproliferative activities against cancer cells. Our findings provide valuable insights for designing dihaloacetamide-based reversible covalent inhibitors.

Functional impact and molecular binding modes of drugs that target the PI3K isoform p110δ

Targeting the PI3K isoform p110δ against B cell malignancies is at the mainstay of PI3K inhibitor (PI3Ki) development. Therefore, we generated isogenic cell lines, which express wild type or mutant p110δ, for assessing the potency, isoform-selectivity and molecular interactions of various PI3Ki chemotypes. The affinity pocket mutation I777M maintains p110δ activity in the presence of idelalisib, as indicated by intracellular AKT phosphorylation, and rescues cell functions such as p110δ-dependent cell viability. Resistance owing to this substitution consistently affects the potency of p110δ-selective in contrast to most multi-targeted PI3Ki, thus distinguishing usually propeller-shaped and typically flat molecules. Accordingly, molecular dynamics simulations indicate that the I777M substitution disturbs conformational flexibility in the specificity or affinity pockets of p110δ that is necessary for binding idelalisib or ZSTK474, but not copanlisib. In summary, cell-based and molecular exploration provide comparative characterization of currently developed PI3Ki and structural insights for future PI3Ki design.

Bioinformatics and computational chemistry approaches to explore the mechanism of the anti-depressive effect of ligustilide

Depression affects people with multiple adverse outcomes, and the side effects of antidepressants are troubling for depression sufferers. Aromatic drugs have been widely used to relieve symptoms of depression with fewer side effects. Ligustilide (LIG) is the main component of volatile oil in angelica sinensis, exhibiting an excellent anti-depressive effect. However, the mechanisms of the anti-depressive effect of LIG remain unclear. Therefore, this study aimed to explore the mechanisms of LIG exerting an anti-depressive effect. We obtained 12,969 depression-related genes and 204 LIG targets by a network pharmacology approach, which were intersected to get 150 LIG anti-depressive targets. Then, we identified core targets by MCODE, including MAPK3, EGF, MAPK14, CCND1, IL6, CASP3, IL2, MYC, TLR4, AKT1, ESR1, TP53, HIF1A, SRC, STAT3, AR, IL1B, and CREBBP. Functional enrichment analysis of core targets showed a significant association with PI3K/AKT and MAPK signaling pathways. Molecular docking showed strong affinities of LIG with AKT1, MAPK14, and ESR1. Finally, we validated the interactions between these proteins and LIG by molecular dynamics (MD) simulations. In conclusion, this study successfully predicted that LIG exerted an anti-depressive effect through multiple targets, including AKT1, MAPK14, and ESR1, and the pathways of PI3K/AKT and MAPK. The study provides a new strategy to explore the molecular mechanisms of LIG in treating depression.

Targeting PI3K/AKT signaling pathway in obesity

Obesity is a disorder with an increasing prevalence, which impairs the life quality of patients and intensifies societal health care costs. The development of safe and innovative prevention strategies and therapeutic approaches is thus of great importance. The complex pathophysiology of obesity involves multiple signaling pathways that influence energy metabolism in different tissues. The phosphatidylinositol 3-kinases (PI3K)/protein kinase B (AKT) pathway is critical for the metabolic homeostasis and its function in insulin-sensitive tissues is described in the context of health, obesity and obesity-related complications. The PI3K family participates in the regulation of diverse physiological processes including but not limited to cell growth, survival, differentiation, autophagy, chemotaxis, and metabolism depending on the cellular context. AKT is downstream of PI3K in the insulin signaling pathway, and promotes multiple cellular processes by targeting a plethora of regulatory proteins that control glucose and lipid metabolism. Natural products are essential for prevention and treatment of many human diseases, including obesity. Anti-obesity natural compounds effect multiple pathophysiological mechanisms involved in obesity development. Numerous recent preclinical studies reveal the advances in using plant secondary metabolites to target the PI3K/AKT signaling pathway for obesity management. In this paper the druggability of PI3K as a target for compounds with anti-obesity potential is evaluated. Perspectives on the strategies and limitations for clinical implementation of obesity management using natural compounds modulating the PI3K/AKT pathway are suggested.

Cu(BF4)2/AC-Catalyzed Synthesis of N-Substituted Anilines, N-Substituted 1,6-Naphthyridin-5(6H)-one, and Isoquinolin-1(2H)-one

Herein, we report practical Cu(BF₄)₂/activated carbon-catalyzed amination of various anilines, isoquinolinone, and naphthyridinone with aryl boronic acids. The ultrasonic and rotary evaporation treatment of the mixture of aq. Cu(BF₄)₂ and activated carbon in methanol afforded a novel Cu(II)-catalyst, which is air-stable and can be effectively applied in the Chan-Lam coupling reaction. The products of N-arylation were isolated in good to excellent yields at low catalytic loading. And Cu(BF₄)₂/AC also showed good reusability.

Akt isoforms in the immune system

Akt is a PI3K-activated serine-threonine kinase that exists in three distinct isoforms. Akt's expression in most immune cells, either at baseline or upon activation, reflects its importance in the immune system. While Akt is most highly expressed in innate immune cells, it plays crucial roles in both innate and adaptive immune cell development and/or effector functions. In this review, we explore what's known about the role of Akt in innate and adaptive immune cells. Wherever possible, we discuss the overlapping and distinct role of the three Akt isoforms, namely Akt1, Akt2, and Akt3, in immune cells.

Enhancing T Cell Chemotaxis and Infiltration in Glioblastoma

Glioblastoma is an immunologically 'cold' tumor, which are characterized by absent or minimal numbers of tumor-infiltrating lymphocytes (TILs). For those tumors that have been invaded by lymphocytes, they are profoundly exhausted and ineffective. While many immunotherapy approaches seek to reinvigorate immune cells at the tumor, this requires TILs to be present. Therefore, to unleash the full potential of immunotherapy in glioblastoma, the trafficking of lymphocytes to the tumor is highly desirable. However, the process of T cell recruitment into the central nervous system (CNS) is tightly regulated. Naïve T cells may undergo an initial licensing process to enter the migratory phenotype necessary to enter the CNS. T cells then must express appropriate integrins and selectin ligands to interact with transmembrane proteins at the blood-brain barrier (BBB). Finally, they must interact with antigen-presenting cells and undergo further licensing to enter the parenchyma. These T cells must then navigate the tumor microenvironment, which is rich in immunosuppressive factors. Altered tumoral metabolism also interferes with T cell motility. In this review, we will describe these processes and their mediators, along with potential therapeutic approaches to enhance trafficking. We also discuss safety considerations for such approaches as well as potential counteragents.