Multi-Target Effect of Aloeresin-A against Bacterial and Host Inflammatory Targets Benefits Contact Lens-Related Keratitis: A Multi-Omics and Quantum Chemical Investigation.

Contact lens-mediated microbial keratitis caused by Pseudomonas aeruginosa and Streptococcus pneumoniae provokes corneal damage and vision loss. Recently, natural phytochemicals have become complementary medicines for corneal destruction. Herein, we aimed to identify multi-targeting Aloe vera-derived phytochemicals capable of inhibiting bacterial and host targets of keratitis through ADME (absorption, distribution, metabolism, and excretion), docking, molecular dynamics (MD) simulation, MMGBSA (molecular mechanics generalized Born surface area) and density functional theory (DFT) investigations. An extensive literature search revealed ExoU, ExoS, ExoT, ExoY, and PLY as virulent bacterial targets. Simultaneously, differential gene expression (DGE) and pathway enrichment analysis-specified host transcription factor (SPI1) influences keratitis pathogenesis. Molecular docking analysis uncovered aloeresin-A as a promising inhibitor against bacterial and host targets, demonstrating strong binding energies ranging from -7.59 to -6.20 kcal/mol. Further, MMGBSA and MD simulation analysis reflect higher binding free energies and stable interactions of aloeresin-A with the targets. In addition, DFT studies reveal the chemical reactiveness of aloeresin-A through quantum chemical calculations. Hence, our findings show aloeresin-A to be a promising candidate for effectively inhibiting keratitis. However, additional research is imperative for potential integration into lens care solutions.

A rohitukine derivative IIIM-290 induces p53 dependent mitochondrial apoptosis in acute lymphoblastic leukemia cells.

Rohitukine, a chromone alkaloid extracted from Dysoxylum binectariferum, has a propitious anticancer activity. Our previous study shows that a new Rohitukine derivative IIIM-290 restricts the growth of pancreatic cancer in vivo and in vitro. In the present findings, we report the mechanism of cell death induced by IIIM-290 in MOLT-4 cells (acute lymphoblastic leukemia) and its anticancer potential against various murine leukemic tumor models in vivo. We found that IIIM-290 induced apoptosis through upregulation of different apoptotic proteins like PUMA, BAX, cytochrome c, cleaved (active) caspase-3, and cleaved PARP in MOLT-4 cells. Moreover, IIIM-290 abated mitochondrial membrane potential, elevated calcium levels, reactive oxygen species, and arrested growth of MOLT-4 cells in the synthesis (S) phase of the cell cycle. Interestingly, the elevation in proapoptotic markers was p53 dependent-the silencing of p53 abrogated apoptosis (programmed cell death) triggered by IIIM-290 in MOLT-4 cells. Furthermore, IIIM-290 significantly enhanced the survival of animals with P388 and L1210 leukemia. Thus, our results put IIIM-290 as a potential candidate for the anticancer lead.

Safranal inhibits NLRP3 inflammasome activation by preventing ASC oligomerization.

NLRP3 inflammasome is involved in several chronic inflammatory diseases. The inflammatory effect of the NLRP3 inflammasome is executed through IL-1ß and IL-18. Therefore, IL-1ß is one of the primary targets in chronic inflammatory conditions. However, current treatment regimens are dependent on anti- IL-1ß biologicals. The therapies targeting IL-1ß through inhibition of NLRP3 inflammasome are thus being actively explored. We identified safranal, a small molecule responsible for the essence of saffron as a potential inhibitor of the NLRP3 inflammasome. Safranal significantly suppressed the release of IL-1ß from ATP stimulated J774A.1 and bone marrow-derived macrophages (BMDMs) by regulating CASP1 and CASP8 dependent cleavage of pro-IL-1ß. Safranal markedly suppressed the expression of NLRP3 and its ATPase activity. Safranal treatment enhanced the expression of NRF2, whereas, si-RNA mediated silencing of Nrf2 abrogated the anti-NLRP3 effect of safranal. Furthermore, safranal inhibited ASC oligomerization and formation of ASC specks. Safranal also displayed anti-NLRP3 activity in multiple mice models. Treatment of animals with safranal reduced the production of IL-1ß in ATP elicited peritoneal inflammation, MSU induced air pouch inflammation, and MSU injected foot paw edema in mice. Thus, our data projects safranal as a potential preclinical drug candidate against NLRP3 inflammasome triggered chronic inflammation.

Artemisia amygdalina Upregulates Nrf2 and Protects Neurons Against Oxidative Stress in Alzheimer Disease.

Alzheimer disease is a complex neurodegenerative disorder. It is the common form of dementia in elderly people. The etiology of this disease is multifactorial, pathologically it is accompanied with accumulation of amyloid beta and neurofibrillary tangles. Accumulation of amyloid beta and mitochondrial dysfunction leads to oxidative stress. In this study, neuroprotective effect of Artemisiaamygdalina against H2O2-induced death was studied in differentiated N2a and SH-SY5Ycells. Cells were treated with H2O2 to induce toxicity which was attenuated by Artemisia amygdalina. The nuclear factor erythroid 2-related factor 2 (Nrf2) is an emerging regulator of cellular resistance to oxidants. It controls the basal and induced expression of antioxidant response element-dependent genes. Further, we demonstrated that Artemisia amygdalina protects neurons through upregulation of Nrf2 pathway. Moreover, reactive oxygen species and mitochondrial membrane potential loss formed by H2O2 was attenuated by Artemisia amygdalina. Thus, Artemisia amygdalina may have the possibility to be a therapeutic agent for Alzheimer disease.

Soluble Aß1-42 suppresses TNF-α and activates NLRP3 inflammasome in THP-1 macrophages.

Deposition of amyloid-ß in Alzheimer's disease is accompanied by chronic inflammation, which involves raised levels of pro-inflammatory cytokines TNF-α, IL-6 and IL-1ß. However, the role of Aß1-42 in the inflammatory process, before it gets deposited into aggregates has not been investigated thoroughly. Through this study, we are illustrating the dual role of soluble Aß1-42 (sAß1-42) in activating the NLRP3 inflammasome and simultaneously inhibiting TNF-α secretion. Our data suggested that the treatment of chronically induced THP-1 macrophages and N9 microglial cells with sAß1-42 can suppress the major inflammatory cytokine TNF-α without affecting the level of IL-6. However, the activation of NLRP3 inflammasome was well evidenced by secretion of IL-1ß, increased expression of NLRP3 and caspase-1, implicating sAß1-42 in enhancing and suppressing one or other type of inflammation. Further investigation revealed that sAß1-42 was able to severely abrogate the expression of NF-κB, p50 and restricting the translocation of NF-κB, p65 to nucleus by inhibiting phosphorylation of IκB-α in THP-1 macrophages. These data indicate that the sAß1-42 may play a dual role during inflammatory process, wherein, it may be involved in protecting the cells from inflammatory damage due to TNF-α. This ability of sAß1-42 might be playing some role in protecting the brain cells during the process of aging and Alzheimer's disease, where, chronic inflammatory environment plays a vital role.

The amino analogue of ß-boswellic acid efficiently attenuates the release of pro-inflammatory mediators than its parent compound through the suppression of NF-κB/IκBα signalling axis.

Natural product derivatives have proven to be cutting edge window for drug discovery and development. BA-25 (3-α-o-acetoxy-4ß-amino-11-oxo-24-norurs-12-ene) an amino analogue of ß-boswellic acid exhibited inhibition of TNF-α and IL-6 in THP-1 cells as demonstrated previously, however, the effect on principal inflammatory mediators such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and the pathways that mediate this function remains unknown. This study was designed to examine the comparative anti-inflammatory activity of BA-25 with its parent compound, ß boswellic acid both in vitro and in vivo. The effect of BA and BA-25 on suppression of NO, PGE2, LTB4, COX-2 in LPS-stimulated RAW 264.7 cells was determined by ELISA, RT-PCR and ROS by flow cytometry. Phosphorylation of NF-kBp65, IKB degradation was determined by western blotting and also the nuclear localization of NF-kBp65 was assessed by immunofluorescence. Furthermore, this study was extended on Carrageenan induced paw oedema modelled BALB/c mice. A novel derivative BA-25, reported first time notably decreased the LPS (1 µg/mL) induced upregulation in the transcription of TNF-α, IL-6, iNOS and COX-2. Also the protein expression of iNOS and COX-2 as well as their downstream products NO and PGE2 respectively, were also decreased efficiently at a concentration of 10 µM than BA. Moreover, LPS upregulated NF-kB p65 expression and IκB degradation was significantly decreased after BA-25 treatment. In addition, the treatment of BA-25 also restored the paw oedema and decreased the magnitude of histopathological alterations. Our data together suggested that BA-25 might be regarded as prospective therapeutic anti-inflammatory alternative and demands further investigation in pharmacological studies.

Meridianin derivatives as potent Dyrk1A inhibitors and neuroprotective agents.

Meridianins are a group of marine-derived indole alkaloids which are reported to possess kinase inhibitory activities. In the present Letter, we report synthesis of N1-substituted and C-ring modified meridianin derivatives and their evaluation as Dyrk1A inhibitors and neuroprotective agents. Among the library of 52 compounds screened, morpholinoyl linked derivative 26b and 2-nitro-4-trifluoromethyl phenyl sulfonyl derivative 29v displayed potent inhibition of Dyrk1A with IC50 values of 0.5 and 0.53 µM, respectively. The derivative 26b also inhibited Dyrk2 and Dyrk3 with IC50 values of 1.4 and 2.2 µM, respectively showing 2.2 and 4.4 fold selectivity for Dyrk1A with respect to Dyrk2 and Dyrk3. The compound 26b was not cytotoxic to human neuroblastoma SH-SY5Y cells (IC50>100 µM) and it displayed significant neuroprotection against glutamate-induced neurotoxicity in these cells at 10 µM. Molecular modelling studies of compound 26b led to identification of key interactions in the binding site of Dyrk1A and the possible reasons for observed Dyrk1A selectivity over Dyrk2.

Discovery of 4-acetyl-3-(4-fluorophenyl)-1-(p-tolyl)-5-methylpyrrole as a dual inhibitor of human P-glycoprotein and Staphylococcus aureus Nor A efflux pump.

Polysubstituted pyrrole natural products, lamellarins, are known to overcome multi-drug resistance in cancer via the inhibition of p-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) efflux pumps. Herein, a series of simplified polysubstituted pyrroles, prepared via a one-pot domino protocol, were screened for P-gp inhibition in P-gp overexpressing human adenocarcinoma LS-180 cells using a rhodamine 123 efflux assay. Several compounds showed the significant inhibition of P-gp at 50 µM, as indicated by increase in the intracellular accumulation of Rh123 in LS-180 cells. Furthermore, pyrrole 5i decreased the efflux of digoxin, a FDA approved P-gp substrate in MDCK-MDR1 cells with an IC50 of 11.2 µM. In in vivo studies, following the oral administration of a P-gp substrate drug, rifampicin, along with compound , the Cmax and AUC0-∞ of rifampicin was enhanced by 31% and 46%, respectively. All the compounds were then screened for their ability to potentiate ciprofloxacin activity via the inhibition of Staphylococcus aureus Nor A efflux pump. Pyrrole showed the significant inhibition of S. aureus Nor A efflux pump with 8- and 4-fold reductions in the MIC of ciprofloxacin at 50 and 6.25 µM, respectively. The molecular docking studies of compound with the human P-gp and S. aureus Nor A efflux pump identified its plausible binding site and key interactions. Thus, the results presented herein strongly indicate the potential of this scaffold for its use as multi-drug resistance reversal agent or bioavailability enhancer.

Synthesis and P-glycoprotein induction activity of colupulone analogs.

Brain amyloid-beta (Aß) plaques are one of the primary hallmarks associated with Alzheimer's disease (AD) pathology. Efflux pump proteins located at the blood-brain barrier (BBB) have been reported to play an important role in the clearance of brain Aß, among which the P-glycoprotein (P-gp) efflux transporter pump has been shown to play a crucial role. Thus, P-gp has been considered as a potential therapeutic target for treatment of AD. Colupulone, a prenylated phloroglucinol isolated from Humulus lupulus, is known to activate pregnane-X-receptor (PXR), which is a nuclear receptor controlling P-gp expression. In the present work, we aimed to synthesize and identify analogs of colupulone that are potent P-gp inducer(s) with an ability to enhance Aß transport across the BBB. A series of colupulone analogs were synthesized by modifications at both prenyl as well as acyl domains. All compounds were screened for P-gp induction activity using a rhodamine 123 based efflux assay in the P-gp overexpressing human adenocarcinoma LS-180 cells, wherein all compounds showed significant P-gp induction activity at 5 µM. In the western blot studies in LS-180 cells, compounds 3k and 5f were able to induce P-gp as well as LRP1 at 1 µM. The effect of compounds on the Aß uptake and transport was then evaluated. Among all tested compounds, diprenylated acyl phloroglucinol displayed a significant increase (29%) in Aß transport across bEnd3 cells grown on inserts as a BBB model. The results presented here suggest the potential of this scaffold to enhance clearance of brain Aß across the BBB and thus its promise for development as a potential anti-Alzheimer agent.

3-(Benzo[d][1,3]dioxol-5-ylamino)-N-(4-fluorophenyl)thiophene-2-carboxamide overcomes cancer chemoresistance via inhibition of angiogenesis and P-glycoprotein efflux pump activity.

3-((Quinolin-4-yl)methylamino)-N-(4-(trifluoromethoxy)phenyl)thiophene-2-carboxamide (OSI-930, 1) is a potent inhibitor of c-kit and VEGFR2, currently under phase I clinical trials in patients with advanced solid tumors. In order to understand the structure-activity relationship, a series of 3-arylamino N-aryl thiophene 2-carboxamides were synthesized by modifications at both quinoline and amide domains of the OSI-930 scaffold. All the synthesized compounds were screened for in vitro cytotoxicity in a panel of cancer cell lines and for VEGFR1 and VEGFR2 inhibition. Thiophene 2-carboxamides substituted with benzo[d][1,3]dioxol-5-yl and 2,3-dihydrobenzo[b][1,4]dioxin-6-yl groups 1l and 1m displayed inhibition of VEGFR1 with IC50 values of 2.5 and 1.9 µM, respectively. Compounds 1l and 1m also inhibited the VEGF-induced HUVEC cell migration, indicating its anti-angiogenic activity. OSI-930 along with compounds 1l and 1m showed inhibition of P-gp efflux pumps (MDR1, ABCB1) with EC50 values in the range of 35-74 µM. The combination of these compounds with doxorubicin led to significant enhancement of the anticancer activity of doxorubicin in human colorectal carcinoma LS180 cells, which was evident from the improved IC50 of doxorubicin, the increased activity of caspase-3 and the significant reduction in colony formation ability of LS180 cells after treatment with doxorubicin. Compound 1l showed a 13.8-fold improvement in the IC50 of doxorubicin in LS180 cells. The ability of these compounds to display dual inhibition of VEGFR and P-gp efflux pumps demonstrates the promise of this scaffold for its development as multi-drug resistance-reversal agents.

Synthesis, and the antioxidant, neuroprotective and P-glycoprotein induction activity of 4-arylquinoline-2-carboxylates.

An efficient formic acid catalyzed one-pot synthesis of 4-arylquinoline 2-carboxylates in water via three-component coupling of arylamines, glyoxylates and phenylacetylenes has been described. 4-Arylquinoline 2-carboxylates 1o and 1q displayed significant antioxidant activity as indicated by their Fe-reducing power in the ferric reducing ability of plasma (FRAP) assay. The compounds were found to react directly with hydrogen peroxide, which might be one of the mechanisms of their antioxidant effect. Compounds 1o and 1q effectively quenched H2O2 and amyloid-ß-generated reactive oxygen species (ROS) and also displayed significant protection against H2O2-induced neurotoxicity in human neuroblastoma SH-SY5Y cells. Additionally, all compounds exhibited promising P-glycoprotein induction activity in human adenocarcinoma LS-180 cells, indicating their potential to enhance amyloid-ß clearance from Alzheimer's brains. Furthermore, all compounds were relatively non-toxic to SH-SY5Y and LS-180 cells (IC50 > 50 µM). The promising antioxidant, ROS quenching, neuroprotective and Pgp-induction activity of these compounds strongly indicate their potential as anti-Alzheimer's agents.

Cancer metastasis: Molecular mechanisms and clinical perspectives.

Metastatic progression combined with non-responsiveness towards systemic therapy often shapes the course of disease for cancer patients and commonly determines its lethal outcome. The complex molecular events that promote metastasis are a combination of both, the acquired pro-metastatic properties of cancer cells and a metastasis-permissive or -supportive tumor micro-environment (TME). Yet, dissemination is a challenging process for cancer cells that requires a series of events to enable cancer cell survival and growth. Metastatic cancer cells have to initially detach themselves from primary tumors, overcome the challenges of their intravasal journey and colonize distant sites that are suited for their metastases. The implicated obstacles including anoikis and immune surveillance, can be overcome by intricate intra- and extracellular signaling pathways, which we will summarize and discuss in this review. Further, emerging modulators of metastasis, like the immune-microenvironment, microbiome, sublethal cell death engagement, or the nervous system will be integrated into the existing working model of metastasis.

Pharmacoscreening, molecular dynamics, and quantum mechanics of inermin from Panax ginseng: a crucial molecule inhibiting exosomal protein target associated with coronary artery disease progression.

Background: Exosomes, microvesicles, carry and release several vital molecules across cells, tissues, and organs. Epicardial adipose tissue exosomes are critical in the development and progression of coronary artery disease (CAD). It is hypothesized that exosomes may transport causative molecules from inflamed tissue and deliver to the target tissue and progress CAD. Thus, identifying and inhibiting the CAD-associated proteins that are being transported to other cells via exosomes will help slow the progression of CAD. Methods: This study uses a systems biological approach that integrates differential gene expression in the CAD, exosomal cargo assessment, protein network construction, and functional enrichment to identify the crucial exosomal cargo protein target. Meanwhile, absorption, distribution, metabolism, and excretion (ADME) screening of Panax ginseng-derived compounds was conducted and then docked against the protein target to identify potential inhibitors and then subjected to molecular dynamics simulation (MDS) to understand the behavior of the protein-ligand complex till 100 nanoseconds. Finally, density functional theory (DFT) calculation was performed on the ligand with the highest affinity with the target. Results: Through the systems biological approach, Mothers against decapentaplegic homolog 2 protein (SMAD2) was determined as a potential target that linked with PI3K-Akt signaling, Ubiquitin mediated proteolysis, and the focal adhesion pathway. Further, screening of 190 Panax ginseng compounds, 27 showed drug-likeness properties. Inermin, a phytochemical showed good docking with -5.02 kcal/mol and achieved stability confirmation with SMAD2 based on MDS when compared to the known CAD drugs. Additionally, DFT analysis of inermin showed high chemical activity that significantly contributes to effective target binding. Overall, our computational study suggests that inermin could act against SMAD2 and may aid in the management of CAD.

Activation of lysosomal mediated cell death in the course of autophagy by mTORC1 inhibitor.

Lysosomal biogenesis plays a vital role in cell fate. Under certain conditions, excessive lysosomal biogenesis leads to susceptibility for lysosomal membrane permeabilization resulting in various pathological conditions including cell death. In cancer cells apoptosis machinery becomes dysregulated during the course of treatment, thus allows cancer cells to escape apoptosis. So it is therefore imperative to identify cytotoxic agents that exploit non-apoptotic mechanisms of cell death. Our study showed that pancreatic cancer cells treated with SDS-203 triggered an incomplete autophagic response and a nuclear translocation of transcriptional factor TFEB. This resulted in abundant biosynthesis and accumulation of autophagosomes and lysosomes into the cells leading to their death. It was observed that the silencing of autophagy genes didn't alter the cell fate, whereas siRNA-mediated silencing of TFEB subdued SDS-203 mediated lysosomal biogenesis and associated cell death. Further mouse tumors treated with SDS-203 showed a significant reduction in tumor burden and increased expression of lysosomal markers. Taken together this study demonstrates that SDS-203 treatment triggers non-apoptotic cell death in pancreatic cancer cells through a mechanism of lysosome over accumulation.

Loss-of-function mutation in VCP mimics the characteristic pathology as in FTLD-TARDBP.

VCP (valosin containing protein), a member of the AAA+ protein family, is critical for many cellular processes and functions. Dominant VCP mutations cause a rare neurodegenerative disease known as multisystem proteinopathy (MSP). The spectrum of mechanisms causing fronto-temporal dementia with TARDBP/TDP-43 inclusions (FTLD-TARDBP) by VCP disease mutations remains unclear. Our recent work identified VCP activity as a mediator of FTLD-TARDBP. Specifically, brain atrophy, behavioral changes, neuronal loss, gliosis, and TARDBP pathology were observed in vcp conditional knockout (cKO) mice. We also found that autophago-lysosomal dysfunction, TARDBP inclusions, and ubiquitin-proteasome impairment precede neuronal loss. We further studied conditional expression of the disease-associated mutation VCPR155C in vcp-null mice. We observed features similar to those of VCP inactivation, suggesting that VCP mutation is hypomorphic. Furthermore, proteomic, and transcriptomic signatures in vcp cKO mice resemble those of GRN/Progranulin carriers. Therefore, VCP is essential for neuronal survival by several mechanisms and could be a therapeutic target aimed at restoring protein homeostasis in patients with FTLD-TARDBP.

IIIM-941, a Stilbene Derivative Inhibits NLRP3 Inflammasome Activation by Inducing Autophagy.

Aberrant activation of NLRP3 inflammasome has been implicated in several inflammatory diseases. Autophagy is one of the primary mechanisms that regulate NLRP3 inflammasome activity. In this study, we attempted to target NLRP3 inflammasome activity by a synthetic compound IIIM-941. We found that IIIM-941 inhibits ATP induced NLRP3 inflammasome by induction of autophagy through AMPK pathway in bone marrow derived macrophages (BMDMs) and J774A.1 cells. It was interesting to observe that IIIM-941 did not show any inhibitory activity against LPS induced pro-inflammatory cytokines TNF-α and IL-6. The anti-NLRP3 activity of IIIM-941 was significantly reversed when we attempted to block autophagy by using either pharmacological inhibitor bafilomycin A1or by using siRNA against AMPK. Further, we found that IIIM-941 downregulated the expression of NLRP3 and prevented the oligomerization of ASC to exert its anti-NLRP3 inflammasome effect in J774A.1 cells. We validated inhibitory activity of IIIM-941 against NLRP3 in three different mice models. The anti-inflammatory effect of IIIM-941 was highly significant in ATP induced peritoneal inflammation model. IIIM-941 was similarly effective in suppressing MSU induced IL-1ß in the air pouch model of inflammation without affecting the levels of TNF-α and IL-6. Finally, oral efficacy of IIIM-941 was also proved in MSU indued foot paw edema model of inflammation in mice at 10 and 20 mg/kg (b.w.). The compounds like IIIM-941 can be explored further for the development of therapies against diseases such as Alzheimer's disease and Parkinson's disease, where hampered autophagy and NLRP3 activation play a crucial role in the pathological development.

Crocetin promotes clearance of amyloid-ß by inducing autophagy via the STK11/LKB1-mediated AMPK pathway.

Alzheimer disease (AD) is usually accompanied by two prominent pathological features, cerebral accumulation of amyloid-ß (Aß) plaques and presence of MAPT/tau neurofibrillary tangles. Dysregulated clearance of Aß largely contributes to its accumulation and plaque formation in the brain. Macroautophagy/autophagy is a lysosomal degradative process, which plays an important role in the clearance of Aß. Failure of autophagic clearance of Aß is currently acknowledged as a contributing factor to increased accumulation of Aß in AD brains. In this study, we have identified crocetin, a pharmacologically active constituent from the flower stigmas of Crocus sativus, as a potential inducer of autophagy in AD. In the cellular model, crocetin induced autophagy in N9 microglial and primary neuron cells through STK11/LKB1 (serine/threonine kinase 11)-mediated AMP-activated protein kinase (AMPK) pathway activation. Autophagy induction by crocetin significantly increased Aß clearance in N9 cells. Moreover, crocetin crossed the blood-brain barrier and induced autophagy in the brains' hippocampi of wild-type male C57BL/6 mice. Further studies in transgenic male 5XFAD mice, as a model of AD, revealed that one-month treatment with crocetin significantly reduced Aß levels and neuroinflammation in the mice brains and improved memory function by inducing autophagy that was mediated by AMPK pathway activation. Our findings support further development of crocetin as a pharmacological inducer of autophagy to prevent, slow down progression, and/or treat AD.Abbreviations: Aß: amyloid-ß; ABCB1/P-gp/P-glycoprotein: ATP-binding cassette, subfamily B (MDR/TAP), member 1; AD: Alzheimer disease; AMPK/PRKAA: AMP-activated protein kinase; APP: amyloid beta (A4) precursor protein; ATG: autophagy related; BBB: blood-brain barrier; BECN1: beclin 1, autophagy related; CAMKK2/CaMKKß: calcium/calmodulin-dependent protein kinase kinase 2, beta; CSE: Crocus sativus extract; CTSB: cathepsin B; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; GFAP: glial fibrillary acidic protein; GSK3B/GSK3ß: glycogen synthase kinase 3 beta; Kp: brain partition coefficient; LRP1: low density lipoprotein receptor-related protein 1; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAP2: microtubule-associated protein 2; MAPK/ERK: mitogen-activated protein kinase; MAPT/tau: microtubule-associated protein tau; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MTOR: mechanistic target of rapamycin kinase; MWM: Morris water maze; NFKB/NF-κB: nuclear factor of kappa light polypeptide gene enhancer in B cells; NMDA: N-methyl-d-aspartic acid; RPTOR: regulatory associated protein of MTOR; RPS6KB1/p70S6K: ribosomal protein S6 kinase 1; SQSTM1: sequestosome 1; SRB: sulforhodamine B; STK11/LKB1: serine/threonine kinase 11; TFEB: transcription factor EB; TSC2: TSC complex subunit 2; ULK1: unc-51 like kinase 1.

Neuronal VCP loss of function recapitulates FTLD-TDP pathology.

The pathogenic mechanism by which dominant mutations in VCP cause multisystem proteinopathy (MSP), a rare neurodegenerative disease that presents as fronto-temporal lobar degeneration with TDP-43 inclusions (FTLD-TDP), remains unclear. To explore this, we inactivate VCP in murine postnatal forebrain neurons (VCP conditional knockout [cKO]). VCP cKO mice have cortical brain atrophy, neuronal loss, autophago-lysosomal dysfunction, and TDP-43 inclusions resembling FTLD-TDP pathology. Conditional expression of a single disease-associated mutation, VCP-R155C, in a VCP null background similarly recapitulates features of VCP inactivation and FTLD-TDP, suggesting that this MSP mutation is hypomorphic. Comparison of transcriptomic and proteomic datasets from genetically defined patients with FTLD-TDP reveal that progranulin deficiency and VCP insufficiency result in similar profiles. These data identify a loss of VCP-dependent functions as a mediator of FTLD-TDP and reveal an unexpected biochemical similarity with progranulin deficiency.

Naringenin Upregulates AMPK-Mediated Autophagy to Rescue Neuronal Cells From ß-Amyloid (1-42) Evoked Neurotoxicity.

Deposition of an amyloid-ß peptide is one of the first events in the pathophysiology of Alzheimer's disease (AD) and is clinically characterized by Aß plaques, tau tangles, and behavioral impairments that lead to neuronal death. A substantial number of studies encourage targeting the skewness in the production and degradation of amyloid-ß could be among the promising therapies in the disease. Neuronal autophagy has emerged for an essential role in the degradation of such toxic aggregate-prone proteins in various neurodegenerative diseases. We profiled a small library of common dietary compounds and identified those that can enhance autophagy in neuronal cells. Here we noted naringenin in silico exhibits a robust affinity with AMP-activated protein kinase (AMPK) and upregulated AMPK-mediated autophagy signaling in neurons. Naringenin can induce autophagy promoting proteins such as ULK1, Beclin1, ATG5, and ATG7 in Neuro2a cells and primary mouse neurons as well. The knockdown of AMPK by siRNA-AMPK was complemented by naringenin that restored transcript levels of AMPK. Further, naringenin can reduce the levels of Aß at a nontoxic concentration from neuronal cells. Moreover, it maintained the mitochondrial membrane potential and resisted reactive oxygen species production, which led to the protection against Aß1-42 evoked neurotoxicity. This highlights the neuroprotective potential of naringenin that can be developed as an anti-amyloidogenic nutraceutical.

Murrayanine Attenuates Lipopolysaccharide-induced Inflammation and Protects Mice from Sepsis-associated Organ Failure.

Murrayanine (MK) is the main compound isolated from Murraya koenigii, an aromatic plant belonging to the Rutaceae family, also known as curry leaf tree. Murrayanine was reported to possess potential antioxidant, antimycobacterial and antifungal effects. However, its effect in sepsis remains unclear. This study was designed to investigate the anti-inflammatory effect of MK using both in vitro and in vivo assay. Results of this study indicated that MK decreased NO, TNF-α and IL-6 production in both lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and murine peritoneal macrophages. Moreover, iNOS and COX-2 protein expression as well as their downstream product, PGE2, was also decreased effectively in RAW 264.7 cells. Furthermore, MK decreased the phosphorylation of IKB and repressed NF-kB activity in LPS-activated RAW 264.7 cells. Additionally, we evaluated MK efficacy in vivo using LPS-induced sepsis, a systemic inflammation model in mice. Administration of MK inhibits pro-inflammatory cytokines (TNF-α and IL-6) secretion; decreases AST, ALT, BUN and CRE level in mouse sera; mitigates lung, liver and kidney injuries; and also increases LPS-challenged mice survival rate. Collectively, our results suggest that MK exerts potential as a new anti-inflammatory and immunosuppressive drug in sepsis treatment.