In silico and network pharmacology analysis of fucosterol: a potent anticancer bioactive compound against HCC.

The Fucaceae family of marine brown algae includes Ascophyllum nodosum. Fucosterol (FSL) is a unique bioactive component that was identified through GC-MS analysis of the hydroalcoholic extract of A. nodosum. Fucosterol's mechanism of action towards hepatocellular cancer was clarified using network pharmacology and docking study techniques. The probable target gene of FSL has been predicted using the TargetNet and SwissTargetPred databases. GeneCards and the DisGNet database were used to check the targeted genes of FSL. By using the web programme Venny 2.1, the overlaps of FSL and HCC disease demonstrated that 18 genes (1.3%) were obtained as targeted genes Via the STRING database, a protein-protein interaction (PPI) network with 18 common target genes was constructed. With the aid of CytoNCA, hub genes were screened using the Cytoscape software, and the targets' hub genes were exported into the ShinyGo online tool for study of KEGG and gene ontology enrichment. Using the software AutoDock, a hub gene molecular docking study was performed. Ten genes, including AR, CYP19A1, ESR1, ESR2, TNF, PPARA, PPARG, HMGCR, SRC, and IGF1R, were obtained. The 10 targeted hubs docked with FSL successfully. The active components FSL of ASD, the FSL, are engaged in fatty liver disease, cancer pathways, and other signalling pathways, which could prove beneficial for the management of HCC.

Characterization of a Myeloid Differentiation Factor 2-Derived Peptide that Facilitates THP-1 Macrophage-Mediated Phagocytosis of Gram-Negative Bacteria.

Myeloid differentiation factor 2 (MD2), the TLR4 coreceptor, has been shown to possess opsonic activity and has been implicated in phagocytosis and intracellular killing of Gram-negative bacteria. However, any MD2 protein segment involved in phagocytosis of Gram-negative bacteria is not yet known. A short synthetic MD2 segment, MD54 (amino acid regions 54 to 69), was shown to interact with a Gram-negative bacterial outer membrane component, LPS, earlier. Furthermore, the MD54 peptide induced aggregation of LPS and facilitated its internalization in THP-1 cells. Currently, it has been investigated if MD2-derived MD54 possesses any opsonic property and role in phagocytosis of Gram-negative bacteria. Remarkably, we observed that MD54 facilitated agglutination of Gram-negative bacteria, Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC BAA-427), but not of Gram-positive bacteria, Bacillus subtilis (ATCC 6633) and Staphylococcus aureus (ATCC 25923). The MD54-opsonized Gram-negative bacteria internalized within PMA-treated THP-1 cells and were killed over a longer incubation period. However, both internalization and intracellular killing of the MD54-opsonized Gram-negative bacteria within THP-1 phagocytes were appreciably inhibited in the presence of a phagocytosis inhibitor, cytochalasin D. Furthermore, MD54 facilitated the clearance of Gram-negative bacteria E. coli (ATCC 25922) and P. aeruginosa (ATCC BAA-427) from the infected BALB/c mice whereas an MD54 analog, MMD54, was inactive. Overall, for the first time, the results revealed that a short MD2-derived peptide can specifically agglutinate Gram-negative bacteria, act as an opsonin for these bacteria, and facilitate their phagocytosis by THP-1 phagocytes. The results suggest that the MD54 segment could have a crucial role in MD2-mediated host-pathogen interaction involving the Gram-negative bacteria.

Correction: Yadav et al. PLGA-Quercetin Nano-Formulation Inhibits Cancer Progression via Mitochondrial Dependent Caspase-3,7 and Independent FoxO1 Activation with Concomitant PI3K/AKT Suppression. Pharmaceutics 2022, 14, 1326.

In the published publication [...].

Shaping the Future of Antimicrobial Therapy: Harnessing the Power of Antimicrobial Peptides in Biomedical Applications.

Antimicrobial peptides (AMPs) have emerged as a promising class of bioactive molecules with the potential to combat infections associated with medical implants and biomaterials. This review article aims to provide a comprehensive analysis of the role of antimicrobial peptides in medical implants and biomaterials, along with their diverse clinical applications. The incorporation of AMPs into various medical implants and biomaterials has shown immense potential in mitigating biofilm formation and preventing implant-related infections. We review the latest advancements in biomedical sciences and discuss the AMPs that were immobilized successfully to enhance their efficacy and stability within the implant environment. We also highlight successful examples of AMP coatings for the treatment of surgical site infections (SSIs), contact lenses, dental applications, AMP-incorporated bone grafts, urinary tract infections (UTIs), medical implants, etc. Additionally, we discuss the potential challenges and prospects of AMPs in medical implants, such as effectiveness, instability and implant-related complications. We also discuss strategies that can be employed to overcome the limitations of AMP-coated biomaterials for prolonged longevity in clinical settings.

Network pharmacology of apigeniflavan: a novel bioactive compound of Trema orientalis Linn. in the treatment of pancreatic cancer through bioinformatics approaches.

Pancreatic cancer is the seventh most prevalent cause of mortality globally. Since time immemorial, plant-derived products have been in use as therapeutic agents due to the existence of biologically active molecules called secondary metabolites. Flavonoids obtained from plants participate in cell cycle arrest, induce autophagy and apoptosis, and decrease oxidative stress in pancreatic cancer. The present study involves network pharmacology-based study of the methanolic leaf extract of Trema orientalis (MLETO) Linn. From the high-resolution mass spectrometry (HRMS) analysis, 21 nucleated flavonoids were screened out, of which only apigeniflavan was selected for further studies because it followed Lipinski's rule and showed no toxicity. The pharmacokinetics and physiochemical characteristics of apigeniflavan were performed using the online web servers pkCSM, Swiss ADME, and ProTox-II. This is the first in silico study to report the efficiency of apigeniflavan in pancreatic cancer treatment. The targets of apigeniflavan were fetched from SwissTargetPrediction database. The targets of pancreatic cancer were retrieved from DisGeNET and GeneCards. The protein-protein interaction of the common genes using Cytoscape yielded the top five hub genes: KDR, VEGFA, AKT1, SRC, and ESR1. Upon molecular docking, the lowest binding energies corresponded to best docking score which indicated the highest protein-ligand affinity. Kyoto Encyclopaedia of Genes and Genomes (KEGG) database was employed to see the involvement of hub genes in pathways related to pancreatic cancer. The following, pancreatic cancer pathway, MAPK, VEGF, PI3K-Akt, and ErbB signaling pathways, were found to be significant. Our results indicate the involvement of the hub genes in tumor growth, invasion and proliferation in the above-mentioned pathways, and therefore necessitating their downregulation. Moreover, apigeniflavan can flourish as a promising drug for the treatment of pancreatic cancer in future.

Network pharmacology-based anti-pancreatic cancer potential of kaempferol and catechin of Trema orientalis L. through computational approach.

In pancreatic cancer, healthy cells in the pancreas begin to malfunction and proliferate out of control. According to our conventional knowledge, many plants contain several novel bioactive compounds, having pharmaceutical applications for the treatment of disease like pancreatic cancer. The methanolic fraction of fruit extract of Trema orientalis L. (MFETO) was analysed through HRMS. In this in silico study, pharmacokinetic and physicochemical properties of the identified flavonoids from MFETO were screened out by ADMET analysis. Kaempferol and catechin followed Lipinski rules and showed no toxicity in Protox II. Targets of these compounds were taken from SwissTarget prediction and TCMSP whilst targets for pancreatic cancer were taken from GeneCards and DisGeNET databases. The protein-protein interaction (PPI) network of common genes was generated through STRING and then exported to the Cytoscape to get top 5 hub genes (AKT1, SRC, EGFR, TNF, and CASP3). The interaction between compounds and hub genes was analysed using molecular docking, and high binding affinity between them can be visualised by Biovia discovery studio visualizer. Our study shows that, five hub genes related to pancreatic cancer play an important role in tumour growth induction, invasion and migration. Kaempferol effectively check cell migration by inhibiting ERK1/2, EGFR-related SRC, and AKT pathways by scavenging ROS whilst catechin inhibited TNFα-induced activation and cell cycle arrest at G1 and G2/M phases by induction of apoptosis of malignant cells. Kaempferol and catechin containing MFETO can be used for formulation of potent drugs for pancreatic cancer treatment in future.

A review article on neuroprotective, immunomodulatory, and anti-inflammatory role of vitamin-D3 in elderly COVID-19 patients.

Vitamin D3 is a secosteroid, broad-spectrum immunomodulatory, antioxidant, and anti-inflammatory hormone produced either by the internal subcutaneous pathway in the presence of ultraviolet B (UVB) rays or by the external pathway in the form of supplements. Vitamin D3 deficiency is a common and reversible contributor to mortality and morbidity among critically ill patients, including Coronavirus Disease 2019 (COVID-19) and other viral infections. The major functions of vitamin D3 are inhibiting the proinflammatory pathways, including nuclear factor kappa B (NF-kB), inflammatory cytokines, such as interleukin-6 (ILs-6), interleukin-18 (ILs-18), and tumour necrosis factor (TNF), preventing the loss of neural sensation in COVID-19, maintaining respiratory homeostasis, and acting as an antiviral, antimalarial, and antihypertensive agent. Vitamin D3 has an important role in reversing the COVID-19 infection in patients who have previously suffered from a neurological disease, such as Alzheimer's disease, Parkinson disease, motor neuron disease, multiple sclerosis, Creutzfeldt-Jakob disease, stroke, cardiovascular problems, headache, sleep-associated disorder, and others. Moreover, vitamin D3 plays a key role in regulating the gene expression of different pro-inflammatory cytokines. In addition to the information provided above, the current review article provides the most recent information on Vitamin D against COVID-19 with comorbid neurological disorders. Furthermore, we present the most recent advancement and molecular mechanism of action of vitamin D3. Diabetes, cardiovascular disease, and neurological disorders are comorbid conditions, and vitamin D3 is a critical regulator of COVID-19 infection during these conditions. In the midst of the COVID-19 epidemic, factors such as sex, latitudes, nutrition, demography, pollution, and gut microbiota warrants for additional research on vitamin D supplements.

Molecular and Therapeutic Insights of Alpha-Lipoic Acid as a Potential Molecule for Disease Prevention.

Alpha-lipoic acid is an organic, sulfate-based compound produced by plants, humans, and animals. As a potent antioxidant and a natural dithiol compound, it performs a crucial role in mitochondrial bioenergetic reactions. A healthy human body, on the other hand, can synthesize enough α-lipoic acid to scavenge reactive oxygen species and increase endogenous antioxidants; however, the amount of α-lipoic acid inside the body decreases significantly with age, resulting in endothelial dysfunction. Molecular orbital energy and spin density analysis indicate that the sulfhydryl (-SH) group of molecules has the greatest electron donating activity, which would be responsible for the antioxidant potential and free radical scavenging activity. α-Lipoic acid acts as a chelating agent for metal ions, a quenching agent for reactive oxygen species, and a reducing agent for the oxidized form of glutathione and vitamins C and E. α-Lipoic acid enantiomers and its reduced form have antioxidant, cognitive, cardiovascular, detoxifying, anti-aging, dietary supplement, anti-cancer, neuroprotective, antimicrobial, and anti-inflammatory properties. α-Lipoic acid has cytotoxic and antiproliferative effects on several cancers, including polycystic ovarian syndrome. It also has usefulness in the context of female and male infertility. Although α-lipoic acid has numerous clinical applications, the majority of them stem from its antioxidant properties; however, its bioavailability in its pure form is low (approximately 30%). However, nanoformulations have shown promise in this regard. The proton affinity and electron donating activity, as a redox-active agent, would be responsible for the antioxidant potential and free radical scavenging activity of the molecule. This review discusses the most recent clinical data on α-lipoic acid in the prevention, management, and treatment of a variety of diseases, including coronavirus disease 2019. Based on current evidence, the preclinical and clinical potential of this molecule is discussed. Supplementary Information: The online version contains supplementary material available at 10.1007/s43450-023-00370-1.

Role of Anti-Cancer Peptides as Immunomodulatory Agents: Potential and Design Strategy.

The usage of peptide-based drugs to combat cancer is gaining significance in the pharmaceutical industry. The collateral damage caused to normal cells due to the use of chemotherapy, radiotherapy, etc. has given an impetus to the search for alternative methods of cancer treatment. For a long time, antimicrobial peptides (AMPs) have been shown to display anticancer activity. However, the immunomodulatory activity of anti-cancer peptides has not been researched very extensively. The interconnection of cancer and immune responses is well-known. Hence, a search and design of molecules that can show anti-cancer and immunomodulatory activity can be lead molecules in this field. A large number of anti-cancer peptides show good immunomodulatory activity by inhibiting the pro-inflammatory responses that assist cancer progression. Here, we thoroughly review both the naturally occurring and synthetic anti-cancer peptides that are reported to possess both anti-cancer and immunomodulatory activity. We also assess the structural and biophysical parameters that can be utilized to improve the activity. Both activities are mostly reported by different groups, however, we discuss them together to highlight their interconnection, which can be used in the future to design peptide drugs in the field of cancer therapeutics.

10-Residue MyD88-Peptide Adopts ß-Sheet Structure, Self-Assembles, Binds to Lipopolysaccharides, and Rescues Mice from Endotoxin-Mediated Lung-Infection and Death.

Naturally occurring cationic antimicrobial peptides (AMPs) mostly adopt α-helical structures in bacterial membrane mimetic environments. To explore the design of novel ß-sheet AMPs, we identified two short cationic amphipathic ß-strand segments from the crystal structure of the innate immune protein, MyD88. Interestingly, of these, the 10-residue arginine-valine-rich synthetic MyD88-segment, KRCRRMVVVV (M3), exhibited ß-sheet structure when bound to the outer membrane Gram-negative bacterial component, LPS. Isothermal titration calorimetric data showed that M3 bound to LPS with high affinity, and the interaction was hydrophobic in nature. Supporting these observations, computational studies indicated strong interactions of multiple and consecutive valine residues of M3 with the acyl chain of LPS. Moreover, M3 adopted nanosheet and nanofibrillar structure in 25% acetonitrile/water and isopropanol, respectively. M3 showed substantial antibacterial activities against both Gram-positive and Gram-negative bacteria which it appreciably retained in the presence of human serum and physiological salts. M3 was non-hemolytic against human red blood cells and non-cytotoxic to 3T3 cells up to 200 µM and to mice in vivo at a dose of 40 mg/kg. Furthermore, M3 neutralized LPS-induced pro-inflammatory responses in THP-1 cells and rat bone marrow-derived macrophages. Consequently, M3 attenuated LPS-mediated lung inflammation in mice and rescued them (80% survival at 10 mg/kg dose) against a lethal dose of LPS. The results demonstrate the identification of a 10-mer LPS-interacting, ß-sheet peptide from MyD88 with the ability to form nanostructures and in vivo activity against LPS challenge in mice. The identified M3-template provides scope for designing novel bioactive peptides with ß-sheet structures and self-assembling properties.

Therapeutic potential of short-chain fatty acid production by gut microbiota in neurodegenerative disorders.

Dietary fibers are a major source of short-chain fatty acids (SCFAs) in the body, and the fermentation products of SCFAs induced by intestinal microbiota affect energy metabolism. Apart from serving as an energy source in the intestines, SCFAs also inhibit autophagy, nucleotide-binding oligomerization domain-containing protein, LRR, and pyrin domain-containing protein 3 inflammasome. SCFAs provide numerous therapeutic benefits through their influence on cognitive functioning and neurodegenerative diseases (NDD) pathophysiology. Additionally, NDDs are associated with abnormalities in the gut microbiota, including an increased load of pathogens and opportunistic microbes. SCFAs maintain the healthy mitochondrial function and stimulate the maturation of microglia, which consequently suppresses the progression of NDD and cognitive decline by regulating inflammation and oxidative stress. Basically, SCFAs function as cofactors for the host's mitochondrial enzymes and are being studied for their ability to reverse the alteration in the gut microbiota seen in many NDDs and cardiac diseases. In the present review, the focus is on the detrimental and beneficial roles of SCFAs in NDD, emphasizing the effects of SCFA on following phenomenon: (1) alteration in gut microbiota profile associated with NDD, (2) the molecular mechanism of metabolic regulation by SCFA's, and its co-relation with NDD, (3) use of mitochondrial antioxidants as a strategy for maintaining microbiota diversity in the gut, and (4) the future direction of metabolism and neurodegeneration in the gut-brain axis. In addition, the interplay between gut microbiota, SCFAs, epithelial barrier, and neuroimmune signaling in neurodegeneration has been reviewed.

PLGA-Quercetin Nano-Formulation Inhibits Cancer Progression via Mitochondrial Dependent Caspase-3,7 and Independent FoxO1 Activation with Concomitant PI3K/AKT Suppression.

Quercetin is one of the most important plant flavanols, having several pharmacological and biological uses. Quercetin (Q) is an extremely hydrophobic phytochemical and has poor intracellular absorption, which makes its use limited. Present research demonstrates that quercetin-loaded PLGA nanoparticles (PLGA-QNPs) could overcome its low hydrophilicity and improve its anti-cancer potential. PLGA nanoparticles loaded with Q were prepared by the solvent evaporation technique and its anticancer activity was examined in vitro as well as in vivo. The cell viability was assessed through MTT assay and apoptosis was assayed through Hoechst-PI and EB/AO double staining followed by mitochondrial damage through Mito-tracker RMX-Ros. Gene expression was examined through RT-PCR. Cell cycle arrest in G2/M phase was analyzed through FACS. The results obtained revealed that PLGA-QNPs significantly reduced the viability of human cervical and breast cancer cell lines. PLGA-QNPs induced apoptosis in human cervical cancer cells in a dose dependent manner. The gene expression of PI3K/AKT was down-regulated and FoxO1 was upregulated in PLGA-QNP-treated cells, which showed a high expression level of active Caspase-3 and 7, which are responsible for apoptosis. In addition, PLGA-QNPs reduced the average number of tumors and prolonged the tumor latency period in DMBA-induced mammary adenocarcinoma SD rats. These findings suggest that PLGA-QNPs inhibit cervical and breast cancer progression via mitochondrial dependent Caspase-3 and 7 and mitochondrial independent FoxO1 activation with concomitant suppression of the PI3K/AKT pathway. For future studies, we suggest that potential druggability efficacy and clinical development of anticancer PLGA-QNPs need to be evaluated intensely for successful anticancer drug development.

Molecular and pharmacological aspects of piperine as a potential molecule for disease prevention and management: evidence from clinical trials.

BACKGROUND: Piperine is a type of amide alkaloid that exhibits pleiotropic properties like antioxidant, anticancer, anti-inflammatory, antihypertensive, hepatoprotective, neuroprotective and enhancing bioavailability and fertility-related activities. Piperine has the ability to alter gastrointestinal disorders, drug-metabolizing enzymes, and bioavailability of several drugs. The present review explores the available clinical and preclinical data, nanoformulations, extraction process, structure-activity relationships, molecular docking, bioavailability enhancement of phytochemicals and drugs, and brain penetration properties of piperine in the prevention, management, and treatment of various diseases and disorders. MAIN BODY: Piperine provides therapeutic benefits in patients suffering from diabetes, obesity, arthritis, oral cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Parkinson's disease, Alzheimer's disease, cerebral stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The molecular basis for the pleiotropic activities of piperine is based on its ability to regulate multiple signaling molecules such as cell cycle proteins, anti-apoptotic proteins, P-glycoprotein, cytochrome P450 3A4, multidrug resistance protein 1, breast cancer resistance protein, transient receptor potential vanilloid 1 proinflammatory cytokine, nuclear factor-κB, c-Fos, cAMP response element-binding protein, activation transcription factor-2, peroxisome proliferator-activated receptor-gamma, Human G-quadruplex DNA, Cyclooxygenase-2, Nitric oxide synthases-2, MicroRNA, and coronaviruses. Piperine also regulates multiple signaling pathways such as Akt/mTOR/MMP-9, 5'-AMP-activated protein kinase-activated NLR family pyrin domain containing-3 inflammasome, voltage-gated K+ current, PKCα/ERK1/2, NF-κB/AP-1/MMP-9, Wnt/ß-catenin, JNK/P38 MAPK, and gut microbiota. SHORT CONCLUSION: Based on the current evidence, piperine can be the potential molecule for treatment of disease, and its significance of this molecule in the clinic is discussed.

Genetically modified crops: current status and future prospects.

MAIN CONCLUSION: While transgenic technology has heralded a new era in crop improvement, several concerns have precluded their widespread acceptance. Alternative technologies, such as cisgenesis and genome-editing may address many of such issues and facilitate the development of genetically engineered crop varieties with multiple favourable traits. Genetic engineering and plant transformation have played a pivotal role in crop improvement via introducing beneficial foreign gene(s) or silencing the expression of endogenous gene(s) in crop plants. Genetically modified crops possess one or more useful traits, such as, herbicide tolerance, insect resistance, abiotic stress tolerance, disease resistance, and nutritional improvement. To date, nearly 525 different transgenic events in 32 crops have been approved for cultivation in different parts of the world. The adoption of transgenic technology has been shown to increase crop yields, reduce pesticide and insecticide use, reduce CO2 emissions, and decrease the cost of crop production. However, widespread adoption of transgenic crops carrying foreign genes faces roadblocks due to concerns of potential toxicity and allergenicity to human beings, potential environmental risks, such as chances of gene flow, adverse effects on non-target organisms, evolution of resistance in weeds and insects etc. These concerns have prompted the adoption of alternative technologies like cisgenesis, intragenesis, and most recently, genome editing. Some of these alternative technologies can be utilized to develop crop plants that are free from any foreign gene hence, it is expected that such crops might achieve higher consumer acceptance as compared to the transgenic crops and would get faster regulatory approvals. In this review, we present a comprehensive update on the current status of the genetically modified (GM) crops under cultivation. We also discuss the issues affecting widespread adoption of transgenic GM crops and comment upon the recent tools and techniques developed to address some of these concerns.

Integrating the dynamics of yield traits in rice in response to environmental changes.

Reductions in crop yields as a consequence of global climate change threaten worldwide food security. It is therefore imperative to develop high-yielding crop plants that show sustainable production under stress conditions. In order to achieve this aim through breeding or genetic engineering, it is crucial to have a complete and comprehensive understanding of the molecular basis of plant architecture and the regulation of its sub-components that contribute to yield under stress. Rice is one of the most widely consumed crops and is adversely affected by abiotic stresses such as drought and salinity. Using it as a model system, in this review we present a summary of our current knowledge of the physiological and molecular mechanisms that determine yield traits in rice under optimal growth conditions and under conditions of environmental stress. Based on physiological functioning, we also consider the best possible combination of genes that may improve grain yield under optimal as well as environmentally stressed conditions. The principles that we present here for rice will also be useful for similar studies in other grain crops.

Liquid chromatography-tandem mass spectrometry based method development and validation of S016-1271 (LR8P), a novel cationic antimicrobial peptide for its application to pharmacokinetic studies.

S016-1271 (LR8P) is a broad spectrum novel cationic antimicrobial peptide. The objective of the present study was to develop a selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) based bioanalytical method of S016-1271 peptide in mice and human plasma in order to uncover its pharmacokinetic aspects. The chromatographic separation of S016-1271 (FR8P as internal standard) was achieved on a Waters™ X select CSH-C18 column (75 × 3.0 mm, 2.5 µ) using mixture of acetonitrile and triple distilled water (TDW) both containing 0.05% formic acid as mobile phase. A seven minute linear gradient method was designed to separate analytes from ion suppression at a flow rate of 0.3 mL/min. The extraction of analytes from mice and human plasma was performed through solid phase extraction technique using mixed mode weak cation exchange cartridge (Thermo SOLA WCX 10 mg 1CC) with an extraction recovery of analytes about 75%. Mass spectrometric detection of S016-1271 and FR8P was performed with optimized multiple reaction monitoring (MRM) transitions (Q1/Q3) at 658.8 [M+3H] 3+/653.2 [M+3H-NH3] 3+ and 443.4 [M+5H]5+ /434.7 [y12-NH3]4+,respectively in positive electrospray ionization (ESI) mode. The linearity in mice and human plasma was established over a concentration range of 7.81-250 ng/mL with regression coefficient (r2 > 0.99). The currently developed method was validated as per US-FDA guidelines and found to be within the acceptable limits. The method was successfully applied to intravenous (IV) pharmacokinetic study in mice wherein the levels were detected upto 24 h. The peptide demonstrated poor distribution characteristics which were demonstrated through volume of distribution at steady state (202.71 ± 47.02 mL/kg less than total body water of mice; 580 mL/kg). The clearance of the peptide predominantly occurred through central compartment (central clearance is 25 fold greater than peripheral clearance). Also, the in vitro pharmacokinetic studies demonstrated the stability of S016-1271 in plasma and high plasma protein binding in mice and humans.

HIV-1 Nef CAWLEAQ motif: a regulator of monocytes invasion through ENO1 modulation.

HIV-1 transmission and spread involves significant host-virus interaction. Possible targets for obstacle of HIV-1 lie at the site of mucosal barriers. Thus a better understanding of how HIV-1 infects target cells at such sites and leads their invasion is required, with prime focus on the host determinants regulating HIV-1 spread. For the viral infectivity and pathogenicity, HIV-1 Nef facilitates immune evasion through protein-protein interactions within host cell. HIV-1 Nef is significant for viral infectivity and pathogenicity. It enhances HIV-1 replication, facilitating immune evasion by interacting with various host factors and altering cellular pathways via multiple protein-protein interactions. In this study, HIV-1 Nef forms with specific mutations, revealing sequence variability, were studied for their effects in human SupT1 T cell line and (THP-1) monocyte-macrophage cell line. Proteins being downregulated by Nef in SupT1 were further observed in THP-1, and interestingly two host proteins' (ENO-1 and VDAC1) expression was found to be cell lineage specific, being stimulatory in macrophages/monocytes and inhibitory in T cells. Cell migration, invasion and ADP release studies were employed to determine the biological function affected by Nef-mediated regulation of these two host proteins. ENO1-regulated function: cell invasion was enhanced in THP-1 cells, but was inhibited in SupT1 cells by Nef RP01. In addition, the modulation of proteins and cell invasion remained unaffected by a Nef RP14. These results indicated that regulation of host protein expression and invasive property of host cells by Nef was sequence specific, suggesting involvement of a particular motif of Nef. To precisely determine this site, we designed a heptapeptide including the CAWLEAQ-regulating sequence of Nef. Macrophages/monocytes being the major cells affected by HIV-1 at mucosal barriers were particularly investigated by the peptide. The peptide led to reversal of differential expressions of ENO1 in both SupT1 and THP-1 and inhibition of enhanced invasiveness in THP-1 cells. Further AP-1 was identified as a factor involved in this Nef-mediated regulation of host proteins. Together these findings suggest a possible mechanism of host invasion by HIV-1 through the CAWLEAQ motif of Nef-mediated regulation of ENO1 and identify a potential therapeutic target for HIV-1 entry at mucosal barriers.

An MD2-derived peptide promotes LPS aggregation, facilitates its internalization in THP-1 cells, and inhibits LPS-induced pro-inflammatory responses.

MD2, a 160-residue accessory glycoprotein, is responsible for the recognition and binding of Gram-negative bacterial membrane component, lipopolysaccharide (LPS). Internalization of pathogen inside the mononuclear phagocytes has also been attributed to MD2 which leads to the clearance of pathogens from the host. However, not much is known about the segments in MD2 that are responsible for LPS interaction or internalization of pathogen inside the defense cells. A 16-residue stretch (MD54) from MD2 protein has been identified that possesses a short heptad repeat sequence and four cationic residues enabling it to participate in both hydrophobic and electrostatic interactions with LPS. An MD54 analog of the same size was also designed in which a leucine residue at a heptadic position was replaced with an alanine residue. MD54 but not its analog, MMD54 induced aggregation of LPS and aided in its internalization within THP-1 monocytes. Furthermore, MD54 inhibited LPS-induced nuclear translocation of NF-κB in PMA-treated THP-1 and TLR4/MD2/CD14-transfected HEK-293T cells and the production of pro-inflammatory cytokines. In addition, in in vivo experiments, MD54 showed marked protection and survival of mice against LPS-induced inflammation and death. Overall, we have identified a short peptide with heptad repeat sequence from MD2 that can cause aggregation of LPS and abet in its internalization within THP-1 cells, resulting in attenuation of LPS-induced pro-inflammatory responses in vitro and in vivo.

Knockdown of an inflorescence meristem-specific cytokinin oxidase - OsCKX2 in rice reduces yield penalty under salinity stress condition.

Cytokinins play a significant role in determining grain yield in plants. Cytokinin oxidases catalyse irreversible degradation of cytokinins and hence modulate cellular cytokinin levels. Here, we studied the role of an inflorescence meristem-specific rice cytokinin oxidase - OsCKX2 - in reducing yield penalty under salinity stress conditions. We utilized an RNAi-based approach to study the function of OsCKX2 in maintaining grain yield under salinity stress condition. Ultra-performance liquid chromatography-based estimation revealed a significant increase in cytokinins in the inflorescence meristem of OsCKX2-knockdown plants. To determine if there exists a correlation between OsCKX2 levels and yield under salinity stress condition, we assessed the growth, physiology and grain yield of OsCKX2-knockdown plants vis-à-vis the wild type. OsCKX2-knockdown plants showed better vegetative growth, higher relative water content and photosynthetic efficiency and reduced electrolyte leakage as compared with the wild type under salinity stress. Importantly, we found a negative correlation between OsCKX2 expression and plant productivity as evident by assessment of agronomical parameters such as panicle branching, filled grains per plant and harvest index both under control and salinity stress conditions. These results suggest that OsCKX2, via controlling cytokinin levels, regulates floral primordial activity modulating rice grain yield under normal as well as abiotic stress conditions.

Identification of GXXXXG motif in Chrysophsin-1 and its implication in the design of analogs with cell-selective antimicrobial and anti-endotoxin activities.

Marine fish antimicrobial peptide, chrysophsin-1 possesses versatile biological activities but its non-selective nature restricts its therapeutic possibilities. Often small alterations in structural motifs result in significant changes in the properties of concerned proteins/peptides. We have identified GXXXXG motif in chrysophsin-1. Glycine residue(s) of this motif in Chrysophsin-1 was/were replaced with alanine, valine and proline residue(s). Of these, proline-substituted Chrysophsin-1 analogs exhibited significantly reduced cytotoxicity towards mammalian cells. Further, these analogs showed broad-spectrum activity against Gram-positive, Gram-negative bacteria, Methicillin-resistant Staphylococcus aureus strains and fungi and also retained antibacterial activity in presence of physiological salts, serum and at elevated temperatures indicative of their therapeutic potential. These Chrysophsin-1 analogs also inhibited lipopolysaccharide (LPS) induced pro-inflammatory responses in THP-1 cells and in murine primary macrophages. One of these single proline-substituted Chrysophsin-1 analogs inhibited LPS-stimulated pro-inflammatory cytokine production in BALB/c mice and elicited appreciable survival of mice administered with a lethal dose of LPS in a model of severe sepsis. The data for the first time showed the implication of GXXXXG motifs in functional and biological properties of an antimicrobial peptide and could be useful to design novel anti-microbial and anti-endotoxin peptides by employing this motif.