Disable 2, A Versatile Tissue Matrix Multifunctional Scaffold Protein with Multifaceted Signaling: Unveiling Role in Breast Cancer for Therapeutic Revolution

The Disabled-2 (DAB2) protein, found in 80-90% of various tumors, including breast cancer, has been identified as a potential tumor suppressor protein. On the contrary, some hypothesis suggests that DAB2 is associated with the modulation of the Ras/MAPK pathway by endocytosing the Grb/Sos1 signaling complex, which produces oncogenes and chemoresistance to anticancer drugs, leading to increased tumor growth and metastasis. DAB2 has multiple functions in several disorders and is typically under-regulated in several cancers, making it a potential target for treatment of cancer therapy. The primary function of DAB2 is the modulation of transforming growth factor- β (TGF-β) mediated endocytosis, which is involved in several mechanisms of cancer development, including tumor suppression through promoting apoptosis and suppressing cell proliferation. In this review, we will discuss in detail the mechanisms through which DAB2 leads to breast cancer and various advancements in employing DAB2 in the treatment of breast cancer. Additionally, we outlined its role in other diseases. We propose that upregulating DAB2 could be a novel approach to the therapeutics of breast cancer.

Design and synthesis of some novel hybrid molecules based on 4-thiazolidinone bearing pyridine-pyrazole scaffolds: molecular docking and molecular dynamics simulations of its major constituent onto DNA gyrase inhibition

Due to multidrug resistance, microbial infections have become significant on a global level. As infections caused by several resistant bacteria and fungi severely harm mankind, scientists have developed new antibiotics to combat these infections. In order to develop novel antimicrobial agents, a series of 4-thiazolidinone-based 5-arylidene hybrids (5a-o) have been designed and synthesized to evaluate their antibacterial and antifungal activities. For the determination of the structure of a novel synthesized hybrid, various spectral techniques, e.g., IR, 1H NMR, 13C NMR, and Mass spectroscopy, were used. Two bacterial gram-negative (Escherichia coli and Pseudomonas aeruginosa), two gram-positive strains (Staphylococcus aureus and Streptococcus pyogenes), and one fungal strain (Candida albicans) were used to evaluate antimicrobial activity. Compounds 5c, 5g, and 5i were effective due to their MIC values of 62.5 μg/mL against tested bacterial strains (S. pyogenes (5c), P. aeruginosa (5g), and E. coli (5i), respectively.) and 250 μg/mL against C. albicans fungal strains, respectively. Additionally, molecular docking and 100 ns molecular dynamic simulations were carried out to investigate the stability of molecular contacts and to establish how the newly synthesized inhibitors fit together in the most stable conformations.

Disabled-2, a versatile tissue matrix multifunctional scaffold protein with multifaceted signaling: Unveiling its potential in the cancer battle

A multifunctional scaffold protein termed Disabled-2 (Dab2) has recently gained attention in the scientific community and has emerged as a promising candidate in the realm of cancer research. Dab2 protein is involved in a variety of signaling pathways, due to which its significance in the pathogenesis of several carcinomas has drawn considerable attention. Dab2 is essential for controlling the advancement of cancer because it engages in essential signaling pathways such as the Wnt/β-catenin, epidermal growth factor receptor (EGFR), and transforming growth factor-beta (TGF-β) pathways. Dab2 can also repress epithelial-mesenchymal transition (EMT) which is involved in tumor progression with metastatic expansion and adds another layer of significance to its possible impact on cancer spread. Furthermore, the role of Dab2 in processes such as cell growth, differentiation, apoptosis, invasion, and metastasis has been explored in certain investigative studies suggesting its significance. The present review examines the role of Dab2 in the pathogenesis of various cancer subtypes including breast cancer, ovarian cancer, gastric cancer, prostate cancer, and bladder urothelial carcinoma and also sheds some light on its potential to act as a therapeutic target and a prognostic marker in the treatment of various carcinomas. By deciphering this protein's diverse signaling, we hope to provide useful insights that may pave the way for novel therapeutic techniques and tailored treatment approaches in cancer management. Preclinical and clinical trial data on the impact of Dab2 regulation in cancer have also been included, allowing us to delineate role of Dab2 in tumor suppressor function, as well as its correlation with disease stage classification and potential therapy options. However, we observed that there is very scarce data in the form of studies on the evaluation of Dab2 role and treatment function in carcinomas, and further research into this matter could prove beneficial in the generation of novel therapeutic agents for patient-centric and tailored therapy, as well as early prognosis of carcinomas.

Pathophysiological Aspects and Therapeutic Armamentarium of Alzheimer's Disease: Recent Trends and Future Development

Alzheimer's disease (AD) is the primary cause of dementia and is characterized by the death of brain cells due to the accumulation of insoluble amyloid plaques, hyperphosphorylation of tau protein, and the formation of neurofibrillary tangles within the cells. AD is also associated with other pathologies such as neuroinflammation, dysfunction of synaptic connections and circuits, disorders in mitochondrial function and energy production, epigenetic changes, and abnormalities in the vascular system. Despite extensive research conducted over the last hundred years, little is established about what causes AD or how to effectively treat it. Given the severity of the disease and the increasing number of affected individuals, there is a critical need to discover effective medications for AD. The US Food and Drug Administration (FDA) has approved several new drug molecules for AD management since 2003, but these drugs only provide temporary relief of symptoms and do not address the underlying causes of the disease. Currently, available medications focus on correcting the neurotransmitter disruption observed in AD, including cholinesterase inhibitors and an antagonist of the N-methyl-D-aspartate (NMDA) receptor, which temporarily alleviates the signs of dementia but does not prevent or reverse the course of AD. Research towards disease-modifying AD treatments is currently underway, including gene therapy, lipid nanoparticles, and dendrimer-based therapy. These innovative approaches aim to target the underlying pathological processes of AD rather than just managing the symptoms. This review discusses the novel aspects of pathogenesis involved in the causation of AD of AD and in recent developments in the therapeutic armamentarium for the treatment of AD such as gene therapy, lipid nanoparticles, and dendrimer-based therapy, and many more.

A Quinquennial Review on Recent Advancements and Developments in Search of Anti- malarial Agents

Malaria has been a major parasitic disease in tropical and subtropical regions and is estimated to kill between one and two million people (mainly children) every year. Novel anti-malarial agents are urgently needed to combat the malarial parasites enduring resistance to the current medications, leading to increased morbidity and mortality. The heterocycles, holding a prominent position in chemistry and found in both natural and synthetic sources, have shown several biological activities including anti-malarial activity. Towards this goal, several research groups have reported the design and development of novel and potential anti-malarial agents like artemisinin, benzimidazole, benzothiazole, chalcone, cyclopeptide, fosmidomycin, furan, indole oxadiazole, 2-oxindoles, peroxides, pyrazole, pyrazolines, pyridines, pyrimidine, pyrrolidine, quinazoline, quinazolinone, quinolone, quinoline, thiazole, triazole and other scaffolds acting against newly emerging anti-malarial targets. The present work reports the complete quinquennial coverage of anti-malarial agents reported during 2016-2020 with a view of providing the merits and demerits of reported anti-malarial scaffolds, structure-activity relationship, along with their in vitro/ in vivo/ in silico profiles to the medicinal chemists working in the field of design and discovery of novel anti-malarial agents.

Unveiling the modulation of Nogo receptor in neuroregeneration and plasticity: Novel aspects and future horizon in a new frontier

Neurodegenerative diseases (NDs) such as Alzheimer's, Parkinson's, Multiple Sclerosis, Hereditary Spastic Paraplegia, and Amyotrophic Lateral Sclerosis have emerged as the most dreaded diseases due to a lack of precise diagnostic tools and efficient therapies. Despite the fact that the contributing factors of NDs are still unidentified, mounting evidence indicates the possibility that genetic and cellular changes may lead to the significant production of abnormally misfolded proteins. These misfolded proteins lead to damaging effects thereby causing neurodegeneration. The association between Neurite outgrowth factor (Nogo) with neurological diseases and other peripheral diseases is coming into play. Three isoforms of Nogo have been identified Nogo-A, Nogo-B and Nogo-C. Among these, Nogo-A is mainly responsible for neurological diseases as it is localized in the CNS (Central Nervous System), whereas Nogo-B and Nogo-C are responsible for other diseases such as colitis, lung, intestinal injury, etc. Nogo-A, a membrane protein, had first been described as a CNS-specific inhibitor of axonal regeneration. Several recent studies have revealed the role of Nogo-A proteins and their receptors in modulating neurite outgrowth, branching, and precursor migration during nervous system development. It may also modulate or affect the inhibition of growth during the developmental processes of the CNS. Information about the effects of other ligands of Nogo protein on the CNS are yet to be discovered however several pieces of evidence have suggested that it may also influence the neuronal maturation of CNS and targeting Nogo-A could prove to be beneficial in several neurodegenerative diseases.

Emerging Pathophysiological Mechanisms Linking Diabetes Mellitus and Alzheimer’s Disease: An Old Wine in a New Bottle

Type-2 diabetes mellitus (T2DM) is a chronic immuno-inflammatory and metabolic disease characterized by hyperglycemia and insulin resistance with corresponding hyperinsulinemia. On the other hand, Alzheimer’s disease (AD) is a neurodegenerative disease involving cognitive impairment, neuronal dysfunction, and memory loss. Several recently published literatures suggest a causal relationship between T2DM and AD. In this review, we have discussed several potential mechanisms underlying diabetes-induced cognitive impairment which include, abnormal insulin signaling, amyloid-β accumulation, oxidative stress, immuno-inflammation, mitochondrial dysfunction, advanced glycation end products, acetylcholinesterase and butyrylcholinesterase, advanced lipid peroxidation products, and apolipoprotein E. All these interconnected mechanisms may act either individually or synergistically which eventually leads to neurodegeneration and AD.

Chemical characterization and quantification of siderophores produced by marine and terrestrial aspergilli

Ten aspergilli (five each from marine and terrestrial habitats) were screened for siderophore production. All test isolates produced siderophores as indicated by a positive reaction in the FeCl(3) test, chrome azurol sulphonate assay, and chrome azurol sulphonate agar plate test. Further, the test isolates were compared for their siderophore production potential and chemical characteristics. Examination of the chemical nature of the siderophores revealed that all test isolates produced hydroxamate siderophores that were trihydroxamate hexadentates. Wide-spread occurrence of siderophores in marine isolates indicate their functional role in maintaining overall productivity of coastal waters. Among all test aspergilli, marine Aspergillus versicolor was found to be the largest siderophore producer (182.5 microg/mL desferrioxamine mesylate equivalent), least siderophore production was recorded in a marine strain of Aspergillus niger (3.5 microg/mL desferrioxamine mesylate equivalent).

Siderophores of halophilic archaea and their chemical characterization

Nine halophilic archaea viz., Halobacterium salinarum, Halobacterium sp.1, Halobacterium sp.2, Halobaculum sp., Halococcus saccharolyticus, Halorubrum saccharovorum, Haloterrigena turkmenica, Halogeometricum sp. and Natrialba sp. isolated from marine salterns around Bhavnagar coast were screened for siderophore production. Five isolates viz., Halococcus saccharolyticus, Halorubrum saccharovorum, Haloterrigena turkmenica, Halogeometricum sp. and Natrialba sp. produced siderophores as evidenced by positive reaction in FeCl3 test, CAS assay and CAS agar plate test. Determination of chemical nature of siderophores by chemical assays and bioassays identified them as carboxylates. Quantification of siderophores indicated Halorubrum saccharovorum to be the maximum siderophore producer (2.62 RE mg/ml) and Halococcus saccharolyticus to be the least (1.33 RE mg/ml). The present study is the first report on siderophore production in Indian haloarchaeal strains. Mechanism of iron assimilation in four non-siderophore isolates still needs to be investigated further.

Chemical properties and NMR spectroscopic identification of certain fungal siderophores

Siderophores of six fungi viz. Aspergillus sp. ABp4, Aureobacidium pullulans, Penicillium oxalicum, P. chrysosporium, Mycotypha africana and Syncephalastrum racemosum were examined for their (1) electrophoretic mobilities to determine the acidic, basic or neutral charge; (2) Fe (III) binding nature viz., mono-, di-, or trihydroxamate; (3) amino acid composition; and (4) NMR (nuclear magnetic resonance) spectroscopy to determine their structure. Electrophoretic mobilities of siderophores of 3 fungi (P. oxalicum, P. chrysosporium, and M, africana) exhibited net basic charge, siderophores of 2 fungi (Aspergillus sp. ABp4 and S. racemosum) were acidic and 1 fungus (A. pullullans) was neutral. Electrophoresis of ferrated siderophore at pH 2 and colour of the spots indicated that siderophores of Aspergillus sp. ABp4 and P. oxalicum and A. pullulans were trihydroxamates, whereas siderophore of P. chrysosporium was dihydroxamate. Amino acid composition of siderophores purified by XAD-2 column chromatography, revealed the presence of asparagine, histidine, and proline in Aspergillus sp. ABp4, serine and alanine in P. chrysosporium, and valine in M. africana. The structure of purified siderophores as revealed by NMR spectroscopy identified siderophore of AB - 2670 (A. pullulans) as asperchrome F1, and AB-513 (M. africana) as rhizoferrin. The peak obtained for siderophore AB-5 (Aspergillus sp. ABp4) did not show resemblance to any known siderophore, therefore may be an exception.

Ferric reductase, superoxide dismutase and alkaline phosphatase activities in siderophore producing fungi

Enzymes associated with release of iron from internalized ferrated siderophore (ferrisiderophore reductase), with damage to the cell at high iron concentration (superoxide dismutase) and siderophore synthesis (alkaline phosphatase), were examined in 3 test fungi viz., Aspergillus sp. ABp4, Aureobasidium pullulans and Rhizopus sp. Extracellular ferrisiderophore reductase activity was present in all the three fungi, but Aureobasidium pullulans, that showed the highest activity (84.3 microM min(-1)), was the only one to produce intra-cellular ferric reductase (147.9 microM min(-1)). Superoxide dismutase was produced by Aureobasidium pullulans and Rhizopus sp., but not by Aspergillus sp. ABp4, that showed intra-cellular enzyme activity in case of ferric reductase and alkaline phosphatase. Maximum SOD activity was seen in Aureobasidium pullulans both extra-cellularly (93.83 ng ml(-1)) and intra-cellularly (57.14 ng ml(-1)). All the test fungi examined, produced intra-cellular alkaline phosphatase. There was no extracellular alkaline phosphatase. Among the three fungi, Aureobasidium pullulans showed highest alkaline phosphatase activity (129.9 microM min(-1)) and Aspergillus sp. ABp4 the least (76.4 microM min(-1)).

Chemical nature, ligand denticity and quantification of fungal siderophores

Thirtyfive siderophore producing fungi were categorized for their hydroxamate, catecholate or carboxylate nature by chemical and bioassays. Out of 35 fungi, 30 were hydroxamates and 5 showed carboxylate nature. However, none of the fungi produced catecholate type of siderophores. Eighteen out of 29 fungi were trihydroxamate and the rest 11 fungi were dihydroxamates. Twenty-three fungi were hexadentate and 6 were tetradentate in nature. Quantification of siderophores using standard compounds deferrioxamine mesylate and rhizoferrin revealed that Phanerochaete chrysosporium produced maximum among the hydroxamate producing fungi and Mycotypha africana resulted maximum among the carboxylate producing fungi.

Siderophore production by fluorescent pseudomonads colonizing roots of certain crop plants

Twelve fluorescent Pseudomonas isolates colonizing roots of four crop plants, chilli, cotton, groundnut and soybean, were examined for extracellular siderophore production in different media under iron deficient conditions. While all the organisms produced siderophores, they varied in the quantity of siderophores produced and in their preference to the medium. The siderophores were invariably hydroxamates (pyoverdine) of trihydroxamate type which formed bidentate ligands with Fe III ions.

Regulation of siderophore production by iron Fe(III) in certain fungi and fluorescent pseudomonads

Regulation of siderophore production in response to iron concentration in the medium was examined. Threshold concentration was recorded for twenty fungi and three rhizobacterial pseudomonads. Organisms showed difference in threshold values at which they stopped siderophore elaboration. In nine fungi (3 aspergilli, 1 penicillium, N. crassa, F. dimerum and 3 mucors) siderophore production was repressed at 3 microM Fe(III). Siderophore production was repressed at 27 microM of Fe (III) in 3 aspergilli, 2 penicillia and 3 pseudomonads. Rest of the fungi had cut off values at 6, 9, 15, 21 microM of Fe(III) concentration.

Chemical characterization of fungal siderophores

Siderophores of twenty fungi belonging to Zygomycotina (5 Mucorales), Ascomycotina (7 aspergilli, 6 penicillia, Neurospora crassa) and Deuteromycotina (Fusarium dimerum) were examined for their chemical nature. Siderophores produced by fungi other than Mucorales were all hydroxamates. Mucorales produced carboxylate siderophores. Catecholate type of siderophores were not detectable. Hydroxamate siderophores were mostly (9 out of 15) trihydroxamates, while six were dihydroxamates. Monohydroxamate nature was not shown by any of the 15 test fungal siderophores. In ligand properties, 12 out of 15 hydroxamate siderophores formed hexadentate ligands, while two formed tetradentates and one bidentate. There was good correlation between number of hydroxamate groups and ligand property.