p17/C18-ceramide-mediated mitophagy is an endogenous neuroprotective response in preclinical and clinical brain injury.

Repeat concussions (or repetitive mild traumatic brain injury [rmTBI]) are complex pathological processes consisting of a primary insult and long-term secondary complications and are also a prerequisite for chronic traumatic encephalopathy (CTE). Recent evidence implies a significant role of autophagy-mediated dysfunctional mitochondrial clearance, mitophagy, in the cascade of secondary deleterious events resulting from TBI. C18-ceramide, a bioactive sphingolipid produced in response to cell stress and damage, and its synthesizing enzyme (CerS1) are precursors to selective stress-mediated mitophagy. A transporter, p17, mediates the trafficking of CerS1, induces C18-ceramide synthesis in the mitochondrial membrane, and acts as an elimination signal in cell survival. Whether p17-mediated mitophagy occurs in the brain and plays a causal role in mitochondrial quality control in secondary disease development after rmTBI are unknown. Using a novel repetitive less-than-mild TBI (rlmTBI) injury paradigm, ablation of mitochondrial p17/C18-ceramide trafficking in p17 knockout (KO) mice results in a loss of C18-ceramide-induced mitophagy, which contributes to susceptibility and recovery from long-term secondary complications associated with rlmTBI. Using a ceramide analog with lipid-selenium conjugate drug, LCL768 restored mitophagy and reduced long-term secondary complications, improving cognitive deficits in rlmTBI-induced p17KO mice. We obtained a significant reduction of p17 expression and a considerable decrease of CerS1 and C18-ceramide levels in cortical mitochondria of CTE human brains compared with age-matched control brains. These data demonstrated that p17/C18-ceramide trafficking is an endogenous neuroprotective mitochondrial stress response following rlmTBI, thus suggesting a novel prospective strategy to interrupt the CTE consequences of concussive TBI.

A novel method for conserved sequence extraction with prospective mutation prediction for SARS-CoV-2 PCR primer design.

While the whole genomic sequence of SARS-CoV-2 had been revealed, it was also demonstrated that the genome of SARS-CoV-2 exhibits identity with the genome of SARS-CoV and MERS-CoV with ratios of 80 % and 50 % respectively. In the light of SARS-CoV-2 infection and mortality data, diagnosis and treatment of COVID-19 came into prominence around the world. As such many RT-PCR kits have been developed by biotechnology scientists. However viruses are fast mutating organisms and in order to increase accuracy, feasibility in long term and avoid the off target results of RT-PCR assays, regions of viral genome with low mutation rate and designing of primers targeting these regions are quite important. In this scope, we are presenting a novel algorithm that could be used for finding low mutation rate regions of SARS-CoV-2 and primers that were designed according to findings from our algorithm in this study.

A comprehensive drug repurposing study for COVID19 treatment: novel putative dihydroorotate dehydrogenase inhibitors show association to serotonin-dopamine receptors.

Dihydroorotate dehydrogenase (DHODH) is a key enzyme required for de novo pyrimidine synthesis and it is suggested as a target for COVID19 treatment due to high pyrimidine demand by the virus replication in the infected host cells as well as its proven effect of blocking of cytokine release by the immune cells to prevent inflammation leading to acute respiratory distress. There are a number of clinical trials underway for COVID19 treatment using DHODH inhibitors; however, there are only a small number of known DHODH antagonists available for testing. Here, we have applied a methodology to identify DHODH antagonist candidates, and compared them using in silico target prediction tools. A large set of 7900 FDA-approved and clinical stage drugs obtained from DrugBank were docked against 20 different structures DHODH available in PDB. Drugs were eliminated according to their predicted affinities by Autodock Vina. About 28 FDA-approved and 79 clinical trial ongoing drugs remained. The mode of interaction of these molecules was analyzed by repeating docking using Autodock 4 and DS Visualiser. Finally, the target region predictions of 28 FDA-approved drugs were determined through PASS and SwissTargetPrediction tools. Interestingly, the analysis of in silico target predictions revealed that serotonin-dopamine receptor antagonists could also be potential DHODH inhibitors. Our candidates shared a common attribute, a possible interaction with serotonin-dopamine receptors as well as other oxidoreductases, like DHODH. Moreover, the Bruton Tyrosine Kinase-inhibitor acalabrutunib and serotonin-dopamine receptor inhibitor drugs on our list have been found in the literature that have shown to be effective against Sars-CoV-2, while the path of activity is yet to be identified. Identifying an effective drug that can suppress both inflammation and virus proliferation will play a crucial role in the treatment of COVID. Therefore, we suggest experimental investigation of the 28 FDA-approved drugs on DHODH activity and Sars-CoV-2 virus proliferation. Those who are found experimentally effective can play an important role in COVID19 treatment. Moreover, we suggest investigating COVID19 case conditions in patients using schizophrenia and depression drugs.

Gene editing and RNAi approaches for COVID-19 diagnostics and therapeutics.

The novel coronavirus pneumonia (COVID-19) is a highly infectious acute respiratory disease caused by Severe Acute Respiratory Syndrome-Related Coronavirus (SARS-CoV-2) (Prec Clin Med 2020;3:9-13, Lancet 2020;395:497-506, N. Engl J Med 2020a;382:1199-207, Nature 2020;579:270-3). SARS-CoV-2 surveillance is essential to controlling widespread transmission. However, there are several challenges associated with the diagnostic of the COVID-19 during the current outbreak (Liu and Li (2019), Nature 2020;579:265-9, N. Engl J Med 2020;382:727-33). Firstly, the high number of cases overwhelms diagnostic test capacity and proposes the need for a rapid solution for sample processing (Science 2018;360:444-8). Secondly, SARS-CoV-2 is closely related to other important coronavirus species and subspecies, so detection assays can give false-positive results if they are not efficiently specific to SARS-CoV-2. Thirdly, patients with suspected SARS-CoV-2 infection sometimes have a different respiratory viral infection or co-infections with SARS-CoV-2 and other respiratory viruses (MedRxiv 2020a;1-18). Confirmation of the COVID-19 is performed mainly by virus isolation followed by RT-PCR and sequencing (N. Engl J Med 2020;382:727-33, MedRxiv 2020a, Turkish J Biol 2020;44:192-202). The emergence and outbreak of the novel coronavirus highlighted the urgent need for new therapeutic technologies that are fast, precise, stable, easy to manufacture, and target-specific for surveillance and treatment. Molecular biology tools that include gene-editing approaches such as CRISPR-Cas12/13-based SHERLOCK, DETECTR, CARVER and PAC-MAN, antisense oligonucleotides, antisense peptide nucleic acids, ribozymes, aptamers, and RNAi silencing approaches produced with cutting-edge scientific advances compared to conventional diagnostic or treatment methods could be vital in COVID-19 and other future outbreaks. Thus, in this review, we will discuss potent the molecular biology approaches that can revolutionize diagnostic of viral infections and therapies to fight COVID-19 in a highly specific, stable, and efficient way.

Design, Synthesis, Anti-Proliferative, Anti-microbial, Anti-Angiogenic Activity and In Silico Analysis of Novel Hydrazone Derivatives.

BACKGROUND: Cancer is the second leading cause of death globally. Hydrazone and hydrazone derivatives have high activity, and for this reason, these compound are greatly used by researchers to synthesize new anti-cancer drug. The aim of this research work is to synthesize novel anticancer agents. METHODS: New hydrazone derivatives were synthesized via a reaction between 3-formylphenyl methyl carbonate and benzhydrazide, 4-methylbenzoic hydrazide, 4-tert-butylbenzoic hydrazide, 4-nitrobenzoic hydrazide and 3- methoxybenzoic hydrazide, and were successfully characterized using elemental analysis, 1H-NMR, 13C-NMR, FT-IR and LC-MS techniques. The synthesized compounds were evaluated for their antimicrobial (some grampositive and -negative bacteria, filamentous fungi and yeasts), anti-proliferative (T47D and HCC1428-breast cancer cells) and anti-angiogenic (HUVEC-endothelial cells) activities. The anti-proliferative activities of the hydrazone compounds R1-R5 were studied on these cell lines by MTT assay. The anti-angiogenic potential of the compounds was determined by the endothelial tube formation assay. To identify structural features related to the anti-proliferative activity of these compounds, 2D-QSAR was performed. RESULT: The results indicated that compound R3 exhibited strong anti-angiogenic and anti-proliferative activity on breast cancer cell lines and healthy cell lines. Also, this compound; possessing a tertiary butyl moiety on the hydrazine, exhibited the highest inhibitory effect against all tested microorganisms; in particular, it inhibited Candida albicans at a lower concentration than ketoconazole. Among the investigated compounds, those bearing methyl, tertiary butyl (compound R2, R3) and methoxy (compound R5) moiety were found to be more successful anticandidal derivatives than standard antifungal antibiotics. The QSAR analysis suggested that the tumor specificity of the hydrazone correlated with their molecular weight, lipophilicity, molar refractivity, water solubility, DipolHybrid:(MOPAC) and ExchangeEnergy:(MOPAC). Absorption, Distribution, Metabolism and Elimination (ADME) analysis of the hydrazone compounds showed that they have favorable pharmacokinetic and drug-likeness properties. The ADME results clarify that R3 is the best compound in terms of pharmacokinetic properties. In contrast to other compounds; target prediction analysis of the compound R3 showed inhibitory activity on estrogen-related receptor alpha transcription factor (ESRRA). The target prediction analysis was supported by molinspiration bioactivity score. CONCLUSION: The R3 compound is considered to be an important candidate for future studies with its suitability for the Lipinski's rule of five for drug-likeness, and effective in vitro and in silico results.

G-quadruplex prediction in E. coli genome reveals a conserved putative G-quadruplex-Hairpin-Duplex switch.

Many studies show that short non-coding sequences are widely conserved among regulatory elements. More and more conserved sequences are being discovered since the development of next generation sequencing technology. A common approach to identify conserved sequences with regulatory roles relies on topological changes such as hairpin formation at the DNA or RNA level. G-quadruplexes, non-canonical nucleic acid topologies with little established biological roles, are increasingly considered for conserved regulatory element discovery. Since the tertiary structure of G-quadruplexes is strongly dependent on the loop sequence which is disregarded by the generally accepted algorithm, we hypothesized that G-quadruplexes with similar topology and, indirectly, similar interaction patterns, can be determined using phylogenetic clustering based on differences in the loop sequences. Phylogenetic analysis of 52 G-quadruplex forming sequences in the Escherichia coli genome revealed two conserved G-quadruplex motifs with a potential regulatory role. Further analysis revealed that both motifs tend to form hairpins and G quadruplexes, as supported by circular dichroism studies. The phylogenetic analysis as described in this work can greatly improve the discovery of functional G-quadruplex structures and may explain unknown regulatory patterns.