Pharmacological Progress of Mitophagy Regulation.

With the advancement in novel drug discovery, biologically active compounds are considered pharmacological tools to understand complex biological mechanisms and the identification of potent therapeutic agents. Mitochondria boast a central role in different integral biological processes and mitochondrial dysfunction is associated with multiple pathologies. It is, therefore, prudent to target mitochondrial quality control mechanisms by using pharmacological approaches. However, there is a scarcity of biologically active molecules, which can interact with mitochondria directly. Currently, the chemical compounds used to induce mitophagy include oligomycin and antimycin A for impaired respiration and acute dissipation of mitochondrial membrane potential by using CCCP/FCCP, the mitochondrial uncouplers. These chemical probes alter the homeostasis of the mitochondria and limit our understanding of the energy regulatory mechanisms. Efforts are underway to find molecules that can bring about selective removal of defective mitochondria without compromising normal mitochondrial respiration. In this report, we have tried to summarize and status of the recently reported modulators of mitophagy.

miR-125-3p and miR-276b-3p Regulate the Spermatogenesis of Bactrocera dorsalis by Targeting the orb2 Gene.

Bactrocera dorsalis is considered a major threat to horticultural crops. It has evolved resistance against insecticides. It is believed that development of new methods is highly desirable to control this destructive agricultural pest. Sterile insect technique is emerging as a potential tool to control this insect pest by reducing their reproductive ability. Here we report that orb2 has high expression in the testis of B. dorsalis which is the target of miR-125-3p and miR-276b-3p and plays a critical role in the spermatogenesis. Dual luciferase reporter assay using HEKT293 cells demonstrates that orb2 gene is downregulated by miR-125-3p and miR-276b-3p and is a common target of these miRNAs. Dietary treatment of adult male flies separately and in combination of agomir-125-3p (Ago-125-3p) and agomir-276b-3p (Ago-276b-3p) significantly downregulated the mRNA of orb2. The combined treatments of agomirs suppressed the level of mRNA of orb2 significantly more than any single treatment. Altered expression of miR-125-3p and miR-276b-3p significantly decreased the total and live spermatozoa in the testis which ultimately caused reduction in male fertility. Furthermore, we demonstrate that miR-125-3p, miR-276b-3p, and orb2 dsRNA are the novel agents that could be used in a genetic-based sterile insect technique (SIT) to control the B. dorsalis.

Epitope-based peptide vaccine design and elucidation of novel compounds against 3C like protein of SARS-CoV-2.

Coronaviruses (CoVs) are positive-stranded RNA viruses with short clubs on their edges. CoVs are pathogenic viruses that infect several animals and plant organisms, as well as humans (lethal respiratory dysfunctions). A noval strain of CoV has been reported and named as SARS-CoV-2. Numerous COVID-19 cases were being reported all over the World. COVID-19 and has a high mortality rate. In the present study, immunoinformatics techniques were utilized to predict the antigenic epitopes against 3C like protein. B-cell epitopes and Cytotoxic T-lymphocyte (CTL) were designed computationally against SARS-CoV-2. Multiple Sequence Alignment (MSA) of seven complete strains (HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1, SARS-CoV, MERS-CoV, and SARS-CoV-2) was performed to elucidate the binding domain and interacting residues. MHC-I binding epitopes were evaluated by analyzing the binding affinity of the top-ranked peptides having HLA molecule. By utilizing the docked complexes of CTL epitopes with antigenic sites, the binding relationship and affinity of top-ranked predicted peptides with the MHC-I HLA protein were investigated. The molecular docking analyses were conducted on the ZINC database library and twelve compounds having least binding energy were scrutinized. In conclusion, twelve CTL epitopes (GTDLEGNFY, TVNVLAWLY, GSVGFNIDY, SEDMLNPNY, LSQTGIAV, VLDMCASLK, LTQDHVDIL, TTLNDFNLV, CTSEDMLNP, TTITVNVLA, YNGSPSGVY, and SMQNCVLKL) were identified against SARS-CoV-2.

Fluorenone-Based Fluorescent and Colorimetric Sensors for Selective Detection of I- Ions: Applications in HeLa Cell Imaging and Logic Gate.

Fluorenone-based fluorescent and colorimetric sensors 1 and 2 have been developed that displayed selective detection of iodide ions in the presence of interferences. Sensors displayed the fluorescence emission enhancement response toward I- with detection limits of 8.0 and 11.0 nM, respectively, which is accomplished through inhibition of intramolecular charge transfer and C=N isomerization. Excellent sensitivity and unique fluorescence enhancement response of sensors toward I- make them superior because most of the previously reported iodide sensors are based on the fluorescence quenching mechanism and are less sensitive. The sensing potential of sensors toward I- ions was investigated through 1H NMR titration, dynamic light scattering, Job's plots, and density functional theory analysis. Further, sensors displayed reversible behavior by the alternate addition of I- and Cu2+ ions that substantiate their role as recyclable sensors for the on-site detection of I- ions. Advantageously, fluorescence enhancement response of sensors was favorably used for fluorescence imaging of I- in live HeLa cells and the design of the logic gate. These sensors were successfully applied in diversified applications such as the preparation of sensors' coated paper strips and the determination of I- ions in blood serum, food, and real water samples.

RNAi-Mediated Knockdown of Tssk1 and Tektin1 Genes Impair Male Fertility in Bactrocera dorsalis.

The genetic-based sterile insect technique (SIT) is an effective and environmentally safe strategy to diminish populations of agricultural and horticultural insect pests. Functional characterization of genes related to male fertility can enhance the genetic-based SIT. Tssk1 has been involved to control male fertility in both mammals and insects. Moreover, Tektin1 has also been revealed to influence male fertility in both human and mammals. These findings suggested that Tssk1 and Tektin1 identified from Bactrocera dorsalis could be required for male fertility in B. dorsalis. In this study, expression profiles of these two genes were studied at different developmental stages and in various tissues of adult males. Remarkably, it was found that Tssk1 and Tektin1 were highly expressed in the testis of mature adult males of B. dorsalis. Furthermore, Tssk1 and Tektin1 genes were downregulated by using the RNA interference (RNAi) method. Fertility assays including egg laying, hatching, and spermatozoa count were also performed to investigate male fertility of B. dorsalis. Results showed that knockdown of Tssk1 and Tektin1 caused male sterility up to 58.99% and 64.49%, respectively. As expected, the total numbers of spermatozoa were also significantly reduced by 65.83% and 73.9%, respectively. These results suggested that male sterility was happened wing to the low number of spermatozoa. In conclusion, we demonstrate that Tssk1 and Tektin1 are the novel agents that could be used to enhance the genetic-based SIT, or their double-stranded RNA (dsRNA) can be used as biopesticides to control the population of B. dorsalis.

RNA interference-mediated knockdown of voltage-gated sodium channel (MpNav) gene causes mortality in peach-potato aphid, Myzus persicae.

Voltage-gated sodium channels (VGSC) are transmembrane proteins that generate an action potential in excitable cells and play an essential role in neuronal signaling. Since VGSCs play a crucial role in nerve transmission they have become primary targets for a broad range of commercial insecticides. RNA interference (RNAi) is a valuable reverse genetics tool used in functional genomics, but recently, it has also shown promise as a novel agent that could be used to control agricultural insect pests. In this study, we targeted the VGSC (MpNav) gene in the peach-potato aphid Myzus persicae, by oral feeding of artificial diets mixed with dsRNAs. Knock-down of MpNav gene expression caused up to 65% mortality in 3rd instar nymphs. Moreover, significantly lower fecundity and longevity was observed in adult aphids that had been fed with dsMpNav solution at the nymphal stage. Analysis of gene expression by qRT-PCR indicated that the aphid mortality rates and the lowered fecundity and longevity were attributable to the down-regulation of MpNav by RNAi. Taken together, our results show that MpNav is a viable candidate target gene for the development of an RNAi-based bio-aphicide.

A genetically enhanced sterile insect technique against the fruit fly, Bactrocera dorsalis (Hendel) by feeding adult double-stranded RNAs.

RNAi based sterile insect technique (SIT) is an authentic insect management approach but requires proper target genes. During this study, spermless males were developed by interfering with germ cell differentiation and azoospermia related genes. Data demonstrates significant reductions in the target genes expressions (boul, zpg, dsx M , fzo and gas8) after oral dsRNAs administration. Knock down of target genes significantly affected the reproductive ability of males and reduced egg-hatching as compared to the control group. Furthermore, different combinations of selected gene dsRNAs (boul + zpg, boul + dsx M and zpg + dsx M ) were made, which resulted up to 85.40% of male sterility. The most effective combination was selected to prepare different concentrations of dsRNA, 250, 500, 750 and 1000 ng/µl, that caused 18.97%, 38.68%, 58.02% and 85.40% male sterility, respectively. Subsequently, 1000 ng/µl of the same combination of ds-RNAs was used against differently aged adult flies (1, 5, 7, 10 days) which lead to 85.40%, 31.42%, 21.76% and 9.90% male sterility, respectively. SIT developed in this study showed that, boul + zpg combination of dsRNA feeding for 6 hours significantly reduced the number of spermatozoa and viability of sperm in 1-day-old B. dorsalis flies. In short, this study provides an effective SIT technique for long-term B. dorsalis management.

miR-8-3p regulates mitoferrin in the testes of Bactrocera dorsalis to ensure normal spermatogenesis.

Genetics-enhanced sterile insect techniques (SIT) are promising novel approaches to control Bactrocera dorsalis, the most destructive horticultural pest in East Asia and the Pacific region. To identify novel genetic agents to alter male fertility of B. dorsalis, previous studies investigated miRNA expression in testes of B. dorsalis. One miRNA, miR-8-3p was predicted to bind the 3'UTR of putative B. dorsalis mitoferrin (bmfrn). The ortholog of bmfrn in D. melanogaster is essential for male fertility. Here we show that bmfrn has all conserved amino acid residues of known mitoferrins and is most abundantly expressed in B. dorsalis testes, making miR-8-3p and mitoferrin candidates for genetics-enhanced SIT. Furthermore, using a dual-luciferase reporter system, we show in HeLa cells that miR-8-3p interacts with the 3'UTR of bmfrn. Dietary treatments of adult male flies with miR-8-3p mimic, antagomiR, or bmfrn dsRNA, altered mitoferrin expression in the testes and resulted in reduced male reproductive capacity due to reduced numbers and viability of spermatozoa. We show for the first time that a mitoferrin is regulated by a miRNA and we demonstrate miR-8-3p as well as bmfrn dsRNA to be promising novel agents that could be used for genetics-enhanced SIT.