Adult intervertebral discs (IVDs) have poor endogenous healing capacity, because of their challenging microenvironment and complex mechanical demands, which can result in painful IVD herniation. There are no regenerative strategies available to improve IVD healing and restore its function. Neonatal mice are excellent models of mammalian regeneration, but there are no studies of the regenerative capacity of neonatal IVDs. In this study, we developed a neonatal model of improved IVD healing to inform repair strategies after herniation. In vivo puncture injuries were performed to simulate herniation with complete annulus fibrosus (AF) tears in caudal IVDs of neonatal (postnatal d 5) and adult (4-6 mo) Scleraxis green fluorescent protein ( ScxGFP) mice. Acute and long-term healing responses were assessed with histologic, radiologic, and biomechanical measurements. Neonates underwent accelerated IVD healing compared to adults with functional restoration and enhanced structural repair after herniation. A population of ScxGFP cells identified in the neonatal repair site may be associated with this improved healing and warrants future investigation. In summary, function of neonatal IVDs was restored after herniation injury, whereas that of adult discs was not. This improved healing response is likely driven by multiple mechanisms that may include differences in mechanical loading and available repair cells during growth.-Torre, O. M., Das, R., Berenblum, R. E., Huang, A. H., Iatridis, J. C. Neonatal mouse intervertebral discs heal with restored function following herniation injury.

Genome-wide analysis was carried out to identify and analyze differential expression pattern of tomato membrane bound NAC transcription factors (SlNACMTFs) during stresses. Two biotic-stress-related SlNACMTFs have been characterized to elucidate their regulatory function. NAC transcription factors are known regulators of stress-related gene expression. As Stresses are perceived and transmitted by membrane-bound proteins, functional characterization of membrane-associated NAC transcription factors in tomato can reveal valuable insight about membrane-mediated stress-signalling. Tomato genome encodes 13 NAC genes which have predicted transmembrane domain(s) (SlNACMTFs). mRNA of 12 SlNACMTFs were readily detected in multiple tissues, and also in polysome isolated from leaf, confirming active transcription and translation from these genes occur under normal physiological condition. Additionally, most of the SlNACMTFs were differentially regulated during stresses and stress-related transcription factor binding sites are prevalent in their promoters. SlNACMTF3 and 8 were majorly regulated in biotic and abiotic stresses. Like other MTFs, SlNACMTF3 was translocated to the plasma membrane, whereas the C-terminus truncated (ΔC) form localized in the cytoplasm and the nucleus. Accordingly, the ΔC forms significantly influenced the activity of promoters harbouring NAC binding sites (NACbs). Furthermore, the NAC domain of these transcription factors could directly interact with an NACbs, and the proteins failed to regulate a promoter lacking a crucial NACbs. Interestingly, the type of influence to an NACbs containing promoter was dependent on the context of the NACbs, as the same SlNACMTF showed an alternative mode of regulation on different promoters, as well as the same promoter activity was oppositely regulated by two different SlNACMTF. Finally, both SlNACMTFs demonstrated the differential regulatory effect on the expression of several stress-related genes by interacting with the putative NACbs in their promoter region, suggesting their direct role in plant stress response.

Besides their definite role in plant developmental processes miR167 also serve as mediator of stress response. Although differential expression of miR167 occurs during stresses, the regulatory-mechanism of biogenesis remained elusive. Therefore, using tomato as the model plant we have explored the mechanism of regulation of miR167a expression during stresses. Fungus or virus infections and exposure to cold stress raised the level of miR167a expression. Whereas, salt, drought and heat treatments resulted in the downregulation, indicating different stresses activated alternative mechanisms for miR167a regulation. Interestingly, the relative expression level of precursors in control versus temperature stressed plants differed from the pattern observed in the mature miR167a expression, suggesting that both transcriptional and processing regulation were important for biogenesis. The promoter-regulatory sequence of the major isoform MIR167a harbours several development and stress-related regulatory sites. Accordingly, promoter assays using transient transformation and transgenic tobacco plants proved stress-dependent regulation of the promoter. Further analyses corroborated the role of tomato DREB2A protein in the transcriptional regulation during temperature stress. Finally, in vitro assays established the importance of processing factors in cold-stress dependent efficient processing of MIR167a precursors. These data confirm distinct role of transcriptional and processing machinery in stress-influenced regulation of tomato miR167a biogenesis.

Among all serious diseases globally, diabetes (type 1 and type 2) still poses a major challenge to the world population. Several target proteins have been identified, and the etiology causing diabetes has been reasonably well studied. But, there is still a gap in deciding on the choice of a drug, especially when the target is mutated. Mutations in the KCNJ11 gene, encoding the kir6.2 channel, are reported to be associated with congenital hyperinsulinism, having a major impact in causing type 1 diabetes, and due to the lack of its 3D structure, an attempt has been made to predict the structure of kir6.2, applying fold recognition methods. The current work is intended to investigate the affinity of four phytochemicals namely, curcumin (Curcuma longa), genistein (Genista tinctoria), piperine (Piper nigrum), and pterostilbene (Vitis vinifera) in a normal as well as in a mutant kir6.2 model by adopting a molecular docking methodology. The phytochemicals were docked in both wild and mutated kir6.2 models in two rounds: blind docking followed by ATP-binding pocket-specific docking. From the binding pockets, the common interacting amino acid residues participating strongly within the binding pocket were identified and compared. From the study, we conclude that these phytochemicals have strong affinity in both the normal and mutant kir6.2 model. This work would be helpful for further study of the phytochemicals above for the treatment of type 1 diabetes by targeting the kir6.2 channel.

Acute myeloid leukemia is a well characterized blood cancer in which the unnatural growth of immature white blood cell takes place, where several genes transcription is regulated by the micro RNAs (miRNAs). Argonaute (AGO) protein is a protein family that binds to the miRNAs and mRNA complex where a strong binding affinity is crucial for its RNA silencing function. By understanding pattern recognition between the miRNAs-mRNA complex and its binding affinity with AGO protein, one can decipher the regulation of a particular gene and develop suitable siRNA for the same in disease condition. In the current work, HOXA9 gene has been selected from literature, whose deregulation is well-established in acute myeloid leukemia. Four miRNAs (mir-145, mir-126, let-7a, and mir-196b) have been selected to target mRNA of HOXA9 (NCBI accession No. NM_152739.3). The binding interaction between mRNAs and mRNA of HOXA9 gene was studied computationally. From result, it was observed mir-145 has highest affinity for HOXA9 gene. Furthermore, the interaction between miRNAs-mRNA duplex of all chosen miRNAs are docked with AGO protein (PDB ID: 3F73, chain A) to study their interaction at molecular level through an in silico approach. The residual interaction and hydrogen bonding are inspected in Discovery Studio 3.5 suites. The current investigation throws light on understanding of AGO-assisted miRNA based gene silencing mechanism in HOXA9 gene associated in acute myeloid leukemia computationally.

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