Month: March 2020

In this study, using both pharmacological and genetic approaches, we demonstrate that Panx1 channels and P2X7R are functionally co-expressed in urothelial cells. This functional interplay between P2X7R and Panx1 is clearly observed here in the YoPro uptake, ATP release and ICW spread experiments performed with TRT-HU1 cells. Most notable, however, are our findings that Panx1 channels not only provide the distensioninduced ATP release that can initiate paracrine signaling between urothelial cells, but may also provide ATP release from neighboring non-stimulated cells through P2X7R stimulation. In this scenario, ATP-induced ATP release mediated by activation of the P2X7R-Panx1 complex would not only support the mechanically-initiated intercellular signaling among urothelial cells but provide a Dinaciclib mechanism for mechanosensory amplification. A role for urothelial-derived ATP as the transmitter that communicates bladder distension to the CNS through activation of P2Rs in suburothelial afferent nerve terminals is broadly accepted. However, the actual role played by distension-induced ATP mediated signaling within the urothelium is still largely unknown, but is expected to be important for urothelial function as a syncytium, providing for synchronization and coordination of the urothelial cells. For example, activation of P2Rs has been shown to be essential for increasing the apical surface area of the urothelium during bladder filling. In this regard, ATP release and signaling within the same and between urothelial layers is likely essential to convey the information of bladder distension and provide for proper synchronization of urothelial cell response and adaptation to bladder wall distension. In this study we focused on investigating the role of Panx1 channels and P2X7Rs in urothelial ATP release and signaling. Our immunohistochemical studies, however, indicate that in the rat bladder mucosa Panx1 channels and PX7R are also expressed by spindle-shape cells in the lamina propria that likely correspond to suburothelial myofibroblasts. These cells are in close contact with suburothelial nerves and form a network functionally connected by gap junctions. Isolated suburothelial myofibroblasts have been shown to respond to exogenous ATP with generation of intracellular Ca2+ transients and when mechanically stimulated in intact bladder cross-sections they initiate transmission of ICWs, which spread across the suburothelial network and invade the underlying detrusor layer. These features prompted the proposal that suburothelial myofibroblasts may act as amplifiers in the sensory response to bladder wall distension. Future studies are needed to determine whether Panx1 channels are functionally expressed in suburothelial myofibroblasts. Given the characteristic properties of Panx1 channels and findings presented here for urothelial cells, we can speculate that Panx1 channels and P2X7R may also participate in responses of suburothelial myofibroblasts to mechanical stimulation and in ATP signaling among these cells. Similar to its role discussed here for the urothelium, the P2X7R-Panx1 complex could be a key participant in a mechanism for mechanosensory amplification at the level of the suburothelial layer.

The UCMB5113 strain seems to have high capacity to produce different kinds of antibiotics and also secrete a large number of enzymes to improve nutrient acquisition in the rhizosphere. This strain also seems to have potential for production of hormones and volatile compounds that support plant growth and thereby improve plant roots and biomass improving plant quality as a colonization partner and at the same time also increase surface area for colonization and the nutrient resource for the bacteria. UCMB5113 seems able to use a wide range of sugars and other organic compounds that could be present in root exudates. In return the bacteria antagonize detrimental soil microorganisms and strengthen plants improving their nutrient and stress handling capabilities. The ability of UCMB5113 to quench reactive oxygen species should be beneficial for the plant to decrease stress damage. The annotation of UCMB5113 from this study will pave way in elucidating the mechanism involved in plant-bacterial interation. Comparison with other related B. amyloliquefaciens genomes that differ in their capability of plant colonization, growth promotion and stress tolerance provides an excellent basis for in silico predictions of gene candidates and regulatory factors that are involved in these processes. We are currently searching for plant genotypes that vary in the interaction with Bacillus strains as a basis to pinpoint plant genes important for the interactions. Deciphering of the molecular determinants for these processes open up possibilities to identify even more efficient Bacillus strains, engineer improved strains, and optimize conditions that favour interaction and colonization to support durable crop production. In response to deprivation of combined nitrogen, some filamentous cyanobacteria produce cells called heterocysts that are specialized in the fixation of N2. Heterocyst differentiation involves drastic changes in gene expression that are coordinated by two DNA-binding factors, the global regulator NtcA and the development-specific factor HetR. The distribution of heterocysts in the diazotrophic filaments of cyanobacteria represents a simple and old example of developmental patterns in the living world. In strains of the genera Anabaena and Nostoc the pattern consists of long CYT387 linear chains of cells with heterocysts separated by ca. 10 vegetative cells. Several gene products that influence the pattern of heterocyst distribution have been identified.

The ability of B. pseudomallei to invade, survive, and replicate intracellularly allows it to persist in the body during latent, chronic infection. A number of virulence factors have been identified for B. pseudomallei infection of mammalian cells; these include type III and type VI secretion systems, quorum-sensing molecules, capsular polysaccharide, lipopolysaccharide, flagella, type IV pili, siderophores, and secreted proteins such as hemolysin, lipases and proteases. Symptoms of acute disease include tissue destruction, multiple organ failure, and septic shock. In contrast, C57BL/ 6 mice, Th1 prototype, can effectively control B. pseudomallei infection, as demonstrated by moderate increases in cytokine levels and greater macrophage infiltration, allowing time for an adaptive immune response to occur. At present, the relative importance of the cell-mediated and humoral arms of the innate and adaptive immune responses is unclear. Obstructive sleep apnea is a common disorder that increases in prevalence with age, although the mechanisms are unclear. The genioglossus is a major upper airway dilator muscle whose activity is thought to be representative of muscles critical for maintaining pharyngeal patency. Thus, research into the motor control of the genioglossus is likely to provide insights into sleep apnea pathogenesis. Motor unit potential analysis provides insight into the normal function of skeletal muscle and aids in the assessment of neuromuscular disorders. For example, skeletal muscle remodeling is associated with physiological factors that can change the characteristics of MUPs. MUPs with increased durations can be detected in many skeletal muscles, reflected as remodeled motor units as a result of denervation, collateral sprouting and reinnervation. Anatomically the genioglossus muscle is one of the largest extrinsic muscles of the tongue. The hypoglossal nerve branches that innervate the genioglossus muscle are much denser in humans compared to other species, likely reflecting small motor unit territories AZ 960 required for the high level of fine motor control required for speech. The complex innervation of the muscles of the tongue may indicate they are less prone to aging effects than is seen in other skeletal muscles. Structural remodeling changes previously reported in the tongue musculature of obstructive sleep apnea patients may not be characterized by a proximal weakness, such as, overt dysphagia, but, may nevertheless predispose the pharyngeal airway to collapse with increasing age.

Indeed, a mutant of CDX2/AS in which the carboxy-terminal domain enriched in serine and arginine was eliminated failed to co-localize with ASF/SF2 or SC35 in the nucleus. Supporting its roll in pre-mRNA processing, we demonstrated that CDX2/AS can change splice site selection in human colon-derived cells using exogenous minigenes. Taken together, these data strongly suggest that CDX2 encodes two proteins, one that regulates gene transcription and a novel protein that can influence gene expression by regulating pre-mRNA processing. Whether or not CDX2/AS belongs to the SR- or SR-like families of proteins is worth considering. The RS domain of SRand SR-like proteins is required for protein-protein interactions as well as nuclear localization. The prototypical SR splicing factors contain one or two amino-terminal RNA recognition motifs followed by a carboxy-terminal RS domain enriched in serine and arginine residues. Additionally, SR proteins contain signature sequences including RDAEDA, RDADDA, and SWQDLKD. Homology searches of the entire CDX2/ AS protein failed to reveal RRMs or signature sequences characteristic of SR proteins. These observations suggest that CDX2/AS may not be a Rapamycin member of the SR family of proteins but, rather, belongs to the SR-like family of splicing factors. Interestingly, there was no clear homology in the carboxyterminal domain of CDX2/AS with the RS domain of other proteins. Despite approximately 31% amino acid consensus with the RS domain of SR- and SR-like proteins, CDX2/AS contains only two S/R dipeptides. However, the role of the RS domain in CDX2/AS in nuclear localization is similar to that of the recently identified SR-like protein NSrp70. Moreover, perinuclear localization of the carboxy-terminally truncated CDX2/AS is identical to that seen for an RS-domain deleted mutant of the SRlike protein XE7. Taken together, these data suggest that CDX2/AS should be included in the SR-like family of splicing factors. In the context of a single gene giving rise to alternatively spliced transcripts that produce proteins regulating transcription or splicing, CDX2 shares considerable similarity with the Wilms’ tumor gene, WT1. The WT1 transcript undergoes alternative splicing to produce several variants, most notably a transcription factor and a splicing factor. The unique ability of WT1 to regulate gene expression by encoding proteins that influence transcription and splicing in conjunction with the role of its various isoforms in normal cellular development and pathophysiologic processes suggests a similar function for CDX2/AS.

Thus, our study is the first to show genome-wide gene expression profiles of neutrophils of CF patients colonized by bacteria in their airways and in a clinical condition of acute exacerbation. Recent work has focused on CF blood mononuclear cells in order to identify circulating transcripts as EX 527 biomarkers of the treatment for an acute exacerbation. Saavedra et al. found that 10 genes significantly changed with therapy and that three genes enhanced the predictive discriminating value of FEV1 alone. However, seven of the 10 genes are not specific to CF and they need further evaluation as their role and biomarker status in the CF disease. Interestingly, the same group has recently validated the 10 genes in a study on the whole blood in a cohort of CF patients treated for acute exacerbations. Their findings show that six out of 10 genes strongly predicted a reduction in airway bacterial load beyond FEV1 and CRP, adding specificity in predicting reduced pulmonary infection. The six genes were not coincident with our three-genes panel sensitive to treatment for an acute exacerbation. This may reflect that these six genes are related more to mononuclear cells than to neutrophils. One of the aims of this work is to find a set of genes which is differentially transcribed in CF as compared to “healthy” condition. This “CF signature” could be useful to identify CF patients unequivocally and start with therapy as soon as possible. A net separation between CF patients and healthy controls was obtained. A caveat to these findings is that, although we define a set of regulated genes in CF patients at the onset of an acute exacerbation, this clinical condition is not representative of the initial steps of disease, thereby further studies with different cohorts of patients in various clinical conditions are needed. It is not surprising that a distinct separation could be not possible when comparing patients before and after treatment, suggesting that patients can respond differently to antibiotic treatment for an acute exacerbation. Noxa is a member of Bcl-2 family of proteins, a critical mediator of the p53-dependent apoptosis and has been implicated in hypoxia-induced apoptosis. Noxa is also likely involved in apoptosis of virus-infected cells to limit viral dissemination. Recently, a strong pro-apoptotic role of Noxa in the final steps of neutrophil differentiation from progenitors has been described. A delayed apoptotic response has been described in blood neutrophils isolated from CF patients.