Post-Translational Inhibition of IP-10 Secretion in IEC by Probiotic Bacteria: Impact on Chronic Inflammation

Peer reviewedPublisher PD

Regulation of pH During Amelogenesis

During amelogenesis, extracellular matrix proteins interact with growing hydroxyapatite crystals to create one of the most architecturally complex biological tissues. The process of enamel formation is a unique biomineralizing system characterized first by an increase in crystallite length during the secretory phase of amelogenesis, followed by a vast increase in crystallite width and thickness in the later maturation phase when organic complexes are enzymatically removed. Crystal growth is modulated by changes in the pH of the enamel microenvironment that is critical for proper enamel biomineralization. Whereas the genetic bases for most abnormal enamel phenotypes (amelogenesis imperfecta) are generally associated with mutations to enamel matrix specific genes, mutations to genes involved in pH regulation may result in severely affected enamel structure, highlighting the importance of pH regulation for normal enamel development. This review summarizes the intra- and extracellular mechanisms employed by the enamel-forming cells, ameloblasts, to maintain pH homeostasis and, also, discusses the enamel phenotypes associated with disruptions to genes involved in pH regulation

Erratum: Reduced Abundance of Butyrate-Producing Bacteria Species in the Fecal Microbial Community in Crohn's Disease

<b><i>Background:</i></b> The global alteration of the gut microbial community (dysbiosis) plays an important role in the pathogenesis of inflammatory bowel diseases (IBDs). However, bacterial species that characterize dysbiosis in IBD remain unclear. In this study, we assessed the alteration of the fecal microbiota profile in patients with Crohn's disease (CD) using 16S rRNA sequencing. <b><i>Summary:</i></b> Fecal samples from 10 inactive CD patients and 10 healthy individuals were subjected to 16S rRNA sequencing. The V3-V4 hypervariable regions of 16S rRNA were sequenced by the Illumina MiSeq™II system. The average of 62,201 reads per CD sample was significantly lower than the average of 73,716 reads per control sample. The genera <i>Bacteroides</i>, <i>Eubacterium</i>, <i>Faecalibacterium</i> and <i>Ruminococcus</i> significantly decreased in CD patients as compared to healthy controls. In contrast, the genera <i>Actinomyces</i> and <i>Bifidobacterium</i> significantly increased in CD patients. At the species level, butyrate-producing bacterial species, such as <i>Blautia faecis</i>, <i>Roseburia inulinivorans</i>, <i>Ruminococcus torques</i>, <i>Clostridium lavalense</i>, <i>Bacteroides uniformis</i> and <i>Faecalibacterium prausnitzii</i> were significantly reduced in CD patients as compared to healthy individuals (p < 0.05). These results of 16S rRNA sequencing were confirmed in additional CD patients (n = 68) and in healthy controls (n = 46) using quantitative PCR. The abundance of <i>Roseburia inulinivorans</i> and <i>Ruminococcus torques</i> was significantly lower in C-reactive protein (CRP)-positive CD patients as compared to CRP-negative CD patients (p < 0.05). <b><i>Key Message:</i></b> The dysbiosis of CD patients is characterized by reduced abundance of multiple butyrate-producing bacteria species