Targeted Delivery of Probiotics: Perspectives on Research and Commercialization

Probiotics and Antimicrobial Proteins - Considering the significance of the gut microbiota on human health, there has been ever-growing research and commercial interest in various aspects of...     

Differential expression and functions of neuronal and glial neurofascin isoforms and splice variants during PNS development

The cell adhesion molecule neurofascin (NF) has a major neuronal isoform (NF186) containing a mucin-like domain followed by a fifth fibronectin type III repeat while these domains are absent from glial NF155. Neuronal NF isoforms lacking one or both of these domains are expressed transiently in embryonic dorsal root ganglia (DRG). These two domains are co-expressed in mature NF186, which peaks in expression prior to birth and then persists almost exclusively at nodes of Ranvier on myelinated axons. In contrast, glial NF155 is only detected postnatally with the onset of myelination. All these forms of NF bound homophilically and to Schwann cells but only the mature NF186 isoform inhibits cell adhesion, and this activity may be important in formation of the node of Ranvier. Schwann cells deficient in NF155 myelinated DRG axons in a delayed manner and they showed significantly decreased clustering of both NF and Caspr in regions where paranodes normally form. The combined results suggest that NF186 is expressed prenatally on DRG neurons and it may modulate their adhesive interactions with Schwann cells, which express NF155 postnatally and require it for development of axon-glial paranodal junctions.     

Steroids modulate the expression of alpha4 integrin in mouse blastocysts and uterus during implantation

Blastocyst implantation and successful establishment of pregnancy require delicate interactions between the embryo and the maternal uterine milieu, which are controlled at the embryo-maternal interface by the coordinated interplay of a variety of growth factors, cytokines, hormones, and cell adhesion molecules expressed by both the decidualized endometrium and the trophoblast cells. Proper implantation of the embryo is solely dependent on the initial endometrial receptivity and the preparation of the blastocyst to glue itself to the uterine wall. Both these events are considered to be mediated by cell adhesion molecules and integrins expressed by the blastocyst as well by as the maternal endometrium. Integrin expression by the blastocyst and the uterus is a dynamic process. However, reports on the expression and the hormonal modulation of integrins and their role in blastocyst activation and uterine receptivity during implantation are meager. The present study investigates the expression and hormonal regulation of alpha4beta1 integrin by steroid hormones in the blastocyst and the receptive uterus using an in vivo, delayed-implantation mouse model system. The dormant and activated blastocysts as well as the uteri were recovered from ovariectomized mice after progesterone-alone and progesterone-plus-estrogen therapy, respectively. Immunolocalization of protein expression of alpha4 and beta1 integrin subunits indicate that steroids modulate the expression of alpha4beta1 integrin receptor in the mouse blastocyst as well as the uterus and that a differential expression is observed with exposure to progesterone and estrogen. Intrauterine blocking of alpha4 integrin by specific antibody resulted in implantation failure in normal as well as in delayed-implantation mice. Based on our data, we propose here, to our knowledge for the first time, that alpha4beta1 integrin, which is responsible for binding to fibronectin and vascular cell adhesion molecule-1, is induced by estradiol and is down-regulated by progesterone in mice during implantation. Furthermore, the results also indicate the direct role of alpha4 integrin in the process of implantation.     

Phylogenetic and evolutionary implications of complete chloroplast genome sequences of four early-diverging angiosperms: Buxus (Buxaceae), Chloranthus (Chloranthaceae), Dioscorea (Dioscoreaceae), and Illicium (Schisandraceae)

We have determined the complete chloroplast genome sequences of four early-diverging lineages of angiosperms, Buxus (Buxaceae), Chloranthus (Chloranthaceae), Dioscorea (Dioscoreaceae), and Illicium (Schisandraceae), to examine the organization and evolution of plastid genomes and to estimate phylogenetic relationships among angiosperms. For the most part, the organization of these plastid genomes is quite similar to the ancestral angiosperm plastid genome with a few notable exceptions. Dioscorea has lost one protein-coding gene, rps16; this gene loss has also happened independently in four other land plant lineages, liverworts, conifers, Populus, and legumes. There has also been a small expansion of the inverted repeat (IR) in Dioscorea that has duplicated trnH-GUG. This event has also occurred multiple times in angiosperms, including in monocots, and in the two basal angiosperms Nuphar and Drimys. The Illicium chloroplast genome is unusual by having a 10 kb contraction of the IR. The four taxa sequenced represent key groups in resolving phylogenetic relationships among angiosperms. Illicium is one of the basal angiosperms in the Austrobaileyales, Chloranthus (Chloranthales) remains unplaced in angiosperm classifications, and Buxus and Dioscorea are early-diverging eudicots and monocots, respectively. We have used sequences for 61 shared protein-coding genes from these four genomes and combined them with sequences from 35 other genomes to estimate phylogenetic relationships using parsimony, likelihood, and Bayesian methods. There is strong congruence among the trees generated by the three methods, and most nodes have high levels of support. The results indicate that Amborella alone is sister to the remaining angiosperms; the Nymphaeales represent the next-diverging clade followed by Illicium; Chloranthus is sister to the magnoliids and together this group is sister to a large clade that includes eudicots and monocots; and Dioscorea represents an early-diverging lineage of monocots just internal to Acorus.     

Protein Paucimannosylation Is an Enriched N‐Glycosylation Signature of Human Cancers

While aberrant protein glycosylation is a recognized characteristic of human cancers, advances in glycoanalytics continue to discover new associations between glycoproteins and tumorigenesis. This glycomics‐centric study investigates a possible link between protein paucimannosylation, an under‐studied class of human N‐glycosylation [Man_1‐3GlcNAc₂Fuc_0‐1], and cancer. The paucimannosidic glycans (PMGs) of 34 cancer cell lines and 133 tissue samples spanning 11 cancer types and matching non‐cancerous specimens are profiled from 467 published and unpublished PGC‐LC‐MS/MS N‐glycome datasets collected over a decade. PMGs, particularly Man_2‐3GlcNAc₂Fuc₁, are prominent features of 29 cancer cell lines, but the PMG level varies dramatically across and within the cancer types (1.0–50.2%). Analyses of paired (tumor/non‐tumor) and stage‐stratified tissues demonstrate that PMGs are significantly enriched in tumor tissues from several cancer types including liver cancer (p = 0.0033) and colorectal cancer (p = 0.0017) and is elevated as a result of prostate cancer and chronic lymphocytic leukaemia progression (p < 0.05). Surface expression of paucimannosidic epitopes is demonstrated on human glioblastoma cells using immunofluorescence while biosynthetic involvement of N‐acetyl‐β‐hexosaminidase is indicated by quantitative proteomics. This intriguing association between protein paucimannosylation and human cancers warrants further exploration to detail the biosynthesis, cellular location(s), protein carriers, and functions of paucimannosylation in tumorigenesis and metastasis.     

Novel nicotinamide analog as inhibitor of nicotinamide N-methyltransferase

Nicotinamide N-methyltransferase (NNMT) has been linked to obesity and diabetes. We have identified a novel nicotinamide (NA) analog, compound 12 that inhibited NNMT enzymatic activity and reduced the formation of 1-methyl-nicotinamide (MNA), the primary metabolite of NA by ～80% at 2?h when dosed in mice orally at 50?mg/kg.     

Post-transcriptional regulation of MMP2 mRNA by its interaction with miR-20a and Nucleolin in breast cancer cell lines

Molecular Biology Reports - Matrix-metalloproteinase-2 (MMP2) is a foremost MMP, governing invasion of breast cancer cells during metastasis. miR-20a was reported to induce mesenchymal to...     

Human protein paucimannosylation: cues from the eukaryotic kingdoms

Paucimannosidic proteins (PMPs) are bioactive glycoproteins carrying truncated α‐ or β‐mannosyl‐terminating asparagine (N)‐linked glycans widely reported across the eukaryotic domain. Our understanding of human PMPs remains limited, despite findings documenting their existence and association with human disease glycobiology. This review comprehensively surveys the structures, biosynthetic routes and functions of PMPs across the eukaryotic kingdoms with the aim of synthesising an improved understanding on the role of protein paucimannosylation in human health and diseases. Convincing biochemical, glycoanalytical and biological data detail a vast structural heterogeneity and fascinating tissue‐ and subcellular‐specific expression of PMPs within invertebrates and plants, often comprising multi‐α1,3/6‐fucosylation and β1,2‐xylosylation amongst other glycan modifications and non‐glycan substitutions e.g. O‐methylation. Vertebrates and protists express less‐heterogeneous PMPs typically only comprising variable core fucosylation of bi‐ and trimannosylchitobiose core glycans. In particular, the Manα1,6Manβ1,4GlcNAc(α1,6Fuc)β1,4GlcNAcβAsn glycan (M2F) decorates various human neutrophil proteins reportedly displaying bioactivity and structural integrity demonstrating that they are not degradation products. Less‐truncated paucimannosidic glycans (e.g. M3F) are characteristic glycosylation features of proteins expressed by human cancer and stem cells. Concertedly, these observations suggest the involvement of human PMPs in processes related to innate immunity, tumorigenesis and cellular differentiation. The absence of human PMPs in diverse bodily fluids studied under many (patho)physiological conditions suggests extravascular residence and points to localised functions of PMPs in peripheral tissues. Absence of PMPs in Fungi indicates that paucimannosylation is common, but not universally conserved, in eukaryotes. Relative to human PMPs, the expression of PMPs in plants, invertebrates and protists is more tissue‐wide and constitutive yet, similar to their human counterparts, PMP expression remains regulated by the physiology of the producing organism and PMPs evidently serve essential functions in development, cell–cell communication and host–pathogen/symbiont interactions. In most PMP‐producing organisms, including humans, the N‐acetyl‐β‐hexosaminidase isoenzymes and linkage‐specific α‐mannosidases are glycoside hydrolases critical for generating PMPs via N‐acetylglucosaminyltransferase I (GnT‐I)‐dependent and GnT‐I‐independent truncation pathways. However, the identity and structure of many species‐specific PMPs in eukaryotes, their biosynthetic routes, strong tissue‐ and development‐specific expression, and diverse functions are still elusive. Deep exploration of these PMP features involving, for example, the characterisation of endogenous PMP‐recognising lectins across a variety of healthy and N‐acetyl‐β‐hexosaminidase‐deficient human tissue types and identification of microbial adhesins reactive to human PMPs, are amongst the many tasks required for enhanced insight into the glycobiology of human PMPs. In conclusion, the literature supports the notion that PMPs are significant, yet still heavily under‐studied biomolecules in human glycobiology that serve essential functions and create structural heterogeneity not dissimilar to other human N‐glycoprotein types. Human PMPs should therefore be recognised as bioactive glycoproteins that are distinctly different from the canonical N‐glycoprotein classes and which warrant a more dedicated focus in glycobiological research.