Chulalongkorn University

About: Chulalongkorn University is a education organization based out in Bangkok, Thailand. It is known for research contribution in the topics: Population & Catalysis. The organization has 20156 authors who have published 34324 publications receiving 647815 citations. The organization is also known as: Chula & CU.

The Neuro-Immune Pathophysiology of Central and Peripheral Fatigue in Systemic Immune-Inflammatory and Neuro-Immune Diseases.

Abstract: Many patients with systemic immune-inflammatory and neuro-inflammatory disorders, including depression, rheumatoid arthritis, systemic lupus erythematosus, Sjogren's disease, cancer, cardiovascular disorder, Parkinson's disease, multiple sclerosis, stroke, and chronic fatigue syndrome/myalgic encephalomyelitis, endure pathological levels of fatigue. The aim of this narrative review is to delineate the wide array of pathways that may underpin the incapacitating fatigue occurring in systemic and neuro-inflammatory disorders. A wide array of immune, inflammatory, oxidative and nitrosative stress (ON ON activation of the Toll-Like Receptor Cycle through pathogen-associated (PAMPs) and damage-associated (DAMPs) molecular patterns, including heat shock proteins; altered glutaminergic and dopaminergic neurotransmission; mitochondrial dysfunctions; and O&NS-induced defects in the sodium-potassium pump. Fatigue is also associated with altered activities in specific brain regions and muscle pathology, such as reductions in maximum voluntary muscle force, downregulation of the mitochondrial biogenesis master gene peroxisome proliferator-activated receptor gamma coactivator 1-alpha, a shift to glycolysis and buildup of toxic metabolites within myocytes. As such, both mental and physical fatigue, which frequently accompany immune-inflammatory and neuro-inflammatory disorders, are the consequence of interactions between multiple systemic and central pathways.

Isolation and characterization of a halotolerant Bacillus subtilis BBK-1 which produces three kinds of lipopeptides: bacillomycin L, plipastatin, and surfactin.

Abstract: Twenty-three halotolerant and biosurfactant producing strains were collected from salty conditions in central Thailand. One of the strains designated BBK-1 produced the biosurfactants with the highest activity. BBK-1 was isolated from fermented foods and was identified as B. subtilis based on its physiological characteristics and 16S rRNA gene sequence. We show that the strain grows in media containing NaCl up to 16% (w/v) and produces biosurfactants in NaCl up to 8%. We found that B. subtilis BBK-1 produces three kinds of surface-active lipopeptides simultaneously. By their respective molecular weights and amino acid compositions, it is indicated that these lipopeptides are bacillomycin L, plipastatin, and surfactin. In order to analyze the production mechanism of lipopeptides further in the strain, a generally important biosynthetic gene encoding 4'-phosphopantetheinyl transferase was cloned and sequenced. The gene existed in a single copy in the genome and the deduced amino acid sequence was almost identical to that of Lpa-14 from B. subtilis strain RB14, which co-produces iturin A and surfactin.

A bacteriophage nucleus-like compartment shields DNA from CRISPR nucleases

Abstract: All viruses require strategies to inhibit or evade the immune pathways of cells that they infect. The viruses that infect bacteria, bacteriophages (phages), must avoid immune pathways that target nucleic acids, such as CRISPR-Cas and restriction-modification systems, to replicate efficiently1. Here we show that jumbo phage ΦKZ segregates its DNA from immunity nucleases of its host, Pseudomonas aeruginosa, by constructing a proteinaceous nucleus-like compartment. ΦKZ is resistant to many immunity mechanisms that target DNA in vivo, including two subtypes of CRISPR-Cas3, Cas9, Cas12a and the restriction enzymes HsdRMS and EcoRI. Cas proteins and restriction enzymes are unable to access the phage DNA throughout the infection, but engineering the relocalization of EcoRI inside the compartment enables targeting of the phage and protection of host cells. Moreover, ΦKZ is sensitive to Cas13a-a CRISPR-Cas enzyme that targets RNA-probably owing to phage mRNA localizing to the cytoplasm. Collectively, we propose that Pseudomonas jumbo phages evade a broad spectrum of DNA-targeting nucleases through the assembly of a protein barrier around their genome.

Cloning, expression and antimicrobial activity of crustinPm1, a major isoform of crustin, from the black tiger shrimp Penaeus monodon

Abstract: Crustin antibacterial homologues, containing a whey acidic protein (WAP) domain, have been identified from the haemocyte library of the black tiger shrimp, Penaeus monodon . Sequence analysis of these cDNAs indicates the presence of several isoforms of crustin in P. monodon . Crustin Pm 1, the most abundant isoform, contains an open reading frame of 435 bp encoding a precursor of 145 amino acids that comprises 17 amino acid signal peptides and 128 amino acid mature peptides. The peptides contain a Gly–Pro rich region at the amino-terminus and a single whey acidic protein (WAP) domain at the carboxyl-terminus. In order to characterize the properties and biological activities of this peptide, crustin Pm 1 was overexpressed in Escherichia coli . The recombinant crustin Pm 1 has a molecular mass of 14.7 kDa with a predicted p I of 8.3. Antimicrobial assays demonstrated that recombinant crustin Pm 1 exhibited antimicrobial activity against only Gram-positive bacteria with strong inhibition against Staphylococcus aureus and Streptococcus iniae . In addition, the study of inhibition mechanism revealed that the antimicrobial activity of crustin Pm 1 was a result of bactericidal effect. In situ hybridization with crustin Pm 1 antisense probes showed strong hybridization signals in a certain haemocyte population of unchallenged shrimp, indicating that crustin Pm 1 transcript is differentially expressed in different subsets of haemocyte cells.