Disease relevance of CHIA

• RESULTS: AMCase mRNA was detected in the sinus mucosa of 72% of control subjects and in 72% of patients with eosinophilic CRS with nasal polyps (CRSwNP) [1].
• Circulating immune complexes were assayed employing the method recently described by Barnett and Chia in a group of patients with myasthenia gravis [2].
• Roles of four chitinases (chia, chib, chic, and chid) in the chitin degradation system of marine bacterium Alteromonas sp. strain O-7 [3].
• Immunoglobulin G antibodies to granulocytic ehrlichiosis were detected by an immunofluorescence assay using Ehrli- chia equi as antigen [4].
• Recently we have described association of polymorphisms of AMCase with bronchial asthma in a pediatric population [5].

High impact information on CHIA

• AMCase is capable of cleaving artificial chitin-like substrates as well as crab shell chitin and chitin as present in the fungal cell wall [6].
• Human acidic mammalian chitinase (AMCase), a member of the family 18 glycosyl hydrolases, is one of the important proteins involved in Th2-mediated inflammation and has been implicated in asthma and allergic diseases [7].
• Steady state kinetics shows that human AMCase has "low" intrinsic transglycosidase activity, which leads to the observation of apparent substrate inhibition [7].
• Human AMCase also appears to cleave chitooligosaccharides from the nonreducing end primarily by disaccharide units [7].
• ECF-L is a novel autocrine stimulator of osteoclast (OCL) formation that enhances the effects of 1,25-(OH)(2)D(3) and RANK ligand (RANKL) and is increased in inflammatory conditions such as rheumatoid arthritis [8].

Biological context of CHIA

• These AMCase-expressing cells retain expression of FOXA2, a transcription factor whose downregulation in association with IL-13 signaling has previously been associated with production of mucus in proximal airway epithelial cells [9].
• Its cDNA contains an open reading frame 1421 bp long and encodes a protein with a characteristic N-terminal 21 amino acid endoplasmic reticulum signal peptide and the putative protein is highly homologous to acidic mammalian chitinase (AMCase) precursor of mouse and human [10].
• Genetics of qualitative traits in domesticated chia (Salvia hispanica L.) [11].

Anatomical context of CHIA

• Immunostaining using mouse tissues detected intense immunoreactivity for AMCase in serous-type secretory cells of the parotid gland and von Ebner's gland [12].
• At least in the mouse, AMCase is secreted into the saliva and gastric juice, and may function as a digestive enzyme or play a defensive role against chitinous pathogens [12].
• Gastric chief cells, localized at the bottom of gastric glands, were also immunoreactive for AMCase [12].
• AMCase mRNA expression has been demonstrated in the salivary gland and stomach of mice and in the stomach of humans, while a bovine homologue of AMCase is produced in the liver and secreted into the blood [12].
• Among distal cells, AMCase colocalizes with epithelial cells expressing the Clara cell marker Clara cell secretory protein [9].

Associations of CHIA with chemical compounds

• Quantitation of Fatty Acids, Sterols, and Tocopherols in Turpentine (Pistacia terebinthus Chia) Growing Wild in Turkey [13].
• The highest amount of alpha-tocopherol was found in P. lentiscus var. chia [14].

Other interactions of CHIA

• Isolation and mapping of a human lung-specific gene, TSA1902, encoding a novel chitinase family member [15].
• Failure of medical and surgical therapy in CRSwNP is associated with significantly increased expression of AMCase, but not the Th2 cytokines IL-13 and eotaxin [1].

Analytical, diagnostic and therapeutic context of CHIA

• Western blot analysis confirmed the existence of AMCase in the parotid gland and stomach, and in their secretions in mice [12].
• RNA was extracted from surgically obtained ethmoid mucosa, and real-time PCR was used to determine expression of AMCase, eotaxin, and IL-13 [1].
• HPLC characterization of cleavage of chitooligosaccharides (4-6-mers) suggests that human AMCase prefers the beta anomer of chitooligosaccharides as substrate [7].
• Quantitative determination of alpha-tocopherol in Pistacia lentiscus, Pistacia lentiscus var. chia, and Pistacia terebinthus by TLC-densitometry and colorimetry [14].

References