Metaplasia part 1 Flashcards
What is transdifferentiation?
The conversion of one differentiated cell type to another (e.g. pancreatic cell to a liver cell)
What is metaplasia?
The conversion of one cell type to another
Diff between transdifferentiation and metaplasia?
Metaplasia can include conversion of one tissue stem cell to another
Other name for Barretts Metaplasia?
Barrett’s Oesophagus
What is Barrett’s Metaplasia?
The conversion of normal stratified squamous epithelium to columnar-line intestinal epithelium, in the oesophagus
Where in the body does Barrett’s Metaplasia occur?
Oesophagus
Which type of epithelium usually lines the oesphagus?
Stratified squamous epithelium
What is the only known precursor to oesophageal adenocarcinoma?
Barrett’s Metaplasia
What is Stratified Squamous Epithelium?
Flattened scale-like multi-layered epithelium
Where in the oesophagus does Barrett’s occur?
Lower end
What is an adenocarcinoma?
A malignant tumour of epithelial glandular origin
What are some possible indicators of Barrett’s Metaplasia?
Difficulty swallowing combined w/ weight loss
Where other than the oesophagus is SSQE found?
Skin and parts of the cervix
Functions of SSQE in the oesophagus?
Protects against mechanical friction (food and liquid)
Protects against stomach acid which
What happens in the oesophagus that allows stomach acid to enter?
The lower esophageal sphincter relaxes, allowing the acid to enter the oesophagus
Which markers identify the basal layer of oesophageal SSQE
p63 TF, cytokeratins 5 and 14
What is p63?
Master TF for SSQE
What happens if p63 is knocked out in mice?
They don’t develop SSQE
What kind of pairs are the cytokeratin pairs?
Acidic and basic pairs
Which cytokeratin pairs are expressed higher up in the SSQE?
Cytokeratin 4/13, or 5/10
What is expressed in the terminally differentiated SSQE cells?
Involucrin and loricrin
Which cell types are present in the intestine?
Enterocyte, enteroendocrine, goblet cells, pitt cells, pallas cells
Role of enterocyte in the intestine?
Absorption of nutrients into the blood
Where are enterocytes found in the intestine?
Tips of the villus
Which enzyme do enterocyte express?
Glucose-6-phosphatase
Role of enteroendocrine cells?
Secretion of endocrine hormones–> e.g. glucagon-like peptide 1
Which drug is a synthetic GLP1?
Ozempic
Role of goblet cells?
Secretion of mucus
Role of mucus in the intestine?
Lubrication of the contents of the intestine, protective layer over intestinal epithelium–> against stomach acid
Role of pitt cells?
Unknown, believed to be involved in immune system
Role of pallas cells?
Secrete lysosomes–> bactericidal agent
What are pallas cells associated with?
Intestinal stem cell
