PMID- 8033821
OWN - NLM
STAT- MEDLINE
DCOM- 19940818
LR  - 20231213
IS  - 0013-7227 (Print)
IS  - 0013-7227 (Linking)
VI  - 135
IP  - 2
DP  - 1994 Aug
TI  - Differential control of connexin-32 and connexin-43 expression in thyroid 
      epithelial cells: evidence for a direct relationship between connexin-32 
      expression and histiotypic morphogenesis.
PG  - 724-34
AB  - Thyroid epithelial cells cultured either as a monolayer or in the form of 
      follicles, rapidly reconstitute functional gap junctions (Gj). We previously 
      reported that the thyroid Gj gating is regulated by TSH. We have now performed 
      molecular analyses of Gj proteins 1) to detect the connexin(s) (Cx) that is 
      expressed in thyroid epithelial cells, 2) to determine whether the expression of 
      Cx is hormonally regulated, and 3) to analyze the relationship between Cx 
      expression and histiotypic morphogenesis, i.e. folliculogenesis. Studies were 
      carried out on thyrocytes freshly isolated from the gland and on corresponding 
      thyrocytes after 1-7 days in culture as monolayers or in the form of 
      reconstituted follicles. The Cx gene transcription products were analyzed by 
      Northern blot using specific complementary DNA probes for Cx26, Cx32, and Cx43. 
      Cx proteins were identified and estimated by Western blot and indirect 
      immunofluorescence using polyclonal antipeptide antibodies. Cx32 and Cx43 
      proteins and their corresponding messenger RNA (mRNA) were detected in thyrocytes 
      freshly isolated from the gland. Thyrocytes contained a high amount of the 
      1.6-kilobase Cx32 mRNA and only traces of the 3-kilobase Cx43 transcript. No Cx26 
      transcripts could be detected. Thyrocytes cultured at a density of 0.2-0.5 x 
      10(6) cells/cm2 in the absence of TSH formed monolayers. Surprisingly, monolayer 
      cells lost Cx32 protein within 24 h, and their Cx32 mRNA content decreased from 
      high to barely detectable levels; Cx32 protein was no longer detected throughout 
      the 1-week culture period. On the contrary, Cx43 mRNA and Cx43 protein rapidly 
      increased in monolayer cells to reach very high levels within 2-4 days. 
      Thyrocytes cultured at the same density, but in the presence of TSH also rapidly 
      lost Cx32, but as soon as they reorganized into follicular structures, 
      reexpressed Cx32 at a level (in terms of protein and mRNA) comparable to that 
      found in cells freshly extracted from the gland. As observed for cell monolayers, 
      reconstituted follicles overexpressed Cx43. The Cx43 protein and Cx43 mRNA 
      contents of cultured thyrocytes were 20- to 50-fold higher than those found in 
      isolated thyrocytes at the outset of culture. When thyrocytes were cultured with 
      TSH, but at a low density (< 0.2 x 10(6) cells/cm2) to prevent follicle 
      formation, a TSH-dependent increase in Cx43 was observed in monolayer cells. 
      However, TSH did not cause any reexpression of Cx32.(ABSTRACT TRUNCATED AT 400 
      WORDS)
FAU - Munari-Silem, Y
AU  - Munari-Silem Y
AD  - Institut National de la Sante et de la Recherche Medicale U-369, Faculte de 
      Medecine A. Carrel, Lyon, France.
FAU - Guerrier, A
AU  - Guerrier A
FAU - Fromaget, C
AU  - Fromaget C
FAU - Rabilloud, R
AU  - Rabilloud R
FAU - Gros, D
AU  - Gros D
FAU - Rousset, B
AU  - Rousset B
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - United States
TA  - Endocrinology
JT  - Endocrinology
JID - 0375040
RN  - 0 (Connexin 43)
RN  - 0 (Connexins)
RN  - 0 (RNA, Messenger)
RN  - 9002-71-5 (Thyrotropin)
SB  - IM
MH  - Animals
MH  - Blotting, Western
MH  - Cells, Cultured
MH  - Connexin 43/analysis/*genetics
MH  - Connexins/analysis/*genetics
MH  - Epithelium/metabolism
MH  - Fluorescent Antibody Technique
MH  - *Gene Expression Regulation/drug effects
MH  - Kinetics
MH  - *Morphogenesis/drug effects
MH  - RNA, Messenger/metabolism
MH  - Swine
MH  - Thyroid Gland/*metabolism
MH  - Thyrotropin/pharmacology
MH  - Gap Junction beta-1 Protein
EDAT- 1994/08/01 00:00
MHDA- 1994/08/01 00:01
CRDT- 1994/08/01 00:00
PHST- 1994/08/01 00:00 [pubmed]
PHST- 1994/08/01 00:01 [medline]
PHST- 1994/08/01 00:00 [entrez]
AID - 10.1210/endo.135.2.8033821 [doi]
PST - ppublish
SO  - Endocrinology. 1994 Aug;135(2):724-34. doi: 10.1210/endo.135.2.8033821.