Limits...
Laminin receptor 37/67LR regulates adhesion and proliferation of normal human intestinal epithelial cells.

Khalfaoui T, Groulx JF, Sabra G, GuezGuez A, Basora N, Vermette P, Beaulieu JF - PLoS ONE (2013)

Bottom Line: Immunolocalization studies revealed that 37/67LR was predominantly present in the undifferentiated/proliferative region of the human intestinal crypt in both the immature and adult intestine.Using a human intestinal epithelial crypt (HIEC) cell line as experimental model, we determined that 37/67LR was expressed in proliferative cells in both the cytoplasmic and membrane compartments.Small-interfering RNA-mediated reduction of 37/67LR expression led to HIEC cell-cycle reduction and loss of the ability to adhere to laminin-related peptides under conditions not altering ribosomal function.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.

ABSTRACT
Interactions between the cell basal membrane domain and the basement membrane are involved in several cell functions including proliferation, migration and differentiation. Intestinal epithelial cells can interact with laminin, a major intestinal basement membrane glycoprotein, via several cell-surface laminin-binding proteins including integrin and non-integrin receptors. The 37/67kDa laminin receptor (37/67LR) is one of these but its role in normal epithelial cells is still unknown. The aim of this study was to characterise the expression pattern and determine the main function of 37/67LR in the normal human small intestinal epithelium. Immunolocalization studies revealed that 37/67LR was predominantly present in the undifferentiated/proliferative region of the human intestinal crypt in both the immature and adult intestine. Using a human intestinal epithelial crypt (HIEC) cell line as experimental model, we determined that 37/67LR was expressed in proliferative cells in both the cytoplasmic and membrane compartments. Small-interfering RNA-mediated reduction of 37/67LR expression led to HIEC cell-cycle reduction and loss of the ability to adhere to laminin-related peptides under conditions not altering ribosomal function. Taken together, these findings indicate that 37/67LR regulates proliferation and adhesion in normal intestinal epithelial cells independently of its known association with ribosomal function.

Show MeSH

Related in: MedlinePlus

Characterization of 37/67LR in human intestinal epithelial crypt (HIEC) cells.(A) Western blot analysis of subconfluent (SC) and 5 day postconfluent (PC) HIEC cells revealed expression of 37/67LR in proliferative cells and a significant reduction of its expression in quiescent cells relative to β-actin (mean ± SEM, n=3, *: p < 0.02). (B) Cell counts over a 10 day period after seeding confirmed that cell number stabilizes after confluence (c ->). (C) Representative Western blot analysis of 37/67LR in enriched HIEC cytoplasmic (F1), membrane (F2), nuclear (F3) and cytoskeletal (F4) fractions showing that 37/67LR was essentially found in the cytoplasmic and membrane fractions. Enriched fractions were verified by the detection of p27KIP1 (p27; cytoplasmic fraction F1), the β1 integrin subunit (β1; membrane fraction F2), trimethylated lysine 27 on histone 3 (H3K27me3e; nuclear fraction F3) and keratin 18 (K18; cytoskeletal fraction F4; also detectable in the cytoplasmic F1 and membrane F2 fractions). (D) Indirect immunofluorescence for the detection of 37/67LR in HIEC cells showing mainly perinuclear granular and weak membrane staining. Nuclei were stained with DAPI (blue). Scale bar in D: 50 µm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3750003&req=5

pone-0074337-g003: Characterization of 37/67LR in human intestinal epithelial crypt (HIEC) cells.(A) Western blot analysis of subconfluent (SC) and 5 day postconfluent (PC) HIEC cells revealed expression of 37/67LR in proliferative cells and a significant reduction of its expression in quiescent cells relative to β-actin (mean ± SEM, n=3, *: p < 0.02). (B) Cell counts over a 10 day period after seeding confirmed that cell number stabilizes after confluence (c ->). (C) Representative Western blot analysis of 37/67LR in enriched HIEC cytoplasmic (F1), membrane (F2), nuclear (F3) and cytoskeletal (F4) fractions showing that 37/67LR was essentially found in the cytoplasmic and membrane fractions. Enriched fractions were verified by the detection of p27KIP1 (p27; cytoplasmic fraction F1), the β1 integrin subunit (β1; membrane fraction F2), trimethylated lysine 27 on histone 3 (H3K27me3e; nuclear fraction F3) and keratin 18 (K18; cytoskeletal fraction F4; also detectable in the cytoplasmic F1 and membrane F2 fractions). (D) Indirect immunofluorescence for the detection of 37/67LR in HIEC cells showing mainly perinuclear granular and weak membrane staining. Nuclei were stained with DAPI (blue). Scale bar in D: 50 µm.

Mentions: Considering the distribution pattern of immunoreactive 37/67LR in intestinal crypts in situ, we used the normal human intestinal crypt (HIEC) cell line to further investigate 37/67LR expression in relation to cell proliferation. As shown in Figure 3, 37/67LR expression was observed in actively proliferating HIEC cells (Figure 3A, SC) and a significant reduction was observed in HIEC cells maintained for 5 days at confluence (Figure 3A, PC). Indeed, while subconfluent HIEC cell growth is linear before confluence, proliferation is totally inhibited after confluence (Figure 3B).


Laminin receptor 37/67LR regulates adhesion and proliferation of normal human intestinal epithelial cells.

Khalfaoui T, Groulx JF, Sabra G, GuezGuez A, Basora N, Vermette P, Beaulieu JF - PLoS ONE (2013)

Characterization of 37/67LR in human intestinal epithelial crypt (HIEC) cells.(A) Western blot analysis of subconfluent (SC) and 5 day postconfluent (PC) HIEC cells revealed expression of 37/67LR in proliferative cells and a significant reduction of its expression in quiescent cells relative to β-actin (mean ± SEM, n=3, *: p < 0.02). (B) Cell counts over a 10 day period after seeding confirmed that cell number stabilizes after confluence (c ->). (C) Representative Western blot analysis of 37/67LR in enriched HIEC cytoplasmic (F1), membrane (F2), nuclear (F3) and cytoskeletal (F4) fractions showing that 37/67LR was essentially found in the cytoplasmic and membrane fractions. Enriched fractions were verified by the detection of p27KIP1 (p27; cytoplasmic fraction F1), the β1 integrin subunit (β1; membrane fraction F2), trimethylated lysine 27 on histone 3 (H3K27me3e; nuclear fraction F3) and keratin 18 (K18; cytoskeletal fraction F4; also detectable in the cytoplasmic F1 and membrane F2 fractions). (D) Indirect immunofluorescence for the detection of 37/67LR in HIEC cells showing mainly perinuclear granular and weak membrane staining. Nuclei were stained with DAPI (blue). Scale bar in D: 50 µm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3750003&req=5

pone-0074337-g003: Characterization of 37/67LR in human intestinal epithelial crypt (HIEC) cells.(A) Western blot analysis of subconfluent (SC) and 5 day postconfluent (PC) HIEC cells revealed expression of 37/67LR in proliferative cells and a significant reduction of its expression in quiescent cells relative to β-actin (mean ± SEM, n=3, *: p < 0.02). (B) Cell counts over a 10 day period after seeding confirmed that cell number stabilizes after confluence (c ->). (C) Representative Western blot analysis of 37/67LR in enriched HIEC cytoplasmic (F1), membrane (F2), nuclear (F3) and cytoskeletal (F4) fractions showing that 37/67LR was essentially found in the cytoplasmic and membrane fractions. Enriched fractions were verified by the detection of p27KIP1 (p27; cytoplasmic fraction F1), the β1 integrin subunit (β1; membrane fraction F2), trimethylated lysine 27 on histone 3 (H3K27me3e; nuclear fraction F3) and keratin 18 (K18; cytoskeletal fraction F4; also detectable in the cytoplasmic F1 and membrane F2 fractions). (D) Indirect immunofluorescence for the detection of 37/67LR in HIEC cells showing mainly perinuclear granular and weak membrane staining. Nuclei were stained with DAPI (blue). Scale bar in D: 50 µm.
Mentions: Considering the distribution pattern of immunoreactive 37/67LR in intestinal crypts in situ, we used the normal human intestinal crypt (HIEC) cell line to further investigate 37/67LR expression in relation to cell proliferation. As shown in Figure 3, 37/67LR expression was observed in actively proliferating HIEC cells (Figure 3A, SC) and a significant reduction was observed in HIEC cells maintained for 5 days at confluence (Figure 3A, PC). Indeed, while subconfluent HIEC cell growth is linear before confluence, proliferation is totally inhibited after confluence (Figure 3B).

Bottom Line: Immunolocalization studies revealed that 37/67LR was predominantly present in the undifferentiated/proliferative region of the human intestinal crypt in both the immature and adult intestine.Using a human intestinal epithelial crypt (HIEC) cell line as experimental model, we determined that 37/67LR was expressed in proliferative cells in both the cytoplasmic and membrane compartments.Small-interfering RNA-mediated reduction of 37/67LR expression led to HIEC cell-cycle reduction and loss of the ability to adhere to laminin-related peptides under conditions not altering ribosomal function.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.

ABSTRACT
Interactions between the cell basal membrane domain and the basement membrane are involved in several cell functions including proliferation, migration and differentiation. Intestinal epithelial cells can interact with laminin, a major intestinal basement membrane glycoprotein, via several cell-surface laminin-binding proteins including integrin and non-integrin receptors. The 37/67kDa laminin receptor (37/67LR) is one of these but its role in normal epithelial cells is still unknown. The aim of this study was to characterise the expression pattern and determine the main function of 37/67LR in the normal human small intestinal epithelium. Immunolocalization studies revealed that 37/67LR was predominantly present in the undifferentiated/proliferative region of the human intestinal crypt in both the immature and adult intestine. Using a human intestinal epithelial crypt (HIEC) cell line as experimental model, we determined that 37/67LR was expressed in proliferative cells in both the cytoplasmic and membrane compartments. Small-interfering RNA-mediated reduction of 37/67LR expression led to HIEC cell-cycle reduction and loss of the ability to adhere to laminin-related peptides under conditions not altering ribosomal function. Taken together, these findings indicate that 37/67LR regulates proliferation and adhesion in normal intestinal epithelial cells independently of its known association with ribosomal function.

Show MeSH
Related in: MedlinePlus