Novel goblet cell gene related to IgGFc
BP
is regulated in adapting gut after small bowel resection
Deborah C.
Rubin1,2,
Elzbieta A.
Swietlicki1,
Hristo
Iordanov1,
Christine
Fritsch1, and
Marc S.
Levin1,2,3
1 Department of Medicine, Washington University School of
Medicine, 2 Barnes-Jewish Hospital, and 3 Specialty Care,
Department of Veterans Affairs Medical Center, St. Louis, Missouri
63110
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ABSTRACT |
The loss of functional small
bowel surface area leads to a well-described adaptive response in the
remnant intestine. To elucidate its molecular regulation, a cohort of
cDNAs were cloned using a rat gut resection model and
subtractive/differential hybridization cloning techniques. This study
reports a novel cDNA termed "ileal remnant repressed" (IRR)-219,
which shares 80% nucleotide identity with the 3'end of a human
intestinal IgG Fc binding protein (IgGFc
BP) and is homologous to
human and rat mucins. IRR-219 mRNA is expressed in intestine and colon
only. At 48 h after 70% intestinal resection, mRNA levels
decreased two- to fivefold in the adaptive small bowel but increased
two- to threefold in the colon. Expression of IRR-219 was suppressed in
adaptive small bowel as late as 1 wk after resection. IRR-219
expression is also regulated during gut ontogeny. In situ hybridization
revealed IRR-219 expression in small intestinal and colonic goblet
cells only. Its unique patterns of expression during ontogeny and after
small bowel resection suggest distinctive roles in small bowel and
colonic adaptation.
colonic adaptation; small intestinal adaptation; gene regulation
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INTRODUCTION |
THE SMALL
INTESTINE has a remarkable capacity to adapt to the loss of small
bowel surface area. This response occurs after surgical resection due
to vascular injury or abdominal trauma or because of loss of functional
intestine resulting from a variety of small bowel disorders such as
Crohn's disease or radiation enteritis. The morbidity resulting from
short bowel syndrome is a major source of health care costs,
particularly when long-term total parenteral nutrition is required to
sustain life (4, 5). The critical importance of the
adaptive response in facilitating discontinuation from total parenteral
nutritional support underscores the need for better therapies to hasten
and enhance this process. These treatments might also prove effective
in a variety of other intestinal disorders, by enhancing small bowel
recovery after injury (e.g., ischemia or caused by inflammation in
Crohn's disease, etc.).
In rodent models of small bowel adaptation after massive resection, the
remnant intestine exhibits increased crypt cell proliferation, resulting in enhanced villus height and crypt depth followed by increased absorption of fluid, electrolytes, and nutrients. The adaptive response is quite complex and includes alterations in processes as diverse as cellular proliferation, apoptosis, epithelial migration, and epithelial cell gene expression (6, 14,
20, 21, 24). This process is also temporally regulated. As early as 16 h after resection, there is an increase in crypt cell
proliferation rate (27), and by 48 h enhanced
expression of a variety of enterocyte-specific genes is seen (6,
20, 21). This is followed by villus epithelial hyperplasia and
increased enterocyte migration rate by 1-2 wk (7).
Much progress has been made in identifying growth factors and peptides
that initiate enhanced crypt cell proliferation (such as epidermal
growth factor, keratinocyte growth factor, and glucagon-like peptide-2)
(8, 9, 22, 25). However, the intracellular pathways that
mediate growth factor effects in the crypt cell and the genetic
regulation of other facets of this complex response have not yet been identified.
To begin to elucidate the molecular mechanisms that regulate the
adaptive response, we have used subtractive hybridization techniques to
isolate novel cDNAs that are specifically regulated during this process
(6, 21). In this study, we report the cloning and
characterization of a novel rat cDNA [termed "ileal remnant
repressed" (IRR)-219] that encodes a protein homologous to a
recently identified human IgG Fc binding protein (IgGFc
BP) (13), a mucinlike intestinal protein that specifically
binds the Fc portion of IgG. IRR-219 mRNA is only expressed in goblet cells, and it is differentially regulated during early gut adaptation (at 48 h after resection) in small bowel and colon. These findings suggest that the goblet cell may play distinctive roles in small bowel
and colonic adaptation.
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METHODS |
Rat model of intestinal adaptation.
For intestinal resection and control surgery, male Sprague-Dawley rats
(225-260 g) were subjected to either 70% small intestinal resection or transection control surgery as previously described (6, 20, 21). For 70% small bowel resection, the bowel was divided 5 cm distal to the ligament of Treitz and 15 cm proximal to
the ileocecal valve, and the remnant jejunum was anastomosed to
the ileum after removal of the intervening intestine. In the transected group, the bowel was divided 5 cm distal to the ligament of Treitz and then reanastomosed end to end. Rats were killed and
tissues harvested at 48 h after surgery (n = 7 per
experimental and control group), or at 2, 4, 8, 16, 24, and 168 (1 wk)
h postoperatively (n = 3 per group).
Tissue harvesting.
Tissues were frozen in liquid nitrogen for RNA preparation or were
fixed in 4% paraformaldehyde in 1× phosphate-buffered saline for in
situ hybridization analysis. For regional analysis of IRR-219 expression, segments of intestine were isolated from duodenum, jejunum,
ileum, and proximal and distal colon. For analysis of IRR-219
expression during adaptation, the adaptive intestine was divided into
two segments. The portion "proximal" to the anastomosis consisted
of duodenum and 5.0 cm of jejunum, and the portion "distal" to the
anastomosis consisted of the remnant ileum. For tissue-specific expression analyses, liver, kidney, lung, heart, brain, and testes were
harvested from 8-wk-old male Sprague-Dawley rats. To examine the
developmental regulation of IRR-219 expression in the gut, segments
were harvested on fetal days 13 and 14 (whole
intestine) and days 18, 20, and
21 (jejunum) and postnatal weeks 2, 3,
4, 6, and 8 [proximal and
midintestine (representing jejunum) or distal intestine (representing
ileum)].
Cloning, sequencing, and database analysis of IRR-219 cDNA.
The IRR-219 cDNA was cloned by subtractive hybridization techniques as
previously described (6). Briefly, an adaptive, size-selected cDNA library was synthesized from rat ileal mRNA isolated
from tissues harvested 48 h after small bowel resection. High
specific activity subtracted cDNA probes were generated as follows.
Ileal poly(A)+ RNA from animals subjected to 70% intestinal resection
was labeled by reverse transcription. Ileal poly(A)+ RNA from the
transected control animals was biotinylated, and subtraction was
performed by hybridizing radiolabeled adaptive probe with the
biotinylated RNA (1:15 ratio, hybridized at 65°C for 48 h).
Biotinylated RNA (free and bound to cDNA) was removed by extraction
with streptavidin. Two rounds of subtraction were performed. The
subtracted probe and a control probe [created by subtracting
radiolabeled cDNA from transected animal (control) ileum with
biotinylated ileal adaptive mRNA] were used to screen the adaptive
cDNA library. Clones that exhibited differential hybridization to the
subtracted compared with the control probe were selected for sequence
analysis by the Sanger method using Sequenase 2.0 as described
previously (6). The nonredundant Genbank/European
Molecular Biology Laboratory databases were searched on the National
Center for Biotechnology Information server, using the BLASTn, TBLASTn,
and BLASTx algorithms.
Northern blot hybridization.
Total RNA was prepared from various intestinal segments and
extraintestinal tissues, and Northern blot hybridization was performed as previously described (6, 20, 27). IEC-18 and Caco-2 cell lines were grown as described (21) and harvested at 3 days after plating (IEC-18) or 21 days after confluence (Caco-2) for total RNA isolation. Briefly, Northern blots containing 20 µg of
total RNA were incubated with IRR-219 cDNA probe, rat intestinal trefoil factor (RITF) cDNA probe (gift of Daniel Podolsky,
Massachusetts General Hospital; Ref. 23), or rat
-actin cDNA probe,
radiolabeled by the random oligonucleotide primer method. Blots were
stringently washed at 55°C in 0.1× sodium chloride sodium citrate
(SSC) and exposed for various times to Kodak BioMax MS films and
intensifying screens. The relative abundance of each mRNA per sample
was determined by NIH Image 1.55 analysis of digitized images obtained
with a UMAX PS-2400X scanner using UMAX Magicscan version 1.2. Results were normalized for differences in RNA loading by digitized image analysis of 18S rRNA bands as visualized by ethidium bromide staining of RNA gels.
In situ hybridization.
Tissues were subjected to in situ hybridization analyses as previously
described (10, 11). The 1,700-bp IRR-219 cDNA was subcloned into the Bluescript II SK
vector, linearized by
Hpa I and transcribed to produce a 341-bp antisense probe,
or cut with Nde 1 and hybridized with a 506-bp sense control
probe, labeled with 35S-UTP. Paraformaldehyde-fixed frozen
cryostat sections (6-8 µm thick) were hybridized overnight to
the radiolabeled antisense or sense control RNA probes (5 × 106 cpm/ml of hybridization solution) and then washed
stringently in 0.1× SSC at 55°C. Slides were dipped in Kodak NTB-2
photoemulsion and exposed at 4°C for 6 days.
 |
RESULTS |
Sequence analysis of clone IRR-219 reveals homology to a human IgG
Fc binding protein.
As previously described, subtractive and differential hybridization
cloning techniques were used to identify genes that are differentially
regulated during intestinal adaptation (6). IRR-219, a
cDNA demonstrating suppressed expression in adaptation, was identified
after three rounds of hybridization screening of an adaptive ileal cDNA
library derived from ileal RNA harvested 48 h after 70%
resection. The partial nucleotide and amino acid sequences are
indicated in Fig. 1. Nucleic acid
homology searches revealed 80% sequence identity to the 3'-end of a
human IgG Fc binding protein (known as IgGFc
BP). IgGFc
BP is a
very large (encoded by a 17-kb mRNA), mucinlike protein that binds the
Fc portion of IgG (13). It is secreted with mucin and is
expressed only in intestine and placenta. Protein database analysis
also revealed homology of IRR-219 to the rat and human mucins MUC2 and
human mucin MUC5b (~30% amino acid sequence identity; data not
shown). Northern blots of jejunal, ileal, or colonic total RNA
hybridized with the IRR-219 cDNA demonstrated a single band specifying
a large mRNA of >10.0 kb.

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Fig. 1.
Partial nucleotide (A) and amino acid
(B) sequence of IRR-219 and homology to the human IgG Fc
binding protein (IgGFc BP). The nonredundant Genbank/European
Molecular Biology Laboratory databases were searched on the National
Center for Biotechnology Information server, using the BLASTn, TBLASTn,
and BLASTx algorithms. A: 219, ileal remnant repressed
(IRR)-219; IgG, IgGFc BP. B: 219, IRR-219; IgGFc,
IgGFc BP; +, conserved amino acids.
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Expression of IRR-219 mRNA is restricted to the intestine and
colon.
The tissue-specific expression of IRR-219 was examined by Northern blot
hybridization (Fig. 2). IRR-219 mRNA was
found in small intestine and colon but was undetectable in stomach,
liver, kidney, brain, lung, heart, and testes harvested from 8-wk-old rats. The regional intestinal expression of IRR-219 was examined by
isolating total RNA from intestinal segments including duodenum, jejunum, ileum, and proximal and distal colon. IRR-219 mRNA expression was most abundant in the ileum and jejunum, with lower levels in the
duodenum and proximal and distal colon (Fig. 2A). However, unlike the human IgGFc
BP (13), IRR-219 is not expressed
in rat placenta (Fig. 2B). In addition, two epithelial cell
lines, IEC-18, a proliferating cryptlike cell line derived from rat
ileum, and human Caco-2, a colon cancer cell line that exhibits
enterocytic characteristics on achieving confluence, do not express
IRR-219.

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Fig. 2.
IRR-219 mRNA is expressed in the small bowel and colon.
A: total RNA was prepared from 8-wk-old rat duodenum (D),
jejunum (J), ileum (I), proximal colon (PC), distal colon (DC), liver
(L), kidney (K), lung (P), heart (H), brain (B), and testes (T).
Stomach not shown. Northern blot hybridization was performed using a
radiolabeled IRR-219 cDNA probe, as described in
METHODS. B: total RNA was prepared from 11-day rat
placenta (lane 1), rat ileum (lane 2), IEC-18
cells harvested at 3 days after plating (lane 3) and Caco-2
cells harvested at 21 days after confluence (lane 4).
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IRR-219 expression is regulated during small bowel and colonic
adaptation.
To assess the regulation of IRR-219 mRNA expression during gut
adaptation, Northern blot hybridization analyses were performed. Because IRR-219 mRNA is expressed in small bowel and colon, both tissues were analyzed for the response after small bowel resection (Fig. 3). Cloning experiments were
designed to isolate cDNAs that are regulated during "early" gut
adaptation (e.g., at 48 h after resection), so this time point was
the first examined by Northern blot hybridization. At 48 h after
resection surgery, the crypt cell proliferation rate is increased
(27), although villus height and crypt depth have not yet
changed. The adaptive ileum also exhibits increased expression of a
variety of enterocytic genes, including the immediate-early gene,
PC4/TIS7, a sensitive marker of early adaptation (6, 20,
21). Intestinal adaptation was documented in the tissues used
for these studies by showing that expression of PC4/TIS7 was increased
in adaptive compared with sham-resected control ileum
(21).

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Fig. 3.
Regulation of IRR-219 expression during intestinal
adaptation after small bowel resection. Rats were subjected to 70%
small intestinal resection or sham-control surgery and killed at
48 h after surgery. Duodenal-jejunal or ileal segments
(n = 7/group) or colonic segments (n = 3/group) were removed for total RNA preparation, and Northern blot
hybridization was performed as described in METHODS.
A: representative Northern blot hybridization. B:
relative IRR-219 mRNA levels in sham-resected (SHR) vs. resected (RE)
small bowel or colon. Data are expressed as mean densitometric units
per group. *P < 0.04 vs. SHR.
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IRR-219 mRNA expression is differentially regulated in small bowel and
colon. Steady-state IRR-219 mRNA levels are decreased in adaptive
jejunum compared with sham-resected jejunum (2.7- to 5-fold;
P < 0.04) and in adaptive ileum vs. sham-resected
ileum (2-fold; P < 0.04) at 48 h after resection
(Fig. 3A). In contrast, IRR-219 mRNA was increased in
adaptive proximal and distal colon compared with sham-resected colon
(2- to 3.5-fold; P < 0.04) by 48 h
postoperatively (Fig. 3B). The increase in IRR-219 mRNA in adaptive colon was not caused by a change in goblet cell numbers, because at 48 h after resection, adaptive hyperplasia had not yet
taken place and there were no differences in small bowel or colonic
goblet cell populations compared with control.
The temporal regulation of IRR-219 expression after small bowel
resection was examined by harvesting proximal, mid-, or distal ileum
from rats killed at 2, 4, 8, 16, 24, 48, or 168 h after resection.
IRR-219 mRNA levels began to decrease in resected compared with control
gut as early as 24 h after resection and remained decreased as
late as 1 wk after resection (Fig. 4). Of
note, the decrease in IRR-219 mRNA expression occurred despite the
adaptive increase in goblet cell numbers that is apparent by 1 wk after resection (1.87-fold increase in goblet cell number in adaptive vs.
sham-resected ileal villus; P < 0.0001).

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Fig. 4.
Temporal regulation of IRR-219 expression during small
bowel adaptation. Rats were subjected to intestinal resection or sham
control surgery and killed at 2, 4, 8, 16, 24, 48 and 168 h (1 wk)
postoperatively (n = 3/group). IRR-219 mRNA expression
was quantitated by dot blot hybridization of total RNA prepared from
each segment at each time point. Data are expressed as the ratio of
relative mRNA levels from resected/sham-resected rats.
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Ontogeny of IRR-219 mRNA expression in gut.
The developmental regulation of IRR-219 expression was examined in
whole intestine harvested from fetuses on gestation days 13 and 14 and from jejunum on fetal days 18,
20, and 21. Segments of proximal and midintestine
(jejunum) and distal intestine (ileum) were also isolated at postnatal
weeks 2, 3, 4, 6, and
8. IRR-219 mRNA was first detected from fetal day
18 onward in jejunum (data not shown) and continued to exhibit low
levels of expression in small bowel at postnatal weeks 2,
3, and 4 (Fig. 5).
By week 6, mRNA levels were markedly upregulated and
abundant expression of IRR-219 mRNA was noted.

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Fig. 5.
The expression of IRR-219 mRNA is developmentally
regulated. Representative autoradiogram from Northern blot
hybridization of total RNA prepared from intestinal segments including
duodenum (DU) proximal (P, representing proximal jejunum), mid (M,
representing midjejunum), and distal (D, representing ileum) intestine,
harvested from 2-, 3-, 4-, 6-, and 8-wk-old rats. Northern blots were
prepared and probed as described in Fig. 2.
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IRR-219 mRNA is detected exclusively in intestinal goblet cells.
To identify the intestinal cells that express IRR-219, in situ
hybridization analyses were performed using neonatal and adult rat
intestine (Fig. 6) from rats at fetal
day 18 and at postnatal weeks 2, 4,
and 8. Beginning with the onset of villus morphogenesis, IRR-219 mRNA was expressed exclusively in goblet cells (Fig. 6). Relatively low IRR-219 mRNA levels are expressed in goblet cells during
the suckling and weaning period (Fig. 6, B and
C), and a marked increase in expression occurs in the adult
intestine (Fig. 6D), consistent with the Northern blot
hybridization results shown in Fig. 5. mRNA expression was not detected
in enterocytes, Paneth cells, or enteroendocrine cells in the lamina
propria or muscle layers. A sense control probe revealed no specific
signal (Fig. 7A), and IRR-219
mRNA was not present in other tissues such as liver (Fig.
7B). Furthermore, during small bowel adaptation, the
decrease in IRR-219 mRNA expression occurred specifically in ileal
goblet cells (Fig. 8).

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Fig. 6.
IRR-219 mRNA is expressed in goblet cells. In situ hybridization
analysis was performed on sections of fetal day 18 (A), and postnatal week 2 (B),
4 (C), and 8 (D) proximal
ileum to determine the cell-specific expression of IRR-219 mRNA.
Sections are viewed by darkfield microscopy. A: IRR-219 mRNA
is present in goblet cells on fetal day 18, coincident with
villus morphogenesis. Multiple small lumens are present, and small
thumblike villi are beginning to emerge. Arrows depict scattered goblet
cells with silver grains, indicating IRR-219 mRNA expression.
B: ileum from 2-wk-old rat pups. Villi and crypts are
well-formed. Many goblet cells are present and scattered silver grains
overly these cells. Two representative goblet cells are depicted by the
arrows. C: ileum from a 4-wk-old rat pup. Two representative
goblet cells that contain white grains are depicted by arrows.
D: ileum from 8-wk-old rat. IRR-219 is abundantly expressed
in goblet cells (arrows). Magnification, ×200.
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Fig. 7.
Specificity of IRR-219 expression by in situ hybridization
analyses. To determine the specificity of the signal detected by the
antisense IRR-219 probe, a sense IRR-219 cRNA was hybridized to
sections of adult rat ileum, as depicted in A. Goblet cells
are devoid of white grains. White cells in the lamina propria are
macrophages that reflect light under darkfield microscopy. The
antisense IRR-219 probe was also hybridized to liver (B),
which does not express IRR-219, as shown in Fig. 2. No specific signal
was seen on either tissue. (A, ×400; B,
×200).
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Fig. 8.
In
situ hybridization analysis of IRR-219 expression during intestinal
adaptation. Cell-specific expression of IRR-219 mRNA was detected in
ileal sections from resected (A) or sham-resected control
(B) rats killed at 48 h after surgery. Representative
goblet cells are depicted by arrows. Sections are viewed by darkfield
microscopy (×200).
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Expression of goblet cell-specific RITF is unaltered in adaptive
intestine at 48 h after resection.
To determine the specificity of the alteration in IRR-219 mRNA levels
at 48 h after intestinal resection, the expression pattern of
another goblet cell-specific gene, RITF, was examined by Northern blot
hybridization in adaptive vs. sham-resected control ileum and colon
(Fig. 9). RITF is expressed exclusively
in goblet cells of colon and small bowel and is secreted with mucin
(23). Unlike IRR-219, RITF mRNA levels were unchanged in
adaptive vs. control small bowel and colon.

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Fig. 9.
Rat intestinal trefoil factor (RITF) mRNA levels are
unchanged in adaptive (resected, RE) compared with control SHR small
bowel and colon. Total RNAs were prepared as in Fig. 3, and Northern
blot hybridization was performed as described in METHODS
using a radiolabeled RITF cDNA probe. No significant differences were
found comparing SHR to RE proximal small intestine, ileum, or colon.
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DISCUSSION |
The intestinal adaptive response is a complex process
characterized by alterations in crypt cell proliferation, epithelial cell migration, and apoptosis (7, 14, 24, 26). To identify the molecular pathways responsible for initiating the adaptive response, we have used subtractive hybridization techniques to identify
genes that are regulated in the early adaptive period (6,
21). This methodology led to the identification of several groups of cDNAs that encode proteins that affect nutrient absorption, the cell cycle, and protein synthesis and processing (6,
21). In this study, we report the cloning and expression
analysis of a unique cDNA, IRR-219, that is expressed only in goblet
cells and is differentially regulated in the small bowel and colon
during adaptation after intestinal resection.
Sequence analysis of the IRR-219 cDNA revealed 80% nucleotide identity
with the 3'-end of the human IgGFc
BP (13), suggesting that it is the rat homologue of this gene. The human IgGFc
BP is
distinct from both the IgG Fc receptor located on the apical surface of
the enterocyte that mediates transcytosis of milk immunoglobulin and
from the IgG Fc receptor on leukocytes. This very large protein is
expressed only in intestinal and colonic goblet cells, which secrete it
with mucus into the gut lumen (15, 16). The mRNA is also
expressed in human placenta (13). The physiological function of this protein is not known. Its ability to specifically bind
the Fc portion of IgG and its secretion with mucus are consistent with
presumptive roles such as protection of IgG molecules from bacterial
degradation, promotion of multivalent IgG formation, and combination
with antigen-IgG complexes to prevent antigen invasion into the mucosa
(13).
Our in situ hybridization data support the supposition that IRR-219 is
the rat homologue of the human IgG Fc binding protein, because IRR-219
mRNA is expressed exclusively in goblet cells of the small bowel and
colon, as is the human protein (13). However, previous
data indicated that this binding site is not present in rodents
(16), because horseradish peroxidase-labeled IgG stained
only human goblet cells and not rat or rabbit small and large bowel
epithelium. The region containing the putative Fc binding site is not
present in the partial IRR-219 cDNA clone. In addition, nonstringent
Southern blot hybridization of genomic DNA from various animal species
detected IgGFc
BP sequence only in humans and primates
(13). The probe used for Southern blot hybridization was
derived from a sequence upstream of the region represented in our rat
IRR-219 cDNA, suggesting that IRR-219 may be a homologue with greater
sequence divergence in the 5' region.
The role of IRR-219 in the normal and adapting intestine remains to be
clarified. From 24 h to 1 wk after small bowel resection, IRR-219
mRNA levels were decreased in the adaptive small intestine compared
with the sham-operated control yet were increased in the adapting
colon. In contrast, the expression of another goblet cell-specific gene
product, RITF, was unchanged, indicating the specificity of this
response. The increase in colonic mRNA levels is consistent with a
cytoprotective role for IRR-219, similar to one postulated for the
human IgGFc
BP, in response to the increased exposure of the colonic
mucosa to antigens, bile acids, undigested and partially digested food,
acid, and other enteral contents. The observation that IRR-219 mRNA
levels did not similarly increase in the adaptive ileum suggests that
innate differences between small bowel and colonic goblet cells, or
differences in their luminal environments, might affect this response.
For example, the heterogeneity in goblet cell populations between small
bowel and colon can be demonstrated by variations in goblet cell
sialomucin and sulfomucin content (1). Luminal contents
also vary in the postresective intestine, e.g., there is a relatively
greater change in luminal bile salt concentration in the postresective
cecum/colon compared with small bowel. Intestinal isograft experiments
in which fetal intestine is grown to maturity in the subcutaneous space
of a syngeneic host in the absence of luminal contents (11, 17-19) may prove useful to begin to answer these questions.
If IRR-219 is the rat IgG Fc
binding protein, then factors
that regulate expression of the human IgGFc
BP might also be expected to affect IRR-219 expression in gut. On the basis of the putative role
for IgGFc
BP in the intestinal immune response, cytokine regulation
of binding site expression was examined in HT29-N2 cells, a subclone of
HT29 cells that differentiate into goblet cells when grown in media
containing galactose (12). Tumor necrosis factor-
(TNF-
) was shown to decrease binding site expression independent of
effects on cell proliferation, whereas interferon-
had no effect.
Other cytokines were not studied. The regulation and effects of TNF-
in small bowel adaptation after resection are unknown. An inflammatory
response is not typically seen after small bowel resection, so whether
TNF-
or other cytokines might affect IRR-219 expression during
adaptation remains to be clarified.
In conclusion, a goblet cell-specific gene has been cloned that
is expressed in a unique pattern during intestinal adaptation after
resection. Few markers of colonic adaptation have been identified, making IRR-219 potentially useful in furthering our understanding of
the large bowel's response to loss of small bowel surface area. Further determination of its relationship to the human IgG Fc binding
protein awaits isolation of the full-length cDNA. Its regulation in
other models of intestinal injury and repair (such as irradiation or
infection) may help further define its function in small bowel and colon.
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ACKNOWLEDGEMENTS |
We gratefully acknowledge our colleague Alan E. Davis for providing
excellent technical assistance.
 |
FOOTNOTES |
These studies were supported by National Institute of Diabetes and
Digestive and Kidney Diseases Grants DK-46122, DK-50466, and DK-52574
and the Barnes-Jewish Foundation. C. Fritsch was supported by a
postdoctoral fellowship award from the Association pour la Recherche
sur le Cancer, Paris, France.
Address for reprint requests and other correspondence: D. C. Rubin, Division of Gastroenterology, Washington Univ. School of
Medicine, Campus Box 8124, 660 South Euclid Ave., St. Louis MO 63110 (E-mail: drubin{at}im.wustl.edu).
The costs of publication of this
article were defrayed in part by the
payment of page charges. The article
must therefore be hereby marked
"advertisement"
in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Received 12 October 1999; accepted in final form 4 May 2000.
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REFERENCES |
1.
Antonioli, DA,
and
Madara JL.
Functional anatomy of the gastrointestinal tract.
In: Pathology of the Gastrointestinal Tract, edited by Ming SC,
and Goldman H.. Philadelphia: Saunders, 1992, p. 14-36.
2.
Appleton, GV,
Wheeler EE,
al-Mufti R,
Challacombe DN,
and
Williamson RC.
Rectal hyperplasia after jejunoileal bypass for morbid obesity.
Gut
29:
1544-1548,
1988[Abstract].
3.
Bristol, JB,
Wells M,
and
Williamson RC.
Adaptation to jejunoileal bypass promotes experimental colorectal carcinogenesis.
Br J Surg
71:
123-126,
1984[ISI][Medline].
4.
Burnes, JU,
O'Keefe SJ,
Fleming CR,
Devine RM,
Berkner S,
and
Herrick L.
Home parenteral nutrition
a 3 year analysis of clinical and laboratory monitoring.
JPEN J Parenter Enteral Nutr
16:
327-332,
1992[Abstract].
5.
Curtas, S,
Hariri R,
and
Steiger E.
Case management in home total parenteral nutrition: a cost identification analysis.
JPEN J Parenter Enteral Nutr
20:
113-119,
1996[Abstract].
6.
Dodson, BD,
Wang JL,
Swietlicki EA,
Rubin DC,
and
Levin MS.
Analysis of cloned cDNAs differentially expressed in adaptive remnant small intestine after partial resection.
Am J Physiol Gastrointest Liver Physiol
271:
G347-G356,
1996[Abstract/Free Full Text].
7.
Dowling, RH.
Small bowel adaptation and its regulation.
Scand J Gastroenterol Suppl
74:
53-74,
1982.
8.
Drucker, DJ.
Epithelial cell growth and differentiation. I. Intestinal growth factors.
Am J Physiol Gastrointest Liver Physiol
273:
G3-G6,
1997[Free Full Text].
9.
Drucker, DJ,
Erlich P,
Asa SL,
and
Brubaker PL.
Induction of intestinal epithelial proliferation by glucagon-like peptide 2.
Proc Natl Acad Sci USA
93:
7911-7916,
1996[Abstract/Free Full Text].
10.
Goyal, A,
Singh R,
Swietlicki EA,
Levin MS,
and
Rubin DC.
Characterization of rat intestinal epimorphin/syntaxin2 expression suggests a role in crypt-villus morphogenesis.
Am J Physiol Gastrointest Liver Physiol
275:
G114-G124,
1998[Abstract/Free Full Text].
11.
Gutierrez, ED,
Grapperhaus KJ,
and
Rubin DC.
Ontogenic regulation of spatial differentiation in the gut epithelium in the crypt-villus axis of normal and isografted small intestine.
Am J Physiol Gastrointest Liver Physiol
269:
G500-G511,
1995[Abstract/Free Full Text].
12.
Hamada, Y,
Kobayashi K,
and
Brown WR.
Tumour necrosis factor-
decreases expression of the intestinal IgG Fc binding site by HT29-N2 cells.
Immunology
74:
298-303,
1991[ISI][Medline].
13.
Harada, N,
Iijima S,
Kobayashi K,
Yoshida T,
Brown WR,
Hibi T,
Oshima A,
and
Morikawa M.
Human IgGFc binding protein (Fc
BP) in colonic epithelial cells exhibits mucin-like structure.
J Biol Chem
272:
15232-15241,
1997[Abstract/Free Full Text].
14.
Helmrath, MA,
Erwin CR,
Shin CE,
and
Warner BW.
Enterocyte apoptosis is increased following small bowel resection.
J Gastrointest Surg
2:
44-49,
1998[Medline].
15.
Kobayashi, K,
Hamada Y,
Blaser MJ,
and
Brown WR.
The molecular configuration and ultrastructural locations of an IgG Fc binding site in human colonic epithelium.
J Immunol
146:
68-74,
1991[Abstract/Free Full Text].
16.
Kobayashi, K,
Blaser MJ,
and
Brown WR.
Identification of a unique IgG Fc binding site in human intestinal epithelium.
J Immunol
143:
2567-2574,
1989[Abstract/Free Full Text].
17.
Rubin, DC,
Roth KA,
Birkenmeier EH,
and
Gordon JI.
Epithelial cell differentiation in normal and transgenic mouse intestinal isografts.
J Cell Biol
113:
1183-1192,
1991[Abstract].
18.
Rubin, DC,
Swietlicki E,
and
Gordon JI.
Use of isografts to study proliferation and differentiation programs of mouse stomach epithelia.
Am J Physiol Gastrointest Liver Physiol
267:
G27-G39,
1994[Abstract/Free Full Text].
19.
Rubin, DC,
Swietlicki E,
Roth KA,
and
Gordon JI.
Use of fetal intestinal isografts from normal and transgenic mice to study the programming of positional information along the duodenal-to-colonic axis.
J Biol Chem
267:
15122-15133,
1992[Abstract/Free Full Text].
20.
Rubin, DC,
Swietlicki E,
Wang J,
Dodson BD,
and
Levin MS.
Enterocytic gene expression in intestinal adaptation: evidence for a specific cellular response.
Am J Physiol Gastrointest Liver Physiol
270:
G143-G152,
1996[Abstract/Free Full Text].
21.
Rubin, DC,
Swietlicki EA,
Wang JL,
and
Levin MS.
Regulation of PC4/TIS7 expression in adapting remnant intestine after resection.
Am J Physiol Gastrointest Liver Physiol
275:
G506-G513,
1998[Abstract/Free Full Text].
22.
Scott, RB,
Kirk D,
MacNaughton WK,
and
Meddings JB.
GLP-2 augments the adaptive response to massive intestinal resection in rat.
Am J Physiol Gastrointest Liver Physiol
275:
G911-G921,
1998[Abstract/Free Full Text].
23.
Suemori, S,
Lynch-Devaney K,
and
Podolsky DK.
Identification and characterization of rat intestinal trefoil factor: tissue- and cell-specific member of the trefoil protein family.
Proc Natl Acad Sci USA
88:
11017-11021,
1991[Abstract].
24.
Swartz Basile, DA,
Swietlicki EA,
Rubin DC,
and
Levin MS.
Expression of apoptosis-associated genes in the adapting small intestine following partial resection (Abstract).
Gastroenterology
116:
A935,
1999[ISI].
25.
Tsai, CH,
Hill M,
Asa SL,
Brubaker PL,
and
Drucker DJ.
Intestinal growth-promoting properties of glucagon-like peptide-2 in mice.
Am J Physiol Endocrinol Metab
273:
E77-E84,
1997[Abstract/Free Full Text].
26.
Vanderhoof, JA,
and
Langnas AN.
Short-bowel syndrome in children and adults.
Gastroenterology
113:
1767-1778,
1997[ISI][Medline].
27.
Wang, JL,
Rubin DC,
and
Levin MS.
In vivo effects of retinoic acid administration on cellular proliferation and gene expression during intestinal adaptation.
J Nutr
127:
1297-1303,
1997[Abstract/Free Full Text].
Am J Physiol Gastrointest Liver Physiol 279(5):G1003-G1010