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Histopathology of melanosis coli and determination of its associated genes by comparative analysis of expression microarrays.

Li XΑ, Zhou Y, Zhou SΧ, Liu HR, Xu JM, Gao L, Yu XJ, Li XH - Mol Med Rep (2015)

Bottom Line: The results demonstrated that the pigment deposits in MC consisted of lipofuscin.Western blotting and immunofluorescence assays indicated that the expression of CYP3A4 in the normal tissue was higher than in the MC tissue.The results of the present study provided a comprehensive description of the histopathological characteristics and pathogenesis of MC and for the first time, to the best of our knowledge, demonstrated that the cytochrome P450‑associated genes were significantly downregulated in melanosis coli.

View Article: PubMed Central - PubMed

Affiliation: The Gastroenterology Tumor and Microenvironment Laboratory, Department of Gastroenterology, The First Affiliated Hospital of Chengdu Medical College, Chengdu Medical College, Chengdu, Sichuan 610041, P.R. China.

ABSTRACT
Melanosis coli (MC) refers to the condition characterized by abnormal brown or black pigmentation deposits on the colonic mucosa. However, the histopathological findings and genes associated with the pathogenesis of melanosis coli remain to be fully elucidated. The present study aimed to examine the histopathological features and differentially expressed genes of MC. This involved performing hematoxylin and eosin staining, specific staining and immunohistochemistry on tissues sections, which were isolated from patients diagnosed with MC. DNA expression microarray analysis, western blotting and immunofluorescence assays were performed to analyze the differentially expressed genes of melanosis coli. The results demonstrated that the pigment deposits in MC consisted of lipofuscin. A TUNEL assay revealed that a substantial number of apoptotic cells were present within the macrophages and superficial lamina propria of the colonic epithelium. Expression microarray analysis revealed that the significantly downregulated genes were CYP3A4, CYP3A7, UGT2B11 and UGT2B15 in melanosis coli. Western blotting and immunofluorescence assays indicated that the expression of CYP3A4 in the normal tissue was higher than in the MC tissue. The results of the present study provided a comprehensive description of the histopathological characteristics and pathogenesis of MC and for the first time, to the best of our knowledge, demonstrated that the cytochrome P450‑associated genes were significantly downregulated in melanosis coli. This novel information can be used to assist in further investigations of melanosis coli.

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Apoptosis of the colonic cells in MC, determined using a TUNEL assay. (A and B) Sections detected using a TUNEL assay (magnification, ×40). (C) Apparent increase in number of apoptotic cells and apoptotic index within the MC tissues, compared with the normal colon tissues. The bar graph indicates the mean ± standard deviation. *P<0.05, compared with the normal colon tissues. MC, melanosis coli. TUNEL, Terminal deoxynucleotidyl transferase dUTP nick-end labeling.
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f3-mmr-12-04-5807: Apoptosis of the colonic cells in MC, determined using a TUNEL assay. (A and B) Sections detected using a TUNEL assay (magnification, ×40). (C) Apparent increase in number of apoptotic cells and apoptotic index within the MC tissues, compared with the normal colon tissues. The bar graph indicates the mean ± standard deviation. *P<0.05, compared with the normal colon tissues. MC, melanosis coli. TUNEL, Terminal deoxynucleotidyl transferase dUTP nick-end labeling.

Mentions: Apoptosis of the colonic cells in MC tissues was evaluated using a TUNEL assay, with which the 26 MC tissues and 10 normal colon specimens were analyzed. Numerous apoptotic cells were observed in the MC tissue sections, and the apoptotic rate was higher than that observed in the normal colon tissue sections. Apoptotic bodies were observed within the macrophages and superficial lamina propria of the colonic epithelium (Fig. 3). These results indicates that pigment storage is a consequence of apoptosis in colonic epithelial cells.


Histopathology of melanosis coli and determination of its associated genes by comparative analysis of expression microarrays.

Li XΑ, Zhou Y, Zhou SΧ, Liu HR, Xu JM, Gao L, Yu XJ, Li XH - Mol Med Rep (2015)

Apoptosis of the colonic cells in MC, determined using a TUNEL assay. (A and B) Sections detected using a TUNEL assay (magnification, ×40). (C) Apparent increase in number of apoptotic cells and apoptotic index within the MC tissues, compared with the normal colon tissues. The bar graph indicates the mean ± standard deviation. *P<0.05, compared with the normal colon tissues. MC, melanosis coli. TUNEL, Terminal deoxynucleotidyl transferase dUTP nick-end labeling.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581826&req=5

f3-mmr-12-04-5807: Apoptosis of the colonic cells in MC, determined using a TUNEL assay. (A and B) Sections detected using a TUNEL assay (magnification, ×40). (C) Apparent increase in number of apoptotic cells and apoptotic index within the MC tissues, compared with the normal colon tissues. The bar graph indicates the mean ± standard deviation. *P<0.05, compared with the normal colon tissues. MC, melanosis coli. TUNEL, Terminal deoxynucleotidyl transferase dUTP nick-end labeling.
Mentions: Apoptosis of the colonic cells in MC tissues was evaluated using a TUNEL assay, with which the 26 MC tissues and 10 normal colon specimens were analyzed. Numerous apoptotic cells were observed in the MC tissue sections, and the apoptotic rate was higher than that observed in the normal colon tissue sections. Apoptotic bodies were observed within the macrophages and superficial lamina propria of the colonic epithelium (Fig. 3). These results indicates that pigment storage is a consequence of apoptosis in colonic epithelial cells.

Bottom Line: The results demonstrated that the pigment deposits in MC consisted of lipofuscin.Western blotting and immunofluorescence assays indicated that the expression of CYP3A4 in the normal tissue was higher than in the MC tissue.The results of the present study provided a comprehensive description of the histopathological characteristics and pathogenesis of MC and for the first time, to the best of our knowledge, demonstrated that the cytochrome P450‑associated genes were significantly downregulated in melanosis coli.

View Article: PubMed Central - PubMed

Affiliation: The Gastroenterology Tumor and Microenvironment Laboratory, Department of Gastroenterology, The First Affiliated Hospital of Chengdu Medical College, Chengdu Medical College, Chengdu, Sichuan 610041, P.R. China.

ABSTRACT
Melanosis coli (MC) refers to the condition characterized by abnormal brown or black pigmentation deposits on the colonic mucosa. However, the histopathological findings and genes associated with the pathogenesis of melanosis coli remain to be fully elucidated. The present study aimed to examine the histopathological features and differentially expressed genes of MC. This involved performing hematoxylin and eosin staining, specific staining and immunohistochemistry on tissues sections, which were isolated from patients diagnosed with MC. DNA expression microarray analysis, western blotting and immunofluorescence assays were performed to analyze the differentially expressed genes of melanosis coli. The results demonstrated that the pigment deposits in MC consisted of lipofuscin. A TUNEL assay revealed that a substantial number of apoptotic cells were present within the macrophages and superficial lamina propria of the colonic epithelium. Expression microarray analysis revealed that the significantly downregulated genes were CYP3A4, CYP3A7, UGT2B11 and UGT2B15 in melanosis coli. Western blotting and immunofluorescence assays indicated that the expression of CYP3A4 in the normal tissue was higher than in the MC tissue. The results of the present study provided a comprehensive description of the histopathological characteristics and pathogenesis of MC and for the first time, to the best of our knowledge, demonstrated that the cytochrome P450‑associated genes were significantly downregulated in melanosis coli. This novel information can be used to assist in further investigations of melanosis coli.

Show MeSH
Related in: MedlinePlus