Abnormal expression of M1/MUC5AC mucin in distal colon of patients with diverticulitis, ulcerative colitis and cancer.

The abnormal expression of gastric M1/MUC5AC mucin in precancerous lesions and colon cancer evidenced by immunohistochemistry led us to check for its presence in the mucus obtained directly from patients undergoing surgery for cancerous (adenocarcinoma) or inflammatory (diverticulitis or ulcerative colitis) diseases. In parallel, the authors quantified aberrant crypt foci (ACF) and their immunolabelling by M1/MUC5AC in mucosae of cancer and diverticulitis patients. Immuno-Radio-Metric Assay of M1/MUC5AC mucin developed by the authors was used to detect M1/MUC5AC mucin in the colonic mucus scraped from surgical specimens. M1/MUC5AC mucin was detected in the mucus of 51/69 (74%) patients with colon adenocarcinoma, versus 7/27 (26%) patients with diverticulitis (threshold: 30 units of M1 mucin per mg protein, area under ROC curve: 0.80). M1/MUC5AC was present in significantly (p < 0.001) larger amounts in the mucus of cancer versus diverticulitis patients. All (10/10) patients with ulcerative colitis tested showed levels above the threshold and their mucosae were strongly labelled with the anti-M1/MUC5AC antibody by immunohistochemistry. Patients with cancer exhibited 3 fold more ACF than those with diverticulitis, but no significant difference was observed in the mean size and M1/MUC5AC expression pattern of ACF between these two groups. The expression of M1/MUC5AC was in correlation with their size. In macroscopically normal mucosa, ACF were the most important source of M1/MUC5AC mucin. Testing of M1/MUC5AC can enhance the detection of precancerous lesions and colon cancer.

Mice lacking cystathionine beta synthase have lung fibrosis and air space enlargement.

Cystathionine beta synthase (CBS) is a crucial regulator of plasma concentrations of homocysteine. Severe hyperhomocysteinemia due to CBS deficiency confers diverse clinical manifestations, notably pulmonary thrombotic disease. However, the association between hyperhomocysteinemia and chronic obstructive pulmonary disease is not well understood. To investigate the role of hyperhomocysteinemia in lung injury and pulmonary fibrosis, we analyzed the lung of CBS-deficient mice, a murine model of severe hyperhomocysteinemia. The degree of lung injury was assessed by histologic examination. Analysis of profibrogenic factors was performed by real-time quantitative reverse transcription-polymerase chain reaction. CBS-deficient mice develop fibrosis and air space enlargement in the lung, concomitant with an enhanced expression of heme oxygenase-1, pro(alpha)1 collagen type I, transforming growth factor-beta1 and alpha-smooth muscle actin. However, lung fibrosis was found in the absence of increased inflammatory cell infiltrates as determined by histology, without changes in gene expression of proinflammatory cytokines TNFalpha and interleukin 6. The increased expression of alpha-smooth muscle actin and transforming growth factor-beta1 emphasizes the role of myofibroblasts differentiation in case of lung fibrosis due to CBS deficiency in mice.

Progression of tumors arising from large ACF is associated with the MUC5AC expression during rat colon MNNG carcinogenis.

Aberrant crypt foci (ACF) are microscopic lesions which have been postulated to precede the development of adenomas, precursors of colon cancer. The gastric M1/MUC5AC mucin has also been described as an early marker of colon carcinogenesis in the human and in the rat. To study changes in mucin expression associated with the genesis of tumors, Wistar rats were treated by intrarectal instillations of MNNG, twice a week for 2 weeks, and were sacrificed 10 (n = 20), 14 (n = 20), 22 (n = 20), 30 (n = 10) and 66 (n = 16) weeks after the beginning of the treatment. In the treated rats, the MUC5AC mucin was mainly expressed in ACF compared with the histologically normal mucosae, which showed few isolated MUC5AC-positive normal crypts. During carcinogenesis, the percentage of large ACF [> or =10 aberrant crypts] increased and the number of MUC5AC-positive (NCs) decreased. At Week 30, small tumors were observed arising from large ACF, both types of lesions expressing MUC5AC. At Week 66, large tumors showed remnants of MUC5AC-positive ACF in their adjacent mucosae. This observation suggests that the expression of MUC5AC is associated with the ACF/adenoma sequence and supports the notion of large ACF as precursors of adenomas/adenocarcinomas. Moreover, the expression of MUC5AC in the transitional mucosa adjacent to both rat and human colon tumors suggests that some human tumors could arise from large ACF, and reinforces the concept of the premalignant potential of these lesions.

Cystathionine beta synthase deficiency affects mouse endochondral ossification.

Cystathionine beta synthase (CBS) is a crucial regulator of plasma concentrations of homocysteine. Severe hyperhomocysteinemia due to CBS deficiency confers diverse clinical manifestations, notably characteristic skeletal abnormalities. To investigate this aspect of hyperhomocysteinemia, we analyzed the skeleton of CBS-deficient mice, a murine model of severe hyperhomocysteinemia. Radiography, Alcian Blue/Alizarin Red S-stained whole skeletal preparations, and histological comparisons were used to determine the extent, pattern, and distribution of skeletal abnormalities in CBS-deficient mice. Disruption of the murine CBS gene leads to skeletal abnormalities, notably kyphoscoliosis, with temporal shortening of long bones due to impaired cartilage differentiation, albeit to differing degrees.

Hyperkeratosis in cystathionine beta synthase-deficient mice: an animal model of hyperhomocysteinemia.

Cystathionine beta synthase (CBS) is a crucial regulator of plasma concentrations of homocysteine. Severe hyperhomocysteinemia due to CBS deficiency confers diverse clinical manifestations. Patients with severe hyperhomocysteinemia have fine hair and thin skin, but it is unclear whether these changes are related to CBS deficiency or are coincidental. To investigate these aspects of hyperhomocysteinemia, we characterized skin abnormalities of CBS-deficient mice, a murine model of severe hyperhomocysteinemia. Histological and histomorphometric analyses revealed that CBS-deficient mice have wrinkled skin with hyperkeratinosis of the epidermis and thinning of the dermis.

Maternal phenylketonuria: the French survey.

UNLABELLED: We report the French experience regarding pregnancies in maternal phenylketonuria (PKU). In 2001, a questionnaire was sent to each referring PKU specialist in the 20 centres of each region of France, collecting reports on 135 pregnancies in 79 women born between 1958 and 1980. The majority of the 135 pregnancies occurred after 1990. A total of 42 women were informed of the risks of untreated pregnancy, while 26 were not informed (no data for 11). A strict diet was achieved in 83% of informed and in 16% of uninformed mothers prior to conception. Healthy offspring were observed in 43% of the 135 pregnancies, spontaneous abortions in 10.4%, elective abortions in 4.4%, therapeutic abortions in 12.6%, and embryopathies (EP) in 21.5%. In 8.1% of cases, the outcomes (in earliest pregnancies) are unknown. The proportion of healthy children increased over time and reached 80% of the pregnancies of informed females. There were seven heart defects, all in cases of EP, but although microcephaly and intrauterine growth retardation (IUGR) were almost constant in EP, we also found nine healthy children with IUGR. A continuum between EP and healthy children is suggested. The anthropometric data of the mothers showed that their body mass index (BMI) distribution was shifted to the left compared to women of the general population. This lower BMI and poor weight gain during pregnancy could contribute to the IUGR observed in normal babies whose mothers received a phenylalanine-restricted diet during pregnancy. CONCLUSION: the information and the preconception diet are effective for avoiding embryopathies in maternal phenylketonuria. Nutritional parameters can influence fetal growth and the nutritional state must be closely monitored throughout pregnancies of women with phenylketonuria.