Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The capacities of the adipocyte precursor pools to form new fat cells were compared in the abdominal and femoral adipose tissue regions of obese women. Adipose tissue samples were obtained from 24 females by needle biopsy. The stromal-vascular cells isolated by collagenase digestion were cultured in a chemically defined medium supplemented with 0.5 mumol/l insulin and 0.1 mumol/l cortisol. The extent of adipose differentiation was assessed by determination of glycerol-3-phosphate dehydrogenase (GPDH) activity after 18 days in culture. No significant differences were found between the two depots with regard to mean fat cell diameter and the number of stromal-vascular cells (abdominal vs femoral site: 134,800 +/- 7900 vs 138,800 +/- 6700 cells/g wet adipose tissue, n.s.). However, GPDH activities were significantly higher in cultured cells from the abdominal region as compared to those from the femoral depot (253.1 +/- 40.9 vs 155.8 +/- 21.4 mU/mg protein, P less than 0.01). These results suggest that regional differences exist in the capacity of adipose tissue depots to form new fat cells. This finding may help to understand changes in adipose tissue distribution during adult life.
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PMID:Regional variation of adipose differentiation in cultured stromal-vascular cells from the abdominal and femoral adipose tissue of obese women. 204 May 49

A reproducible cell culture system is described that allows the study of adipose conversion in fibroblast-like cells isolated by collagenase digestion of epididymal and perirenal adipose tissue from male rats weighing 70-200 g. Adipose conversion as measured by lipid accumulation and increase in glycerophosphate dehydrogenase (GPDH) activity during differentiation strongly depends on the density at which cells are inoculated and starts only when cells are confluent and when physiological amounts of corticosterone and insulin are added. beta-Estradiol, testosterone, thyroxine, triiodothyronine, and growth hormone do not affect the differentiation process. Methylisobutylxanthine added during the first 2 days after confluence, added with insulin and corticosterone, potentiates the effect of insulin on GPDH activity and accelerates triglyceride accumulation. The effect of methyl-isobutylxanthine seems to be mediated by increased cyclic AMP concentrations, inasmuch as it may be replaced by forskolin.
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PMID:Hormonal regulation of the differentiation of rat adipocyte precursor cells in primary culture. 244 Sep 70

Stromal-vascular (S-V) cells isolated from adipose tissue of newborn pigs (NBPC) and mature pigs (MPC) by collagenase digestion were used to evaluate differences in preadipocyte culture and development. Cells were seeded at a density of 3 x 10(4) cells/cm2 on six-well (35-mm) tissue culture plates in 3 mL of DMEM/HAM's F12 medium plus 10% fetal calf serum and cultured at 37 degrees C under a humidified atmosphere of 95% air:5% CO2 for 24 h. Cells were then washed thoroughly in DMEM/HAM's F12 medium without fetal calf serum and maintained in serum free (SF) medium or SF medium supplemented with 2.5% newborn pig serum (NBPS) or mature pig serum (MPS) for 12 d. After 1 d, more NBPC adhered to the culture plates, as indicated by DNA values. After 12 d, protein per culture well was not significantly different, but DNA concentration per well remained higher (P < .05) in cultures of NBPC than in the MPC cultured in the same medium, indicating fewer MPC. Protein:DNA ratios were higher (P < .05) in cultures of MPC regardless of the medium, reflecting larger cell size. More cells containing fat deposits were seen with NBPC in all conditions in comparison with MPC, and more fat was deposited in NBPC in SF than in SF plus NBPS or MPS. The NBPC had higher (P < .05) sn-glycerol-3-phosphate dehydrogenase (GPDH; EC 1.1.1.8) per protein than MPC regardless of the medium. For both cell types, GPDH activity in either serum was less than activity of cells grown in SF.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of age on the differentiation of porcine adipose stromal-vascular cells in culture. 773 Jan 75

Using a primary culture system of guinea pig Harderian gland cells, we investigated the metabolism of a unique lipid: 1-alkyl-2,3-diacylglycerol containing methyl-branched fatty acids. The cells were obtained by collagenase digestion, and cells with lipid-droplets were collected by two-step centrifugation. We cultured these cells, and examined their lipid and fatty acid compositions. The de novo synthesis of lipids in these cells was studied as to the incorporation of [1(2)-14C]acetate and [U-14C]glucose. The major lipid proved to be 1-alkyl-2,3-diacylglycerol, as in tissue, and it contained a large amount of methylbranched fatty acids specific to this gland. The incorporation of [14C]acetate and [14C]glucose into 1-alkyl-2,3-diacylglycerol in the cultured cells amounted to 79.7 and 88.2% of the total incorporation into the lipid fraction, respectively. The incorporation of [14C]acetate into fatty acids in the cultured cells was detected for the chain lengths of C14 to C25. The activities of glycerol-3-phosphate dehydrogenase in the cultured cells and Harderian gland were lower than that in adipose tissue. These results confirm that cultured cells reflect the lipid metabolism originating in the Harderian gland and show that this culture system can serve as one part of the armamentarium for further study of this unique lipid metabolism.
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PMID:1-Alkyl-2,3-diacylglycerol synthesis in primary culture cells of guinea pig harderian gland. 827 58

Fat and liver are the major sites for the deposition of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) given in vivo to rats. Although a great deal of information is available on the effects of TCDD in liver, very little is known of the effects in fat. The epididymal fat pads were removed and the stromal-vascular cells, released by collagenase digestion, were put into primary culture, 2, 4, 6 and 8 days after intubating 175 micrograms/kg TCDD into male Sprague-Dawley rats. Following 7 days in culture, the cells were examined morphologically, and assayed for an early (lipoprotein lipase, LPL) and late marker of fat cell differentiation (glycerol-3-phosphate dehydrogenase, GPDH). With rats sacrificed 6 or 8 days after TCCD intubation, the harvested cells from pair-fed rats contained significantly more fat and had a significantly higher level of GPDH enzyme activity, indicating more differentiation. The mRNA for LPL and GPDH genes was also higher for cells from pair-fed rats. In addition, for the rats that were sacrificed 4-8 days after TCDD intubation, despite similar food intake, the pair-fed control rats gained more total body weight than the treated rats. Although there was a body weight difference, there was no significant different between the weights of the epididymal fat pads. This is the first report to demonstrate that TCDD inhibits the differentiation of fat cells.
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PMID:2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) inhibition of fat cell differentiation. 859 78

Studies with human adipose tissue have demonstrated the presence of key enzymes of fat synthesis. However, long-term regulation of these enzymes has not been reported. To address this issue, we used human adipocytes in primary culture. Human adipose tissue was obtained from abdominal fat of patients undergoing abdominal surgery. Adipocytes were isolated by collagenase digestion and cultured in media supplemented with 1% fetal bovine serum. To evaluate metabolic activity of cultured cells, we assessed the following during the culture: DNA pattern, cell size, glucose consumption and activities for two lipogenic enzymes, fatty acid synthase (FAS) and glycerol-3-phosphate dehydrogenase (GPDH). Analysis of DNA pattern showed that human adipocytes cultured under the above condition did not undergo cell apoptosis. In addition, no significant change in the cell size occurred during 22 d of culture. Glucose consumption by cultured cells was also constant during the culture and was 60% greater in the presence of 10 nmol/L of insulin. Treatment of cultured human adipocytes with insulin for 3-22 d increased GPDH and FAS activity by 60% and 2.8-fold, respectively, compared to cells cultured without insulin. Furthermore, the increase in FAS activity due to insulin treatment was dose dependent and maximal at 10 nmol/L. Our studies show for the first time that human adipocytes can be maintained viable and metabolically active for 2-3 wk in culture. Interestingly, cultured cells remain responsive to insulin. Therefore, this system will allow further characterization of long-term regulation of lipogenesis in human adipocytes and will be useful for developing pharmacological treatments of obesity.
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PMID:Insulin increases lipogenic enzyme activity in human adipocytes in primary culture. 861 89

Free fat transplantation for soft tissue augmentation yields variable results, which may be related to the technique of fat harvest. To compare the viability of adipocytes harvested by liposuction (sal) or by excision (exc), fat harvested by both techniques from seven lipectomy patients was analyzed by glycerol-3-phosphate dehydrogenase (G3PDH) enzyme assay. Leakage of this lipogenic enzyme through the plasma membrane is a potential indicator of fat cell damage. Preliminary experiments showed this assay to be sensitive and specific for adipocyte G3PDH activity. Treatment of fat tissue with collagenase H resulted in complete release of the component fat cells for analysis with less loss of G3PDH activity, compared to other collagenase preparations. Each sample was digested and separated into three compartments: mature adipocytes-floating layer (F), acellular supernatant (S), and stromal pellet (P). Samples from each compartment were assayed for G3PDH activity, normalized to DNA content, and represented as a percentage of the whole (F + S + P). Within the subgroups, the fat cell fraction of the liposuction samples (Fsal) showed statistically more activity than the excised samples (Fexc) by paired Student's t test (P = 0.004). The supernatant (representing leaked G3PDH) and pellet fractions of excised samples revealed more G3PDH activity than the same fractions from liposuctioned tissue; the former (Sexc) to a significant degree (P = 0.036). Using this assay, the results indicate that liposuction fat harvest does not result in increased fat cell damage compared to fat harvested by excision.
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PMID:Biochemical assessment of cellular damage after adipocyte harvest. 922 35

Previous studies on the etiology of obesity have revealed that human adipocytes have the ability to revert or dedifferentiate in culture to a morphology and replicative capacity similar to that of adipocyte precursors. To characterize some of the events of this process, we isolated adipocytes from the greater omentum of 61 morbidly obese and ten normal weight individuals with collagenase, and cultured them for 0, 4, and 7 days. In both lean and obese patients, sn-glycerol-3-phosphate dehydrogenase specific activity decreased significantly after days 4 and 7 compared to day 0. Dedifferentiation was also monitored by phase-contrast microscopy, which revealed that adipocytes from the lean had lost appreciable lipid and had assumed an elongated contour more rapidly than those from the obese. Reversion was also corroborated by reverse transcription-polymerase chain reaction, which indicated a decrease in the expression of sn-glycerol-3-phosphate dehydrogenase mRNA, and an increase in actin and glyceraidehyde-3-phosphate dehydrogenase mRNA over the 7 days. Thus, this work has described some biochemical and molecular genetic characteristics of dedifferentiation. The relative resistance of adipocytes from morbidly obese patients to revert in culture may reflect the inordinately high propensity of fat cells in massively obese persons to preserve the differentiated, triacylglycerol-overfilled state.
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PMID:Relative Resistance of Adipocytes from Massively Obese Persons to Dedifferentiation. 1075 44

Excess intra-abdominal fat is associated with a higher risk for type 2 diabetes mellitus and cardiovascular disease, yet little is known about what influences regional adipose tissue accumulation. Adipocytes arise from specialized fibroblast-like preadipocytes within the adipose tissue stromal-vascular compartment. The aim of our study was to determine if there are variations in preadipocyte differentiation between abdominal subcutaneous (SC) and omental (OM) preadipocytes. Abdominal SC and OM preadipocytes were isolated from adipose tissue obtained from 18 subjects (7 men, 11 women), undergoing elective abdominal surgery, by collagenase treatment and filtration/centrifugation. Preadipocytes were placed in culture and then differentiated for 3 weeks in a serum-free medium containing insulin, dexamethasone, isobutylmethylxanthine, and carbaprostacyclin. The cells were then harvested for measurement of cytosolic glycerol phosphate dehydrogenase (GPDH), a marker of terminal differentiation. Data are expressed as a differentiation index (DI), which was the log of the SC/OM ratio of GPDH values for each patient (calculated as 0 for an equivalent SC v OM responses). The mean DI for the group (n = 18) was 0.04, with a 95% confidence interval (CI) of -0.11 to 0.20. The mean DI for men was 0.07 (95% CI, -0.06 to 0.19), and that for women was 0.03 (95% CI, -0.21 to 0.27). This indicates that SC versus OM preadipocyte differentiation responses were not significantly different from each other, either for the group as a whole or when divided by gender. Overall, 8 subjects had a DI favoring SC preadipocyte differentiation, compared to 11 subjects with a DI reflecting greater OM preadipocyte differentiation. There was no correlation of the DI with body mass index or age. Our results indicate that preadipocytes from the abdominal SC adipose tissue depot do not uniformly differentiate more than those from the OM depot.
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PMID:Comparison of human abdominal subcutaneous versus omental preadipocyte differentiation in primary culture. 1220 Jul 69

This study was designed to develop a culture system from the stromal-vascular fraction of chicken adipose tissue that can be used to characterize hormones that promote preadipocyte differentiation. Abdominal adipose tissue was excised from 2 to 4-week-old male broilers (Gallus domesticus) by sterile dissection. The stromal-vascular cell fraction from the adipose tissue was isolated by collagenase digestion, filtration, and subsequent centrifugation. These preadipocytes were seeded in six well culture plates and proliferated to confluency in 10% fetal bovine serum in DMEM/F12 (50:50) medium. At confluency, experiments were initiated to determine hormonal requirements for differentiation. Insulin (100 nM) stimulated expression of citrate lyase and sn-glycerol-3-phosphate dehydrogenase relative to lactate dehydrogenase in the presence of 2.5% chicken serum (P<0.05), but not with 10% chicken serum (P>0.05). Triiodothyronine (T(3), 1 nM) and insulin-like growth factor 1 (100 ng/ml) had no effect on differentiation. Dexamethasone (Dex, 1 microM) stimulated differentiation in 2.5 or 10% chicken serum (P<0.05). Insulin, Dex and 2.5% chicken serum stimulated enzymatic differentiation to the extent of 10% chicken serum, but heparin (10 U/ml) addition, in combination with insulin and Dex was necessary to stimulate lipid filling of adipocytes.
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PMID:Hormonal regulation of postnatal chicken preadipocyte differentiation in vitro. 1452 50


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