Visfatin expression is hormonally regulated by metabolic and sex hormones in 3T3‐L1 pre‐adipocytes and adipocytes
Bibliographic record
Abstract
AIM: The novel adipokine visfatin has 'insulin-mimicking' effects and is increased in models of diet-induced obesity, but factors that regulate visfatin have not been fully elucidated. METHODS: In order to determine visfatin regulation in adipocyte development and metabolism, as well as in pathophysiological conditions related to metabolic syndrome, endogenous visfatin expression was measured in 3T3-L1 pre-adipocytes and adipocytes using real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR). RESULTS: A marked increase in visfatin expression was observed during differentiation, with a 2.2-fold increase between preconfluent and 2-day confluent cells even before differentiation was initiated. A further 4.1-fold increase was induced from day 0 to day 9 of differentiation (overall ninefold). Overnight incubation with dexamethasone (10(-8) to 10(-2) M) increased visfatin expression in both pre-adipocytes (1.5- to 3.3-fold, p < 0.05) and adipocytes (1.9-fold, p < 0.01). All other treatments decreased visfatin expression. In pre-adipocytes, visfatin expression decreased by 23% at a concentration of 1 microM insulin, 15% at 1-15 nM T3, 15% at 10 nM-1 microM progesterone, 33-44% at 10 nM-1 microM testosterone, 50% with palmitate and 30% with oleate (p < 0.05 for all). In adipocytes, insulin had a much greater effect, decreasing visfatin by 77% at 100 nM (p < 0.01), whereas oleate and sex hormones did not affect visfatin expression. However, tumor necrosis factor alpha, which had no effect on pre-adipocytes, significantly decreased visfatin in adipocytes by 26% at 10 ng/ml (p < 0.05). Interestingly, the thiazolidinedione (TZD) rosiglitizone also decreased visfatin by 28% at a concentration of 1 microM (p < 0.01). CONCLUSION: In summary, while the mechanism of visfatin action remains to be elucidated, the clear effects of multiple hormones on visfatin expression support a physiological role.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".