Effects of beta-conglycinin intake on circulating FGF21 levels and brown adipose tissue activity in Japanese young men: a single intake study and a randomized controlled trial

Fructose-induced FGF21 secretion does not activate brown adipose tissue in Japanese young men: randomized cross-over and randomized controlled trials

BACKGROUND

Human brown adipose tissue (BAT) activity is associated with lower body fatness and favorable glucose metabolism. Previous studies reported that oral fructose loading induces postprandial fibroblast growth factor 21 (FGF21) secretion. FGF21 is a known inducer of adipose tissue thermogenesis; however, the effects of diet-induced FGF21 secretion on BAT thermogenesis remain to be elucidated.

METHODS

The effects of both single load and daily consumption of fructose on BAT activity were examined using a randomized cross-over trial and a 2-week randomized controlled trial (RCT), respectively. In the cross-over trial, 15 young men consumed a single dose of fructose solution or water and then consumed the other on a subsequent day. The RCT enrolled 22 young men, and the participants were allocated to a group that consumed fructose and a group that consumed water daily for 2 weeks. BAT activity was analyzed using thermography with cold exposure. Plasma FGF21 level was determined by enzyme-linked immunosorbent assay.

RESULTS

In the cross-over single-load trial, plasma FGF21 levels were significantly increased at 2 h after oral fructose load (p < 0.01); however, there was no significant difference in BAT activity between the fructose load and drinking water. The 2-week RCT revealed that both plasma FGF21 levels and BAT activity were not significantly increased by daily fructose consumption compared to water. Correlation analyses revealed that BAT activity at the baseline and the final measurements were strongly and positively associated with the RCT (r = 0.869, p < 0.001). Changes in BAT activity were significantly and negatively correlated with changes in plasma glucose levels during the 2-week intervention (r = - 0.497, p = 0.022).

CONCLUSIONS

Oral fructose load induces a temporary increase in circulating FGF21 levels; however, this does not activate BAT thermogenesis in healthy young men. Further studies are needed to elucidate the effect of endogenous FGF21 on physiological function.

TRIAL REGISTRATION

This study is registered with the University Hospital Medical Information Network in Japan (number 000051761, registered 1 August 2023, retrospectively registered, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000052680 ).

Olanzapine-induced decreases of FGF21 in brown adipose tissue via histone modulations drive UCP1-dependent thermogenetic impairment

Long-term olanzapine treatment has been associated with serious metabolism disorders, such as abnormal body weight gain, hyperglycemia, and dyslipidemia. Recently, accumulated evidence points to a link between the metabolic disorders caused by olanzapine and thermogenetic impairment. Fibroblast growth factor 21 (FGF21), a pleiotropic protein, is a potent stimulator of thermogenesis in brown adipose tissue (BAT). However, the relationship between autocrine FGF21 in BAT and thermogenetic impairment induced by olanzapine has not been investigated. In this study, C57BL/6 mice and C3H10T1/2 (a brown adipocyte cell line) were used to investigate the role of FGF21 in modulating thermogenetic impairments caused by olanzapine. Our data found a fall in BAT temperature, with a decrease in the protein levels of uncoupling protein 1 (UCP1) and FGF21 in olanzapine-treatment mice. Olanzapine-induced deficits of mitochondrial activity and the expression of UCP1 and related thermogenetic factors could be improved by FGF21-overexpression in brown adipocytes. Furthermore, ChIP-sequencing showed the H3K9me3 modification in Fgf21 was dramatically increased in BAT of mice with olanzapine treatment. Lysine-specific demethylase 4a (KDM4a), a histone demethylase responsible for site-specific erasure of H3K9me3, was decreased in olanzapine-treated C3H10T1/2 cells, whereas FGF21 and UCP1 expression and thermogenesis were upregulated in KMD2a-overexpressing brown adipocyte. We concluded that FGF21 was a crucial regulator mediating UCP1-dependent thermogenetic impairments by olanzapine-modulating histone methylations. Our results also provide novel insights into identifying a new therapeutic target for treating metabolic side effects caused by the antipsychotic drug.

Effect of Acute Cold Exposure on Energy Metabolism and Activity of Brown Adipose Tissue in Humans: A Systematic Review and Meta-Analysis

Background: The benefit of cold exposure for humans against obesity has brought the energy metabolism and activity of brown adipose tissue (BAT) induced by cold into focus. But the results are inconsistent. This review is aimed to systematically explore the effect of cold exposure on the activity of BAT and energy metabolism in humans.

Methods: We searched relevant papers that were published from 1990 to 2021 and were cited in PubMed Central, Web of science, Embase and Cochrane Library databases to conduct this systematic review and meta-analysis. Energy metabolism, BAT volume, BAT activity and non-esterified fatty acids (NEFA) data reported in eligible researches were extracted. Meta-analysis was applied to combine the mean difference or standard mean difference with their 95% confidence intervals (95%CI). RevMan 5.3 software was used for meta-analysis and evaluating the risk of bias. Stata 16.0 was used for evaluating the publication bias.

Results: Ten randomized controlled trials were included in meta-analysis. Compared with human exposed in room temperature at 24°C, the energy expenditure (EE) was increased after acute cold exposure at 16∼19°C (Z = 7.58, p < 0.05, mean different = 188.43kal/d, 95% CI = 139.73–237.13); BAT volume (Z = 2.62, p < 0.05; standard mean different = 0.41, 95% CI = 0.10–0.73); BAT activity (Z = 2.05, p = 0.04, standard mean difference = 1.61, 95% CI = 0.07–3.14) and the intake of BAT NEFA (Z = 2.85, p < 0.05; standard mean different = 0.53, 95% CI = 0.17–0.90) also increased.

Conclusion: Acute cold exposure could improve the energy expenditure and BAT activity in adults, which is beneficial for human against obesity.

Comparisons of Soybean and Wheat; in the Focus on the Nutritional Aspects and Acute Appetite Sensation

Soybean flour is often used as a gluten-free ingredient. We aimed to compare the nutrients and the difference in satiety of soybean and wheat after ingestion. We measured the amounts of polyphenol and oxygen radical absorbance capacity (ORAC) and examined the acute appetite sensation after the ingestion of soybean powder and bread powder. Japanese women were enrolled in the meal tests. Participants were provided with 18 g of bread or soybean powder, 180 g of yogurt, and 285 mL of bottled water. Subjective satiety (hunger, appetite, satiety, and stomach fullness) was measured using a visual analog scale 120 min after sample ingestion. The polyphenol content and ORAC were 2- and 12-folds higher, respectively, in soybean powder than in bread flour. In the meal tests, the area under the curve (AUC) of satiety 60–120 min after ingestion (n = 44) was significantly higher for soybean powder than bread powder. The AUCs of hunger and appetite 60–120 min after ingestion were significantly lower for soybean powder than bread powder. The effect sizes of hunger and appetite by soybean powder were 0.341 and 0.424, respectively. Thus, these results suggest that soybean is a healthy food and soybeans maintain satiety and suppress hunger more than bread flour.

Plant-derived peptides improving lipid and glucose metabolism

Plant protein-derived peptides, focusing especially on soybean protein-derived peptides have considerable effects on metabolic regulation and modulation such as cholesterol lowering, triglyceride lowering, anti-obesity, inhibition of fatty acid synthase, and antidiabetic effects. The molecules targeted to study the metabolic regulatory functions of the peptides included the following: intestinal cholesterol micelle, cholesterol metabolism-related genes for cholesterol lowering, triglyceride metabolism-related genes for triglyceride lowering and anti-obesity, dipeptidyl peptidase-IV (DPP-IV), α-amylase, α-glucosidase, or glucose metabolism-related genes for lowering blood glucose levels. This review article outlines the physiological functions of plant protein-derived peptides for the improvement of lipid and glucose metabolism in vitro or in vivo.