Total control of fat cells from adipogenesis to apoptosis using a xanthene analog

Multimodal Label-Free Monitoring of Adipogenic Stem Cell Differentiation Using Endogenous Optical Biomarkers

Stem cell-based therapies carry significant promise for treating human diseases. However, clinical translation of stem cell transplants for effective treatment requires precise non-destructive evaluation of the purity of stem cells with high sensitivity (<0.001% of the number of cells). Here, a novel methodology using hyperspectral imaging (HSI) combined with spectral angle mapping-based machine learning analysis is reported to distinguish differentiating human adipose-derived stem cells (hASCs) from control stem cells. The spectral signature of adipogenesis generated by the HSI method enables identifying differentiated cells at single-cell resolution. The label-free HSI method is compared with the standard techniques such as Oil Red O staining, fluorescence microscopy, and qPCR that are routinely used to evaluate adipogenic differentiation of hASCs. HSI is successfully used to assess the abundance of adipocytes derived from transplanted cells in a transgenic mice model. Further, Raman microscopy and multiphoton-based metabolic imaging is performed to provide complementary information for the functional imaging of the hASCs. Finally, the HSI method is validated using matrix-assisted laser desorption/ionization-mass spectrometry imaging of the stem cells. The study presented here demonstrates that multimodal imaging methods enable label-free identification of stem cell differentiation with high spatial and chemical resolution.

PUNICALAGIN AND PUNICALIN SUPPRESS THE ADIPOCYTE DIFFERENTIATION THROUGH THE TRANSCRIPTION FACTORS

BACKGROUND

Pomegranate is a rich source of many polyphenolic compounds including ellagitannins (punicalagin, punicalin and others).

AIM

The effects of punicalagin and punicalin on adipogenesis were investigated in this study.

MATERIALS AND METHODS

To examine the effect of punicalagin and punicalin on adipocyte differentiation, various concentrations of punicalagin and punicalin (2-10 µM) were applied to differentiated 3T3-L1 cells. Glyceraldehyde-3-phosphate dehydrogenase (GPDH) activity, Oil red O staining, intracellular triglyceride levels, and gene expressions of transcription factors (Peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT-enhancer-binding proteins-α (C/EBPα), Sterol regulatory element-binding protein 1c (SREBP-1c)) and lipolysis-associated genes (hormone-sensitive lipase (HSL), Perilipin A, tumor necrosis factor-α (TNF-α)) were examined in order to investigate the effects of punicalagin and punicalin on adipocyte differentiation.

RESULTS

Punicalagin and punicalin applications caused a continuous decrease in cell size and intracellular triglyceride accumulation. GPDH activity and transcription gene expressions decreased significantly in groups that were applicated punicalagin and punicalin at high concentrations. Punicalagin, but not punicalin, down-regulated the expression of HSL and perilipin A and up-regulated the expression of TNF-α in a dose-dependent manner. In conclusion, both punicalagin and punicalin were able to inhibit the adipocyte differentiation.

Antihyperlipidemic effect of iridoid glycoside deacetylasperulosidic acid isolated from the seeds of Spermacoce hispida L. - A traditional antiobesity herb

ETHNOBOTANICAL RELEVANCE

The interest on herbal health supplements for obesity is increasing globally. Our previous ethnobotanical survey in Tiruvallur district, Tamil Nadu, India indicated the use of Spermacoce hispida L. seeds for the treatment of obesity.

AIM OF THE STUDY

This study was aimed to validate the traditional claim and to identify the antihyperlipidemic principle in the seeds of Spermacoce hispida using bioassay guided fractionation method.

METHODS

Bioassay monitored fractionation of the aqueous extract from Spermacoce hispida seeds was carried out using triton WR 1339 induced hyperlipidemic animals. It yielded deacetylasperulosidic acid (DAA) as the active ingredient. Pharmacokinetic properties of DAA were predicted using DataWarrior and SwissADME tools. In vitro antiobesity and antihyperlipidemic effects of DAA were evaluated in 3T3L1 preadipocytes and HepG2 cells, respectively. The chronic antihyperlipidemic efficacy of DAA was evaluated in high fat diet fed rats.

RESULTS

DAA did not show any mutagenic and tumorigenic properties. It bound with PPARα with comparable ligand efficiency as fenofibrate. The treatment with DAA significantly lowered the proliferation of matured adipocytes, but not preadipocytes. The treatment of steatotic HepG2 cells with DAA significantly decreased the LDH leakage by 43.03% (P < 0.05) at 50 μM concentration. In triton WR 1339 induced hyperlipidemic animals, the treatment with 50 mg/kg dose significantly lowered the TC, TG and LDL-c levels by 40.27, 46.00 and 63.65% respectively. In HFD fed animals, the treatment at 10 mg/kg decreased BMI and AC/TC ratio without altering SRBG. It also improved serum lipid, transaminases and phosphatases levels of HFD fed animals. The treatment lowered adipocyte hypertrophy and steatosis of hepatocytes.

CONCLUSION

This preliminary report supported the traditional use of Spermacoce hispida for the treatment of obesity. Further detailed investigations on the long term safety, efficacy and molecular mode of action of Spermacoce hispida and DAA will throw more light on their usefulness for the management of obesity.

Bardet-Biedl syndrome obesity: BBS4 regulates cellular ER stress in early adipogenesis

BACKGROUND

Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy, presenting with early obesity onset. The etiology of BBS obesity involves both central and peripheral defects, through mechanisms mostly yet to be deciphered. We previously showed BBS4 expression in adipogenesis, peaking at day 3 of differentiation. Obesity is characterized by cellular stress which promotes pathological consequences.

AIMS

We set out to test a possible role of BBS4 in adipocyte endoplasmic reticulum (ER) stress-induced unfolding protein response (UPR).

METHODS

BBS4 silenced (SiBBS4) and overexpressing (OEBBS4) pre-adipocyte murine cell lines were subjected to ER-stress induction (Tunicamycin, TM) during adipogenesis. ER-stress UPR was analyzed at the transcript, protein and biochemical levels (microscopy, immunocytochemistry, western blotting, quantitative RT-PCR and X-box binding protein 1 (XBP-1) splicing).

RESULTS

In silico analysis showed that BBS4 harbors an ER localization sequences indicative of ER localization. We verified BBS4's ER localization in adipocytes by immunocytochemistry and cellular protein fractionation. Furthermore, we demonstrated that BBS4 expression is significantly up-regulated by ER-stress, as indicated by protein and transcript levels. SiBBS4 adipocytes exhibited swollen ER typical to ER-stress and significant XBP-1 down-regulation at day 3 of differentiation. Following ER-stress, SiBBS4 adipocytes exhibited XBP-1 ER retention, failure to translocate to the nucleus and depletion of the nuclear active cleaved ATF6α. BBS4 did not alter ATF6α processing by S1P and S2P in the Golgi. Notably, SiBBS4 cells demonstrated significant reduction in the downstream activated phospho-IRE1α, independent of ER-stress.

CONCLUSIONS

At day 3 of adipogenesis, coinciding with the timing of its peak expression, BBS4 is localized to the ER and is involved in the ER stress response and trafficking. BBS4 depletion results in swollen ER with impaired intracellular nucleus translocation of XBP-1 and ATF6α. Thus, BBS4 affects the ER stress response in early adipogenesis, altering ER stress responsiveness and the adipocyte ER phenotype.

Inflammatory Microenvironment and Adipogenic Differentiation in Obesity: The Inhibitory Effect of Theobromine in a Model of Human Obesity In Vitro

Objective

Obesity is considered a clinic condition characterized by a state of chronic low-grade inflammation. The role of macrophages and adipocytokines in adipose tissue inflammation is in growing investigation. The physiopathological mechanisms involved in inflammatory state in obesity are not fully understood though the adipocytokines seem to characterize the biochemical link between obesity and inflammation. The aim of this work is to analyze the effect of theobromine, a methylxanthine present in the cocoa, on adipogenesis and on proinflammatory cytokines evaluated in a model of fat tissue inflammation in vitro.

Methods

In order to mimic in vitro this inflammatory condition, we investigated the interactions between human-like macrophages U937 and human adipocyte cell lines SGBS. The effect of theobromine on in vitro cell growth, cell cycle, adipogenesis, and cytokines release in the supernatants has been evaluated.

Results

Theobromine significantly inhibits the differentiation of preadipocytes in mature adipocytes and reduces the levels of proinflammatory cytokines as MCP-1 and IL-1β in the supernatants obtained by the mature adipocytes and macrophages interaction.

Conclusion

Theobromine reduces adipogenesis and proinflammatory cytokines; these data suggest its potential therapeutic effect for treating obesity by control of macrophages infiltration in adipose tissue and inflammation.