Metformin Inhibits Lipid Droplets Fusion and Growth via Reduction in Cidec and Its Regulatory Factors in Rat Adipose-Derived Stem Cells.

Metformin is still being investigated due to its potential use as a therapeutic agent for managing overweight or obesity. However, the underlying mechanisms are not fully understood. Inhibiting the adipogenesis of adipocyte precursors may be a new therapeutic opportunity for obesity treatments. It is still not fully elucidated whether adipogenesis is also involved in the weight loss mechanisms by metformin. We therefore used adipose-derived stem cells (ADSCs) from inguinal and epididymal fat pads to investigate the effects and mechanisms of metformin on adipogenesis in vitro. Our results demonstrate the similar effect of metformin inhibition on lipid accumulation, lipid droplets fusion, and growth in adipose-derived stem cells from epididymal fat pads (Epi-ADSCs) and adipose-derived stem cells from inguinal fat pads (Ing-ADSCs) cultures. We identified that cell death-inducing DFFA-like effector c (Cidec), Perilipin1, and ras-related protein 8a (Rab8a) expression increased ADSCs differentiation. In addition, we found that metformin inhibits lipid droplets fusion and growth by decreasing the expression of Cidec, Perilipin1, and Rab8a. Activation of AMPK pathway signaling in part involves metformin inhibition on Cidec, Perilipin1, and Rab8a expression. Collectively, our study reveals that metformin inhibits lipid storage, fusion, and growth of lipid droplets via reduction in Cidec and its regulatory factors in ADSCs cultures. Our study supports the development of clinical trials on metformin-based therapy for patients with overweight and obesity.

Brown adipose tissue activation in a rat model of Parkinson's disease.

Loss of body weight and fat mass is one of the nonmotor symptoms of Parkinson's disease (PD). Weight loss is due primarily to reduced energy intake and increased energy expenditure. Whereas inadequate energy intake in PD patients is caused mainly by appetite loss and impaired gastrointestinal absorption, the underlying mechanisms for increased energy expenditure remain largely unknown. Brown adipose tissue (BAT), a key thermogenic tissue in humans and other mammals, plays an important role in thermoregulation and energy metabolism; however, it has not been tested whether BAT is involved in the negative energy balance in PD. Here, using the 6-hydroxydopamine (6-OHDA) rat model of PD, we found that the activity of sympathetic nerve (SN), the expression of Ucp1 in BAT, and thermogenesis were increased in PD rats. BAT sympathetic denervation blocked sympathetic activity and decreased UCP1 expression in BAT and attenuated the loss of body weight in PD rats. Interestingly, sympathetic denervation of BAT was associated with decreased sympathetic tone and lipolysis in retroperitoneal and epididymal white adipose tissue. Our data suggeste that BAT-mediated thermogenesis may contribute to weight loss in PD.

Flipped classroom assisted by Rain Classroom for anatomy practical classes: Challenges and opportunities of anatomy education.

Anatomy practical classes are an essential part of learning human anatomy. The flipped classroom teaching model has been used in medical education in recent years. However, its precise impacts on anatomical knowledge acquisition and learning outcomes remain controversial. With the development of information technology, new educational tools, such as Rain Classroom, have recently attracted much interest. The Rain Classroom is an application that can easily connect students and teachers through smartphones or computers. However, whether and how to apply it to the flipped classroom in anatomy practical classes needs to be evaluated. In this study, we designed a teaching model of flipped classroom assisted by Rain Classroom and carried it out in anatomy practical classes at our university. Results showed that the final exam scores of the experimental group were significantly improved, compared with the control group (p < 0.01); the final exam score was significantly correlated with both the pre-class quiz score (p < 0.05) and the in-class quiz score (p < 0.001). Student satisfaction was measured by a questionnaire on a Likert scale of 1-5. All the mean scores were greater than 4.5, indicating that most students had positive attitudes toward this teaching model. The present study suggests that the Rain Classroom helps support students throughout the learning processes of the flipped classroom, and the model of flipped classroom assisted by Rain Classroom could improve students' learning efficiency and ultimately increase their exam performance in anatomy practical classes.

Ups and downs: The PPARγ/p-PPARγ seesaw of follistatin-like 1 and integrin receptor signaling in adipogenesis.

OBJECTIVE: Although Follistatin-like protein 1 (FSTL1), as an "adipokine", is highly expressed in preadipocytes, the detail role of FSTL1 in adipogenesis and obesity remains not fully understood. METHODS: In vitro differentiation of both Fstl1-/- murine embryonic fibroblasts (MEFs) and stromal vascular fraction (SVF) were measured to assess the specific role of FSTL1 in adipose differentiation. Fstl1 adipocyte-specific knockout mice were generated to evaluate its role in obesity development. Gene expression analysis and phosphorylation patterns were performed to check out the molecular mechanism of the biological function of FSTL1. RESULTS: FSTL1 deficiency inhibited preadipocytes differentiation in vitro and obesity development in vivo. Glycosylation at N142 site was pivotal for the biological effect of FSTL1 during adipogenesis; the conversion between PPARγ and p-PPARγ was the key factor for the function of FSTL1. Molecular mechanism studies showed that FSTL1 functions through the integrin/FAK/ERK signaling pathway. CONCLUSIONS: Our results suggest that FSTL1 promotes adipogenesis by inhibiting the conversion of PPARγ to p-PPARγ through the integrin/FAK/ERK signaling pathway. Glycosylated modification at N142 of FSTL1 is the key site to exert its biological effect.

Inducible beige adipocytes improve impaired glucose metabolism in interscapular BAT-removal mice.

Inducible beige adipocytes are emerging as an interesting issue in obesity and metabolism research. There is a neglected possibility that brown adipocytes are equally activated when external stimuli induce the formation of beige adipocytes. Thus, the question is whether beige adipocytes have the same functions as brown adipocytes when brown adipose tissue (BAT) is lacking. This question has not been well studied. Therefore we determine the beneficial effects of beige adipocytes upon cold challenge or CL316243 treatments in animal models of interscapular BAT (iBAT) ablation by surgical denervation. We found that denervated iBAT were activated by cold exposure and CL316243 treatments. The data show that beige adipocytes partly contribute to the improvement of impaired glucose metabolism resulting from denervated iBAT. Thus, we further used iBAT-removal animal models to abolish iBAT functions completely. We found that beige adipocytes upon cold exposure or CL316243 treatments improved impaired glucose metabolism and enhanced glucose uptake in iBAT-removal mice. The insulin signaling was activated in iBAT-removal mice upon cold exposure. Both the activation of insulin signaling and up-regulation of glucose transporter expression were observed in iBAT-removal mice with CL316243 treatments. The data show that inducible beige adipocytes may have different mechanisms to improve impaired glucose metabolism. Inducible beige adipocytes can also enhance energy expenditure and lipolytic activity of white adipose tissues when iBAT is lacking. We provide direct evidences for the beneficial effect of inducible beige adipocytes in glucose metabolism and energy expenditure in the absence of iBAT in vivo.

The glycoprotein follistatin-like 1 promotes brown adipose thermogenesis.

OBJECTIVES: The thermogenic brown adipose tissue (BAT) has been proposed as a potential target to prevent or treat obesity and related metabolic diseases. BAT secretes adipokines to regulate the thermogenic program in an autocrine or paracrine manner. Follistatin-like 1 (FSTL1), a glycoprotein involved in adipogenesis and obesity, however, the function of FSTL1 in BAT thermogenesis and in the regulation of systemic energy homeostasis are not fully understood. METHODS: Whole-body ablation Fstl1 heterozygous mice (Fstl1+/-) and its littermates control were injected with CL316,243 to assess energy balance. A series of FSTL1 overexpression and knockdown experiments were carried out to evaluate its function in regulating thermogenic gene expression in brown adipocytes. RESULTS: FSTL1 expression was induced upon BAT activation during cold challenge or ß3-adrenergic activation. FSTL1 haploinsufficiency in mice led to reduced thermogenic gene expression, impaired BAT recruitment, and decreased heat production. FSTL1 cell-autonomously promoted the ß3-adrenergic signaling, which was required to upregulate PPARγ and UCP1 in brown adipocytes. Furthermore, only glycosylated FSTL1 could be secreted from brown adipocytes to induce the ß3-adrenergic activation. CONCLUSIONS: Our results suggest FSTL1 as a novel stimulator of the ß-adrenergic signaling and BAT thermogenesis.

Effects of FSTL1 on cell proliferation in breast cancer cell line MDA­MB­231 and its brain metastatic variant MDA­MB­231­BR.

In the past decades, altered Follistatin­like 1 (FSTL1) expression has been documented in a variety of cancers, while its functional roles are poorly understood. Particularly in breast cancer, the expression of FSTL1 and its signaling pathway remain to be determined. In the present study, an elevated FSTL1 expression and a supressed cell proliferation were detected in a specific brain metastatic cell line MDA­MB­231­BR (231­BR), compared with its parental cell line MDA­MB­231. However, this protein was hardly detected in the other three breast cancer cell lines. Next, lentiviral vectors encoding FSTL1 or FSTL1 specific shRNAs were used to overexpress or knock down FSTL1 in MDA­MB­231 or 231­BR, respectively (MDA­MB­231FSTL1 or 231­BRsh FSTL1). Results showed that overexpression of FSTL1 inhibited MDA­MB­231 cell proliferation, while knockdown of FSTL1 in 231­BR cells promotes cell proliferation, compared with their corresponding control groups. These results were further confirmed in nude mouse xenografts. The tumor volume in 231­BR cell-bearing mice was significantly smaller than that of MDA­MB­231 group, and reduction of tumor volume was detected in MDA­MB­231FSTL1 cell-bearing mice compared with the control group. Previous studies revealed that TGF­ß-Smad2/3 signaling pathway was activated in 231­BR and MDA­MB­231FSTL1 cells, which may contribute to the inhibited cell proliferation. In addition, Smad3 knockdown could restore the inhibition of cell proliferation induced by FSTL1 overexpression in MDA­MB­231FSTL1 cells, indicating that the anti­proliferative effect of FSTL1 overexpression may be associated with Smad3 involved TGF­ß signaling pathway regulation. This study identified FSTL1 as an inhibitor of cell proliferation in MDA­MB­231 and 231­BR cell lines, which may provide new insights into the development and management of breast cancer.

[Feasibility and safety assessment of fossa infratemporalis approach for blind-needle at sphenopalatine ganglion].

OBJECTIVE: To identify the feasibility and safety of fossa infratemporalis approach for blind-needle at sphenopalatine ganglion so as to provide anatomical evidence for the operation and the prevention of non-immediate adverse reaction. METHODS: The variations of pterygopalatine fossae in sixty dry skulls were observed by selecting measuring points for facial skull width. The brains of six wet skulls were taken out,then acupuncture of fossa infratemporalis approach was applied. Sphenopalatine ganglion was separated accurately with the pterygopalatine segment of maxillary arteria retained in the pterygopalatine fossa after its paries posterior was opened. We detected whether the needle was inserted into pterygopalatine fossa. Measurements showed needle inserted depth, facial skull width,the distance between the needle and sphenopalatine ganglion,the distance between the needle and the pterygopalatine segment of maxillary arteria,the distance between the pterygopalatine segment of maxillary arteria and the crotaphitic nerve in pterygopalatine fossa. RESULTS: The distance between the slight hollow under bilateral arcus superciliaris was selected as skull width, and 3 dry skulls showed the variation of pterygopalatine fossa. Needles were inserted into the pterygopalatine fossae of the wet skulls (12 times). The proportion of the inserting depth to the distance between the slight hollow under bilateral arcus superciliaris was 44%-54%. Only twice did the needle contact sphenopalatine ganglion. The average distances between the sphenopalatine ganglion and the needle were (5.88±3.70) mm in the left side and (6.43±5.54) mm in the right side. The average distances between the needle and the pterygopalatine segment of maxillary arteria were (2.77±3.99) mm left and (2.53±3.10) mm right. The average distances between the pterygopalatine segment of maxillary arteria and the crotaphitic nerve in pterygopalatine fossa were (2.83±4.05) mm left and (2.67±4.95) mm right. The mean data between the two sides had no statistic significance about all the above indices (all P>0.05). CONCLUSIONS: Fossa infratemporalis approach is feasible for blind-needle at sphenopalatine ganglion with less possibility to contact it. The effect of treating nasitis may achieved by little distance to nerve. Pricking at the pterygopalatine segment of maxillary arteria may induce non-immediate adverse reaction. The safety and efficacy should be comprehensively considered. There is a proportional relationship between the width of the skull and the insertion depth of the needle. The inserting depth of 44 percent may appropriate accounted for skull width.