In Vitro Detection of S100B and Severity Evaluation of Traumatic Brain Injury Based on Biomimetic Peptide-Modified Nanochannels.

The diagnosis and evaluation of traumatic brain injury (TBI) are crucial steps toward the treatment and prognosis of patients. A common question remains as to whether it is possible to introduce an ideal device for signal detection and evaluation that can directly connect digital signals with TBI, thereby enabling prompt response of the evaluation signal and sensitive and specific functioning of the detection process. Herein, a method is presented utilizing polymetric porous membranes with TRTK-12 peptide-modified nanochannels for the detection of S100B (a TBI biomarker) and assessment of TBI severity. The method leverages the specific bonding force between TRTK-12 peptide and S100B protein, along with the nanoconfinement effect of nanochannels, to achieve high sensitivity (LOD: 0.002 ng mL-1) and specificity (∆I/I0: 44.7%), utilizing ionic current change as an indicator. The proposed method, which is both sensitive and specific, offers a simple yet responsive approach for real-time evaluation of TBI severity. This innovative technique provides valuable scientific insights into the advancement of future diagnostic and therapeutic integration devices.

Mechanisms of adverse mammary effect induced by olanzapine and therapeutic interventions in rat model.

BACKGROUND: Olanzapine antagonizes dopamine receptors and is prescribed to treat multiple psychiatric conditions. The main side effect of concern for olanzapine is weight gain and metabolic syndrome. Olanzapine induces hyperprolactinemia, however its effect on the mammary gland is poorly documented. METHODS: Rats received olanzapine by gavage or in drinking water at 1, 3, and 6 mg/kg/day for 5-40 days or 100 days, with and without coadministration of bromocriptine or aripiprazole and using once daily or continuous administration strategies. Histomorphology of the mammary gland, concentrations of prolactin, estradiol, progesterone, and olanzapine in serum, mammary gland and adipose tissue, and mRNA and protein expressions of prolactin receptors were analyzed. RESULTS: In adult and prepubescent female rats and male rats, olanzapine induced significant development of mammary glands in dose- and time-dependent manners, with histopathological hyperplasia of mammary ducts and alveoli with lumen dilation and secretion, marked increase of mammary prolactin receptor expression, a marker of breast tissue, and with mild increase of circulating prolactin. This side effect can be reversed after medication withdrawal, but long-term olanzapine treatment for 100 days implicated tumorigenic potentials indicated by usual ductal epithelial hyperplasia. Olanzapine induced mammary development was prevented with the coaddition of the dopamine agonist bromocriptine or partial agonist aripiprazole, or by continuous administration of medication instead of a once daily regimen. CONCLUSIONS: These results shed light on the previously overlooked effect of olanzapine on mammary development and present experimental evidence to support current clinical management strategies of antipsychotic induced side effects in the breast.

Bio-inspired Two-dimensional Nanofluidic Ionic Transistor for Neuromorphic Signal Processing.

Voltage-gated ion channels prevalent in neurons play important roles in generating action potential and information transmission by responding to transmembrane potential. Fabricating bio-inspired ionic transistors with ions as charge carriers will be crucial for realizing neuro-inspired devices and brain-liking computing. Here, we reported a two-dimensional nanofluidic ionic transistor based on a MXene membrane with sub-1 nm interlayer channels. By applying a gating voltage on the MXene nanofluidic, a transmembrane potential will be generated to active the ionic transistor, which is similar to the transmembrane potential of neuron cells and can be effectively regulated by changing membrane parameters, e.g., thickness, composition, and interlayer spacing. For the symmetric MXene nanofluidic, a high on/off ratio of ~2000 can be achieved by forming an ionic depletion or accumulation zone, contingent on the sign of the gating potential. An asymmetric PET/MXene-composited nanofluidic transitioned the ionic transistor from ambipolar to unipolar, resulting in a more sensitive gate voltage characteristic with a low subthreshold swing of 560 mV/decade. Furthermore, ionic logic gate circuits, including the "NOT", "NAND", and "NOR" gate, were implemented for neuromorphic signal processing successfully, which provides a promising pathway towards highly parallel, low energy consumption, and ion-based brain-like computing.

Hepatocellular cystathionine γ lyase/hydrogen sulfide attenuates nonalcoholic fatty liver disease by activating farnesoid X receptor.

BACKGROUND AND AIMS: Hydrogen sulfide (H2 S) plays a protective role in NAFLD. However, whether cystathionine γ lyase (CSE), a dominant H2 S generating enzyme in hepatocytes, has a role in the pathogenesis of NAFLD is currently unclear. APPROACH AND RESULTS: We showed that CSE protein expression is dramatically downregulated, especially in fibrotic areas, in livers from patients with NAFLD. In high-fat diet (HFD)-induced NAFLD mice or an oleic acid-induced hepatocyte model, the CSE/H2 S pathway is also downregulated. To illustrate a regulatory role for CSE in NAFLD, we generated a hepatocyte-specific CSE knockout mouse (CSELKO ). Feeding an HFD to CSELKO mice, they showed more hepatic lipid deposition with increased activity of the fatty acid de novo synthesis pathway, increased hepatic insulin resistance, and higher hepatic gluconeogenic ability compared to CSELoxp control mice. By contrast, H2 S donor treatment attenuated these phenotypes. Furthermore, the protection conferred by H2 S was blocked by farnesoid X receptor (FXR) knockdown. Consistently, serum deoxycholic acid and lithocholic acid (FXR antagonists) were increased, and tauro-ß-muricholic acid (FXR activation elevated) was reduced in CSELKO . CSE/H2 S promoted a post-translation modification (sulfhydration) of FXR at Cys138/141 sites, thereby enhancing its activity to modulate expression of target genes related to lipid and glucose metabolism, inflammation, and fibrosis. Sulfhydration proteomics in patients' livers supported the CSE/H2 S modulation noted in the CSELKO mice. CONCLUSIONS: FXR sulfhydration is a post-translational modification affected by hepatic endogenous CSE/H2 S that may promote FXR activity and attenuate NAFLD. Hepatic CSE deficiency promotes development of nonalcoholic steatohepatitis. The interaction between H2 S and FXR may be amenable to therapeutic drug treatment in NAFLD.

Suramin, an antiparasitic drug, stimulates adipocyte differentiation and promotes adipogenesis.

BACKGROUND: Previous studies demonstrated that mast cells with their degranulated component heparin are the major endogenous factors that stimulate preadipocyte differentiation and promote fascial adipogenesis, and this effect is related to the structure of heparin. Regarding the structural and physiological properties of the negatively charged polymers, hexasulfonated suramin, a centuries-old medicine that is still used for treating African trypanosomiasis and onchocerciasis, is assumed to be a heparin-related analog or heparinoid. This investigation aims to elucidate the influence of suramin on the adipogenesis. METHODS: To assess the influence exerted by suramin on adipogenic differentiation of primary white adipocytes in rats, this exploration was conducted both in vitro and in vivo. Moreover, it was attempted to explore the role played by the sulfonic acid groups present in suramin in mediating this adipogenic process. RESULTS: Suramin demonstrated a dose- and time-dependent propensity to stimulate the adipogenic differentiation of rat preadipocytes isolated from the superficial fascia tissue and from adult adipose tissue. This stimulation was concomitant with a notable upregulation in expression levels of pivotal adipogenic factors as the adipocyte differentiation process unfolded. Intraperitoneal injection of suramin into rats slightly increased adipogenesis in the superficial fascia and in the epididymal and inguinal fat depots. PPADS, NF023, and NF449 are suramin analogs respectively containing 2, 6, and 8 sulfonic acid groups, among which the last two moderately promoted lipid droplet formation and adipocyte differentiation. The number and position of sulfonate groups may be related to the adipogenic effect of suramin. CONCLUSIONS: Suramin emerges as a noteworthy pharmaceutical agent with the unique capability to significantly induce adipocyte differentiation, thereby fostering adipogenesis.

CD4+ T-Cell Endogenous Cystathionine γ Lyase-Hydrogen Sulfide Attenuates Hypertension by Sulfhydrating Liver Kinase B1 to Promote T Regulatory Cell Differentiation and Proliferation.

BACKGROUND: Hydrogen sulfide (H2S) has antihypertension and anti-inflammatory effects, and its endogenous-generation key enzyme cystathionine γ lyase (CSE) is expressed in CD4+ T cells. However, the role of CD4+ T-cell endogenous CSE/H2S in the development of hypertension is unclear. METHODS: Peripheral blood lymphocytes were isolated from hypertensive patients or spontaneously hypertensive rats, then H2S production and expression of its generation enzymes, cystathionine ß synthase and CSE, were measured to determine the major H2S generation system changes in hypertension. Mice with CSE-specific knockout in T cells (conditional knockout, by CD4cre mice hybridization) and CD4 null mice were generated for investigating the pathophysiological relevance of the CSE/H2S system. RESULTS: In lymphocytes, H2S from CSE, but not cystathionine ß synthase, responded to blood pressure changes, supported by lymphocyte CSE protein changes and a negative correlation between H2S production with systolic blood pressure and diastolic blood pressure, but positive correlation with the serum level of interleukin 10 (an anti-inflammatory cytokine). Deletion of CSE in T cells elevated BP (5-8 mm Hg) under the physiological condition and exacerbated angiotensin II-induced hypertension. In keeping with hypertension, mesenteric artery dilation impaired association with arterial inflammation, an effect attributed to reduced immunoinhibitory T regulatory cell (Treg) numbers in the blood and kidney, thus causing excess CD4+ and CD8+ T cell infiltration in perivascular adipose tissues and kidney. CSE knockout CD4+ T cell transfer into CD4 null mice, also showed the similar phenotypes' confirming the role of endogenous CSE/H2S action. Adoptive transfer of Tregs (to conditional knockout mice) reversed hypertension, vascular relaxation impairment, and immunocyte infiltration, which confirmed that conditional knockout-induced hypertension was attributable, in part, to the reduced Treg numbers. Mechanistically, endogenous CSE/H2S promoted Treg differentiation and proliferation by activating AMP-activated protein kinase. In part, it depended on activation of its upstream kinase, liver kinase B1, by sulfhydration to facilitate its substrate binding and phosphorylation. CONCLUSION: The constitutive sulfhydration of liver kinase B1 by CSE-derived H2S activates its target kinase, AMP-activated protein kinase, and promotes Treg differentiation and proliferation, which attenuates the vascular and renal immune-inflammation, thereby preventing hypertension.

Sulfhydration of perilipin 1 is involved in the inhibitory effects of cystathionine gamma lyase/hydrogen sulfide on adipocyte lipolysis.

Hydrogen sulfide (H2S) is a novel adipokine mediating glucose uptake, lipid storage and mobilization, thus contributing to the genesis of obesity and associated diseases. Our previous work demonstrated that H2S inhibited isoproterenol-stimulated lipolysis by reducing the phosphorylation of perilipin 1 (plin-1), a lipid-droplet protein blocking lipase access. How H2S modulates plin-1 phosphorylation is still unclear. Our present study found that an H2S donor slightly increased adipose tissue weight and reduced lipolysis in mice; by contrast, deleting the key H2S generation enzyme cystathionine gamma lyase (CSE) in adipocytes lowered adipose accumulation and enhanced lipolysis. Intriguingly, an H2S donor induced sulfhydration of plin-1 but not hormone-sensitive lipase, and CSE deletion abolished the post-translational modification of plin-1. During isoproterenol-stimulated lipolysis, plin-1 sulfhydration was associated with reduced phosphorylation, and removing sulfhydration by dithiothreitol recovered the phosphorylation. Finally, plin-1 knockout abolished the effect of H2S on lipolysis, which indicates that plin-1 sulfhydration is a major direct target of H2S in lipolysis. We have identified a new post-translation modification, sulfhydration (direct action by H2S) of plin-1, causing reduced phosphorylation then decreased lipolysis. This finding also highlights a novel molecular regulatory mechanism of lipolysis.

Identification and analysis of the human sex-biased genes.

Tremendous differences between human sexes are universally observed. Therefore, identifying and analyzing the sex-biased genes are becoming basically important for uncovering the mystery of sex differences and personalized medicine. Here, we presented a computational method to identify sex-biased genes from public gene expression databases. We obtained 1407 female-biased genes (FGs) and 1096 male-biased genes (MGs) across 14 different tissues. Bioinformatics analysis revealed that compared with MGs, FGs have higher evolutionary rate, higher single-nucleotide polymorphism density, less homologous gene numbers and smaller phyletic age. FGs have lower expression level, higher tissue specificity and later expressed stage in body development. Moreover, FGs are highly involved in immune-related functions, whereas MGs are more enriched in metabolic process. In addition, cellular network analysis revealed that MGs have higher degree, more cellular activating signaling and tend to be located in cellular inner space, whereas FGs have lower degree, more cellular repressing signaling and tend to be located in cellular outer space. Finally, the identified sex-biased genes and the discovered biological insights together can be a valuable resource helpful for investigating sex-biased physiology and medicine, for example sex-biased disease diagnosis and therapy, which represents one important aspect of personalized and precision medicine.

Spatial distribution and correlation of adipocytes and mast cells in superficial fascia in rats.

Superficial fascia has abundant preadipocytes capable of spontaneous and induced differentiation and is thought to be a novel origin of adipocytes. This study aimed to quantitatively evaluate the spatial distribution and correlation of adipocytes and mast cells in rat superficial fascia. Panoramic images were obtained from whole-mounted fascia stained by toluidine blue. Adipocytes increased gradually in superficial fascia of growing rats. Abundant mast cells, with the degranulation and exocytosis of abundant secretory granules, appeared in fascia where partially differentiating adipocytes and mature adipocytes occurred. Quantitative histological analysis by variance-mean ratio and Morisita index of dispersion indicated that both mast cells and adipocytes in fascia were distributed individually in cluster, but not random or uniform. Spearman's correlation coefficient revealed that the spatial cluster distributions of mast cells and adipocytes positively correlated with each other and correlated with increased number and size of adipocytes and adipogenic areas in fascia. Morphometry analysis indicated the strong correlation between fascial adipocytes and mast cells during the periods of rat growth. The correlation coefficient increased significantly at 8 weeks compared to 4 weeks, consistent with the increasing trend of the number and size of fascia adipocytes in growing rats. This finding provided the first quantitative histological analysis for the spatial distribution and correlation of fascia adipocytes and mast cells, which could be the histocytological basis for further exploring spatial and functional interactions between fascial mast cells and adipocytes. Also, the present data were informative for the research on physiologies and pathologies of fascia and fascia-related connective tissues.

Spontaneous development of hepatosteatosis in perilipin-1 null mice with adipose tissue dysfunction.

Fatty liver features triglyceride accumulation in hepatocytes and often occurs with obesity and lipodystrophy in humans. Here, we investigated the mechanism of maladaptive hepatosteatosis with adipose-tissue dysfunction. Perilipin 1 (Plin1) did not exist in hepatocytes but was expressed exclusively in adipocytes as a dual modulator for regulating two principal adipose-tissue functions, triglyceride storage and breakdown. Plin1-/- mice showed decreased fat storage but increased lipolysis and efflux of fatty acids from adipose tissue, and hepatosteatosis spontaneously developed without altered circulating inflammatory adipocytokine levels. Plin1-/- adipose dysfunction impaired insulin sensitivity and hepatic glucose metabolism, which might inhibit gluconeogenesis to produce more intermediates for hepatic lipid synthesis. Indeed, the livers of Plin1-/- mice exhibited upregulated mRNA and protein expression of key enzymes and transcriptional factors for the uptake and transport of fatty acids and for de novo synthesis of triglycerides, but the expression of key enzymes and transcriptional factors for fatty-acid oxidation was downregulated. Biochemical assays in Plin1-/- mice confirmed increased fatty acid synthase activity but decreased activity of mitochondrial carnitine palmitoyltransferase 1 and [3H]-palmitate oxidation in the liver. We concluded that dysregulation of two principal functions, adipose storage and hydrolysis, had deleterious consequences on the hepatic lipid metabolism and thereby caused maladaptive hepatosteatosis. This mouse model might mimic and explain the pathogenesis of hepatosteatosis occurring in two typical disorders of adipose tissue dysfunction, obesity and lipodystrophy, particularly in lipodystrophic patients with Plin1 mutation.

Large-scale in silico identification of drugs exerting sex-specific effects in the heart.

BACKGROUND: Major differences exist between men and women in both physiology and pathophysiology. Dissecting the underlying processes and contributing mechanisms of sex differences in health and disease represents a crucial step towards precision medicine. Considering the significant differences between men and women in the response to pharmacotherapies, our aim was to develop an in silico model able to predict sex-specific drug responses in a large-scale. METHODS: For this purpose, we focused on cardiovascular effects because of their high morbidity and mortality. Our model predicted several drugs (including acebutolol and tacrine) with significant differences in the heart between men and women. To validate the sex-specific drug responses identified by our model, acebutolol was selected to lower blood pressure in spontaneous hypertensive rats (SHR), tacrine was used to assess cardiac injury in mice and metformin as control for a non-sex-specific response. RESULTS: As our model predicted, acebutolol exhibited a stronger decrease in heart rate and blood pressure in female than male SHRs. Tacrine lowered heart rate in male but not in female mice, induced higher plasma cTNI level and increased cardiac superoxide (DHE staining) generation in female than male mice, indicating stronger cardiac toxicity in female than male mice. To validate our model in humans, we employed two Chinese cohorts, which showed that among patients taking a beta-receptor blocker (metoprolol), women reached significantly lower diastolic blood pressure than men. CONCLUSIONS: We conclude that our in silico model could be translated into clinical practice to predict sex-specific drug responses, thereby contributing towards a more appropriate medical care for both men and women.

Spontaneous hypertension occurs with adipose tissue dysfunction in perilipin-1 null mice.

Perilipin-1 (Plin1) coats lipid droplets exclusively in adipocytes and regulates two principle functions of adipose tissue, triglyceride storage and hydrolysis, which are disrupted upon Plin1 deficiency. In the present study, we investigated the alterations in systemic metabolites and hormones, vascular function and adipose function in spontaneous hypertensive mice lacking perilipin-1 (Plin1-/-). Plin1-/- mice developed spontaneous hypertension without obvious alterations in systemic metabolites and hormones. Plin1 expressed only in adipose cells but not in vascular cells, so its ablation would have no direct effect in situ on blood vessels. Instead, Plin1-/- mice showed dysfunctions of perivascular adipose tissue (PVAT), a fat depot that anatomically surrounds systemic arteries and has an anticontractile effect. In Plin1-/- mice, aortic and mesenteric PVAT were reduced in mass and adipocyte derived relaxing factor secretion, but increased in basal lipolysis, angiotensin II secretion, macrophage infiltration and oxidative stress. Such multiple culprits impaired the anticontractile effect of PVAT to promote vasoconstriction of aortic and mesenteric arteries of Plin1-/- mice. Furthermore, arterial vessels of Plin1-/- mice showed increasing angiotensin II receptor type 1, monocyte chemotactic protein-1 and interlukin-6 expression, structural damage of endothelial and smooth muscle cells, along with impaired endothelium-dependent relaxation. Hypertension in Plin1-/- mice might occur as a deleterious consequence of PVAT dysfunction. This finding provides the direct evidence that links dysfunctional PVAT to vascular dysfunction and hypertension, particularly in pathophysiological states. This hypertensive mouse model might mimic and explain the hypertension occurring in patients with adipose tissue dysfunction, particularly with Plin1 mutations.

Cystathionine γ lyase-hydrogen sulfide increases peroxisome proliferator-activated receptor γ activity by sulfhydration at C139 site thereby promoting glucose uptake and lipid storage in adipocytes.

Adipocytes express the cystathionine γ lyase (CSE)-hydrogen sulfide (H2S) system. CSE-H2S promotes adipogenesis but ameliorates adipocyte insulin resistance. We investigated the mechanism of how CSE-H2S induces these paradoxical effects. First, we confirmed that an H2S donor or CSE overexpression promoted adipocyte differentiation. Second, we found that H2S donor inhibited but CSE inhibition increased phosphodiesterase (PDE) activity. H2S replacing isobutylmethylxanthine in the differentiation program induced adipocyte differentiation in part. Inhibiting PDE activity by H2S induced peroxisome proliferator activated receptor γ (PPARγ) protein and mRNA expression. Of note, H2S directly sulfhydrated PPARγ protein. Sulfhydrated PPARγ increased its nuclear accumulation, DNA binding activity and adipogenesis gene expression, thereby increasing glucose uptake and lipid storage, which were blocked by the desulfhydration reagent DTT. H2S induced PPARγ sulfhydration, which was blocked by mutation of the C139 site of PPARγ. In mice fed a high-fat diet (HFD) for 4 weeks, the CSE inhibitor decreased but H2S donor increased adipocyte numbers. In obese mice fed an HFD for 13 weeks, H2S treatment increased PPARγ sulfhydration in adipose tissues and attenuated insulin resistance but did not increase obesity. In conclusion, CSE-H2S increased PPARγ activity by direct sulfhydration at the C139 site, thereby changing glucose into triglyceride storage in adipocytes. CSE-H2S-mediated PPARγ activation might be a new therapeutic target for diabetes associated with obesity.

Fascia Origin of Adipose Cells.

Adipocytes might arise from vascular stromal cells, pericytes and endothelia within adipose tissue or from bone marrow cells resident in nonadipose tissue. Here, we identified adipose precursor cells resident in fascia, an uninterrupted sheet of connective tissue that extends throughout the body. The cells and fragments of superficial fascia from the rat hindlimb were highly capable of spontaneous and induced adipogenic differentiation but not myogenic and osteogenic differentiation. Fascial preadipocytes expressed multiple markers of adipogenic progenitors, similar to subcutaneous adipose-derived stromal cells (ASCs) but discriminative from visceral ASCs. Such preadipocytes resided in fascial vasculature and were physiologically active in vivo. In growing rats, adipocytes dynamically arose from the adventitia to form a thin adipose layer in the fascia. Later, some adipocytes appeared to overlay on top of other adipocytes, an early sign for the formation of three-dimensional adipose tissue in fascia. The primitive adipose lobules extended invariably along blood vessels toward the distal fascia areas. At the lobule front, nascent capillaries wrapped and passed ahead of mature adipocytes to form the distal neovasculature niche, which might replenish the pool of preadipocytes and supply nutrients and hormones necessary for continuous adipogenesis. Our findings suggest a novel model for the origin of adipocytes from the fascia, which explains both neogenesis and expansion of adipose tissue. Fascial preadipocytes generate adipose cells to form primitive adipose lobules in superficial fascia, a subcutaneous nonadipose tissue. With continuous adipogenesis, these primitive adipose lobules newly formed in superficial fascia may be the rudiment of subcutaneous adipose tissue. Stem Cells 2016;34:1407-1419.

Lipid droplet remodeling and interaction with mitochondria in mouse brown adipose tissue during cold treatment.

Brown adipose tissue (BAT) maintains animal body temperature by non-shivering thermogenesis, which is through uncoupling protein 1 (UCP1) that uncouples oxidative phosphorylation and utilizes ß-oxidation of fatty acids released from triacylglycerol (TAG) in lipid droplets (LDs). Increasing BAT activity and "browning" other tissues such as white adipose tissue (WAT) can enhance the expenditure of excess stored energy, and in turn reduce prevalence of metabolic diseases. Although many studies have characterized the biology of BAT and brown adipocytes, BAT LDs especially their activation induced by cold exposure remain to be explored. We have isolated LDs from mouse interscapular BAT and characterized the full proteome using mass spectrometry. Both morphological and biochemical experiments showed that the LDs could tightly associate with mitochondria. Under cold treatment mouse BAT started expressing LD structure protein PLIN-2/ADRP and increased expression of PLIN1. Both hormone sensitive lipase (HSL) and adipose TAG lipase (ATGL) were increased in LDs. In addition, isolated BAT LDs showed increased levels of the mitochondrial protein UCP1, and prolonged cold exposure could stimulate BAT mitochondrial cristae biogenesis. These changes were in agreement with the data from transcriptional analysis. Our results provide the BAT LD proteome for the first time and show that BAT LDs facilitate heat production by coupling increasing TAG hydrolysis through recruitment of ATGL and HSL to the organelle and expression of another LD resident protein PLIN2/ADRP, as well as by tightly associating with activated mitochondria. These findings will benefit the study of BAT activation and the interaction between LDs and mitochondria.

FAM3A activates PI3K p110α/Akt signaling to ameliorate hepatic gluconeogenesis and lipogenesis.

UNLABELLED: FAM3A belongs to a novel cytokine-like gene family, and its physiological role remains largely unknown. In our study, we found a marked reduction of FAM3A expression in the livers of db/db and high-fat diet (HFD)-induced diabetic mice. Hepatic overexpression of FAM3A markedly attenuated hyperglycemia, insulin resistance, and fatty liver with increased Akt (pAkt) signaling and repressed gluconeogenesis and lipogenesis in the livers of those mice. In contrast, small interfering RNA (siRNA)-mediated knockdown of hepatic FAM3A resulted in hyperglycemia with reduced pAkt levels and increased gluconeogenesis and lipogenesis in the livers of C57BL/6 mice. In vitro study revealed that FAM3A was mainly localized in the mitochondria, where it increases adenosine triphosphate (ATP) production and secretion in cultured hepatocytes. FAM3A activated Akt through the p110α catalytic subunit of PI3K in an insulin-independent manner. Blockade of P2 ATP receptors or downstream phospholipase C (PLC) and IP3R and removal of medium calcium all significantly reduced FAM3A-induced increase in cytosolic free Ca(2+) levels and attenuated FAM3A-mediated PI3K/Akt activation. Moreover, FAM3A-induced Akt activation was completely abolished by the inhibition of calmodulin (CaM). CONCLUSION: FAM3A plays crucial roles in the regulation of glucose and lipid metabolism in the liver, where it activates the PI3K-Akt signaling pathway by way of a Ca(2+) /CaM-dependent mechanism. Up-regulating hepatic FAM3A expression may represent an attractive means for the treatment of insulin resistance, type 2 diabetes, and nonalcoholic fatty liver disease (NAFLD).

[The Integration and Regulation of Hormone-Sensitive Lipase in Reproductive System].

Hormone-sensitive lipase (HSL) has long been considered as a classical rate-limiting enzyme during lipolysis since it was first described in 1960s. HSL is regulated mainly by catecholamine, including adrenalin. Studies in recent years indicated that the substrates for HSL are not only triglycerides, but also diacylglycerol with the catalytic activity is ten times that of triglycerides, glycerol esters and cholesterol esters, which overthrow the opinion that HSL is specific to triglyceride. The scientists have generated HSL gene knockout mice and confirmed HSL is widely located in the reproductive system, which indicates that HSL may play an important role in the regulation of physiological and pathophysiological process in the reproductive system. Here, we will focus on the features of the HSL gene, mRNA and its protein, and summarize the HSL functions in the reproductive system.

Hyperhomocysteinemia promotes insulin resistance by inducing endoplasmic reticulum stress in adipose tissue.

Type 2 diabetes is a chronic inflammatory metabolic disease, the key point being insulin resistance. Endoplasmic reticulum (ER) stress plays a critical role in the pathogenesis of type 2 diabetes. Previously, we found that hyperhomocysteinemia (HHcy) induced insulin resistance in adipose tissue. Here, we hypothesized that HHcy induces ER stress, which in turn promotes insulin resistance. In the present study, the direct effect of Hcy on adipose ER stress was investigated by the use of primary rat adipocytes in vitro and mice with HHcy in vivo. The mechanism and the effect of G protein-coupled receptor 120 (GPR120) were also investigated. We found that phosphorylation or expression of variant ER stress markers was elevated in adipose tissue of HHcy mice. HHcy activated c-Jun N-terminal kinase (JNK), the downstream signal of ER stress in adipose tissue, and activated JNK participated in insulin resistance by inhibiting Akt activation. Furthermore, JNK activated c-Jun and p65, which in turn triggered the transcription of proinflammatory cytokines. Both in vivo and in vitro assays revealed that Hcy-promoted macrophage infiltration aggravated ER stress in adipose tissue. Chemical chaperones PBA and TUDCA could reverse Hcy-induced inflammation and restore insulin-stimulated glucose uptake and Akt activation. Activation of GPR120 reversed Hcy-induced JNK activation and prevented inflammation but not ER stress. Therefore, HHcy inhibited insulin sensitivity in adipose tissue by inducing ER stress, activating JNK to promote proinflammatory cytokine production and facilitating macrophage infiltration. These findings reveal a new mechanism of HHcy in the pathogenesis of insulin resistance.

FAM3A is a target gene of peroxisome proliferator-activated receptor gamma.

BACKGROUND: To date, the biological function of FAM3A, the first member of FAM3 gene family, remains unknown. We aimed to investigate whether the expression of FAM3A in liver cells is regulated by peroxisome proliferator-activated receptors (PPARs). METHODS AND RESULTS: The transcriptional activity of human and mouse FAM3A gene promoters was determined by luciferase reporter assay system. PPARγ agonist rosiglitazone induced FAM3A expression in primary cultured mouse hepatocytes and human HepG2 cells. PPARγ antagonism blocked rosiglitazone-induced FAM3A expression, whereas PPARγ overexpression stimulated FAM3A expression in HepG2 cells. In contrast, PPARα agonist fenofibrate or PPARß agonist GW0742 failed to affect FAM3A expression in HepG2 cells. The transcriptional activities of human and mouse FAM3A promoters were markedly stimulated by PPARγ activation, but not by PPARα and PPARß activation. Chromatin immunoprecipitation (ChIP) assay revealed a direct binding of PPARγ to the putative peroxisome proliferator response element (PPRE) located at -1258/-1246 in the human FAM3A promoter. Site-directed mutagenesis of this PPRE-like motif abolished PPARγ's stimulatory effect on the transcriptional activity of human FAM3A promoter. In vivo, oral rosiglitazone treatment upregulated FAM3A expression in the livers of C57BL/6 mice and db/db mice. Moreover, upregulation of FAM3A by PPARγ activation was correlated with increased level of phosphorylated Akt (pAkt) in liver cells. CONCLUSIONS: FAM3A as a novel target gene of PPARγ. Upregulation of FAM3A by PPARγ activation is correlated with increased pAkt level in liver cells. GENERAL SIGNIFICANCE: Upregulation of FAM3A might contribute to PPARγ's metabolic effects in the liver.

Thyroid hormone-responsive SPOT 14 homolog promotes hepatic lipogenesis, and its expression is regulated by liver X receptor α through a sterol regulatory element-binding protein 1c-dependent mechanism in mice.

UNLABELLED: The protein, thyroid hormone-responsive SPOT 14 homolog (Thrsp), has been reported to be a lipogenic gene in cultured hepatocytes, implicating an important role of Thrsp in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Thrsp expression is known to be regulated by a variety of transcription factors, including thyroid hormone receptor, pregnane X receptor, and constitutive androstane receptor. Emerging in vitro evidence also points to a critical role of liver X receptor (LXR) in regulating Thrsp transcription in hepatocytes. In the present study, we showed that Thrsp was up-regulated in livers of db/db mice and high-fat-diet-fed mice, two models of murine NAFLD. Hepatic overexpression of Thrsp increased triglyceride accumulation with enhanced lipogenesis in livers of C57Bl/6 mice, whereas hepatic Thrsp gene silencing attenuated the fatty liver phenotype in db/db mice. LXR activator TO901317 induced Thrsp expression in livers of wild-type (WT) and LXR-ß gene-deficient mice, but not in LXR-α or LXR-α/ß double-knockout mice. TO901317 treatment significantly enhanced hepatic sterol regulatory element-binding protein 1c (SREBP-1c) expression and activity in WT mice, but failed to induce Thrsp expression in SREBP-1c gene-deficient mice. Sequence analysis revealed four LXR response-element-like elements and one sterol regulatory element (SRE)-binding site within a -2,468 ∼+1-base-pair region of the Thrsp promoter. TO901317 treatment and LXR-α overexpression failed to induce, whereas overexpression of SREBP-1c significantly increased Thrsp promoter activity. Moreover, deletion of the SRE site completely abolished SREBP-1c-induced Thrsp transcription. CONCLUSION: Thrsp is a lipogenic gene in the liver that is induced by the LXR agonist through an LXR-α-mediated, SREBP-1c-dependent mechanism. Therefore, Thrsp may represent a potential therapeutic target for the treatment of NAFLD.