Structural Insights and Development of LRRK2 Inhibitors for Parkinson's Disease in the Last Decade.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease, characterized by the specific loss of dopaminergic neurons in the midbrain. The pathophysiology of PD is likely caused by a variety of environmental and hereditary factors. Many single-gene mutations have been linked to this disease, but a significant number of studies indicate that mutations in the gene encoding leucine-rich repeat kinase 2 (LRRK2) are a potential therapeutic target for both sporadic and familial forms of PD. Consequently, the identification of potential LRRK2 inhibitors has been the focus of drug discovery. Various investigations have been conducted in academic and industrial organizations to investigate the mechanism of LRRK2 in PD and further develop its inhibitors. This review summarizes the role of LRRK2 in PD and its structural details, especially the kinase domain. Furthermore, we reviewed in vitro and in vivo findings of selected inhibitors reported to date against wild-type and mutant versions of the LRRK2 kinase domain as well as the current trends researchers are employing in the development of LRRK2 inhibitors.

Derhamnosylmaysin Inhibits Adipogenesis via Inhibiting Expression of PPARγ and C/EBPα in 3T3-L1 Cells.

We investigated the effects of derhamnosylmaysin (DM) on adipogenesis and lipid accumulation in 3T3-L1 adipocytes. Our data showed that DM inhibited lipid accumulation and adipocyte differentiation in 3T3-L1 cells. Treatment of 3T3-L1 adipocytes with DM decreased the expression of major transcription factors, such as sterol regulatory element-binding protein-1c (SREBP-1c), the CCAAT-enhancer-binding protein (CEBP) family, and peroxisome proliferator-activated receptor gamma (PPARγ), in the regulation of adipocyte differentiation. Moreover, the expression of their downstream target genes related to adipogenesis and lipogenesis, including adipocyte fatty acid-binding protein (aP2), lipoprotein lipase (LPL), stearyl-CoA-desaturase-1 (SCD-1), acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS), was also decreased by treatment with DM during adipogenesis. Additionally, DM attenuated insulin-stimulated phosphorylation of Akt. These results first demonstrated that DM inhibited adipogenesis and lipogenesis through downregulation of the key adipogenic transcription factors SREBP-1c, the CEBP family, and PPARγ and inactivation of the major adipogenesis signaling factor Akt, which is intermediated in insulin. These studies demonstrated that DM is a new bioactive compound for antiadipogenic reagents for controlling overweight and obesity.

Iridin Induces G2/M Phase Cell Cycle Arrest and Extrinsic Apoptotic Cell Death through PI3K/AKT Signaling Pathway in AGS Gastric Cancer Cells.

Iridin is a natural flavonoid found in Belamcanda chinensis documented for its broad spectrum of biological activities like antioxidant, antitumor, and antiproliferative effects. In the present study, we have investigated the antitumor potential of iridin in AGS gastric cancer cells. Iridin treatment decreases AGS cell growth and promotes G2/M phase cell cycle arrest by attenuating the expression of Cdc25C, CDK1, and Cyclin B1 proteins. Iridin-treatment also triggered apoptotic cell death in AGS cells, which was verified by cleaved Caspase-3 (Cl- Caspase-3) and poly ADP-ribose polymerase (PARP) protein expression. Further apoptotic cell death was confirmed by increased apoptotic cell death fraction shown in allophycocyanin (APC)/Annexin V and propidium iodide staining. Iridin also increased the expression of extrinsic apoptotic pathway proteins like Fas, FasL, and cleaved Caspase-8 in AGS cells. On the contrary, iridin-treated AGS cells did not show variations in proteins related to an intrinsic apoptotic pathway such as Bax and Bcl-xL. Besides, Iridin showed inhibition of PI3K/AKT signaling pathways by downregulation of (p-PI3K, p-AKT) proteins in AGS cells. In conclusion, these data suggest that iridin has anticancer potential by inhibiting PI3K/AKT pathway. It could be a basis for further drug design in gastric cancer treatment.

Acer tegmentosum Maxim Inhibits Adipogenesis in 3t3-l1 Adipocytes and Attenuates Lipid Accumulation in Obese Rats Fed a High-Fat Diet.

We investigated the effect of Acer tegmentosum Maxim (ATM) on adipocyte differentiation in 3T3-L1 cells and anti-obesity properties in obese rats fed a high-fat diet (HFD). Cellular lipid content in DMI (dexamethasone, 3-isobutyl-1-methylxanthine, and insulin mixture)-treated cells increased, while ATM treatment caused a significant reduction in lipid accumulation in differentiated 3T3-L1 cells. ATM (60 ug/mL) caused inhibition of adipogenesis via down-regulation of the CCAAT/enhancer binding protein ß (C/EBPß) (48%), C/EBPα (66%), and peroxisome proliferator-activated receptor γ (PPARγ) (64%) expressions in 3T3-L1 cells. Moreover, ATM induced a decrease in the expressions of adipocyte-specific genes, such as adipocyte fatty acid-binding protein-2 (aP2), fatty acid synthase (FAS), and lipoprotein lipase (LPL). Protein kinase B (Akt) and glycogen synthase kinase 3ß (GSK3ß) phosphorylation was also decreased by ATM treatment of 3T3-L1 adipocytes. We investigated the anti-obesity effects of ATM on HFD-induced obese rats. Rats fed with an HFD demonstrated elevations in body weight gain, while the administration of ATM reversed body weight (BW) gains and adipose tissue weights in rats fed an HFD. ATM supplementation caused a decrease in the circulating triglyceride and total cholesterol levels and led to inhibition of lipid accumulation in the adipose tissues in HFD-induced obese rats. Epididymal fat exhibited significantly larger adipocytes in the HFD group than it did in the ATM-treated group. These results demonstrate that ATM administration caused a reduction in adiposity via attenuation in adipose tissue mass and adipocyte size.

Rotenoisin A is a novel anti-adipogenic compound.

The purpose of this study was to investigate the mechanisms underlying the inhibitory effects of rotenoisin A on adipogenesis in 3T3-L1 preadipocytes. 3T3-L1 cells were treated with rotenoisin A for 8 days after the induction of differentiation. Oil-red O staining showed that rotenoisin A significantly inhibited DMI-induced lipid accumulation and adipocyte differentiation. We found that rotenoisin A treatment of 3T3-L1 preadipocytes significantly reduced the mRNA and protein levels of the key adipocyte-specific transcription factors C/EBPß, C/EBPα, and PPARγ and markedly inhibited the expression of fatty acid-binding protein (aP2), fatty acid synthase (FAS), and lipoprotein lipase (LPL). Furthermore, we observed that rotenoisin A substantially increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target phosphorylated acetyl CoA carboxylase (ACC). However, co-treatment with Compound C, an AMPK inhibitor, reversed the rotenoisin A-induced inhibition of the expression of the adipogenic transcription factors C/EBPα and PPARγ and decreased the levels of phosphorylated AMPK in differentiated 3T3-L1 cells. These results demonstrated that the anti-adipogenesis mechanism involves the down-regulation of critical adipogenic transcription factors, including C/EBPß, C/EBPα, and PPARγ, through activation of the AMPK signaling pathway by rotenoisin A.

Inhibition of IAP's and activation of p53 leads to caspase-dependent apoptosis in gastric cancer cells treated with Scutellarein.

Gastric cancer is the fifth most common cancer and the third leading cause of cancer deaths worldwide. South Korea is in first place with 9,180 death alone attributed to gastric cancer in 2013. Plenty of literature suggests the evasion of apoptosis is implicated in neurodegeneration, autoimmune diseases, and tumors development due to dysregulation in the apoptotic mechanism. Reduced apoptosis or its resistance in cancer cells plays a significant role in carcinogenesis. It's imperative to understand apoptosis, which provides the basis for novel targeted therapies that can induce cancer cell death or sensitize them to cytotoxic agents by regulating key factors like IAPs, MDM2, p53, caspases and much more. Studies have demonstrated that Scutellarein have the ability to inhibit several cancer cells by inducing apoptosis with both: Scutellarein monomers as well as scutellarein containing flavonoids. MTT results revealed that scutellarein inhibited cell viability in both dose and time dependent manner. Flow cytometry and western blot analysis showed that scutellarein induces apoptosis in both AGS and SNU-484 human gastric cancer cells and G2/M phase cell cycle arrest in SNU-484 cells. This study demonstrated that the Scutellarein on AGS and SNU-484 cells significantly inhibits cell proliferation and induces apoptotic cell death via down regulating MDM2 and activated the tumor suppresser protein p53, subsequently down regulating the IAP family proteins (cIAP1, cIAP2, and XIAP) leading to caspase-dependent apoptosis in AGS and SNU-484 cells.

Anticancer Effect of Nemopilema nomurai Jellyfish Venom on HepG2 Cells and a Tumor Xenograft Animal Model.

Various kinds of animal venoms and their components have been widely studied for potential therapeutic applications. This study evaluated whether Nemopilema nomurai jellyfish venom (NnV) has anticancer activity. NnV strongly induced cytotoxicity of HepG2 cells through apoptotic cell death, as demonstrated by alterations of chromatic morphology, activation of procaspase-3, and an increase in the Bax/Bcl-2 ratio. Furthermore, NnV inhibited the phosphorylation of PI3K, PDK1, Akt, mTOR, p70S6K, and 4EBP1, whereas it enhanced the expression of p-PTEN. Interestingly, NnV also inactivated the negative feedback loops associated with Akt activation, as demonstrated by downregulation of Akt at Ser473 and mTOR at Ser2481. The anticancer effect of NnV was significant in a HepG2 xenograft mouse model, with no obvious toxicity. HepG2 cell death by NnV was inhibited by tetracycline, metalloprotease inhibitor, suggesting that metalloprotease component in NnV is closely related to the anticancer effects. This study demonstrates, for the first time, that NnV exerts highly selective cytotoxicity in HepG2 cells via dual inhibition of the Akt and mTOR signaling pathways, but not in normal cells.

Annual Wormwood Leaf Inhibits the Adipogenesis of 3T3-L1 and Obesity in High-Fat Diet-Induced Obese Rats.

Annual wormwood (AW) (Artemisia annua L.) has anti-malarial, anti-bacterial, anti-oxidant, anti-tumour, and anti-inflammatory activities. In the present study, we evaluated the effects of annual wormwood leaves (AWL) on adipocyte differentiation in 3T3-L1 cells and high-fat diet (HFD)-induced obese rats. 3T3-L1 adipocytes and HFD-induced obese rats were treated with AWL, and its effect on gene expression was analyzed using RT-PCR and Western blotting experiments. Treatment with AWL effectively prevented triglyceride accumulation during adipogenesis in a dose-dependent manner. Consistently, AWL suppressed the differentiation of 3T3-L1 preadipocytes into adipocytes through the downregulation of dexamethasone, 3-isobutyl-1- methylxanthine, and insulin (DMI)-induced serine/threonine kinase protein kinase B (PKB/Akt) activation and the expression of adipogenic genes, including the CCAAT/enhancer binding protein-α (C/EBPα) and peroximal proliferator-activated receptor-γ (PPARγ). Moreover, the expression of adipocyte fatty acid-binding protein 4 (aP2), which is a known PPARγ-target gene, was downregulated by AWL treatment. Oral administration of AWL extracts significantly decreased the body weight gain, adipose tissue mass, adipocyte cell size, serum triglyceride (TG), and total cholesterol (TC) levels in HFD-induced obese rats. These results provide novel insight into the molecular mechanisms underlying the anti-obesity effects of AWL that are mediated by the downregulation of the expression of major adipogenic transcription factors, C/EBPα and PPARγ and Akt signalling.

Maysin and Its Flavonoid Derivative from Centipedegrass Attenuates Amyloid Plaques by Inducting Humoral Immune Response with Th2 Skewed Cytokine Response in the Tg (APPswe, PS1dE9) Alzheimer's Mouse Model.

Alzheimer's disease (AD) is a slow, progressive neurodegenerative disease and the most common type of dementia in the elderly. The etiology of AD and its underlying mechanism are still not clear. In a previous study, we found that an ethyl acetate extract of Centipedegrass (CG) (i.e., EA-CG) contained 4 types of Maysin derivatives, including Luteolin, Isoorientin, Rhamnosylisoorientin, and Derhamnosylmaysin, and showed protective effects against Amyloid beta (Aß) by inhibiting oligomeric Aß in cellular and in vitro models. Here, we examined the preventative effects of EA-CG treatment on the Aß burden in the Tg (Mo/Hu APPswe PS1dE9) AD mouse model. We have investigated the EA-CG efficacy as novel anti-AD likely preventing amyloid plaques using immunofluorescence staining to visually analyze Aß40/42 and fibril formation with Thioflavin-S or 6E10 which are the profile of immunoreactivity against epitope Aß1-16 or neuritic plaque, the quantitation of humoral immune response against Aß, and the inflammatory cytokine responses (Th1 and Th2) using ELISA and QRT-PCR. To minimize the toxicity of the extracted CG, we addressed the liver toxicity in response to the CG extract treatment in Tg mice using relevant markers, such as aspartate aminotransferase (AST)/ alanine aminotransferase (ALT) measurements in serum. The EA-CG extract significantly reduced the Aß burden, the concentration of soluble Aß40/42 protein, and fibril formation in the hippocampus and cortex of the Tg mice treated with EA-CG (50 mg/kg BW/day) for 6 months compared with the Tg mice treated with a normal diet. Additionally, the profile of anti-inflammatory cytokines revealed that the levels of Th2 (interleukin-4 (IL-4) and interleukin-10 (IL-10)) cytokines are more significantly increased than Th1 (interferon-γ (IFN-γ), interleukin-2(IL-2)) in the sera. These results suggest that the EA-CG fraction induces IL-4/IL-10-dependent anti-inflammatory cytokines (Th2) rather than pro-inflammatory cytokines (Th1), which are driven by IL-2/IFN-γ. With regard to the immune response, EA-CG induced an immunoglobulin IgG and IgM response against the EA-CG treatment in the Tg mice. Furthermore, EA-CG significantly ameliorated the level of soluble Aß42 and Aß40. Similarly, we observed that the fibril formation was also decreased by EA-CG treatment in the hippocampus and cortex after quantitative analysis with Thioflavin-S staining in the Tg brain tissues. Taken together, our findings suggested that Maysin and its derivative flavonoid compounds in the EA-CG fraction might be beneficial therapeutic treatments or alternative preventative measures to adjuvant for boosting humoral and cellular include immune response and anti-inflammation which may lead to amyloid plaque accumulation in Alzheimer's patients' brains.

Dopamine D3 receptor-modulated neuroprotective effects of lisuride.

Dopamine (DA) contributes to the regulation of voluntary movement, and a deficiency in DAergic neurons leads to movement disorders. The objective of this study was to examine the neuroprotective effect of DA D2-like receptor agonist, lisuride, and the role of DA receptors in this protection. Treatment with lisuride alleviated loss of tyrosine hydroxylase (TH) both direct and intraperitoneal injection in 6-hydroxydopamine (6-OHDA) mouse model. Similar results were obtained in primary neuronal cultures treated with lisuride. Lisuride protected TH expression against 6-OHDA-induced cytotoxicity in a concentration-dependent manner. Then, we evaluated the role of DA D2 and D3 receptor in neuroprotective effect of lisuride. Treatment of neuronal cultures with L-741,626, a DA D2 receptor-selective antagonist, did not alter neuroprotective effect of lisuride. However, protective effect of lisuride on TH expression was abolished when cells were treated with GR103691, a D3 receptor selective antagonist. Furthermore, whether lisuride can alleviate mitochondrial damage of DAergic neurons induced by 6-OHDA, we investigated the expression of the mitochondrial regulatory protein, paraplegin, and changes in mitochondria morphology. Treatment with lisuride countered a 6-OHDA-induced reduction in paraplegin and TH expression, and co-treatment with GR103691 blocked this effect of lisuride. Transmission electron microscopy confirmed the lisuride mitigation of 6-OHDA-induced damage to the mitochondrial membrane and cristae. These results suggest that the DA D3 receptor mediates the neuroprotective effects of lisuride by preventing mitochondrial damage.

Rubus crataegifolius Bunge regulates adipogenesis through Akt and inhibits high-fat diet-induced obesity in rats.

BACKGROUND: Obesity is one of the greatest public health problems and major risk factors for serious metabolic diseases and significantly increases the risk of premature death. The aim of this study was to determine the inhibitory effects of Rubus crataegifolius Bunge (RCB) on adipocyte differentiation in 3 T3-L1 cells and its anti-obesity properties in high fat diet (HFD)-induced obese rats. METHODS: 3 T3-L1 adipocytes and HFD-induced obese rats were treated with RCB, and its effect on gene expression was analyzed using RT-PCR and Western blotting experiments. RESULTS: RCB treatment significantly inhibited adipocyte differentiation by suppressing the expression of C/EBPß, C/EBPα, and PPARγ in the 3 T3-L1 adipocytes. Subsequently, the expression of the PPARγ target genes aP2 and fatty acid synthase (FAS) decreased following RCB treatment during adipocyte differentiation. In uncovering the specific mechanism that mediates the effects of RCB, we demonstrated that the insulin-stimulated phosphorylation of Akt strongly decreased and that its downstream substrate phospho-GSK3ß was downregulated following RCB treatment in the 3 T3-L1 adipocytes. Moreover, LY294002, an inhibitor of Akt phosphorylation, exerted stronger inhibitory effects on RCB-mediated suppression of adipocyte differentiation, leading to the inhibition of adipocyte differentiation through the downregulation of Akt signaling. An HFD-induced obesity rat model was used to determine the inhibitory effects of RCB on obesity. Body weight gain and fat accumulation in adipose tissue were significantly reduced by the supplementation of RCB. Moreover, RCB treatment caused a significant decrease in adipocyte size, associated with a decrease in epididymal fat weight. The serum total cholesterol (TC) and triglyceride (TG) levels decreased in response to RCB treatment, whereas HDL cholesterol (HDL-C) increased, indicating that RCB attenuated lipid accumulation in adipose tissue in HFD-induced obese rats. CONCLUSION: Our results demonstrate an inhibitory effect of RCB on adipogenesis through the reduction of the adipogenic factors PPARγ, C/EBPα, and phospho-Akt. RCB had a potent anti-obesity effect, reducing body weight gain in HFD-induced obese rats.

Scanning Electron Microscopic Study of the Developing Vallate Papillaein the Korean Native Goat (Capra hircus).

The purpose of the present study was to investigate the morphological characteristics of the developing vallate papillae (VP) of Korean native goats using scanning electron microscopy. In prenatal development of the VP, primordia of the VP were observed and the moat was shallowly spread in 60-day-old fetuses. The moat of the vallate papillae was shallowly spread and still undifferentiated in 90-day-old fetuses. The trench wall of the moat of the VP was well developed in 120-day-old fetuses. In neonates, the moat of the VP was more widely and deeply engraved and VP were developed as completely as those of adults. In postnatal development, VP were observed to have continually increased in size with slight morphological changes until 90-days after birth. Taste pores of the VP were shaped like flower leaves in 120-days after birth. The microridges and microplicaes were well developed on the epithelial surface of the VP in goats ranging from 120-day-old fetuses to 120-day-old postnatal animals. These results suppose that the sensing ability for gestation of VP was already well developed by the time of its birth and VP were differentiated into a variety of different shape and size during development.

Protective effect of centipedegrass against Aß oligomerization and Aß-mediated cell death in PC12 cells.

CONTEXT: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the abnormal accumulation of ß-amyloid (Aß). Multiple Aß-aggregated species have been identified, and neurotoxicity appears to be correlated with the amount of non-fibrillar oligomers. Potent inhibitors of Aß oligomer formation or Aß-induced cell toxicity have emerged as attractive means of therapeutic intervention. Eremochloa ophiuroide Hack. (Poaceae), also known as centipedegrass (CG), originates from China and South America and is reported to contain several C-glycosyl flavones and phenolic constituents. OBJECTIVE: We investigated whether CG could suppress Aß aggregation, BACE1 activity, and toxicity at neuronal cell. MATERIALS AND METHODS: The inhibitory effect of CG extracts toward aggregation of Aß42 was investigated in the absence and presence of 50 µg/mL CG. We investigated the inhibitory effects of CG (0-5 µg/mL) on BACE1 using fluorescence resonance energy transfer (FRET)-based assay. The effects of CG (0-75 µg/mL) on Aß42-induced neurotoxicity were examined in PC12 cells in the presence or absence of maysin and its derivatives of CG. RESULTS: We isolated EA-CG fraction (70% MeOH fraction from EtOAc extracts) from methanol extracts of CG, which contained approximately 60% maysin and its derivatives. In the present studies, we found that several Aß oligomeric forms such as the monomer, dimer, trimer, and highly aggregated oligomeric forms were remarkably inhibited in the presence of 50 µg/mL of EA-CG. EA-CG also inhibited BACE1 enzyme activity in a dose-dependent manner. EA-CG treatment generated approximately 50% or 85% inhibition to the control at the tested concentrations of 1 or 5 µg/mL, respectively. Moreover, the neurotoxicity induced by Aß42 was significantly reduced by treatment of EA-CG, and the 75 µg/mL EA-CG treatment significantly increased cell viability up to 82.5%. DISCUSSION AND CONCLUSION: These results suggested that the anti-Alzheimer's effects of CG occurred through inhibition of neuronal cell death by intervening with oligomeric Aß formation and reducing BACE1 activity. Maysin in CG could be an excellent therapeutic candidate for the prevention of AD.

Pramipexole protects dopaminergic neurons through paraplegin against 6-hydroxydopamine.

The neurotransmitter dopamine (DA) regulates various physiological and psychological functions, such as movement, motivation, behavior, and learning. DA exerts its function through DA receptors and a series of studies have reported the role of DAergic receptors in preventing DAergic neuronal degeneration. Here, we studied the DA receptor-mediated neuroprotective effect of the D2-like receptor agonists against 6-hydroxydopamine (6-OHDA)-induced DAergic neurodegeneration. D2-like receptor agonists were administered in the substantia nigra in vivo and to primary cultured neurons. Treatment of 6-OHDA decreased tyrosine hydroxylase (TH) and paraplegin (mitochondrial regulation protein) immunoreactivity, whereas pretreatment with quinpirole (a full D2-like receptor agonist) preserved TH and paraplegin reactivity. This led us to test which DA receptors were necessary for the neuroprotective effect and whether paraplegin can be regulated by D2 or D3 receptor agonists. Pretreatment with the D2 receptor selective agonist, sumanirole, did not preserve TH and paraplegin reactivity from 6-OHDA. However, the D3 receptor agonist, pramipexole, protected TH reactivity and restored paraplegin expression to the control level in the presence of 6-OHDA. Interestingly, pretreatment with the D3 receptor antagonist GR103691 reduced TH and paraplegin expression levels. These results suggest that the D3 receptor agonist may protect DA neurons from the effect of 6-OHDA through the modulation of the mitochondrial regulation protein paraplegin.

Coprinus comatus cap inhibits adipocyte differentiation via regulation of PPARγ and Akt signaling pathway.

This study assessed the effects of Coprinus comatus cap (CCC) on adipogenesis in 3T3-L1 adipocytes and the effects of CCC on the development of diet-induced obesity in rats. Here, we showed that the CCC has an inhibitory effect on the adipocyte differentiation of 3T3-L1 cells, resulting in a significant decrease in lipid accumulation through the downregulation of several adipocyte specific-transcription factors, including CCAAT/enhancer binding protein ß, C/EBPδ, and peroxisome proliferator-activated receptor gamma (PPARγ). Moreover, treatment with CCC during adipocyte differentiation induced a significant down-regulation of PPARγ and adipogenic target genes, including adipocyte protein 2, lipoprotein lipase, and adiponectin. Interestingly, the CCC treatment of the 3T3-L1 adipocytes suppressed the insulin-stimulated Akt and GSK3ß phosphorylation, and these effects were stronger in the presence of an inhibitor of Akt phosphorylation, LY294002, suggesting that CCC inhibited adipocyte differentiation through the down-regulation of Akt signaling. In the animal study, CCC administration significantly reduced the body weight and adipose tissue weight of rats fed a high fat diet (HFD) and attenuated lipid accumulation in the adipose tissues of the HFD-induced obese rats. The size of the adipocyte in the epididymal fat of the CCC fed rats was significantly smaller than in the HFD rats. CCC treatment significantly reduced the total cholesterol and triglyceride levels in the serum of HFD rats. These results strongly indicated that the CCC-mediated decrease in body weight was due to a reduction in adipose tissue mass. The expression level of PPARγ and phospho-Akt was significantly lower in the CCC-treated HFD rats than that in the HFD obesity rats. These results suggested that CCC inhibited adipocyte differentiation by the down-regulation of major transcription factor involved in the adipogenesis pathway including PPARγ through the regulation of the Akt pathway in 3T3-L1 cells and HFD adipose tissue.

Autonomous vascular networks synchronize GABA neuron migration in the embryonic forebrain.

Gamma-aminobutyric acid neurons, born in remote germinative zones in the ventral forebrain (telencephalon), migrate tangentially in two spatially distinct streams to adopt their specific positions in the developing cortex. The cell types and molecular cues that regulate this divided migratory route remains to be elucidated. Here we show that embryonic vascular networks are strategically positioned to fulfil the task of providing support as well as critical guidance cues that regulate the divided migratory routes of gamma-aminobutyric acid neurons in the telencephalon. Interestingly, endothelial cells of the telencephalon are not homogeneous in their gene expression profiles. Endothelial cells of the periventricular vascular network have molecular identities distinct from those of the pial network. Our data suggest that periventricular endothelial cells have intrinsic programs that can significantly mould neuronal development and uncovers new insights into concepts and mechanisms of central nervous system angiogenesis from both developmental and disease perspectives.

Dopaminergic neurons modulate GABA neuron migration in the embryonic midbrain.

Neuronal migration, a key event during brain development, remains largely unexplored in the mesencephalon, where dopaminergic (DA) and GABA neurons constitute two major neuronal populations. Here we study the migrational trajectories of DA and GABA neurons and show that they occupy ventral mesencephalic territory in a temporally and spatially specific manner. Our results from the Pitx3-deficient aphakia mouse suggest that pre-existing DA neurons modulate GABA neuronal migration to their final destination, providing novel insights and fresh perspectives concerning neuronal migration and connectivity in the mesencephalon in normal as well as diseased brains.

Identification of proteins regulated by ferulic acid in a middle cerebral artery occlusion animal model-a proteomics approach.

Ferulic acid plays a neuroprotective role in cerebral ischemia. The aim of this study was to identify the proteins that are differentially expressed following ferulic acid treatment during ischemic brain injury using a proteomics technique. Middle cerebral artery occlusion (MCAO) was performed to induce a focal cerebral ischemic injury in adult male rats, and ferulic acid (100 mg/kg) or vehicle was administered immediately after MCAO. Brain tissues were collected 24 hr after MCAO. The proteins in the cerebral cortex were separated using two-dimensional gel electrophoresis and were identified by mass spectrometry. We detected differentially expressed proteins between vehicle- and ferulic acid-treated animals. Adenosylhomocysteinase, isocitrate dehydrogenase [NAD(+)], mitogen-activated protein kinase kinase 1 and glyceraldehyde-3-phosphate dehydrogenase were decreased in the vehicle-treated group, and ferulic acid prevented the injury-induced decreases in these proteins. However, pyridoxal phosphate phosphatase and heat shock protein 60 were increased in the vehicle-treated group, while ferulic acid prevented the injury-induced increase in these proteins. It is accepted that these enzymes are involved in cellular metabolism and differentiation. Thus, these findings suggest evidence that ferulic acid plays a neuroprotective role against focal cerebral ischemia through the up- and down-modulation of specific enzymes.

Citrus aurantium flavonoids inhibit adipogenesis through the Akt signaling pathway in 3T3-L1 cells.

BACKGROUND: Obesity is a health hazard that is associated with a number of diseases and metabolic abnormalities, such as type-2 diabetes, hypertension, dyslipidemia, and coronary heart disease. In the current study, we investigated the effects of Citrus aurantium flavonoids (CAF) on the inhibition of adipogenesis and adipocyte differentiation in 3T3-L1 cells. METHODS: During adipocyte differentiation, 3T3-L1 cells were treated with 0, 10, and 50 µg/ml CAF, and then the mRNA and protein expression of adipogenesis-related genes was assayed. We examined the effect of CAF on level of phosphorylated Akt in 3T3-L1 cells treated with CAF at various concentrations during adipocyte differentiation. RESULTS: The insulin-induced expression of C/EBPß and PPARγ mRNA and protein were significantly down-regulated in a dose-dependent manner following CAF treatment. CAF also dramatically decreased the expression of C/EBPα, which is essential for the acquisition of insulin sensitivity by adipocytes. Moreover, the expression of the aP2 and FAS genes, which are involved in lipid metabolism, decreased dramatically upon treatment with CAF. Interestingly, CAF diminished the insulin-stimulated serine phosphorylation of Akt (Ser473) and GSK3ß (Ser9), which may reduce glucose uptake in response to insulin and lipid accumulation. Furthermore, CAF not only inhibited triglyceride accumulation during adipogenesis but also contributed to the lipolysis of adipocytes. CONCLUSIONS: In the present study, we demonstrate that CAF suppressed adipogenesis in 3T3-L1 adipocytes. Our results indicated that CAF down-regulates the expression of C/EBPß and subsequently inhibits the activation of PPARγ and C/EBPα. The anti-adipogenic activity of CAF was mediated by the inhibition of Akt activation and GSK3ß phosphorylation, which induced the down-regulation of lipid accumulation and lipid metabolizing genes, ultimately inhibiting adipocyte differentiation.