Aging selectively dampens oscillation of lipid abundance in white and brown adipose tissue

Lipid metabolism is under the control of the circadian system and circadian dysregulation has been linked to obesity and dyslipidemia. These factors and outcomes have also been associated to, or affected by, the process of aging. Here, we investigated whether murine white (WAT) and brown (BAT) adipose tissue lipids exhibit rhythmicity and if this is affected by aging. To this end, we have measured the 24 h lipid profiles of WAT and BAT using a global lipidomics analysis of >1100 lipids. We observed rhythmicity in nearly all lipid classes including glycerolipids, glycerophospholipids, sterol lipids and sphingolipids. Overall, similar to 22% of the analyzed lipids were considered rhythmic in WAT and BAT. Despite a general accumulation of lipids upon aging the fraction of oscillating lipids decreased in both tissues to 14% and 18%, respectively. Diurnal profiles of lipids in BAT appeared to depend on the lipid acyl chain length and this specific regulation was lost in aged mice. Our study revealed how aging affects the rhythmicity of lipid metabolism and could contribute to the quest for targets that improve diurnal lipid homeostasis to maintain cardiometabolic health during aging.Diabetes mellitus: pathophysiological changes and therap

PENGGUNAAN METODE INKUIRI DALAM PENINGKATAN HASIL BELAJAR MATEMATIKA DI KELAS V SEKOLAH DASAR

Dwi Ari Istianto1, Triyono2, Kartika Chrysti Suryandari3 PGSD FKIP Universitas Negeri Sebelas Maret, Jl. Kepodang 67A Panjer Kebumen Email [email protected] Mahasiswa PGSD FKIP UNSDosen PGSD FKIP UNS   Abstract: Using Inquiry Methods in Increasing  Result of Mathematic Study in five grade of Elementary School. The purpose of this research were (1) to describe steps of inquiry method in increasing  result of mathematic study in five grade of Elementary School, (2) identify constraints and solutions using inquiry methods in increasing  result of mathematic study in five grade of state elementary school. This study is classroom action research (CAR) conducted in three cycles, each cycle includes the planning, implementation, observation and reflection. The data were analysis using Miles and Huberman interactive model consist of three components are: data reduction, data display, and conclusion drawing/verification. The results showed that (1) the steps of inquiry method can be run apropriate to the scenario, (2) using inquiry method can increasing  result of mathematic study in five grade of Elementary School. Increasing  result of mathematic study from pre-test were 40%, in the first cycle were 60%, in the second cycle were 73% and the third cycle increase until 80%. Key words: result of study, mathematic, inquiry method   Abstrak: Penggunaan Metode Inkuiri dalam Peningkatan Hasil Belajar Matematika di Kelas V Sekolah Dasar. Penelitian ini bertujuan untuk mendeskripsikan (1) mendiskripsikan langkah-langkah metode inkuiri dalam peningkatan hasil belajar Matematika kelas V sekolah dasar, (2) mengidentifikasi kendala dan solusi dalam penggunaan langkah-langkah metode Inkuiri kelas V sekolah dasar. Penelitian ini adalah penelitian tindakan kelas yang dilaksanakan dalam tiga siklus, masing-masing siklus mencakup tahap perencanaan, pelaksanaan, observasi dan refleksi. Teknik analisis data menggunakan teknik  interaktif  model Miles dan Huberman yang terdiri dari tiga komponen analisis yaitu reduksi data, sajian data dan penarikan kesimpulan dan verifikasi. Hasilnya menunjukkan bahwa: (1) penggunaan langkah-langkah metode Inkuiri dapat berjalan sesuai skenario, (2) penggunaan metode inkuiri dapat meningkatkan hasil belajar matematika siswa kelas V sekolah dasar. Peningkatan hasil belajar matematika dari pratindakan mencapai 40%, di siklus I 60%, di siklus II 73% dan siklus III meningkat menjadi 80%.   Kata Kunci: metode Inkuiri, hasil belajar matematik

Lipidomic analysis of fibroblasts from Zellweger spectrum disorder patients identifies disease-specific phospholipid ratios

Peroxisomes are subcellular organelles involved in various metabolic processes, including fatty acid and phospholipid homeostasis. The Zellweger spectrum disorders (ZSDs) represent a group of diseases caused by a defect in the biogenesis of peroxisomes. Accordingly, cells from ZSD patients are expected to have an altered composition of fatty acids and phospholipids. Using an LC/MS-based lipidomics approach, we show that the phospholipid composition is characteristically altered in cultured primary skin fibroblasts from ZSD patients when compared with healthy controls. We observed a marked overall increase of phospholipid species containing very long-chain fatty acids, and a decrease of phospholipid species with shorter fatty acid species in ZSD patient fibroblasts. In addition, we detected a distinct phosphatidylcholine profile in ZSD patients with a severe and mild phenotype when compared with control cells. Based on our data, we present a set of specific phospholipid ratios for fibroblasts that clearly discriminate between mild and severe ZSD patients, and those from healthy controls. Our findings will aid in the diagnosis and prognosis of ZSD patients, including an increasing number of mild patients in whom hardly any abnormalities are observed in biochemical parameters commonly used for diagnosis

Functional characterisation of peroxisomal β-oxidation disorders in fibroblasts using lipidomics

Peroxisomes play an important role in a variety of metabolic pathways, including the α‐ and β‐oxidation of fatty acids, and the biosynthesis of ether phospholipids. Single peroxisomal enzyme deficiencies (PEDs) are a group of peroxisomal disorders in which either a peroxisomal matrix enzyme or a peroxisomal membrane transporter protein is deficient. To investigate the functional consequences of specific enzyme deficiencies on the lipidome, we performed lipidomics using cultured skin fibroblasts with different defects in the β‐oxidation of very long‐chain fatty acids, including ABCD1‐ (ALD), acyl‐CoA oxidase 1 (ACOX1)‐, D‐bifunctional protein (DBP)‐, and acyl‐CoA binding domain containing protein 5 (ACBD5)‐deficient cell lines. Ultra‐high performance liquid chromatography coupled with high‐resolution mass spectrometry revealed characteristic changes in the phospholipid composition in fibroblasts with different fatty acid β‐oxidation defects. Remarkably, we found that ether phospholipids, including plasmalogens, were decreased. We defined specific phospholipid ratios reflecting the different enzyme defects, which can be used to discriminate the PED fibroblasts from healthy control cells

Multi-omics in classical galactosemia: Evidence for the involvement of multiple metabolic pathways

Classical galactosemia (CG) is one of the more frequent inborn errors of metabolism affecting approximately 1:40.000 people. Despite a life-saving galactose-restricted diet, patients develop highly variable long-term complications including intellectual disability and movement disorders. The pathophysiology of these complications is still poorly understood and development of new therapies is hampered by a lack of valid prognostic biomarkers. Multi-omics approaches may discover new biomarkers and improve prediction of patient outcome. In the current study, (semi-)targeted mass-spectrometry based metabolomics and lipidomics were performed in erythrocytes of 40 patients with both classical and variant phenotypes and 39 controls. Lipidomics did not show any significant changes or deficiencies. The metabolomics analysis revealed that CG does not only compromise the Leloir pathway, but also involves other metabolic pathways including glycolysis, the pentose phosphate pathway, and nucleotide metabolism in the erythrocyte. Moreover, the energy status of the cell appears to be compromised, with significantly decreased levels of ATP and ADP. This possibly is the consequence of two different mechanisms: impaired formation of ATP from ADP possibly due to reduced flux though the glycolytic pathway and trapping of phosphate in galactose-1-phosphate (Gal-1P) which accumulates in CG. Our findings are in line with the current notion that the accumulation of Gal-1P plays a key role in the pathophysiology of CG not only by depletion of intracellular phosphate levels but also by decreasing metabolite abundance downstream in the glycolytic pathway and affecting other pathways. New therapeutic options for CG could be directed towards the restoration of intracellular phosphate homeostasis

Adaptations of the 3T3-L1 adipocyte lipidome to defective ether lipid catabolism upon Agmo knockdown

Little is known about the physiological role of alkylglycerol monooxygenase (AGMO), the only enzyme capable of cleaving the 1-O-alkyl ether bond of ether lipids. Expression and enzymatic activity of this enzyme can be detected in a variety of tissues including adipose tissue. This labile lipolytic membrane-bound protein uses tetrahydrobiopterin as a cofactor, and mice with reduced tetrahydrobiopterin levels have alterations in body fat distribution and blood lipid concentrations. In addition, manipulation of AGMO in macrophages led to significant changes in the cellular lipidome, and alkylglycerolipids, the preferred substrates of AGMO, were shown to accumulate in mature adipocytes. Here, we investigated the roles of AGMO in lipid metabolism by studying 3T3-L1 adipogenesis. AGMO activity was induced over 11 days using an adipocyte differentiation protocol. We show that RNA interference-mediated knockdown of AGMO did not interfere with adipocyte differentiation or affect lipid droplet formation. Furthermore, lipidomics revealed that plasmalogen phospholipids were preferentially accumulated upon Agmo knockdown, and a significant shift toward longer and more polyunsaturated acyl side chains of diacylglycerols and triacylglycerols could be detected by mass spectrometry. Our results indicate that alkylglycerol catabolism has an influence not only on ether-linked species but also on the degree of unsaturation in the massive amounts of triacylglycerols formed during in vitro 3T3-L1 adipocyte differentiation

Betulinic acid induces a novel cell death pathway that depends on cardiolipin modification

Cancer is associated with strong changes in lipid metabolism. For instance, normal cells take up fatty acids (FAs) from the circulation, while tumour cells generate their own and become dependent on de novo FA synthesis, which could provide a vulnerability to target tumour cells. Betulinic acid (BetA) is a natural compound that selectively kills tumour cells through an ill-defined mechanism that is independent of BAX and BAK, but depends on mitochondrial permeability transition-pore opening. Here we unravel this pathway and show that BetA inhibits the activity of steroyl-CoA-desaturase (SCD-1). This enzyme is overexpressed in tumour cells and critically important for cells that utilize de novo FA synthesis as it converts newly synthesized saturated FAs to unsaturated FAs. Intriguingly, we find that inhibition of SCD-1 by BetA or, alternatively, with a specific SCD-1 inhibitor directly and rapidly impacts on the saturation level of cardiolipin (CL), a mitochondrial lipid that has important structural and metabolic functions and at the same time regulates mitochondria-dependent cell death. As a result of the enhanced CL saturation mitochondria of cancer cells, but not normal cells that do not depend on de novo FA synthesis, undergo ultrastructural changes, release cytochrome c and quickly induce cell death. Importantly, addition of unsaturated FAs circumvented the need for SCD-1 activity and thereby prevented BetA-induced CL saturation and subsequent cytotoxicity, supporting the importance of this novel pathway in the cytotoxicity induced by BetA.Oncogene advance online publication, 20 April 2015; doi:10.1038/onc.2015.102

Mutations in PCYT2 disrupt etherlipid biosynthesis and cause a complex hereditary spastic paraplegia.

CTP:phosphoethanolamine cytidylyltransferase (ET), encoded by PCYT2, is the rate-limiting enzyme for phosphatidylethanolamine synthesis via the CDP-ethanolamine pathway. Phosphatidylethanolamine is one of the most abundant membrane lipids and is particularly enriched in the brain. We identified five individuals with biallelic PCYT2 variants clinically characterized by global developmental delay with regression, spastic para- or tetraparesis, epilepsy and progressive cerebral and cerebellar atrophy. Using patient fibroblasts we demonstrated that these variants are hypomorphic, result in altered but residual ET protein levels and concomitant reduced enzyme activity without affecting mRNA levels. The significantly better survival of hypomorphic CRISPR-Cas9 generated pcyt2 zebrafish knockout compared to a complete knockout, in conjunction with previously described data on the Pcyt2 mouse model, indicates that complete loss of ET function may be incompatible with life in vertebrates. Lipidomic analysis revealed profound lipid abnormalities in patient fibroblasts impacting both neutral etherlipid and etherphospholipid metabolism. Plasma lipidomics studies also identified changes in etherlipids that have the potential to be used as biomarkers for ET deficiency. In conclusion, our data establish PCYT2 as a disease gene for a new complex hereditary spastic paraplegia and confirm that etherlipid homeostasis is important for the development and function of the brain