BACKGROUND: Renal osteodystrophy (ROD) is a skeletal pathology associated with chronic kidney disease-mineral and bone disorder (CKD-MBD) that is characterized by aberrant bone mineralization and remodeling. ROD increases the risk of fracture and mortality in CKD patients. The underlying mechanisms of ROD remain elusive, partially due to the absence of an appropriate animal model. To address this gap, we established a stable mouse model of ROD using an optimized adenine-enriched diet and conducted exploratory analyses through ribonucleic acid sequencing (RNA-seq). METHODS: Eight-week-old male C57BL/6J mice were randomly allocated into three groups: control group ( n = 5), adenine and high-phosphate (HP) diet group ( n = 20), and the optimized adenine-containing diet group ( n = 20) for 12 weeks. We assessed the skeletal characteristics of model mice through blood biochemistry, microcomputed tomography (micro-CT), and bone histomorphometry. RNA-seq was utilized to profile gene expression changes of ROD. We elucidated the functions of differentially expressed genes (DEGs) using gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and gene set enrichment analysis (GSEA). DEGs were validated via quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: By the fifth week, adenine followed by an HP diet induced rapid weight loss and high mortality rates in the mouse group, precluding further model development. Mice with optimized adenine diet-induced ROD displayed significant abnormalities in serum creatinine and blood urea nitrogen levels, accompanied by pronounced hyperparathyroidism and hyperphosphatemia. The femur bone mineral density (BMD) of the model mice was lower than that of control mice, with substantial bone loss and cortical porosity. ROD mice exhibited substantial bone turnover with an increase in osteoblast and osteoclast markers. Transcriptomic profiling revealed 1907 genes with upregulated expression and 723 genes with downregulated expression in the femurs of ROD mice relative to those of control mice. Pathway analyses indicated significant enrichment of upregulated genes in the sphingolipid metabolism pathway. The significant upregulation of alkaline ceramidase 1 ( Acer1 ), alkaline ceramidase 2 ( Acer2 ), prosaposin-like 1 ( Psapl1 ), adenosine A1 receptor ( Adora1 ), and sphingosine-1-phosphate receptor 5 ( S1pr5 ) were successfully validated in mouse femurs by qRT-PCR. CONCLUSIONS Optimized adenine diet mouse model may be a valuable proxy for studying ROD. RNA-seq analysis revealed that the sphingolipid metabolism pathway is likely a key player in ROD pathogenesis, thereby providing new avenues for therapeutic intervention.
Animals ; Mice ; Chronic Kidney Disease-Mineral and Bone Disorder/genetics* ; Male ; Disease Models, Animal ; Mice, Inbred C57BL ; Sphingolipids/metabolism* ; Transcriptome/genetics* ; Signal Transduction/genetics* ; X-Ray Microtomography ; Adenine

This study aimed to investigate the effect of Jiaotai Pills on protein expression in the hippocampus of the rat model of chronic unpredictable mild stress(CUMS)-induced depression by quantitative proteomics and explore the anti-depression mechanism of Jiaotai Pills. The SD rats were randomized into control, model, Jiaotai Pills, and fluoxetine groups(n=8). Other groups except the control group were subjected to CUMS modeling for 4 weeks. After 4 weeks of continuous administration, the changes of behavior and pathological morphology of the hippocampal tissue were observed. Proteins were extracted from the hippocampal tissue, and bioinformatics analysis was performed for the differentially expressed proteins(DEPs) identified by quantitative proteomics. Western blot was employed to verify the key DEPs. The results showed that Jiaotai Pills significantly alleviated the depression behaviors and hippocampal histopathological changes in the rat model of CUMS-induced depression. A total of 5 412 proteins were identified in the hippocampus of rats, including 65 DEPs between the control group and the model group and 35 DEPs between the Jiaotai Pills group and the model group. There were 16 DEPs with the same trend in the Jiaotai Pills group and the control group, which were mainly involved in sphingolipid, AMPK, and dopaminergic synapse signaling pathways. The Western blot results of Ppp2r2b, Cers1, and Ndufv3 in the hippocampus were consistent with the results of proteomics. In conclusion, Jiaotai Pills may play an anti-depression role by modulating the levels of Ppp2r2b, Cers1, Ndufv3 and other proteins and regulating sphingolipid, AMPK, and dopaminergic synapse signaling pathways.
Rats ; Animals ; Rats, Sprague-Dawley ; Depression/drug therapy* ; AMP-Activated Protein Kinases/metabolism* ; Proteomics ; Hippocampus ; Stress, Psychological/metabolism* ; Sphingolipids/metabolism* ; Disease Models, Animal ; Drugs, Chinese Herbal

The present study investigated the effect of emodin on the serum metabolite profiles in the chronic constriction injury(CCI) model by non-target metabolomics and explored its analgesic mechanism. Twenty-four Sprague Dawley(SD) rats were randomly divided into a sham group(S), a CCI group(C), and an emodin group(E). The rats in the emodin group were taken emodin via gavage once a day for fifteen days(50 mg·kg~(-1)) on the first day after the CCI surgery. Mechanical withdrawal threshold(MWT) and thermal withdrawal threshold(TWL) in each group were performed before the CCI surgery and 3,7, 11, and 15 days after surgery. After 15 days, blood samples were collected from the abdominal aorta. The differential metabolites were screened out by non-target metabolomics and analyzed with Kyoto Encyclopedia of Genes and Genomes(KEGG) and ingenuity pathway analysis(IPA). From the third day after CCI surgery, the MWT and TWL values were reduced significantly in both CCI group and emodin group, compared with the sham group(P<0.01). At 15 days post-surgery, the MWT and TWL values in emodin group increased significantly compared with the CCI group(P<0.05). As revealed by non-target metabolomics, 72 differential serum metabolites were screened out from the C-S comparison, including 41 up-regulated and 31 down-regulated ones, while 26 differential serum metabolites from E-C comparison, including 10 up-regulated and 16 down-regulated ones. KEGG analysis showed that the differential metabolites in E-C comparison were enriched in the signaling pathways, such as sphingolipid metabolism, arginine biosynthesis, glycerophospholipid metabolism, and tryptophan metabolism. IPA showed that the differential metabolites were mainly involved in the lipid metabolism-molecular transport-small molecule biochemistry network. In conclusion, emodin can exert an analgesic role via regulating sphingolipid metabolism and arginine biosynthesis.
Analgesics/pharmacology* ; Animals ; Arginine ; Emodin/pharmacology* ; Neuralgia/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sphingolipids

OBJECTIVE: To elucidate the mechanism of Lizhong Decoction (LZD) in treating dextran sodium sulfate (DSS)-induced colitis in mice based on metabonomics. METHODS: Thirty-six mice were randomly divided into 6 groups, including normal, model, low- (1.365 g/kg), medium- (4.095 g/kg) and high dose (12.285 g/kg) LZD and salazosulfadimidine (SASP) groups, 6 mice in each group. Colitis model mice were induced by DSS admistration for 7 days, and treated with low, medium and high dose LZD extract and positive drug SASP. Metabolic comparison of DSS-induced colitis and normal mice was investigated by using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass (UPLC-Q-TOF/MS) combined with Metabolynx™ software. RESULTS: The metabolic profiles of plasma and urine in colitis mice were distinctly ameliorated after LZD treatment (P<0.05). Potential biomarkers (9 in serum and 4 in urine) were screened and tentatively identified. The endogenous metabolites were mainly involved in primary bile acid, sphingolipid, linoleic acid, arachidonic acid, amino acids (alanine, aspartate, and glutamate), butanoate and glycerophospholipid metabolism in plasma, and terpenoid backbone biosynthesis, glycerophospholipid and tryptophan metabolism in urine. After LZD treatment, these markers notably restored to normal levels. CONCLUSIONS The study revealed the underlying mechanism of LZD on amelioration of ulcerative colitis based on metabonomics, which laid a foundation for further exploring the pathological and physiological mechanism, early diagnosis, and corresponding drug development of colitis.
Mice ; Animals ; Colitis, Ulcerative/drug therapy* ; Tryptophan/adverse effects* ; Aspartic Acid ; Dextrans/adverse effects* ; Drugs, Chinese Herbal/adverse effects* ; Colitis/drug therapy* ; Biomarkers/metabolism* ; Amino Acids/adverse effects* ; Glycerophospholipids/therapeutic use* ; Sphingolipids/adverse effects* ; Bile Acids and Salts/adverse effects* ; Glutamates/adverse effects* ; Alanine/adverse effects* ; Arachidonic Acids/adverse effects* ; Linoleic Acids/adverse effects* ; Terpenes

Objective: To explore the relationship between DNA methylation and occupational noise-induced hearing loss. Methods: A case-control study was conducted. People with hearing loss induced by occupational noise were recruited as the case group and those with normal hearing but still exposed to occupational noise were recruited as the control group. A total of 60 participants were included, of which 30 participants were in the case group and 30 in the control group. The methylation level was detected by 850k genome-wide DNA methylation chip technology. The significance of differential methylated position (DMP) was tested by R-packet 'Champ'. The differential methylated region (DMR) was analyzed by using Champ's Bumphunter algorithm. Cluster profiler was used to analyze the gene list for GO and KEGG pathway enrichment. Results: There was significant difference between two groups in binaural high-frequency average hearing threshold (P<0.05), but there was no significant difference in age, smoking, drinking, hypertension, physical exercise and cumulative noise exposure. The results of DMP and DMR analysis showed that 713875 sites were detected in the case group and the control group, and 439 methylation sites with significant difference, accounting for 0.06%; 650 regions were detected, and 72 methylation regions with significant differences, accounting for 11.08%. Compared with the control group, the results of GO enrichment analysis showed that the case group had statistically significant differences in four pathways: axogenesis of projection neurons in the central nervous system, neuronal development in the central nervous system, axogenesis of neurons in the central nervous system and neuronal differentiation in the central nervous system. KEGG enrichment analysis showed that there were significant differences in sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis pathway between the case group and the control group. Conclusion: The occurrence of occupational noise-induced hearing loss may be related to the regulation of gene expression related to axogenesis of projection neurons in the central nervous system, development of neurons in the central nervous system, axogenesis of neurons in the central nervous system, differentiation of neurons in the central nervous system, sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis and gene methylation related to metabolism.
Aldosterone ; Bile Acids and Salts ; Case-Control Studies ; DNA Methylation ; Hearing Loss, Noise-Induced/genetics* ; Humans ; Noise, Occupational/adverse effects* ; Occupational Diseases ; Occupational Exposure ; Sphingolipids

BACKGROUND: Emerging evidence suggests that sphingolipids may be involved in type 2 diabetes. However, the exact signaling defect through which disordered sphingolipid metabolism induces β-cell dysfunction remains unknown. The current study demonstrated that sphingosine-1-phosphate (S1P), the product of sphingosine kinase (SphK), is an essential factor for maintaining β-cell function and survival via regulation of mitochondrial action, as mediated by prohibitin (PHB). METHODS: We examined β-cell function and viability, as measured by mitochondrial function, in mouse insulinoma 6 (MIN6) cells in response to manipulation of cellular S1P and PHB levels. RESULTS: Lack of S1P induced by sphingosine kinase inhibitor (SphKi) treatment caused β-cell dysfunction and apoptosis, with repression of mitochondrial function shown by decreases in cellular adenosine triphosphate content, the oxygen consumption rate, the expression of oxidative phosphorylation complexes, the mitochondrial membrane potential, and the expression of key regulators of mitochondrial dynamics (mitochondrial dynamin-like GTPase [OPA1] and mitofusin 1 [MFN1]). Supplementation of S1P led to the recovery of mitochondrial function and greatly improved β-cell function and viability. Knockdown of SphK2 using small interfering RNA induced mitochondrial dysfunction, decreased glucose-stimulated insulin secretion (GSIS), and reduced the expression of PHB, an essential regulator of mitochondrial metabolism. PHB deficiency significantly reduced GSIS and induced mitochondrial dysfunction, and co-treatment with S1P did not reverse these trends. CONCLUSION: Altogether, these data suggest that S1P is an essential factor in the maintenance of β-cell function and survival through its regulation of mitochondrial action and PHB expression.
Adenosine Triphosphate ; Animals ; Apoptosis ; GTP Phosphohydrolases ; Insulin ; Insulin-Secreting Cells ; Insulinoma ; Membrane Potential, Mitochondrial ; Metabolism ; Mice ; Mitochondria ; Mitochondrial Dynamics ; Oxidative Phosphorylation ; Oxygen Consumption ; Phosphotransferases ; Repression, Psychology ; RNA, Small Interfering ; Sphingolipids ; Sphingosine

BACKGROUNDThis study was to establish a disease differentiation model for ST-segment elevation myocardial infarction (STEMI) youth patients experiencing ischemia and reperfusion via ultra-performance liquid chromatography and mass spectrometry (UPLC/MS) platform, which searches for closely related characteristic metabolites and metabolic pathways to evaluate their predictive value in the prognosis after discharge.

METHODSForty-seven consecutive STEMI patients (23 patients under 45 years of age, referred to here as "youth," and 24 "elderly" patients) and 48 healthy control group members (24 youth, 24 elderly) were registered prospectively. The youth patients were required to provide a second blood draw during a follow-up visit one year after morbidity (n = 22, one lost). Characteristic metabolites and relative metabolic pathways were screened via UPLC/MS platform base on the Kyoto encyclopedia of genes and genomes (KEGG) and Human Metabolome Database. Receiver operating characteristic (ROC) curves were drawn to evaluate the predictive value of characteristic metabolites in the prognosis after discharge.

RESULTSWe successfully established an orthogonal partial least squares discriminated analysis model (R2X = 71.2%, R2Y = 79.6%, and Q2 = 55.9%) and screened out 24 ions; the sphingolipid metabolism pathway showed the most drastic change. The ROC curve analysis showed that ceramide [Cer(d18:0/16:0), Cer(t18:0/12:0)] and sphinganine in the sphingolipid pathway have high sensitivity and specificity on the prognosis related to major adverse cardiovascular events after youth patients were discharged. The area under curve (AUC) was 0.671, 0.750, and 0.711, respectively. A follow-up validation one year after morbidity showed corresponding AUC of 0.778, 0.833, and 0.806.

CONCLUSIONSBy analyzing the plasma metabolism of myocardial infarction patients, we successfully established a model that can distinguish two different factors simultaneously: pathological conditions and age. Sphingolipid metabolism is the top most altered pathway in young STEMI patients and as such may represent a valuable prognostic factor and potential therapeutic target.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Area Under Curve ; Chromatography, High Pressure Liquid ; methods ; Humans ; Least-Squares Analysis ; Mass Spectrometry ; methods ; Myocardial Ischemia ; metabolism ; Myocardial Reperfusion ; ST Elevation Myocardial Infarction ; metabolism ; Sphingolipids ; metabolism

Sphingolipids, especially ceramide and S1P, are structural components of biological membranes and bioactive molecules which participate in diverse cellular activities such as cell division, differentiation, gene expression and apoptosis. Emerging evidence demonstrates the role of sphingolipids in hepatocellular death, which contributes to the progression of several liver diseases including ischaemia-reperfusion liver injury, steatohepatitis or hepatocarcinogenesis. Furthermore, some data indicate that the accumulation of some sphingolipids contributes to the hepatic dysfunctions. Hence, understanding of sphingolipid may open up a novel therapeutic avenue to liver diseases. This review focuses on the progress in the sphingolipid metabolic pathway with a focus on hepatic diseases and drugs targeting the sphingolipid pathway.
Apoptosis ; Ceramides ; metabolism ; Fatty Liver ; metabolism ; physiopathology ; Humans ; Liver Diseases ; metabolism ; physiopathology ; Lysophospholipids ; metabolism ; Reperfusion Injury ; metabolism ; physiopathology ; Sphingolipids ; metabolism ; Sphingosine ; analogs & derivatives ; metabolism

In order to evaluate the effect and mechanism of the mulberry leaf alkaloid, flavones, and polysaccharide intervention on diabetes, the overall metabolite profiling characteristics for the plasma of diabetic mouse was performed by using an ultra-performance liquid chromatography/electrospray-tandem mass spectrometry (UPLC-ESI-MS). The 8 potential biomarkers were found in diabetic mice plasma based on the data of MS/MS characteristics obtained from the UPLC-OrbitrapMS analysis, which mainly involved in sphingolipids, amino acid metabolic pathway. The principal component analysis showed that the normal group and model group were obviously distinguished and implied that metabolic disturbance was happened in diabetic mice plasma. The extracts of mulberry leaf flavonoids, polysaccharide, alkaloid had exhibited the effects of callback function for diabetic mice through regulating the amino acid metabolism and sphingolipid metabolism.
Alkaloids ; chemistry ; Amino Acids ; metabolism ; Animals ; Biomarkers ; blood ; Chromatography, High Pressure Liquid ; Diabetes Mellitus, Experimental ; drug therapy ; Flavones ; chemistry ; Flavonoids ; chemistry ; Metabolic Networks and Pathways ; Metabolomics ; Mice ; Morus ; chemistry ; Plant Leaves ; chemistry ; Sphingolipids ; metabolism ; Tandem Mass Spectrometry

Fatty acids (FAs) are highly diverse in terms of carbon (C) chain-length and number of double bonds. FAs with C>20 are called very long-chain fatty acids (VLCFAs). VLCFAs are found not only as constituents of cellular lipids such as sphingolipids and glycerophospholipids but also as precursors of lipid mediators. Our understanding on the function of VLCFAs is growing in parallel with the identification of enzymes involved in VLCFA synthesis or degradation. A variety of inherited diseases, such as ichthyosis, macular degeneration, myopathy, mental retardation, and demyelination, are caused by mutations in the genes encoding VLCFA metabolizing enzymes. In this review, we describe mammalian VLCFAs by highlighting their tissue distribution and metabolic pathways, and we discuss responsible genes and enzymes with reference to their roles in pathophysiology.
Carbon ; Demyelinating Diseases ; Fatty Acids* ; Glycerophospholipids ; Ichthyosis ; Intellectual Disability ; Macular Degeneration ; Metabolic Networks and Pathways ; Metabolism* ; Muscular Diseases ; Sphingolipids ; Tissue Distribution