| 41. |
- Cho, Yoon Shin, et al.
(författare)
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Meta-analysis of genome-wide association studies identifies eight new loci for type 2 diabetes in east Asians.
- 2012
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 44:1
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Tidskriftsartikel (refereegranskat)abstract
- We conducted a three-stage genetic study to identify susceptibility loci for type 2 diabetes (T2D) in east Asian populations. We followed our stage 1 meta-analysis of eight T2D genome-wide association studies (6,952 cases with T2D and 11,865 controls) with a stage 2 in silico replication analysis (5,843 cases and 4,574 controls) and a stage 3 de novo replication analysis (12,284 cases and 13,172 controls). The combined analysis identified eight new T2D loci reaching genome-wide significance, which mapped in or near GLIS3, PEPD, FITM2-R3HDML-HNF4A, KCNK16, MAEA, GCC1-PAX4, PSMD6 and ZFAND3. GLIS3, which is involved in pancreatic beta cell development and insulin gene expression, is known for its association with fasting glucose levels. The evidence of an association with T2D for PEPD and HNF4A has been shown in previous studies. KCNK16 may regulate glucose-dependent insulin secretion in the pancreas. These findings, derived from an east Asian population, provide new perspectives on the etiology of T2D.
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| 42. |
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| 43. |
- Guo, Di, et al.
(författare)
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Cholecystokinin-like peptide mediates satiety by inhibiting sugar attraction
- 2021
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Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 17:8
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Tidskriftsartikel (refereegranskat)abstract
- Feeding is essential for animal survival and reproduction and is regulated by both internal states and external stimuli. However, little is known about how internal states influence the perception of external sensory cues that regulate feeding behavior. Here, we investigated the neuronal and molecular mechanisms behind nutritional state-mediated regulation of gustatory perception in control of feeding behavior in the brown planthopper and Drosophila. We found that feeding increases the expression of the cholecystokinin-like peptide, sulfakinin (SK), and the activity of a set of SK-expressing neurons. Starvation elevates the transcription of the sugar receptor Gr64f and SK negatively regulates the expression of Gr64f in both insects. Interestingly, we found that one of the two known SK receptors, CCKLR-17D3, is expressed by some of Gr64f-expressing neurons in the proboscis and proleg tarsi. Thus, we have identified SK as a neuropeptide signal in a neuronal circuitry that responds to food intake, and regulates feeding behavior by diminishing gustatory receptor gene expression and activity of sweet sensing GRNs. Our findings demonstrate one nutritional state-dependent pathway that modulates sweet perception and thereby feeding behavior, but our experiments cannot exclude further parallel pathways. Importantly, we show that the underlying mechanisms are conserved in the two distantly related insect species.
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| 44. |
- Li, Jian Feng, et al.
(författare)
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Transcriptional landscape of B cell precursor acute lymphoblastic leukemia based on an international study of 1,223 cases
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 115:50, s. 11711-11720
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Tidskriftsartikel (refereegranskat)abstract
- Most B cell precursor acute lymphoblastic leukemia (BCP ALL) can be classified into known major genetic subtypes, while a substantial proportion of BCP ALL remains poorly characterized in relation to its underlying genomic abnormalities. We therefore initiated a large-scale international study to reanalyze and delineate the transcriptome landscape of 1,223 BCP ALL cases using RNA sequencing. Fourteen BCP ALL gene expression subgroups (G1 to G14) were identified. Apart from extending eight previously described subgroups (G1 to G8 associated with MEF2D fusions, TCF3–PBX1 fusions, ETV6–RUNX1–positive/ETV6–RUNX1–like, DUX4 fusions, ZNF384 fusions, BCR–ABL1/Ph–like, high hyperdiploidy, and KMT2A fusions), we defined six additional gene expression subgroups: G9 was associated with both PAX5 and CRLF2 fusions; G10 and G11 with mutations in PAX5 (p.P80R) and IKZF1 (p.N159Y), respectively; G12 with IGH–CEBPE fusion and mutations in ZEB2 (p.H1038R); and G13 and G14 with TCF3/4–HLF and NUTM1 fusions, respectively. In pediatric BCP ALL, subgroups G2 to G5 and G7 (51 to 65/67 chromosomes) were associated with low-risk, G7 (with ≤50 chromosomes) and G9 were intermediate-risk, whereas G1, G6, and G8 were defined as high-risk subgroups. In adult BCP ALL, G1, G2, G6, and G8 were associated with high risk, while G4, G5, and G7 had relatively favorable outcomes. This large-scale transcriptome sequence analysis of BCP ALL revealed distinct molecular subgroups that reflect discrete pathways of BCP ALL, informing disease classification and prognostic stratification. The combined results strongly advocate that RNA sequencing be introduced into the clinical diagnostic workup of BCP ALL. four decades, most of the recurring chromosomal abnormalities, including aneuploidy, chromosomal rearrangements/gene fusions (e.g., ETV6–RUNX1, BCR–ABL1, and TCF3–PBX1), and rearrangements of KMT2A (previously MLL), were identified by.
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| 45. |
- Liu, Di, et al.
(författare)
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Differential seeding and propagating efficiency of α-synuclein strains generated in different conditions
- 2021
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Ingår i: Translational Neurodegeneration. - : Springer Science and Business Media LLC. - 2047-9158. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Accumulation of alpha-synuclein (α-syn) is a main pathological hallmark of Parkinson’s and related diseases, which are collectively known as synucleinopathies. Growing evidence has supported that the same protein can induce remarkably distinct pathological progresses and disease phenotypes, suggesting the existence of strain difference among α-syn fibrils. Previous studies have shown that α-syn pathology can propagate from the peripheral nervous system (PNS) to the central nervous system (CNS) in a “prion-like” manner. However, the difference of the propagation potency from the periphery to CNS among different α-syn strains remains unknown and the effect of different generation processes of these strains on the potency of seeding and propagation remains to be revealed in more detail. Methods: Three strains of preformed α-syn fibrils (PFFs) were generated in different buffer conditions which varied in pH and ionic concentrations. The α-syn PFFs were intramuscularly (IM) injected into a novel bacterial artificial chromosome (BAC) transgenic mouse line that expresses wild-type human α-syn, and the efficiency of seeding and propagation of these PFFs from the PNS to the CNS was evaluated. Results: The three strains of α-syn PFFs triggered distinct propagation patterns. The fibrils generated in mildly acidic buffer led to the most severe α-syn pathology, degeneration of motor neurons and microgliosis in the spinal cord. Conclusions: The different α-syn conformers generated in different conditions exhibited strain-specific pathology and propagation patterns from the periphery to the CNS, which further supports the view that α-syn strains may be responsible for the heterogeneity of pathological features and disease progresses among synucleinopathies.
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| 46. |
- Liu, Jian-Jun, et al.
(författare)
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Boswellic acids trigger apoptosis via a pathway dependent on caspase-8 activation but independent on Fas/Fas ligand interaction in colon cancer HT-29 cells.
- 2002
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 23:12, s. 2087-2093
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Tidskriftsartikel (refereegranskat)abstract
- Boswellic acids are the effective components of gum resin of Boswellia serrata, which has anti-inflammatory properties. Recent studies on brain tumors and leukemic cells indicate that boswellic acids may have antiproliferative and apoptotic effects with the mechanisms being not studied in detail. We studied their antiproliferative and apoptotic effects on colon cancer cells and the pathway leading to apoptosis. HT-29 cells were treated with ß-boswellic acid (BA), keto-ß-boswellic acid (K-BA) and acetyl-keto-ß-boswellic acid (AK-BA), respectively. Apoptosis was determined by flow cytometry, by cytoplasmic DNA–histone complex and the activity of caspase-3. The cleavage of poly-(ADP-ribose)-polymerase (PARP) and expression of Fas were examined by western blot. Specific caspase inhibitors, polyclonal Fas antibody, and antagonistic Fas antibody ZB4 were employed to elucidate apoptotic pathways. DNA synthesis and cell viability were examined. Both K-BA and AK-BA increased cytoplasmic DNA–histone complex dose-dependently and increased pre-G1 peak in flow cytometer analysis, with the effects of AK-BA being stronger than K-BA. BA only increased the formation of DNA–histone complex at a high concentration. K-BA and AK-BA increased caspase-8, caspase-9 and caspase-3 activities accompanied by cleavage of PARP. The effects of AK-BA on formation of cytoplasmic DNA histone and on caspase-3 activation were 3.7- and 3.4-fold, respectively, more effective than those induced by camptothecin. The apoptosis induced by AK-BA was inhibited completely by caspase-3 or caspase-8 inhibitor and partially by caspase-9 inhibitor. ZB4 blocked exogenous Fas ligand-induced apoptosis, but had no effect on AK-BA-induced apoptosis. AK-BA had no significant effect on expression of Fas. Apart from apoptotic effect, these acids also inhibited [3H]thymidine incorporation and cell viability to different extent. In conclusion, boswellic acids, particularly AK-BA and K-BA have antiproliferative and apoptotic effects in human HT-29 cells. The apoptotic effect is mediated via a pathway dependent on caspase-8 activation but independent of Fas/FasL interaction.
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| 47. |
- Liu, Jian-Jun, et al.
(författare)
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Hepatic cirrhosis increases sensitivity of kidney to endotoxin in rats
- 2002
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Ingår i: Medical Science Monitor. - 1643-3750. ; 8:2, s. 56-60
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Renal failure in cirrhotic patients is a severe complication and endotoxemia might be involved. We investigated the effect of endotoxin on renal function of cirrhotic rats and the potential protective role of N-acetylcysteine (NAC). MATERIAL/METHODS: Hepatic cirrhosis was generated in a rat model by carbon tetrachloride. Both cirrhotic and normal rats were insulted by endotoxin intravenously, while another cirrhotic group was pre-treated with NAC. Blood urea nitrogen (BUN) and creatinine were assayed eight hours later. The changes in serum tumor necrosis factor-a (TNF-a) were assayed by ELISA. The histological changes in the kidney were observed after hematoxylin and eosin staining. RESULTS: Endotoxin increased the BUN and creatinine levels in both normal and cirrhotic rats, with a much higher elevation in the latter group. TNF-a concentration was also increased by endotoxin; the changes are positively correlated with BUN and creatinine. NAC pretreatment significantly attenuates the effects of endotoxin on BUN, creatinine and TNF-a levels in cirrhotic rats with no improvement in systemic toxicity symptoms. There were no obvious histological changes in the kidney of these animals. CONCLUSIONS: Hepatic cirrhosis increased the sensitivity of renal function to endotoxemia, which may be protected by NAC.
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| 48. |
- Liu, Jian-Jun, et al.
(författare)
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In vitro effects of fat, FA, and cholesterol on sphingomyelin hydrolysis induced by rat intestinal alkaline sphingomyelinase.
- 2002
-
Ingår i: Lipids. - : Wiley. - 0024-4201 .- 1558-9307. ; 37:5, s. 469-474
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Tidskriftsartikel (refereegranskat)abstract
- Dietary sphingomyelin (SM) may have regulatory effects on cell proliferation and tumorigenesis in the colon. Alkaline sphingomyelinase (SMase) is the major enzyme responsible for hydrolysis of SM in the gut. Previously we purified the enzyme and showed that the presence of glycerophospholipids inhibited SM hydrolysis induced by alkaline SMase in vitro. In the present work, we studied the effects of TG, DG, FA, ceramide, and cholesterol on SM hydrolysis catalyzed by purified alkaline SMase. The results showed that both TG (triolein and tristearin) and DG (1,2-dioleoyl-sn-glycerol and 1,2-distearoyl-rac-glycerol) inhibited the activity of alkaline SMase. 1-Monooleoyl-rac-glycerol, 1-monostearoyl-rac-glycerol, stearic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid stimulated the activity of alkaline SMase at 0.4-0.8 mM concentrations but inhibited the enzyme at higher concentrations. There was no difference between the effects induced by saturated and unsaturated FA. A short-chain FA such as lauric acid had a stronger stimulatory effect at low concentrations and weaker inhibitory effect at high concentrations than long-chain FA. Choosing linoleic acid as an example, we found that FA had similar effects on both alkaline SMase and neutral SMase. Cholesterol and ceramide when mixed with FA to increase its solubility in bile salt micelles inhibited SMase activity. In conclusion, glycerides, FA, ceramide, and cholesterol influence SM hydrolysis catalyzed by intestinal alkaline SMase. The presence of lipids in the diet may thus influence the course of SM digestion in the gut and thereby the exposure of colon to SM metabolites.
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| 49. |
- Liu, Jian-Jun, et al.
(författare)
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Keto- and acetyl-keto-boswellic acids inhibit proliferation and induce apoptosis in Hep G2 cells via a caspase-8 dependent pathway.
- 2002
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Ingår i: International Journal of Molecular Medicine. - 1791-244X. ; 10:4, s. 501-505
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Tidskriftsartikel (refereegranskat)abstract
- Boswellic acids are the compounds isolated from the gum resin of Boswellia serrata and have been used for the treatment of inflammatory diseases for many years in the countries of the east. Recently, a few studies showed that the acids may have anti-cancer effect on leukemia and brain tumours. We investigated the apoptotic and anti-proliferative effects of two types of boswellic acids, keto-beta-boswellic acid and acetyl-keto-beta-boswellic acid, on liver cancer Hep G2 cells. After treating the cells with the boswellic acids, cell proliferation, DNA synthesis, and apoptosis were analysed. The activities of caspase-3, -8 and -9 were assayed. To explore the apoptotic pathway, specific caspase inhibitors were employed. It was found that boswellic acids decreased cell viability and [3H]thymidine incorporation, checked the cells in the G1 phase, and increased percentage of sub-G1. Boswellic acids strongly induced apoptosis accompanied by activation of caspase-3, -8 and -9. The apoptosis was blocked completely by caspase-8 or caspase-3 inhibitor, but inhibited partly by caspase-9 inhibitor. However, these caspase inhibitors did not show any effect on the alternations of cell viability caused by boswellic acids. In conclusion, boswellic acids have anti-proliferation and anti-cancer effects on Hep G2 cells. The apoptotic effect is mediated by a pathway dependent on caspase-8 activation. The acids may be a promising drug for the chemoprevention of liver cancer.
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| 50. |
- Liu, Jian-Jun, et al.
(författare)
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LY294002 Enhances Boswellic Acid-induced Apoptosis in Colon Cancer Cells
- 2009
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Ingår i: Anticancer research. - 1791-7530. ; 29:8, s. 2987-2991
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Tidskriftsartikel (refereegranskat)abstract
- Background: Boswellic acids, a type of pentacyclic triterpenoids, have been shown to induce apoptosis in colon cancer cells. The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway is crucial for cell proliferation and survival. Whether the apoptotic effects of boswellic acid could be affected by inhibition of PI3K/Akt pathway was examined. Materials and Methods: Colon cancer HT29 cells were treated with 3-acetyl-11-keto-beta boswellic acid AKBA in the absence and presence of LY294002 or Wortmanin, inhibitors of PI3K. Apoptosis was determined by flow cytometry and caspase assay. The activation of Akt was examined by Western blot. Results: AKBA at 30 mu M only slightly induced apoptosis. Preincubation of the cells with LY294002 or wortmannin significantly enhanced the AKBA-induced apoptosis up to 20-fold. Further study showed that at the doses used, AKBA induced phosphorylation of Akt at both Ser473 and Thr308 positions, indicating an activation of the PI3K/Akt pathway. Conclusion: AKBA may activate the PI3K/Akt pathway and inhibition of the P13K pathway significantly enhances AKBA-induced apoptosis.
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