To study the regulatory and functional differentiation between the mesophyll (M) and bundle sheath (BS) cells of maize (Zea mays), we isolated large quantities of highly homogeneous M and BS cells from newly matured second leaves for transcriptome profiling by RNA sequencing. A total of 52,421 annotated genes with at least one read were found in the two transcriptomes. Defining a gene with more than one read per kilobase per million mapped reads as expressed, we identified 18,482 expressed genes; 14,972 were expressed in M cells, including 53 M-enriched transcription factor (TF) genes, whereas 17,269 were expressed in BS cells, including 214 BS-enriched TF genes. Interestingly, many TF gene families show a conspicuous BS preference in expression. Pathway analyses reveal differentiation between the two cell types in various functional categories, with the M cells playing more important roles in light reaction, protein synthesis and folding, tetrapyrrole synthesis, and RNA binding, while the BS cells specialize in transport, signaling, protein degradation and posttranslational modification, major carbon, hydrogen, and oxygen metabolism, cell division and organization, and development. Genes coding for several transporters involved in the shuttle of C 4 metabolites and BS cell wall development have been identified, to our knowledge, for the first time. This comprehensive data set will be useful for studying M/BS differentiation in regulation and function.C 4 plants, with few exceptions, require the coordination of the mesophyll (M) and bundle sheath (BS) cells, arranged in a wreath structure called Kranz leaf anatomy (Hatch and Agostino, 1992), to confer high rates of photosynthesis. The initial carboxylation phase of the C 4 pathway takes place in the M cells, while the decarboxylation phase is restricted to the BS cells. The high photosynthetic capacity of C 4 plants implies a massive efflux of C 4 -related metabolites between M and BS cells and between the cytosol and organelles in each cell type (Weber and von Caemmerer, 2010).Although research in the past few decades has greatly increased our understanding of the biochemical reactions and the enzymes involved in the C 4 pathway of photosynthesis, little is known about the specific genes involved in the development of the Kranz leaf anatomy, the C 4 biochemical pathway, and the underlying regulatory mechanisms for the high-level expression of C 4 -specific genes in a cell-, organ-, or development-specific manner. With the advancement in genomics, the genomic sequences of several C 3 and C 4 model plants have become available. These advances have allowed in-depth comparative proteomic and transcriptomic analyses of the whole leaves of typical C 3 and C 4 plants and their closely related C 3 -C 4 intermediate species of Cleome and Flaveria . These comparative studies allow deduction on how many genes are required to make a C 4 plant and possibly on how they may have been regulated at the genetic level. In addition, attempts have been made recently to characterize...
Human studies of curcumin extract on lipid-lowering effect have not been completely investigated and have had controversy results. This study tested the effect of daily curcumin extract for 12 weeks on weight, glucose, and lipid profiles in patients with metabolic syndrome. Sixty-five patients were randomized into two groups; 33 patients taking curcumin extract capsule (630 mg thrice daily) and 32 patients taking a placebo capsule thrice daily for 12 weeks. At 12 weeks after the curcumin extract consumption, the level of high-density lipoprotein cholesterol (HDL-C) significantly increased from 40.96 ± 8.59 to 43.76 ± 2.79 mg/dL (p < 0.05), and the level of low-density lipoprotein cholesterol (LDL) was significantly reduced (120.55 ± 36.81 to 106.51 ± 25.02 mg/dL, p < 0.05). The triglyceride-lowering effect, a reduction of 65 mg/dL, was also found in this study. In subgroups analysis, the consumption of curcumin may have a lowering cholesterol effect in male patients and an increasing HDL-C effect in female patients, both of which result in a decrease of T-Chol/HDL-C ratio. The intake of the curcumin extract of 1890 mg/day for 12 weeks was associated with lipid-lowering effect but did not improve weight and glucose homeostasis in the patients with metabolic syndrome. Daily curcumin consumption may be an alternative choice to modify cholesterol-related parameters, especially in metabolic syndrome patients.
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