Influence of Metabolic Syndrome on Vibration Perception Threshold in First-Degree Relatives of Type 2 Diabetes Mellitus

Objectives: To investigate influence of metabolic syndrome on vibration perception threshold in first-degree relatives of type 2 diabetes who were not diagnosed with diabets before. Material and Methods: First-degree relatives of type 2 diabetes at the age of 40 - 60 s who had not been diagnosed with diabetes before were enrolled. Height, weight, waist circumference, hip circumference, blood pressure (systolic and diastolic blood pressure), body fat percentage, fasting plasma lipid, fasting plasma glucose, 2-hour blood glucose after 75 g oral glucose and vibration perception threshold were measured. Results: 58 subjects were diagnosed with the level of vibration perception threshold ≥ 16 V. Vibration perception threshold in the metabolic syndrome group was significantly higher than that in the non-metabolic syndrome group (P < 0.05). Vibration perception threshold increased with the increase of metabolic syndrome component. The group with ≥3 components of metabolic syndrome had a significantly higher level of vibration perception, as compared with that of group with 0 component, group with 1 component of metabolic syndrome (p < 0.01). Group with 2 components of metabolic syndrome had a significantly higher level of vibration perception threshold when comparing with group with 0 component (P < 0.05). Vibration perception threshold was positively correlated with weight, body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, fasting plasma glucose and 2-hour blood glucose. Stepwise multiple regression analysis showed that there was a positive correlation between waist circumference, systolic blood pressure and vibration perception threshold. Conclusion: Some first-degree relatives of type 2 diabetes who have not been diagnosed with diabetes have high risk of peripheral neuropathy, especially those with metabolic syndrome. Waist circumference and blood pressure are the main factors affecting Vibration perception threshold levels. Early detection of vibration perception threshold should be performed in first-degree relatives of type 2 diabetes with metabolic syndrome. Waist circumference and blood pressure may be important risk factors of peripheral neuropathy for them.

Effects of resistin on insulin signaling in endothelial cells

The objective of this study was to investigate the effects of resistin on insulin signaling in human umbilical vein endothelial cells(HUVECs).HUVECs were incubated with recombinant human resistin(0–100 ng/mL)for 24 h.Akt and endothelial nitric oxide synthase(eNOS)phosphorylation levels of endothelial cells under basal or insulin stimulated conditions were measured by Western blot.Nitric oxide(NO)production of HUVECs was also detected.The results showed that resistin could significantly inhibit Akt and eNOS phos-phorylation and NO production in endothelial cells under insulin stimulated conditions(P<0.05 vs control).But under basal conditions,treatment with resistin could result in a decrease in eNOS phosphorylation(P<0.05 vs control)but had no effect on NO production and Akt phosphorylation levels.Thesefindings suggested that resistin exerted an inhibitory effect on NO production by inhibiting insulin signaling and eNOS phosphorylation in endothelial cells.

Natural variations in grain length 10(GL10)regulate rice grain size

Grain size is an important determinant of grain weight and yield in rice.Although several genes related to grain size have been identified,natural variations in these genes that affect grain size are poorly characterized.Here,we describe the grain length QTL GL10,encoding MADS56,which positively regulates grain length and grain weight.A natural allelic variation of NIL-gl10,containing an~1.0-kb deletion in the first exon that abolishes its transcription,results in shorter grain length,lower grain weight and delayed flowering in gl10 plants.The knockout of GL10 in the HJX74 background leads to grain phenotypes similar to that of NIL-gl10,while overexpression of GL10 results in increased grain length and weight and earlier heading date.GL10 regulates grain length by promoting greater longitudinal cell growth in the grain glume.Additionally,GL10 participates in the regulation of gibberellic acid(GA)signaling pathway genes in young panicle tissues.Analysis of GL10 haplotypes shows obvious divergence between the japonica and indica lineages.Our findings reveal an allelic variation of GL10 that may explain differences in grain length among modern cultivars and could be used to breed rice varieties with optimized grain shape.

Methylesterification of cell-wall pectin controls the diurnal flower-opening times in rice

Flowers are the core reproductive organ of plants, and flowering is essential for cross-pollination. Diurnal flower-opening time is thus a key trait influencing reproductive isolation, hybrid breeding, and thermostability in plants. However, the molecular mechanisms controlling this trait remain unknown. Here, we report that rice Diurnal Flower Opening Time 1 (DFOT1) modulates pectin methylesterase (PME) activity to regulate pectin methylesterification levels of the lodicule cell walls, which affect lodicule swelling to control diurnal flower-opening time. DFOT1 is specifically expressed in the lodicules, and its expression gradually increases with the approach to flowering but decreases with flowering. Importantly, a knockout of DFOT1 showed earlier diurnal flower opening. We demonstrate that DFOT1 interacts directly with multiple PMEs to promote their activity. Knockout of PME40 also resulted in early diurnal flower opening, whereas overexpression of PME42 delayed diurnal flower opening. Lower PME activity was observed to be associated with higher levels of pectin methylesterification and the softening of cell walls in lodicules, which contribute to the absorption of water by lodicules and cause them to swell, thus promoting early diurnal flower opening. Higher PME activity had the opposite effect. Collectively, our work uncovers a molecular mechanism underlying the regulation of diurnal flower-opening time in rice, which would help reduce the costs of hybrid breeding and improve the heat tolerance of flowering plants by avoiding higher temperatures at anthesis.