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Pericentrin Is Related to Abnormal β-Cell Insulin Secretion through F-Actin Regulation in Mice.

Zu Y, Gong Y, Wan L, Lv Y, Cui S, Jin X, Li C, Chen X - PLoS ONE (2015)

Bottom Line: The results revealed that PCNT expression in glucose-stimulated MIN6 cells reduced linearly with cytoplasmic insulin levels.The ERK inhibitor affected PCNT expression and F-actin expression linearly.The abnormal insulin secretion observed both in vivo and in vitro was associated with decreased PCNT expression, and F-actin was found to be the target of PCNT regulation.

View Article: PubMed Central - PubMed

Affiliation: Department of Geriatric Endocrinology, Chinese People's Liberation Army General Hospital, Beijing, 100853, China.

ABSTRACT
The aim of this study was to investigate the regulating effect of pericentrin (PCNT) on insulin secretion in the development of insulin resistance and to determine the underlying mechanism. PCNT expression was studied in different tissues of C57/B6 mice by reverse transcriptase-PCR and immunofluorescence. PCNT was highly expressed in organs involved in the regulation of metabolism, while cytoplasmic expression was only enriched in islet cells. PCNT expression was significantly lower in the central regions of insulin resistance (IR) mouse islets than in those of control mouse islets. PCNT expression was further studied in mouse MIN6 cells exposed to glucose stimulation, small interfering RNA (siRNA) against PCNT, and an ERK inhibitor (PD98095). The results revealed that PCNT expression in glucose-stimulated MIN6 cells reduced linearly with cytoplasmic insulin levels. MIN6 cells transfected with PCNT siRNA showed significantly decreased intracellular insulin and F-actin expression. The change in F-actin expression in MIN6 cells during PCNT siRNA interference showed a linear relationship with PCNT expression at different time points. The ERK inhibitor affected PCNT expression and F-actin expression linearly. The abnormal insulin secretion observed both in vivo and in vitro was associated with decreased PCNT expression, and F-actin was found to be the target of PCNT regulation.

No MeSH data available.


Related in: MedlinePlus

Insulin secretion in IR mice and PCNT and insulin expression following glucose stimulation in MIN6 cells.(A) First-phase IPGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in first-phase were shown on histogram cart. First-phase glucose levels in the IR mouse group were higher than those in the control group, while the increase of insulin levels were significantly lower in the IR group (P < 0.05). GLU: glucose level; GLU-15: glucose level at 15 min in IPGTT; INS-15: insulin level at 15 min in IPGTT; ΔGLU-1: change of first-phase glucose level; ΔINS-1: change of first-phase insulin level. (B) Second-phase OGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in second-phase were shown on histogram cart. Second-phase glucose and insulin levels in the IR group were higher than those observed in the control group (P < 0.01). PBS: glucose level at 2 h in OGTT; PINS: insulin level at 2 h in OGTT; ΔGLU-2: change of second-phase glucose level; ΔINS-2: change of second-phase insulin level. (C) Confocal microscopy imaging and (D) histogram showing PCNT and intracellular insulin staining in glucose stimulating MIN6 cells. Results are from quintuplicate experiments with duplicate wells. (E) The fluorescence change of PCNT and insulin in glucose stimulating MIN6 cells had linear relationships. Each plot represents one experiment with duplicate wells.
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pone.0130458.g003: Insulin secretion in IR mice and PCNT and insulin expression following glucose stimulation in MIN6 cells.(A) First-phase IPGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in first-phase were shown on histogram cart. First-phase glucose levels in the IR mouse group were higher than those in the control group, while the increase of insulin levels were significantly lower in the IR group (P < 0.05). GLU: glucose level; GLU-15: glucose level at 15 min in IPGTT; INS-15: insulin level at 15 min in IPGTT; ΔGLU-1: change of first-phase glucose level; ΔINS-1: change of first-phase insulin level. (B) Second-phase OGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in second-phase were shown on histogram cart. Second-phase glucose and insulin levels in the IR group were higher than those observed in the control group (P < 0.01). PBS: glucose level at 2 h in OGTT; PINS: insulin level at 2 h in OGTT; ΔGLU-2: change of second-phase glucose level; ΔINS-2: change of second-phase insulin level. (C) Confocal microscopy imaging and (D) histogram showing PCNT and intracellular insulin staining in glucose stimulating MIN6 cells. Results are from quintuplicate experiments with duplicate wells. (E) The fluorescence change of PCNT and insulin in glucose stimulating MIN6 cells had linear relationships. Each plot represents one experiment with duplicate wells.

Mentions: Intraperitoneal glucose bolus administration is a standard beta cell stimulus of first-phase insulin secretion. OGTT is a standard way to test the glucose tolerance mainly reflecting the function of the second phase. Compared with control mice, insulin secretion in IR mice was relatively lower in the first phase (lower ΔINS-1, Fig 3A), while it was significantly elevated in the second phase (higher ΔINS-2, Fig 3B). To test the possible effect of PCNT on insulin release, corresponding in vitro experiments were designed using MIN6 cells. In MIN6 cells exposed to glucose stimulation, PCNT and insulin expression levels decreased significantly from the 5 mM group to the 25 mM and 35 mM groups. The 25 mM group seemed to have the lowest PCNT and INS levels of the 3 groups. There was no significant difference between the 25 mM and 35 mM groups (Fig 3C and 3D). Linear regression revealed that there was a linear relationship between the fluorescence changes of PCNT and insulin in MIN6 cells under glucose stimulation (Fig 3E). The RNA interference experiment showed that an obvious decrease in intracellular insulin levels was observed in MIN6 cells transfected with PCNT siRNA compared with MIN6 cells transfected with a scrambled siRNA (Fig 4A and 4B).


Pericentrin Is Related to Abnormal β-Cell Insulin Secretion through F-Actin Regulation in Mice.

Zu Y, Gong Y, Wan L, Lv Y, Cui S, Jin X, Li C, Chen X - PLoS ONE (2015)

Insulin secretion in IR mice and PCNT and insulin expression following glucose stimulation in MIN6 cells.(A) First-phase IPGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in first-phase were shown on histogram cart. First-phase glucose levels in the IR mouse group were higher than those in the control group, while the increase of insulin levels were significantly lower in the IR group (P < 0.05). GLU: glucose level; GLU-15: glucose level at 15 min in IPGTT; INS-15: insulin level at 15 min in IPGTT; ΔGLU-1: change of first-phase glucose level; ΔINS-1: change of first-phase insulin level. (B) Second-phase OGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in second-phase were shown on histogram cart. Second-phase glucose and insulin levels in the IR group were higher than those observed in the control group (P < 0.01). PBS: glucose level at 2 h in OGTT; PINS: insulin level at 2 h in OGTT; ΔGLU-2: change of second-phase glucose level; ΔINS-2: change of second-phase insulin level. (C) Confocal microscopy imaging and (D) histogram showing PCNT and intracellular insulin staining in glucose stimulating MIN6 cells. Results are from quintuplicate experiments with duplicate wells. (E) The fluorescence change of PCNT and insulin in glucose stimulating MIN6 cells had linear relationships. Each plot represents one experiment with duplicate wells.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4470688&req=5

pone.0130458.g003: Insulin secretion in IR mice and PCNT and insulin expression following glucose stimulation in MIN6 cells.(A) First-phase IPGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in first-phase were shown on histogram cart. First-phase glucose levels in the IR mouse group were higher than those in the control group, while the increase of insulin levels were significantly lower in the IR group (P < 0.05). GLU: glucose level; GLU-15: glucose level at 15 min in IPGTT; INS-15: insulin level at 15 min in IPGTT; ΔGLU-1: change of first-phase glucose level; ΔINS-1: change of first-phase insulin level. (B) Second-phase OGTT values in IR and control mouse groups. Dynamic change of glucose level at different time points was shown on line chart; final glucose level, final insulin level, the changes of glucose and insulin level in second-phase were shown on histogram cart. Second-phase glucose and insulin levels in the IR group were higher than those observed in the control group (P < 0.01). PBS: glucose level at 2 h in OGTT; PINS: insulin level at 2 h in OGTT; ΔGLU-2: change of second-phase glucose level; ΔINS-2: change of second-phase insulin level. (C) Confocal microscopy imaging and (D) histogram showing PCNT and intracellular insulin staining in glucose stimulating MIN6 cells. Results are from quintuplicate experiments with duplicate wells. (E) The fluorescence change of PCNT and insulin in glucose stimulating MIN6 cells had linear relationships. Each plot represents one experiment with duplicate wells.
Mentions: Intraperitoneal glucose bolus administration is a standard beta cell stimulus of first-phase insulin secretion. OGTT is a standard way to test the glucose tolerance mainly reflecting the function of the second phase. Compared with control mice, insulin secretion in IR mice was relatively lower in the first phase (lower ΔINS-1, Fig 3A), while it was significantly elevated in the second phase (higher ΔINS-2, Fig 3B). To test the possible effect of PCNT on insulin release, corresponding in vitro experiments were designed using MIN6 cells. In MIN6 cells exposed to glucose stimulation, PCNT and insulin expression levels decreased significantly from the 5 mM group to the 25 mM and 35 mM groups. The 25 mM group seemed to have the lowest PCNT and INS levels of the 3 groups. There was no significant difference between the 25 mM and 35 mM groups (Fig 3C and 3D). Linear regression revealed that there was a linear relationship between the fluorescence changes of PCNT and insulin in MIN6 cells under glucose stimulation (Fig 3E). The RNA interference experiment showed that an obvious decrease in intracellular insulin levels was observed in MIN6 cells transfected with PCNT siRNA compared with MIN6 cells transfected with a scrambled siRNA (Fig 4A and 4B).

Bottom Line: The results revealed that PCNT expression in glucose-stimulated MIN6 cells reduced linearly with cytoplasmic insulin levels.The ERK inhibitor affected PCNT expression and F-actin expression linearly.The abnormal insulin secretion observed both in vivo and in vitro was associated with decreased PCNT expression, and F-actin was found to be the target of PCNT regulation.

View Article: PubMed Central - PubMed

Affiliation: Department of Geriatric Endocrinology, Chinese People's Liberation Army General Hospital, Beijing, 100853, China.

ABSTRACT
The aim of this study was to investigate the regulating effect of pericentrin (PCNT) on insulin secretion in the development of insulin resistance and to determine the underlying mechanism. PCNT expression was studied in different tissues of C57/B6 mice by reverse transcriptase-PCR and immunofluorescence. PCNT was highly expressed in organs involved in the regulation of metabolism, while cytoplasmic expression was only enriched in islet cells. PCNT expression was significantly lower in the central regions of insulin resistance (IR) mouse islets than in those of control mouse islets. PCNT expression was further studied in mouse MIN6 cells exposed to glucose stimulation, small interfering RNA (siRNA) against PCNT, and an ERK inhibitor (PD98095). The results revealed that PCNT expression in glucose-stimulated MIN6 cells reduced linearly with cytoplasmic insulin levels. MIN6 cells transfected with PCNT siRNA showed significantly decreased intracellular insulin and F-actin expression. The change in F-actin expression in MIN6 cells during PCNT siRNA interference showed a linear relationship with PCNT expression at different time points. The ERK inhibitor affected PCNT expression and F-actin expression linearly. The abnormal insulin secretion observed both in vivo and in vitro was associated with decreased PCNT expression, and F-actin was found to be the target of PCNT regulation.

No MeSH data available.


Related in: MedlinePlus