Comparative identification of Ca²⁺channel expression in INS-1 and rat pancreatic β cells

Abstract

AIM:To identify and compare the profile of Ca 2+ channel subunit expression in INS-1 and rat pancreatic β cells. METHODS:The rat insulin-secreting INS-1 cell line was cultured in RPMI-1640 with Wistar rats employed as islet donors. Ca 2+ channel subunit expression in INS-1 and isolated rat β cells were examined by reverse transcription polymerase chain reaction (RT-PCR). Absolute real-time quantitative PCR was performed in a Bio-Rad iQ5 Gradient Real Time PCR system and the data analyzed using an iQ5 system to identify the expression level of the Ca 2+ channel subunits. RESULTS:In INS-1 cells, the L-type Ca 2+ channel 1C subunit had the highest expression level and the TPRM2 subunit had the second highest expression. In rat β cells, the TPRC4β subunit expression was dominant and the expression of the L-type 1C subunit exceeded the 1D subunit expression about two-fold. This result agreed with other studies, confirming the important role of the L-type 1C subunit in insulinsecreting cells, and suggested that non-voltageoperated Ca 2+ channels may have an important role in biphasic insulin secretion. CONCLUSION: Twelve major Ca2+ channel subunit types were identified in INS-1 and rat β cells and significant differences were observed in the expression of certain subunits between these cells.

TRP Channels of Islets

“…the effect of neutralization of the antibody by the corresponding antigen is not included in the protocol used by the Human Proteome Research program. Nevertheless, TRPC1 mRNA has been demonstrated in mouse islets, MIN6 cells, rat β-cells and INS-1 cells [5,7]. The level of expression of TRPC1 in rat primary β-cells is higher than that in the rat insulinoma INS-1 cells [7].…”

“…Nevertheless, TRPC1 mRNA has been demonstrated in mouse islets, MIN6 cells, rat β-cells and INS-1 cells [5,7]. The level of expression of TRPC1 in rat primary β-cells is higher than that in the rat insulinoma INS-1 cells [7]. In MIN6 cells, four splice variants of TRPC1 have been identified.…”

“…Thus, TRPC1 is highly expressed in MIN6 cell and TRPC4 is highly expressed in β-TC3 cells [5,6]. TRPC4 is also expressed at high level in INS-1 cells and rat β-cells [7]. TRPC4 has at least two major splice variants: the full length TRPC4α and a shorter TRPC4β which lacks 84 amino acids in the C-terminus.…”

Ca2+-induced Ca2+Release from Internal Stores in INS-1 Rat Insulinoma Cells

“…In fact, the presence of RyRs in insulin secreting β-cells is well-accepted at the present time, although the expression of each type of RyRs is variable, depending on the species studied. The mRNAs for the three types of RyRs have been detected in human β-cells, whereas mRNA for RyR2 but not RyR1 was detected in INS-1 cells and rat islets using RT-PCR methods [18][19][20]. Since there is still no clear consensus on the role of RyR in stimulus-secretion coupling in β-cells, we determined, using in-sulin secreting rat pancreatic β-cells (INS-1 …”

Potentiation of Sulfonylurea Action by an EPAC-selective cAMP Analog in INS-1 Cells: Comparison of Tolbutamide and Gliclazide and a Potential Role for EPAC Activation of a 2-APB-sensitive Ca2+ Influx

“…TRPC channel subtypes are attractive candidates for this activity because they are blocked by 2-APB (Birnbaumer, 2009) and many are positively regulated by PLC activity (Beech, 2012). Interestingly, TRPC1 and TRPC4 are expressed in INS-1 cells and rat b-cells (Li and Zhang, 2009), and TRPC4 is expressed in bTC3 cells (Qian et al, 2002).…”