The property of ion current in human amniotic mesenchymal stem cell (hAMSC)

The study is to determine the distribution of ion channel and property of ion current in human amniotic mesenchymal stem cell (hAMSC). The amniotic membrane was gathered from the healthy and mature newborn after delivery. The hAMSCs were isolated and cultured in DMEM with 10% FBS for 2 weeks. The mRNA of hAMSC was collected after 2 week, and the Reverse transcriptase-polymerase chain reaction (RT-PCR) were then performed to detect the mRNA expression of ion channel. The ion current of hAMSC were recorded under the whole cell mode with patch clamp. Most of the hAMSCs (76/82) cells showed outward current during the patch clamp test. The membranes potential of the hAMSC is - 3.89±7.14mV(−25∼13.9mV), the membranes capacity offset is 300.06±189.81(0∼780pF). There were 3 types of outward current presented in the hAMSC, including the delayed rectifier potassium current (IkDR.), Calcium-activated-potassium current (IkCa) and transient outward current (Ito). The current of IkDR can present in most hAMSCs(93.4%), and half of the cells show a slow activating delayed rectifier K current (Iks). The noisy oscillation like IkCa current was observed in 35.5% hAMSCs, and Ito present in 14.5% hAMSCs. The inward currents such as sodium currents, calcium currents, inward rectifier K current (Ik1) and funny current(If) were absent in our study. The expression of mRNA of certain ion channel subunit of MaxIK(for IkCa), Kir2.1, Kv1.4(for Ito), HminK(for IkDR.).can be detected. This is the first study of the electrophysiology property in hAMSCs. The hAMSC can express a distinct pattern of ion channel mRNA and functional ion channels.The ion current of IkDR, IkCa and Ito can present in the hAMSCs.