Investigation of Ultrasound-Mediated Intracellular Ca2+ Oscillations in HIT-T15 Pancreatic β-Cell Line

Abstract

In glucose-stimulated insulin secretion (GSIS) of pancreatic β-cells, the rise of free cytosolic Ca2+ concentration through voltage-gated calcium channels (VGCCs) triggers the exocytosis of insulin-containing granules. Recently, mechanically induced insulin secretion pathways were also reported, which utilize free cytosolic Ca2+ ions as a direct regulator of exocytosis. In this study, we aimed to investigate intracellular Ca2+ responses on the HIT-T15 pancreatic β-cell line upon low-intensity pulsed ultrasound (LIPUS) stimulation and found that ultrasound induces two distinct types of intracellular Ca2+ oscillation, fast-irregular and slow-periodic, from otherwise resting cells. Both Ca2+ patterns depend on the purinergic signaling activated by the rise of extracellular ATP or ADP concentration upon ultrasound stimulation, which facilitates the release through mechanosensitive hemichannels on the plasma membrane. Further study demonstrated that two subtypes of purinergic receptors, P2X and P2Y, are working in a competitive manner depending on the level of glucose in the cell media. The findings can serve as an essential groundwork providing an underlying mechanism for the development of a new therapeutic approach for diabetic conditions with further validation.

Synergistic Effect of Growth Factor Releasing Polymeric Nanoparticles and Ultrasound Stimulation on Osteogenic Differentiation

“…As can be seen in Figure 1 , low-intensity pulsed ultrasound (LIPUS) was manufactured in a 24-well plate according to a previously reported protocol [ 33 , 34 ]. The distance between the transducer and the plate was 16 mm and was filled with distilled water in order to deliver good ultrasound ( Figure 1 A,B).…”

Electromagnetic fields regulate calcium-mediated cell fate of stem cells: osteogenesis, chondrogenesis and apoptosis

“…After receiving biomechanical stimulation, cells can alter intracellular calcium concentration through a variety of membrane-dependent pathways: (1) Activation of L-type or T-Type voltage-gated ion channels by increasing channel activity and protein expression levels [ 43 , 44 ]. (2) Activation of the purinergic receptor family on the cell membrane is activated, where mechanical signaling receptors on the cell membrane are activated, causing the ATP or ADP increases, and the purinergic signal can upregulate the expression of P2Y1 receptors [ 45 , 46 ]. (3) Activation of the TRP family of cation channels, TRPV4, which exhibits moderate permeability to calcium ion, is activated to alter the permeability of the cell membrane and promote the inward flow of calcium ion [ 47 , 48 ].…”

The application of mechanobiotechnology for immuno-engineering and cancer immunotherapy

“… Parvizi et al (2002) reported that both transient and sustained intracellular calcium elevations can be observed in primary rat chondrocytes upon LIPUS exposure. Since then, ultrasound-induced calcium responses were monitored in different types of cells ( Tyler et al, 2008 ; Hwang et al, 2014 ; Weitz et al, 2017 ; Yoon et al, 2020 ), and found to be directly linked with the activation of various mechanosensitive proteins ( Ibsen et al, 2015 ; Yoon et al, 2017 ; Qiu et al, 2019 ; Yoo et al, 2022 ). Based on the observation that intracellular calcium dynamics can be regulated by ultrasound, a modular method has been developed to engineer immune cells with synthetic genetic circuits that can sense and transduce ultrasound stimulation.…”