The ability of a single Ca 2+ ion to play an important role in cell biology is highlighted by the need for cells to form Ca 2+ signals in the dimensions of space, time, and amplitude. Thus, spatial and temporal changes in intracellular Ca 2+ concentration are important for determining cell fate. Optogenetic technology has been developed to provide more precise and targeted stimulation of cells. Here, U2OS cells overexpressing Ca 2+ translocating channelrhodopsin (CatCh) were used to mediate Ca 2+ influx through blue light illumination with various parameters, such as intensity, frequency, duty cycle, and duration. We identified that several Ca 2+-dependent transcription factors and certain kinases can be activated by specific Ca 2+ waves. Using a wound-healing assay, we found that low-frequency Ca 2+ oscillations increased cell migration through the activation of NF-κB. This study explores the regulation of cell migration by Ca 2+ signals. Thus, we can choose optical parameters to modulate Ca 2+ waves and achieve activation of specific signaling pathways. This novel methodology can be applied to clarify related cell-signaling mechanisms in the future.

Platelet-derived growth factor (PDGF) has mitogenic and chemotactic effects on fibroblasts. An increase in intracellular Ca2+ is one of the first events that occurs following the stimulation of PDGF receptors (PDGFRs). PDGF activates Ca2+ elevation by activating the phospholipase C gamma (PLCγ)-signaling pathway, resulting in ER Ca2+ release. Store-operated Ca2+ entry (SOCE) is the major form of extracellular Ca2+ influx following depletion of ER Ca2+ stores and stromal interaction molecule 1 (STIM1) is a key molecule in the regulation of SOCE. In this study, wild-type and STIM1 knockout mouse embryonic fibroblasts (MEF) cells were used to investigate the role of STIM1 in PDGF-induced Ca2+ oscillation and its functions in MEF cells. The unexpected findings suggest that STIM1 knockout enhances PDGFR–PLCγ–STIM2 signaling, which in turn increases PDGF-BB-induced Ca2+ elevation. Enhanced expressions of PDGFRs and PLCγ in STIM1 knockout cells induce Ca2+ release from the ER store through PLCγ–IP3 signaling. Moreover, STIM2 replaces STIM1 to act as the major ER Ca2+ sensor in activating SOCE. However, activation of PDGFRs also activate Akt, ERK, and JNK to regulate cellular functions, such as cell migration. These results suggest that alternative switchable pathways can be observed in cells, which act downstream of the growth factors that regulate Ca2+ signaling.

GRO-α from OSF-associated fibroblasts paracrinally promotes oral malignant transformation and significantly contributes to OSCC development.

Acupuncture is a key component of Traditional Chinese Medicine in which needles are inserted into specific areas in the body to stimulate certain physiological reactions of the body. Clinical research shows that acupuncture is beneficial in treating a variety of illnesses, such as erectile dysfunction. Therefore, we investigated the effect of electroacupuncture (EA) stimulation of both low- and high frequencies at Guanyuan (CV4) and Zhongji (CV3) acupoints on male copulatory behavior in sexually experienced male rats. The animals were randomly divided into four groups: control, sham EA, EA, and only acupuncture. The administered low and high EA were 2 Hz and 80 Hz, respectively, for which the respective intensities were 1.5 mA (30 min/day for 5 days) and 1.5 mA (30 min once). The only acupuncture-administered group received acupunctures at CV4 and CV3 without electrical stimulation. Following the acupuncture treatments, copulatory behavior test was conducted. Eventually, animals were sacrificed and blood samples were collected for testing the serum hormonal profile including luteinizing hormone (LH), testosterone (T), and serotonin (5-HT). Results showed that low-frequency EA-treated rats exhibited increasing intromissions and ejaculation latency compared to control, sham EA, and acupuncture groups, while high-frequency EA-treated rats displayed lower intromissions and ejaculation frequency when compared with those in controls. Furthermore, serum levels of 5-HT and LH in low-frequency EA-treated rats were higher than all the other groups. These results indicate that compared to high-frequency EA, the low-frequency EA might be efficacious in the treatment of premature ejaculation, thereby improving sexual behavior.