Ionomycin inhibits Jurkat T cell behaviors in the presence of phorbol-12,13-dibutyrate

Improvement of the rituximab-induced cell death by potentiation of the store-operated calcium entry in mantle cell lymphoma cell lines

Mantle Cell Lymphoma (MCL) is one of the worst lymphomas with a median overall survival of 3 to 4 years. Even if the use of rituximab was a great step in therapy, patients commonly develop resistance and relapse. New therapies or complement of existing therapies should be developed. Using spectrofluorimetry, we found that the resting cytosolic Ca²⁺ ion concentration [Ca²⁺]_cyt of MCL patients cells and MCL cell lines was increased. This increase is correlated with a larger store-operated calcium entry (SOCE) amplitude which is responsible for the Ca²⁺ ions influx. Furthermore, using a SOCE potentiating agent, we demonstrated that in the MCL Rec-1 cell line, the SOCE is already activated in resting conditions. Interestingly, this potentiating agent alone, by disturbing the SOCE, induced the apoptosis of Rec-1 cells with the same efficacy than rituximab. The use of the potentiating agent in addition to rituximab strengthens the rituximab-induced apoptosis of rituximab-sensitive Granta-519 and Rec-1 cells. However, this potentiating agent cannot convert the Jeko-1 rituximab-resistant to a rituximab-sensitive cell line. Our results confirm that the use of compound acting on the Ca²⁺ homeostasis could be a new target of interest in complement to existing therapies.

Microarray-based data mining reveals key genes and potential therapeutic drugs for Cadmium-induced prostate cell malignant transformation

Increasing evidence showed that Cadmium (Cd) can accumulate in the body and damage cells, resulting in cancerigenesis of the prostate with complex mechanisms. In the present study, we aimed to explore the possible key genes, pathways and therapeutic drugs using bioinformatics methods. Microarray-based data were retrieved and analyzed to screen differentially expressed genes (DEGs) between Cd-treated prostate cells and controls. Then, functions of the DEGs were annotated and hub genes were screened. Next, key genes were selected from the hub genes via validation in a prostate cancer cohort from The Cancer Genome Atlas (TCGA). Afterward, potential drugs were further predicted. Consequently, a gene expression profile, GSE9951, was retrieved. Then, 361 up-regulated and 30 down-regulated DEGs were screened out, which were enriched in various pathways. Among the DEGs, seven hub genes (HSPA5, HSP90AB1, RHOA, HSPD1, MAD2L1, SKP2, and CCT2) were dysregulated in prostate cancer compared to normal controls, and two of them (HSPD1 and CCT2) might influence the prostate cancer prognosis. Lastly, ionomycin was predicted to be a potential agent reversing Cd-induced prostate cell malignant transformation. In summary, the present study provided novel evidence regarding the mechanisms of Cd-induced prostate cell malignant transformation, and identified ionomycin as a potential small molecule against Cd toxicity.

Panax quinquefolium saponin attenuates cardiac remodeling induced by simulated microgravity

BACKGROUND

Cardiac atrophy and reduced cardiac distensibility have been reported following space flight. Cardiac function is correspondingly regulated in response to changes in loading conditions. Panax quinquefolium saponin (PQS) improves ventricular remodeling after acute myocardial infarction by alleviating endoplasmic reticulum stress and Ca²⁺overload. However, whether PQS can ameliorate cardiac atrophy following exposure to simulated microgravity remains unknown.

PURPOSE

To explore the protective role of PQS in cardiac remodeling under unloading conditions and its underlying mechanisms.

METHODS

Hindlimb unloading (HU) model was used to simulate unloading induced cardiac remodeling. Forty-eight male rats were randomly assigned to four groups, including control, PQS, HU and HU + PQS. At 8 weeks after the experiment, cardiac structure and function, serum levels of Creatine Kinase-MB (CK-MB), Cardiactroponin T (cTnT), ischemia modified albumin (IMA), and cardiomyocyte apoptosis were measured. Network pharmacology analysis was used to predict the targets of the six major constituents of PQS, and the signaling pathways they involved in were analyzed by bioinformatics methods. Changes in the key proteins involved in the protective effects of PQS were further confirmed by Western Blot.

RESULTS

Simulated microgravity led to increases in serum levels of CK-MB, cTnT and IMA, remodeling of cardiac structure, impairment of cardiac function, and increased cardiomyocyte apoptosis as compared with control. PQS treatment significantly reduced serum levels of CK-MB, cTnT and IMA, improved the impaired cardiac structure and function, and decreased cardiomyocyte apoptosis induced by unloading. The activation of AMPK and inhibition of Erk1/2 and CaMKII/HDAC4 were demonstrated in the cardiocytes of HU rats after PQS treatment.

CONCLUSION

PQS provides protection against cardiac remodeling induced by simulated microgravity, partly resulting from changes in the signaling pathways related to energy metabolism reduction, calcium overloading and cell apoptosis.