Intracellular Calcium Handling in Cystic Fibrosis: Normal Cytosolic Calcium and Intracellular Calcium Stores in Neutrophils

1. Alterations in intracellular calcium have been implicated in the pathogenesis of essential hypertension. To see whether this is a generalized phenomenon we assessed cytosolic free calcium and intracellular calcium stores in neutrophils from normo- and hyper-tensive subjects, by trapping the fluorescent calcium indicator quin2 in intact cells. 2. Ten patients with untreated essential hypertension were compared with 10 age- and sex-matched normotensive subjects. The levels of cytosolic free calcium and intracellular calcium stores releasable by the calcium ionophore ionomycin did not differ. No significant relationship was found between blood pressure and the calcium parameters in all 20 subjects studied. 3. The results indicate that essential hypertension is not associated with a membrane defect in calcium handling of all human cell systems, leading to generalized increases in resting values of cytosolic free calcium. 4. Neutrophils do not appear to be a good model for intracellular calcium handling in vascular smooth muscle.

Download Full-text

Peroxisomes contribute to intracellular calcium dynamics

10.1101/2020.09.02.279174 ◽

2020 ◽

Author(s):

Yelena Sargsyan ◽

Uta Bickmeyer ◽

Katrin Streckfuss-Bömeke ◽

Ivan Bogeski ◽

Sven Thoms

Keyword(s):

Intracellular Calcium ◽

Hela Cells ◽

Calcium Influx ◽

Induced Pluripotent Stem Cell ◽

Cytosolic Calcium ◽

Neonatal Rat ◽

Calcium Handling ◽

Calcium Stores ◽

Calcium Dynamics ◽

Rat Cardiomyocytes

AbstractPeroxisomes communicate with other cellular compartments by transfer of various metabolites. However, whether peroxisomes are sites for calcium handling and exchange has remained contentious. Here we generated sensors for assessment of peroxisomal calcium and applied them for single cell-based calcium imaging in HeLa cells and cardiomyocytes. We found that peroxisomes in HeLa cells take up calcium upon depletion of intracellular calcium stores and upon calcium influx across the plasma membrane. Further, we show that peroxisomes of neonatal rat cardiomyocytes and human induced pluripotent stem cell-derived cardiomyocytes can take up calcium in a controlled manner. Our results indicate that peroxisomal and cytosolic calcium signals are tightly interconnected. Hence, peroxisomes may play an important role in shaping cellular calcium dynamics by serving as buffers or sources of intracellular calcium.

Download Full-text

The FPR2-induced rise in cytosolic calcium in human neutrophils relies on an emptying of intracellular calcium stores and is inhibited by a gelsolin-derived PIP2-binding peptide

BMC Cell Biology ◽

10.1186/1471-2121-11-52 ◽

2010 ◽

Vol 11 (1) ◽

Cited By ~ 13

Author(s):

Huamei Forsman ◽

Claes Dahlgren

Keyword(s):

Intracellular Calcium ◽

Cytosolic Calcium ◽

Human Neutrophils ◽

Calcium Stores ◽

Binding Peptide ◽

Intracellular Calcium Stores

Download Full-text

Contribution of intracellular calcium stores to an increase in cytosolic calcium concentration induced byMannheimia haemolyticaleukotoxin

FEMS Microbiology Letters ◽

10.1016/s0378-1097(03)00471-3 ◽

2003 ◽

Vol 225 (1) ◽

pp. 23-27 ◽

Cited By ~ 8

Author(s):

Laura Cudd ◽

Cyril Clarke ◽

Kenneth Clinkenbeard

Keyword(s):

Intracellular Calcium ◽

Calcium Concentration ◽

Cytosolic Calcium ◽

Calcium Stores ◽

Cytosolic Calcium Concentration ◽

Intracellular Calcium Stores

Download Full-text

Peroxisomes contribute to intracellular calcium dynamics in cardiomyocytes and non-excitable cells

Life Science Alliance ◽

10.26508/lsa.202000987 ◽

2021 ◽

Vol 4 (9) ◽

pp. e202000987

Author(s):

Yelena Sargsyan ◽

Uta Bickmeyer ◽

Christine S Gibhardt ◽

Katrin Streckfuss-Bömeke ◽

Ivan Bogeski ◽

...

Keyword(s):

Intracellular Calcium ◽

Hela Cells ◽

Calcium Influx ◽

Induced Pluripotent Stem Cell ◽

Cytosolic Calcium ◽

Neonatal Rat ◽

Calcium Handling ◽

Calcium Stores ◽

Calcium Dynamics ◽

Rat Cardiomyocytes

Peroxisomes communicate with other cellular compartments by transfer of various metabolites. However, whether peroxisomes are sites for calcium handling and exchange has remained contentious. Here we generated sensors for assessment of peroxisomal calcium and applied them for single cell-based calcium imaging in HeLa cells and cardiomyocytes. We found that peroxisomes in HeLa cells take up calcium upon depletion of intracellular calcium stores and upon calcium influx across the plasma membrane. Furthermore, we show that peroxisomes of neonatal rat cardiomyocytes and human induced pluripotent stem cell–derived cardiomyocytes can take up calcium. Our results indicate that peroxisomal and cytosolic calcium signals are tightly interconnected both in HeLa cells and in cardiomyocytes. Cardiac peroxisomes take up calcium on beat-to-beat basis. Hence, peroxisomes may play an important role in shaping cellular calcium dynamics of cardiomyocytes.

Download Full-text