Related Experiment Video
Updated: Jul 27, 2026
08:53
Assay to Measure Nucleocytoplasmic Transport in Real Time within Motor Neuron-like NSC-34 Cells
Published on: May 16, 2017
Elevated lysosomal pH in neuronal ceroid lipofuscinoses (NCLs)
J M Holopainen1, J Saarikoski, P K Kinnunen
1Helsinki Biomembrane & Biophysics Group, Institute of Biomedicine, Biomedicum Helsinki, Finland. jmholopa@rock.helsinki.fi
European Journal of Biochemistry
|November 28, 2001
Summary
Intracellular pH is normal in neuronal ceroid lipofuscinoses (NCLs), but lysosomal pH is elevated in most forms. This pH imbalance likely contributes to the characteristic pigment accumulation in these lysosomal storage diseases.
Area of Science:
- Biochemistry
- Cell Biology
- Genetics
Background:
- Neuronal ceroid lipofuscinoses (NCLs) are a group of inherited lysosomal storage diseases.
- NCLs are characterized by the accumulation of autofluorescent lipopigments in lysosomes.
- The precise mechanisms leading to pigment accumulation are not fully understood.
Purpose of the Study:
- To investigate intracellular (pHi) and lysosomal pH in fibroblasts from six forms of NCLs.
- To determine if altered pH contributes to the pathogenesis of NCLs.
- To introduce a novel method for measuring intralysosomal pH.
Main Methods:
- Measurement of intracellular pH using the dye BCECF.
- Spectrofluorometric assay of lysosomal pH with Lysosensor yellow/blue probe.
- Analysis of fibroblasts from six distinct NCL forms.
Main Results:
- Intracellular pH was found to be normal across all investigated NCL forms.
- Elevated lysosomal pH was observed in all NCL forms except CLN2 and CLN8.
- A novel, fast, and repeatable spectrofluorometric assay for intralysosomal pH was established.
Conclusions:
- Elevated lysosomal pH is a common feature in NCLs, excluding CLN2 and CLN8.
- Altered lysosomal pH may disrupt lysosomal enzyme activity, contributing to ceroid and lipopigment accumulation.
- The developed assay offers an efficient method for assessing intralysosomal pH in cell suspensions for NCL research.
Related Concept Videos
01:37Neural Regulation
Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food.
01:31Lysosomes
Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules and biological polymers that are released during membrane trafficking events such as the secretory, endocytic, autophagic, and phagocytic pathways. The degradation is carried out by several hydrolytic enzymes active in an acidic environment of the lysosomal lumen. These acid hydrolases are involved in cellular processes such as cell signaling,...
01:36Delivery Pathways to the Lysosome
Eukaryotic cells use different mechanisms to eliminate toxic waste obsolete and worn-out substances. Lysosomes play a pivotal role in this, and hence, these substances are carried to the lysosome from other parts of the cell and extracellular space through different pathways. The most elaborately studied pathways to the lysosome are the endocytic pathways.
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
01:22Lysosomal Hydrolases
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...