Membrane-bound organelles and membraneless organelles (MLOs) coordinate various biological processes within eukaryotic cells. Among these, stress granules (SGs) are significant cytoplasmic MLOs that form in response to cellular stress, exhibiting liquid-like properties alongside stable substructures. SGs interact with diverse organelles, thereby influencing cellular pathways that are critical in both health and disease contexts. This review discusses the interplay between SGs and organelles and explores the methodologies employed to analyze interactions between SGs and other MLOs. Furthermore, it highlights the pivotal roles SGs play in regulating cellular responses and the pathogenesis of amyotrophic lateral sclerosis. Gaining insights into these interactions is essential for deciphering the mechanisms underlying both physiological processes and pathological conditions.
Humans ; Stress Granules/pathology* ; Organelles/metabolism* ; Amyotrophic Lateral Sclerosis/pathology* ; Animals ; Stress, Physiological ; Cytoplasmic Granules/metabolism*

Aged ; Cytoplasm ; Cytoplasmic Granules ; Female ; Humans ; Multiple Myeloma ; pathology ; Plasma Cells ; pathology

Although bulk endocytosis has been found in a number of neuronal and endocrine cells, the molecular mechanism and physiological function of bulk endocytosis remain elusive. In pancreatic beta cells, we have observed bulk-like endocytosis evoked both by flash photolysis and trains of depolarization. Bulk-like endocytosis is a clathrin-independent process that is facilitated by enhanced extracellular Ca(2+) entry and suppressed by the inhibition of dynamin function. Moreover, defects in bulk-like endocytosis are accompanied by hyperinsulinemia in primary beta cells dissociated from diabetic KKAy mice, which suggests that bulk-like endocytosis plays an important role in maintaining the exo-endocytosis balance and beta cell secretory capability.
Animals ; Calcium ; metabolism ; Cytoplasmic Granules ; metabolism ; Diabetes Mellitus ; metabolism ; pathology ; Disease Models, Animal ; Dynamins ; metabolism ; Electric Capacitance ; Endocytosis ; physiology ; Insulin ; metabolism ; Insulin-Secreting Cells ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Patch-Clamp Techniques ; Photolysis ; Primary Cell Culture

OBJECTIVETo study the pathological and clinical characteristics of a patient with spontaneous platelet aggregation of his giant and morphologically abnormal platelets.

METHODSPlatelet size and structure were observed under light microscope and electron microscope. Platelet aggregation was measured turbidometrically. Platelet glycoproteins (GP) were analyzed using flow cytometry. PCR and DNA sequencing were performed to identify the gene abnormality.

RESULTSThe patient had spontaneous platelet aggregation of giant platelets with thickened plasma membrane and increased number of granules in various shapes. Aspirin and ticlopidine did not affect the spontaneous aggregation. The expression of GP I b, GP II b, GP III a and P-selectin in the platelet membrane were in normal range. Results of gene analyses for GP I balpha, GP I bbeta and GPIX were also normal.

CONCLUSIONBoth morphological and functional abnormalities of the platelets from the patient were clearly distinguishable from that of other hereditary giant platelet disorders. It would probably represent a novel platelet disorder which had not been reported to date.

Aspirin ; pharmacology ; Bernard-Soulier Syndrome ; metabolism ; pathology ; Blood Platelet Disorders ; metabolism ; pathology ; Cell Size ; physiology ; Child ; Cytoplasmic Granules ; pathology ; ultrastructure ; Female ; Humans ; Platelet Aggregation ; drug effects ; physiology ; Platelet Aggregation Inhibitors ; pharmacology ; Platelet Membrane Glycoproteins ; genetics ; metabolism ; Ticlopidine ; pharmacology

To investigate ultrastructural characteristics of mast cells in urticaria pigmentosa in comparison to mast cells in other conditions and to search for the possible differences of ultrastuctural features amog different types of urticaria pigmentosa as well as those from normal mast cells, 4 cases of urticaria pigmentosa and 1 case of mastocytosis associated with capillary hemangioma were studied by both light and electron microscopic examinations. The cases of urticaria pigmentosa consisted of one case of blister type from a 3 month old ma1e infant, 2 cases of maculo-papular type both from 10 month old male infants, and a case of nodular type from a 14 month old boy. Ultrastructural features of mast cells in urticaria pigmentosa, in general; a) appeared relatively immature; b) mast cells in nodular type of urticaria pigmentosa were mostly round shaped while other types showed spindle or oblong shapes; c) mast cells in the maculo-papular type and those in hemangioma were similar and resembled normal mast cells; and d) marked degranulation of mast cells in the form of expulsion of granules, perigranular vacuole formation and intracellular disolution of granules for the blister type of urticaria pigmentosa.
Adolescent ; Cytoplasmic Granules/ultrastructure ; Human ; Male ; Mast Cells/ultrastructure ; Microscopy, Electron ; Urticaria Pigmentosa/pathology*

Mast cell changes, numbers and degranulations, of 264 cases of skin biopsy lesions were studied. An increase of mast cells was noted in congenital diseases; noninfectious erythematous, papullar, and squamous diseases; vascular diseases; bacterial diseases; fungal diseases; lipidoses; metabolic diseases; connective tissue diseases; tumors and cysts of the epidermis; tumors of epidermal appendages; tumors of fibrous tissue; tumors of vascular tissue; and benign tumors of melanocytes. The increase was noted mainly in the surrounding areas of the lesions rather than within the lesions. In only a few conditions; vascular diseases, connective tissue diseases, and tumors of vascular tissue, an increase of mast cells within the lesion was noted. With regard to the relation between mast cell changes and gross appearance of skin lesions, an increase of mast cells was observed in the surrounding areas of scally, vesicular, nodular or warty, and ulcerated lesions. Relationship between the degree of degranulation to the types of skin disease or gross appearance can not be clearly established. In all conditions, the increase of mast cells was intimately associated with formation of new fibrous connective tissue.
Cytoplasmic Granules/pathology ; Human ; Mast Cells/pathology* ; Skin Diseases/pathology*

The authors have demonstrated the effect of sodium selenite on the hepatotoxicity due to carbon tetrachloride, by observing the distribution and disaggregation of the pyroninophilic granules in the hepatic cell of the mature male albino mice. Each experimental mouse of the selenite and the selenite plus carbon tetrachloride groups was given a single dose of 4 ug. of sodium selenite per kilogram of body weight and that of the control and the carbon tetrachloride groups was given 0.1 ml. of distilled water alone. Six hours after the first administration of distilled water or sodium selenite, the experimental mice of the carbon tetrachloride and the selenite plus carbon tetrachloride groups were given a single dose of l.0 ml. of carbon tetrachloride per kilogram of body weight and those of the selenite groups were given 0.l ml. of paraffin oil alone. Following the 1ast administration of carbon tetrachloride or paraffin oil, the mice were sacrificed by bleeding (cutting the common carotid artery) at the intervals of 2,3,4,6,8, and 12 hours respectively. Histochemical preparations were stained by the methyl-green and pyronin method and oil red 0 method. The hepatotoxicity due to the administration of carbon tetrachoride was evident in the hepatic cells; the pyroninophilic granlues were partly reduced in volume in the hepatic cells of the centrilobular and the intermediate zones as early as the 3 hour-period, and markedly reduced or disappeared in the centrilobular and some part of the intermediate zones associated with hydropic degeneration as well as in the 6 hour-period. Thereafter marked reduction or dissolution of the pyroninophilic granules was found and extended as the periportal zone at the 12 hour-period. However, the pyroninophilic granules in the hepatic cells of selenite plus carbon tetrachbride group showed no significant changes in the hepatic cells of these zones, compared to the histochemical feature of the granules in the hepatic cells of the control and the selenite groups. Consequently it is suggested that the lipid peroxidative decomposition of the microsomal membranes, which is induced with carbon tetrachloride, would be prevented by a previous administration of sodium selenite.
Animal ; Carbon Tetrachloride Poisoning*/pathology ; Cell Nucleus/drug effects ; Cytoplasm/drug effects ; Cytoplasmic Granules ; Lipids ; Liver/drug effects* ; Liver/pathology ; Male ; Mice ; Selenium/pharmacology* ; Vacuoles/drug effects