Osmiophilic Lipid Droplets Research Articles

Effect of the transgenerational exposure to elevated CO2 on low temperature tolerance of winter wheat: Chloroplast ultrastructure and carbohydrate metabolism

AbstractThe transgenerational effect of elevated atmospheric CO2 concentration (e[CO2]) on low temperature response in wheat is still little investigated, through the interaction of e[CO2], and low‐temperature stress has been reported in a single generation. Here, the low temperature‐induced modifications of chloroplast ultrastructure and carbohydrate metabolism in wheat after four generations continuously grown under ambient CO2 concentration (a[CO2]) and e[CO2] (2014–2018) were investigated. The results indicated that the transgenerational exposure to e[CO2] increased the number of grana lamellae and the amounts of osmiophilic lipid droplets, attenuating the negative effect of low temperature on chloroplast ultrastructure. The transgenerational e[CO2] enhanced the activities of antioxidant enzymes (i.e. SOD, POD and CAT) and concentrations of osmotic substances (i.e. proline and soluble sugar), which alleviated the low temperature‐induced oxidative damage to the chloroplast ultrastructure. In addition, transgenerational exposure of wheat to e[CO2] increased activities of vacInv and cwInv, while decreased fructokinase activity, which affected the sucrose metabolism in wheat leaf. These findings elucidated that transgenerational exposure to e[CO2] could improve low temperature tolerance of winter wheat, which provide novel insights to the response of wheat to future climate change.

Crotamine-like from Southern Pacific rattlesnake (Crotalus oreganus helleri) Venom acts on human leukemia (K-562) cell lines and produces ultrastructural changes on mice adrenal gland

ABSTRACTCrotamine is a cationic, non-enzymatic, protein integrating a minor family of myotoxins, composed of 42 amino acid residues, described in Viperidae and Crotalidae snake’s families that has been used in neuroscience research, drug progressing and molecular diversity reports. Crotamine-like protein (CLP) from C.o.helleri venom was isolated in fraction 5 from 7 peaks obtained by sulfopropyl waters protein pak cationic exchange column. In tricine-SDS-PAGE under non-reduced conditions this CLP showed a single band of ~8 kDa molecular weight. CLP induced toxicity of K-562 cells with a CC50 of 11.09 µM. In mice adrenal gland after 24 h of CLP injection, cortical cells exhibited swollen mitochondria with scarce tubular cristae, some elements of smooth and rough endoplasmic reticula, widened nuclear envelope, slightly osmiophilic lipid droplets, and autophagic vacuoles. In some areas cortical cells plasma membrane and endothelial walls disappeared, which indicated a necrosis process. In other areas, endothelial cell cytoplasm did not present the normal caveolae and pinocytotic vesicles. To our knowledge, this is the first report on mice adrenal gland damages, caused by the injection of CLP from rattlesnakes. Our results propose that adrenal cortex lesions may be significant in the envenoming etiopathogenesis by CLP.

Cellular composition of the Corpus luteum of Indian fruit bat, Rousettus leschenaulti (Desmarest) during early embryonic development

The fine structure of luteal cell of the corpus luteum of Indian fruit bat, Rousettus leschenaulti was studied at three stages unilaminar blastocyst stage, Implanted bilaminar blastocyst stage and limb bud stage of early pregnancy. At unilaminar blastocyst stage luteal cells had small nuclei euchromatin. Mitochondria were small, round shaped with tubular cristae. Numerous less osmiophilic lipid droplets were observed in cytoplasmic field of the luteal cells. After implantation at implanted bilaminar blastocyst stage nuclear heterochromatin were reduced and nucleoli were larger and complex. Mitochondria were enlarged and often bizarre shaped with tubular cristae. Golgi complex and agranular endoplasmic reticulum were more conspicuous. Lipid droplets were less osmiophilic. At the stage of limb bud formation the luteal cells suggests different morphological picture, the nuclear size is reduced with clumps of heterochromatin. The agranular endoplasmic reticulum assumes the form of bundles of parallel tubules dispersed in several planes. Mitochondrial size was reduced then the previous stage and they posses vesicular cristae. These observations suggest that the steroidogenic activity of the luteal cells is highest during implantation and comparatively regresses during limb bud formation. It is suggested that the luteal cells is an important ovarian source of pregnancy hormones.

Ultrastructure of the vitellarium in the digeneans Phyllodistomum angulatum (Plagiorchiida, Gorgoderidae) and Azygia lucii (Strigeida, Azygiidae)

Fine structural features of the vitellarium of two digeneans, Phyllodistomum angulatum and Azygia lucii, are documented and compared with those of other digenean species. The cytodifferentiation of immature vitelline cells (vitellocytes) assumes the production and subsequent accumulation in their cytoplasm of several inclusions. Mature vitelline cells of P. angulatum are characterized by the presence of vitelline clusters (∼2.7 μm in diameter, with ∼100 vitelline globules of ∼0.35 μm in diameter) and osmiophobic, saturated lipid droplets (∼2-3 μm in diameter), and in A. lucii vitelline clusters of the same diameter include much fewer vitelline globules (∼50 globules of ∼0.5 μm in diameter), osmiophilic lipid droplets and α-glycogen. In both P. angulatum and A. lucii, interstitial cells are also present within the vitellarium. Two types of contact sites (septate and tight junctions) between adjoining interstitial cells also occur in both digenean species. Judging from the present and previous ultrastructural studies, it is suggested that there are three potential discriminatory characters of the digenean vitellarium (the number of different types of cell components within the vitellarium, the presence and type of junctional complexes between these cells, and the isolation of the vitellarium from the surrounding tissue) which may prove useful for a better understanding of the biology and evolutionary history of the different digenean groups.

Effect of Azadirachtin on vitellogenesis of Labidura riparia (Insect Dermaptera)

This study investigates the effects of the insect growth regulator Azadirachtin (AZA) on the ultrastructure of ovaries and fat body of the earwig Labidura riparia. Ovarian development is severely reduced in AZA-injected females in a dose-dependent manner. Follicles exhibit degenerative changes, separation of follicle cells from the oocyte, and lack of pinocytotic vesicles as of yolk spheres in cortical ooplasm. Adipocytes show fragmented rough endoplasmic reticulum (RER), numerous autophagic vacuoles, multivesicular bodies, osmiophilic lipid droplets, and many large glycogen areas. Gel electrophoresis reveals that vitellogenin is absent from both fat body and hemolymph, and that vitellin is not deposited in the ovary. These pathological effects are not linked to an absence of feeding. The effect of AZA on vitellogenesis is rescuable by Juvenile hormone (JH) treatment. The inhibition of vitellogenesis by AZA is discussed on the basis of its direct cytotoxic effect as well as its interference with the neuroendocrine system.

Hormones regulating structural changes in the adipocytes of the female earwig Labidura riparia

Changes in periovarian fat body fine structure occur during the reproductive cycle of the female earwig Labidura riparia. During the process of vitellogenesis, high levels of protein synthesis are seen in the adipocytes. Simultaneously, the formerly osmiophilic lipid droplets become non-osmiophilic, while an osmiophilic material diffuses from lipid droplets to the cisternae of the rough endoplasmic reticulum (RER). These structural features alter during non-vitellogenic periods: RER and Golgi apparatus regress and seem to be inactive. Lipid droplets are once again osmiophilic and no material enters into RER cisternae. Using microsurgical manipulations, hormonal treatments and light and electron microscopy, we have investigated the regulation of these changes. The neuroendocrine cerebral centre pars intercerebralis, by the action of the juvenile hormone of the corpus allatum. triggers protein metabolism. Another neuroendocrine center, the pars lateralis. and the hormone 20-hydroxyecdysone, regulate structural lipid droplet changes in the adipocytes.

Ultrastructural changes in rat adrenocortical cells produced by a 4-aminopyrazolopyrimidine (4-APP) dosage.

The relation between adrenal cholesterol synthesis and ultrastructural changes was studied in rat adrenal glands stimulated by 4-aminopyrazolopyrimidine (4-APP). Ultrastructural observations were focused on the inner fasciculata-reticularis (Zone I) and the outer fasciculata (Zone O) of the adrenal glands. Zone I in 4-APP-treated rat adrenals had increased tubules and vesicles in the smooth endoplasmic reticulum, mitochondrial enlargement and the accumulated osmiophilic lipid droplets. In contrast, Zone O of the 4-APP-treated rat adrenals showed a decrease in osmiophilic lipid droplets and no increase in any of the elements of the smooth endoplasmic reticulum. These results are strong evidence that under 4-APP treatment cholesterol synthesis takes place in the increased smooth endoplasmic reticulum in Zone I cells. The functional status of the cells of the inner and outer zones of the adrenal cortex also is discussed.

Electron Microscope Study on the Bat Testicular Interstitial Cell with Special Reference to the Cytoplasmic Crystalloid

The testicular interstitial cell of the bat, Myotis schreibersi (Temmink), captured late in August was electron microscopically investigated. The cytoplasm of Myotis interstitial cells is packed by strikingly numerous mitochondria with many electron dense small matrix granules, endoplasmic reticulum and variable numbers of osmiophilic lipid droplets. The Myotis interstitial cell is characterized by alternate development of the SER and RER: In some Leydig cells the major part of the cytoplasm is packed by tubular SER, whereas in others this apparently is replaced by abundant free ribosomes containing sparse cisternae of the RER. These changes in the amounts of ser and RER are likely reversible and probably reflect functional alterations of Leydig cells of the bat, a hibernator. The Myotis interstitial cell possesses small cytoplasmic crystalloids composed of regularly oriented, compressed tubules, 20-28 m mu thick, which are continuous to the tubular SER (SER derived crystalloids). Type I and type II crystalloids are classified, which show, in suitable planes of section, honeycomb-like and fabric-like patterns, respectively. The Myotis Leydig cell extends cytoplasmic processes of irregular shape and long microvilli, the latter often conglomerates on the cell body or cytoplasmic processes. The entire surface of the cell including the processes is completely surrounded by a basal lamina.

Ultrastructure of the cells of the ovarian interstitial gland in hypophysectomized rats. The effects of stimulation of the ovarian plexus and of denervation.

The fine structure of the interstitial gland of the ovary was studied in hypophysectomized rats and in hypophysectomized rats after denervation of the ovary or stimulation of the ovarian plexus. Hypophysectomized rats were used to eliminate gonadotropic influences on interstitial cells. In hypophysectomized rats, there was a large amount of intercellular space and cells had irregularly shaped nuclei and a large nuclear-cytoplasmic ratio. Prominent cytoplasmic features included small mitochondria with an electron-dense matrix, rough and smooth endoplasmic reticulum, polysomes and large osmiophilic lipid droplets. Interstitial cells from stimulated ovaries had reduced intercellular space and a reduced nuclear-cytoplasmic ratio. Mitochondria had tubular cristae; smooth endoplasmic reticulum-surrounded lipid droplets, and large polysomes were present. After section of the ovarian plexus, intercellular space was increased and filopodia were numerous. Cytoplasmic features included mitochondria with a dense matrix and indistinct cristae, large electronlucent lipid droplets, and variously sized multivesicular structures. These observations suggest that stimulation of the ovarian plexus in hypophysectomized rats causes regressed cells to assume the fine structural features of active steroidogenic cells. In contrast, interruption of the ovarian nerve supply causes a qualitative and quantitative increase in ultrastructural features characteristic of regressed steroidogenic cells. These responses of interstitial gland cells to denervation and stimulation provide morphological evidence for a functional role for the adrenergic nerves to this ovarian compartment.

Effects of long-term administration of chlorpromazine on the pineal gland of rats.

Long-term (6 months) administration of 25 mg/kg body weight/day chlorpromazine (CPZ) to rats resulted in remarkable inhibition of normal increase with age of osmiophilic lipid droplets (OLD) in the pineal gland, and atrophy of pinealocytes. The breeding conditions such as illumination, humidity, and room temperature were strictly controlled. Hence, these changes were ascribed solely to the effects of the drug. OLD are considered as an indicator of physiological activity of the gland. In view of the possible functional relations of this organ to endocrine or autonomic nervous activity, our finding may give a clue to the clarification of the possible cause of some side-effects of the drug.

Ultrastructure of rat ovarian interstitial gland cells during pregnancy.

The fine structure of the interstitial gland of the rat ovary was studied at estrus and on Days 4, 6, 10, 14 and 18 of pregnancy. At estrus, ovarian interstitial cells have small nuceli with dense irregular clumps of heterochromatin. Mitochondria are small and rod-shaped and have predominantely lamellar cristae. Numerous osmiophilic lipid droplets are present. At Days 4 and 6, nuclear heterochromatin is reduced, and nucleoli are larger and complex. Mitochondria are enlarged and often bizarre-shaped and have tubular cristae. Golgi and smooth endoplasmic reticulum are more conspicuous. At Day 10, prominent ultrastructural features include nuclei with conspicuous heterochromatin, smaller mitochondria with both lamellar and tubular cristae, numerous ribosomes and lipid droplets with decreased osmiophilia. At Days 14 and 18, nuclei have increased heterochromatin, mitochondria are small and have lamellated cristae and an increase in the size and number of lipid droplets occurs. These observations suggest that steroidogenic activity of interstitial cells is highest during the first half of pregnancy and regresses during the last half. It is suggested that the interstitial gland is an important ovarian source of pregnancy hormone(s) during the first half of gestation and that LH may modulate steroidogenic activity is this ovarian component.

Two distinctive types of lipid histiocytes appearing in the spleen of idiopathic thrombocytopenic purpura. Sea-blue histiocyte and foam cell.

In 11 of 18 spleens surgically removed from patients with idiopathic thrombocytopenic purpura (ITP), the occurrence of sea-blue histiocytes or foam cells were observed. In a few cases, sea-blue histiocytes were found in the lymph nodes or bone marrow. Histochemically the sea-blue histiocytes were proved to contain ceroid or ceroid-like pigments in their cytoplasm. Ultrastructurally numerous intracytoplasmic membrane-bound inclusions, mostly containing tightly laminated materials and intermingling electron-dense amorphous materials or osmiophilic lipid droplets, were present in these cells. In the foam cells, accumulation of excess amounts of phospholipids was histochemically demonstrated in frozen sections, often accompanied by deposition of cholesterol, particularly in advanced cases. Electron microscopically, vacuolar membrane-bound inclusions were found to predominate in their cytoplasm, most of which contained irregularly or loosely laminated materials. Transitional cells between both types of cells were also found light or electron microscopically and ultrastructural transition of sea-blue histiocytes to foam cells was traced. Enhanced phagocytosis of blood cells, including platelets, by sea-blue histiocytes, and gradual transition of the ingested blood cells to the inclusions were confirmed.

Morphogenesis of the fetal membranes of the white-tailed deer.

AbstractMorphogenesis of the fetal membranes of the white‐tailed deer was studied throughout pregnancy. In placentomes, the long, branched, fetal villi occupied corresponding maternal crypts. The bases of the villi and the arching areas connecting them (arcades) were covered with high columnar cytotrophoblast, which apparently had phagocytosed material from the adjacent degenerating rims of the crypts. This arcade cytotrophoblast contained much glycogen and occasional mitochondria, free ribosomes, and pigment granules. Elsewhere, the columnar cytotrophoblast cells usually contained three to five rows of rod‐shaped mitochondria and other cytoplasmic organelles. Interspersed among them were numerous binucleate giant cells which usually contained peripheral lace‐like granular endoplasmic reticulum and many complex lipoprotein droplets. Cryptal epithelium, deep to the degenerate rims, was low columnar, had infranuclear osmiophilic lipid droplets, and sparsely distributed cytoplasmic organelles. The microvilli of cryptal and cytotrophoblastic epithelia interdigitated and appeared as a brush border under light microscopy. The microvilli and their PAS‐positive mucopolysaccharide material appeared capable of holding uterine and chorionic epithelia together during pregnancy. The placentomes were epitheliochorial, but showed “intra‐epithelial” capillaries. Interplacenomal uterine and cytotrophoblasitc epithelia resembled those of the placentomes. Their microvill were inundated by endometrial gland secretion (uterine milk). The cytotrophoblast contained pigment granules and much absorbed uterine milk. The amniotic epithelium showed short microvilli, complexly folded lateral plasma membranes, many desmosomes, abundant glycogen granules, foot processes and other cytoplasmic organelles.

The intestinal absorption of fatty acid: A biochemical and electron microscopic study

Following the administration of 2 ml of C14-labeled oleic acid to rats by stomach tube, osmiophilic droplets and particles, from 10 to 300 mμ in diameter, were demonstrated in the intestinal lumen. The smaller droplets of fatty acid were frequently found between the microvilli of intestinal epithelial cells and were of the same size range as has been proposed for lipid micelles (10 mμ). The radiochemical examination of the lumen contents revealed that the activity was still present in free fatty acids. Larger osmiophilic droplets, averaging 150 mμ in diameter, were found in cytoplasmic vesicles within the epithelial cells. These findings suggest that electron microscopic visualization of lipid droplets cannot distinguish between fatty acid and mono-, di-, and triglycerides. Therefore, conclusions on the nature of osmiophilic lipid droplets in intestinal absorption must be based upon a correlation with biochemical findings. Chemical and radiochemical findings in the absorption of fatty acid indicate that the fatty acid enters the chyle primarily as triglyceride, that the triglyceride content of the intestinal wall is increased, and that there is a significant transfer of the C14 label from fatty acid to triglyceride at some stage during absorption. These observations mean that at least some of the osmiophilic droplets seen with electron microscopy in the intestinal epithelial cells in fatty acid absorption must be triglycerides. The relationship of these findings to the synthesis of triglyceride from fatty acids during internalization and transcellular passage is discussed.