Cisternae Of Endoplasmic Reticulum Research Articles

Echinops Asteraceae extract guards against malathion-induced liver damage via minimizing oxidative stress, inflammation, and apoptosis

Malathion (MAL) is one of the highly toxic organophosphorus (OP) compounds that induces hepatotoxicity. Echinops. ritro leaves extract (ERLE) is traditionally used in the treatment of bacterial/fungal infections. This study's goal was to investigate the potential of extracts from ERLE against hepatotoxicity induced by MAL in male albino rats. Four equal groups of forty mature male albino rats were created: The rats in the first group used as a control. The second group of rats received ERLE orally. The third group received MAL. ERLE and MAL were administered to the fourth group of rats. Six-week treatment groups were conducted. Using lipid peroxidation indicators [malondialdehyde (MDA), alanine aminotransferase (ALT), aspartate aminotransferase (AST)], oxidative stress markers [catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)], apoptotic markers [Bcl-2 & caspase-3] and tumor necrosis factor alpha (TNF-α). Rats treated with MAL underwent a significant increase on MDA, ALT, AST, caspase-3 and TNF-α marker with a significant decrease in antioxidant markers [CAT, SOD, GPx] and Bcl-2. Histologically, MAL-treated group's liver sections displayed damaged hepatocytes with collapsed portions, pyknotic nuclei, vacuolated cytoplasm, and congested central veins. Ultra structurally, rat livers treated with MAL showed dilated cisternae of endoplasmic reticulum, swollen mitochondria with disrupted cristae, nuclei with disrupted chromatin content, multiple lysosomes, multiple vacuolations and a disrupted blood sinusoid. With rats treated with ERLE, these alterations were essentially non-existent. It is possible to conclude that ERLE protects against MAL hepatotoxicity, and that this protection is related, at least in part, to its antioxidant activities.

Western diet-induced ultrastructural changes in mouse pancreatic acinar cells.

Mouse models of diet-induced type 2 diabetes mellitus provide powerful tools for studying the structural and physiological changes that are related to the disease progression. In this study, diabetic-like glucose dysregulation was induced in mice by feeding them a western diet, and light and transmission electron microscopy were used to study the ultrastructural changes in the pancreatic acinar cells. Acinar necrosis and vacuolization of the cytoplasm were the most prominent features. Furthermore, we observed intracellular and extracellular accumulation of lipid compounds in the form of lipid droplets, structural enlargement of the cisternae of the rough endoplasmic reticulum (RER), and altered mitochondrial morphology, with mitochondria lacking the typical organization of the inner membrane. Last, autophagic structures, i.e., autophagosomes, autolysosomes, and residual bodies, were abundant within the acinar cells of western diet-fed mice, and the autolysosomes contained lipids and material of varying electron density. While diets inducing obesity and type 2 diabetes are clearly associated with structural changes and dysfunction of the endocrine pancreas, we here demonstrate the strong effect of dietary intervention on the structure of acinar cells in the exocrine part of the organ before detectable changes in plasma amylase activity, which may help us better understand the development of non-alcoholic fatty pancreas disease and its association with endo- and exocrine dysfunction.

Microscopic Focus on the Thyroid Follicles of the One-Humped Camel (Camelus dromedarius).

The microstructure of the thyroid gland of the one-humped camel (Camelus dromedarius) was described using morphometric, histological, immunohistochemical staining, and ultrastructural standard techniques. The follicular secretory units of the thyroid glands displayed comparable and variable sizes where the large follicles were situated at the peripheral margins; however, the small ones were located in the central region. Semisquamous epithelium (low cuboidal) lined the large thyroid follicles, while high cuboidal (columnar) epithelium lined the small ones. Our electron microscopic findings revealed that the low-sized cuboidal follicular cells lack organelles and are hypoactive. The high cuboidal follicular cells are active cells and rich in cellular organelles such as cisternae of rough endoplasmic reticulum, mitochondria, colloid droplets, scrolled Golgi apparatus, and secretory vesicles. A few degenerate follicular cells appeared on rare occasions. The parafollicular cells appeared with a more prominent and conspicuous nucleus than the follicular cells. The follicular cells were classified as active, inactive, or degenerated using transmission electron microscopy. The follicular and parafollicular cells showed calcitonin-positive immunoreactivity. Overall, the presented results showed particular convergences of the morphostructural aspects of the thyroid gland of C. dromedarius to that of other mammals with some distinctive features to cope with their physiology and harsh niche.

Ultrastructural differences between synovial sarcoma and solitary fibrous tumor: comparative study in adult patients from the National Cancer Institute of Mexico

ABSTRACT Synovial sarcoma (SS) and solitary fibrous tumor (SFT) are entities with considerable morphological and immunohistochemical similarities that sometimes show a non-confirmatory profile (TLE1 negative, CD34 and focal or negative STAT6 and lack of specific fusion IHC markers), in which the utility ultrastructure is unknown. A cross-sectional, retrospective, analytical, nonexperimental study was carried out by the Department of Pathology of the National Cancer Institute of Mexico (INCan) e from January 1, 2009 to December 31, 2018. With 17 SFT cases with diffuse or focal CD34 and STAT6 positivity and 18 cases of SS with positive FISH molecular test t(X:18) breakapart were studied by electron microscopy of fresh glutaraldehyde fixed or paraffin-embedded tissue. The ultrastructural findings with a significant difference present in the SS were tandem tight junctions, desmosomes and abundance of dilated rough endoplasmic reticulum (RER) cisternae (p < 0.001, 0.003, and 0.001, respectively); while in the (SFT) the presence of abundant glycogen, basal lamina, long and slender cytoplasmic processes, pinocytic vesicles, hemidesmosomes, and/or dense plaques, collagen skein, and microvilli-like buds (p = 0.028, 0.005, and <0.001 for the last five). We then infer that the five distinctive markers of the SFT are the collagen skeins intermingled with cellular processes in a shape of “squid can,” and the pinocytic vesicles as they were not observed in any case of SS. Conversely, tandem junctions were not found in any SFT case. Although the presence of multivesicular buds in the SFT was not significant, it had not been previously described.

Dancing with the Stars: Using Image Analysis to Study the Choreography of the Endoplasmic Reticulum and Its Partners and of Movement Within Its Tubules.

In this chapter, approaches to the image analysis of the choreography of the plant endoplasmic reticulum (ER) labeled with fluorescent fusion proteins ("stars," if you wish) are presented. The approaches include the analyses of those parts of the ER that are attached through membrane contact sites to moving or non-moving partners (other "stars"). Image analysis is also used to understand the nature of the tubular polygonal network, the hallmark of this organelle, and how the polygons change over time due to tubule sliding or motion. Furthermore, the remodeling polygons of the ER interact with regions of fundamentally different topologies, the ER cisternae, and image analysis can be used to separate the tubules from the cisternae. ER cisternae, like polygons and tubules, can be motile or stationary. To study which parts are attached to non-moving partners, such as domains of the ER that form membrane contact sites with the plasma membrane/cell wall, an image analysis approach called persistency mapping has been used. To study the domains of the ER that move rapidly and stream through the cell, image analysis of optic flow has been used. However, optic flow approaches confuse the movement of the ER itself with the movement of proteins within the ER. As an overall measure of ER dynamics, optic flow approaches are of value, but their limitation as to what exactly is "flowing" needs to be specified. Finally, there are important imaging approaches that directly address the movement of fluorescent proteins within the ER lumen or in the membrane of the ER. Of these, fluorescence recovery after photobleaching (FRAP), inverse FRAP (iFRAP), and single particle tracking approaches are described.

The presence of Mott cells in the lymph nodes of rats with experimental autoimmune encephalomyelitis.

Mott cells are plasma cells that have multiple spherical Russell bodies packed in their cytoplasm. Russell bodies are dilated endoplasmic reticulum cisternae filled with aggregates of immunoglobulins that are neither secreted nor degraded. Mott cells were observed in our study by light and electron microscope in the lymph nodes of rats with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Mott cells were detected on hematoxylin and eosin (HE)-stained lymph node sections as vacuolated cells with eccentrically positioned nuclei and large number of faint blue spherical inclusions in the cytoplasm. Electron microscopic investigation revealed the presence of Russell bodies of the "medusa" form inside Mott cells in lymph node ultra-thin sections of EAE animals. Mott cells expressed the plasma cell marker CD138 and either kappa or lambda immunoglobulin light chains, indicating their origin from polyclonally activated B cells. Finally, Mott cells were associated with active EAE, as they were not found in the lymph nodes of EAE-resistant Albino Oxford rats. The presence of Russell bodies implies an excessive production of immunoglobulins in EAE, thus further emphasizing the role of B cells, and among them Mott cells, in the pathogenesis of this animal model of multiple sclerosis.

Novel compound heterozygous variants of the SEC23A gene in a Chinese family with cranio-lenticulo-sutural dysplasia based on data from a large cohort of congenital cataract patients

BackgroundCranio-lenticulo-sutural dysplasia (CLSD) is a rare dysmorphic syndrome characterized by skeletal dysmorphism, late-closing fontanels, and cataracts. CLSD is caused by mutations in the SEC23A gene (OMIM# 607812) and can be inherited in either an autosomal dominant or autosomal recessive pattern. To date, only four mutations have been reported to cause CLSD. This study aims to identify the disease-causing variants in a large cohort of congenital cataract patients, to expand the genotypic and phenotypic spectrum of CLSD, and to confirm the association between SEC23A and autosomal recessive CLSD (ARCLSD).MethodsWe collected detailed medical records and performed comprehensive ocular examinations and whole-exome sequencing (WES) on 115 patients with congenital cataracts. After suspecting that a patient may have CLSD based on the sequencing results, we proceeded to conduct transmission electron microscopy (TEM) on the cultured skin fibroblasts. The clinical validity of the reported gene-disease relationships for the gene and the disease was evaluated using the ClinGen gene curation framework.ResultsTwo novel compound heterozygous variants (c.710A > C p.Asp237Ala, c.1946T > C p.Leu649Pro) of the SEC23A gene, classified as variant of uncertain significance, were identified in the proband with skeletal, cardiac, ocular, and hearing defects. The observation of typical distended endoplasmic reticulum cisternae further supported the diagnosis of CLSD. Application of the ClinGen gene curation framework confirmed the association between SEC23A and ARCLSD.ConclusionThis study expands the genotypic and phenotypic spectrum of CLSD, proposes TEM as a supplemental diagnostic method, and indicates that congenital cataracts are a typical sign of ARCLSD.

Morphological features of the rat’s thyroid gland after application of defect in the tibiae

Aim to study the morphological features of the rats thyroid gland after application of a defect in their tibiae.&#x0D; Material and methods. Sixty white mature male rats were divided into two groups. Group I intact animals, Group II rats subjected to a through defect in the proximal metaphysis of the tibiae. The experiment time-line was: 3, 10, 15, 24, and 45 days. The qualitative features of the thyroid gland structure were studied using light and electron microscopy; the quantitative features with histomorphometry.&#x0D; Results. The large follicles lined with simple squamous epithelium on the periphery of the gland as well as large and medium-sized follicles lined with low simple cuboidal, less often squamous epithelium in the center were observed in rats of Group II on days 3, 10, 15 of the experiment. The colloid filled completely or most of the follicle; there were desquamated epitheliocytes and cells with signs of apoptosis. The height of the follicular epithelium of the thyroid gland was smaller than the values of the Group I by 8.44%, 5.52%, 3.86% and 5.53%, 3.70%, 3.25% from 3rd to 15th days; the area of nuclei of follicular cells by 5.22%, 4.93% from 3rd to 10th days and by 5.31% on 3rd day; nucleo-cytoplasmic ratio by 3.11%, 2.29%, 2.28% from 3rd to 15th days and by 4.63%, 3.01% from 3rd to 10th days in the central and peripheral parts of the gland respectively. On the 3rd day, electron-microscopically, thyrocytes were low cuboidal or flat shape, the nucleus had tortuous contours and accumulations of heterochromatin under the karyolemma and in the karyoplasm. The cisternae of the rough endoplasmic reticulum were collapsed or had small slit-like spaces. Single lysosomes and secretory granules in the apical part of the cells and short microvilli were visualized.&#x0D; Conclusion. The application of a defect in the tibiae of rats is accompanied by morphological changes in the thyroid gland from the 3rd to 15th days and then organ adapts to the trauma by the 24th and 45th days.

Neuronal ER-plasma membrane junctions couple excitation to Ca2+-activated PKA signaling

Junctions between the endoplasmic reticulum (ER) and the plasma membrane (PM) are specialized membrane contacts ubiquitous in eukaryotic cells. Concentration of intracellular signaling machinery near ER-PM junctions allows these domains to serve critical roles in lipid and Ca2+ signaling and homeostasis. Subcellular compartmentalization of protein kinase A (PKA) signaling also regulates essential cellular functions, however, no specific association between PKA and ER-PM junctional domains is known. Here, we show that in brain neurons type I PKA is directed to Kv2.1 channel-dependent ER-PM junctional domains via SPHKAP, a type I PKA-specific anchoring protein. SPHKAP association with type I PKA regulatory subunit RI and ER-resident VAP proteins results in the concentration of type I PKA between stacked ER cisternae associated with ER-PM junctions. This ER-associated PKA signalosome enables reciprocal regulation between PKA and Ca2+ signaling machinery to support Ca2+ influx and excitation-transcription coupling. These data reveal that neuronal ER-PM junctions support a receptor-independent form of PKA signaling driven by membrane depolarization and intracellular Ca2+, allowing conversion of information encoded in electrical signals into biochemical changes universally recognized throughout the cell.

Electron microscopic changes in fibroblastic sarcoid in horses

The article presents the results of ultrastructural research on fibroblastic sarcoid, which is one of the most aggressive types of sarcoid in horses. A retrospective study on the prevalence of sarcoids in horses in Ukraine’s western regions was conducted in 2019–2023. It was found that during the period of 2022–2023, the number of horses with sarcoids increased sharply by 15.6% compared to the period 2020–2021. This was associated with the mass movement of animals from eastern regions due to the onset of the war in Ukraine. The fibroblastic type of sarcoid was predominantly localized in the abdominal wall and groin area. To study the ultrastructure of sarcoids, they were surgically removed by excising undamaged skin portions under general anesthesia, adhering to all requirements of the European Convention for the Protection of Animals used for Experimental and Other Scientific Purposes. Electronograms revealed that the tumour formation mainly consisted of fibroblasts of varying differentiation degrees: significant number of vesicles, markedly expanded endoplasmic reticulum cisterns, and irregularly shaped nuclei with numerous invaginations. Open nuclear pores were observed in most nuclei. Active formation of a large number of capillaries was noted between the collagen matrix, fibroblasts, and fibrocytes, indicated by the increased number of endotheliocytes with pseudopodia on the cytoplasm’s marginal part and the basal surface. This suggests their embryonic type. Endotheliocytes contained large round nuclei and a significant number of mitochondria in the cytoplasm. There were both bright and dark endotheliocytes in the blood capillaries’ venous section. The cytoplasm of bright endotheliocytes contained myofilaments, individual mitochondria, free ribosomes, peroxisomes, and vesicles of various sizes. The plasmalemma formed small pseudopodia. The capillary lumen showed moderate electron density. Additionally, high platelet activity was observed, manifested by cell adhesion to the marginal part of the endotheliocyte cytoplasm. It should be noted that most capillaries were of the venous type, as indicated by the endotheliocytes’ height, the presence of an increased number of mitochondria and vesicles. The entire cellular pool was localized among the massive framework consisting of collagen fibers. Elastic fibers could not be detected in the fibrillar component.

Electronic microscopic features of parafollicular cells of rat's thyroid gland after 60 days introduction of tartrazine and Mexidol®

Objective: To establish the effect of the administration of tartrazine for 60 days, as well as Mexidol® under these conditions, on the structural features of the parafollicular cells of the rat's thyroid gland at the electron microscopic level. Material and methods. Thirty white male rats weighing 200-210 g were divided into five groups six rats each. The Group I is the control; the Groups II and III — rats received tartrazine at a concentration of 750 and 1500 mg/kg for 60 days; the Groups IV and V — under similar conditions Mexidol® was administered at the rate of 50 mg/kg. Qualitative changes in parafollicular cells were studied using electron microscopy, and quantitative changes — by morphometry Results. The fine-grained or fibrous contents were detected in the cisterns of the rough endoplasmic reticulum, and areas of the destroyed matrix in some mitochondria after exposure to tartrazine. The ratio of area eu-chromatin/heterochromatin decreased in the Groups II and III by 5.7% and 56.9%, respectively, and the diameter of secretory granules — by 12.3% and 19%, respectively, compared with the Group I. The ratio of area euchromatin/het-erochromatin increased by 79.6% in Group V, and diameter of secretory granules — by 8.2% and 6.5% in the Groups IV and V respectively, compared with the data of the Groups II and III. Conclusions. The introduction of tartrazine in different doses for 60 days causes dose-dependent qualitative and quantitative changes in the ultrastructure of parafollicular cells, and the introduction of Mexidol® against this background causes a decrease in their severity.

Comparison of endocytosis pathways of Duck Tembusu virus in BHK-21 and duck embryo fibroblasts

The Duck Tembusu virus (DTMUV) is a zoonotic flavivirus characterized by nonsuppurative encephalitis and decreasing egg production that has adversely affected the poultry industry. While the way of invasion of DTMUV into different host cells, especially primary cells, remains elusive. In the present study, the ultrastructural pathological characteristics showed that DTMUV underwent a typical maturation and replication process: progeny virus particles gathered in rough endoplasmic reticulum (RER) cisternae, reached the cell membrane via Golgi body's endocrine channel, then were released in the infected baby hamster kidney-21 (BHK-21) and duck embryo fibroblast (DEF). Endoplasmic reticulum vesicles in BHK-21 were short rods and densely arranged like honeycombs, whereas vesicles in DEF were round and dispersed. Further study showed that the virus replication peak in mammalian BHK-21 cells was at 48 hpi, whereas in avian DEF cells was at 24 hpi. DTMUV entry into BHK-21 and DEF cells was blocked by clathrin inhibitor, chlorpromazine (CPZ), indicating that the flavivirus DTMUV enters BHK-21 and DEF both via a clathrin-mediated endocytosis (CME) pathway rather than caveola-mediated endocytosis or micropinocytosis. The endocytic difference in DTMUV entry into BHK-21 and DEF cells might provide insight into understanding the underlying virulence difference between passaged cells and cultured cells.

Two subcompartments of the smooth endoplasmic reticulum in perisynaptic astrocytic processes: ultrastructure and distribution in hippocampal and neocortical synapses

Perisynaptic astrocytic processes involved in the tripartite synapse functioning respond to its activation by local depolarization with calcium release from the intracellular stores inside nodes of astrocytic processes and develop local and generalized calcium events. However, based on the first electron microscopy studies a point of view was formed that terminal astrocytic lamellae are devoid of any organelles, including the main astrocytic calcium store - the cisternae of the smooth endoplasmic reticulum. Indeed, analysis of smooth endoplasmic reticulum cisternae could be limited by their weak electron contrast, the studying of astrocytic processes on single sections, and insufficient optical resolution of the equipment used. Here, by using serial section transmission electron microscopy and 3D reconstructions, we analyzed astrocytic processes in murine hippocampal and cortical synapses. As a result of unit membranes contrast enhancement, it was shown for the first time that perisynaptic processes of astrocytes with a morphology of thin branchlets contain two types of smooth endoplasmic reticulum cisternae and microvesicles. Unlike branchlets, membrane organelles inside terminal lamellae were comprised by only short fragments of thin smooth endoplasmic reticulum cister-nae and microvesicles, whose groups tend to be located in close proximity to active zones of the most active synapses. We speculate both on reliability of the alternative methods in electron microscopy while studying astrocytic microenvironment of synapses and structure-function aspects of smooth endoplasmic reticulum cisternae compartmentalization inside the perisynaptic processes of astrocytes.

Ultramicroscopic features of thyrocytes after 60 days of tartrazine administration and infliction of a defect in the tibiaе and substantiation of the effectiveness of sodium selenite

Aim. Identify the features of the ultramicroscopic structure of thyrocytes in rats under conditions after 60 days of tartrazine administration and simulated traumatic bone defect, as well as to establish the effectiveness of sodium selenite.Material and methods. White mature male rats were divided into 3 groups. In Group 1, a through defect in the tibiae was applied to rats after the previous 60-day intragastric administration of saline solution. In Group 2, rats were subjected to 60-day exposure with tartrazine at a dosage of 750 mg/kg instead of saline solution under similar experimental conditions and in Group 3 – additionally intramuscularly injected sodium selenite at a dose of 40 µg/kg. On days 3, 10, 15, 24 and 45, the animals were removed from the experiment, samples of thyroid gland were processed for electron microscopic examination according to the standard method.Results. In Group 2, inactive chromatin prevailed in the nucleus, expanded cisterns of the rough endoplasmic reticulum, single mitochondria with matrix destruction sites were observed in the cytoplasm from 3rd to 15th days of experiment. There were cells in a state of apoptosis. By the day 24, the ultramicroscopic picture was almost restored to the control values.In Group 3, an increase in the area of active euchromatin in the nucleus, restoration of the lumen of the cisterns of the rough endoplasmic reticulum, an increase in the number of lysosomes in the cytoplasm, a decrease in the number of mitochondria with signs of destruction of crysts and cells with signs of apoptosis were revealed.Conclusion. The bone defect applied after the previous 60-day administration of tartrazine causes an aggravation of ultramicroscopic changes in thyrocytes, compared with the group without the introduction of a food additive. Use of sodium selenite allows, to a certain extent, to neutralize the changes caused by tartrazine in these cells by the time of traumatic injury.

Ultrastructural study of the duck brain infected with duck Tembusu virus.

Duck Tembusu virus (DTMUV) is an emerging avian flavivirus characterized by causing severe ovaritis and neurological symptoms in ducks. The pathology of the central nervous system (CNS) caused by DTMUV is rarely studied. This study aimed to systematically investigate the ultrastructural pathology of the CNS of ducklings and adult ducks infected with DTMUV via transmission electron microscopy technology at a cytopathological level. The results showed that DTMUV caused extensive lesions in the brain parenchyma of ducklings and slight damage in adult ducks. The neuron was the target cell of DTMUV, and virions were mainly observed in their cisternae of rough endoplasmic reticulum and the saccules of Golgi apparatus. The neuron perikaryon showed degenerative changes where the membranous organelles gradually decomposed and disappeared with DTMUV infection. Besides neurons, DTMUV infection induced marked swelling in astrocytic foot processes in ducklings and evident myelin lesions in ducklings and adult ducks. The activated microglia were observed phagocytizing injured neurons, neuroglia cells, nerve fibers, and capillaries after the DTMUV infection. Affected brain microvascular endothelial cells were surrounded by edema and had increased pinocytotic vesicles and cytoplasmic lesions. In conclusion, the above results systematically describe the subcellular morphological changes of the CNS after DTMUV infection, providing an ultrastructural pathological research basis for DTMUV-induced neuropathy.

Gill histology and ultrastructure in Aplysia depilans (Mollusca, Euopisthobranchia).

The gill of Aplysia depilans consists of several wedge-shaped pinnules with a highly folded structure, differing from the typical ctenidial gills of mollusks. Light microscopy and transmission electron microscopy were used to investigate this organ in juveniles and adults. In this species, the gill epithelium comprised ciliated, unciliated, and secretory cells. The ultrastructural analysis suggests other functions for the gill besides respiration. The deep cell membrane invaginations associated with mitochondria in the basal region of epithelium point to a role in ion regulation. Endocytosis and intracellular digestion were other activities detected in epithelial cells. In juveniles, an intranuclear crystalline structure was seen in some ciliated cells. The presence of an intranuclear crystalline structure was frequently associated with chromatin decondensation, swelling of the nuclear envelope and endoplasmic reticulum cisternae, and abundance of Golgi stacks. As these intranuclear inclusions were not found in the gill of the adult specimens, their occurrence in the two juveniles seems likely to be an anomalous condition whose cause cannot be established at the moment. Mucous cells were the most abundant secretory cells in the epithelium, but a few epithelial serous cells were also found. In addition, large protein-secreting subepithelial cells had the main cell body inserted in the connective tissue and a long thin neck crossing the epithelium. Mucous cells can be considered responsible for the production of the mucus layer that protects the epithelium, but the specific functions of the epithelial and subepithelial protein-secreting cells remain elusive. Below the epithelium, a layer of connective tissue with muscle cells lined the narrow hemolymph space. The connective tissue included cells with a large amount of rough endoplasmic reticulum cisternae. Bacteria were found on the surface of the gill, and the most abundant had a thin stalk for attachment to the epithelial cells.

Ultrastructural analysis of monkeypox virus replication in Vero cells.

In early May 2022, the first worldwide monkeypox virus (MPXV) outbreak was reported, with different clinical aspects from previously studied human monkeypox infections. Despite monkeypox medical importance, much of its biological aspects remain to be further investigated. In the present work, we evaluated ultrastructural aspects of MPXVasynchronous infections in Vero cells by transmission electron microscopy (TEM). The viral strain was isolated from a male patient infected during the 2022 outbreak. TEM analysis showed: (i) adhered intracellular mature virus particles before entry of the host cell; (ii) a reorganization of the rough endoplasmic reticulum cisternae into the so-called "mini-nuclei"structure associated with genome replication; and (iii) noticeably different sites within the viral factory presenting granular or fibrillar aspects. We also observed viral crescents, different MPXVparticle morphotypes, and cellular alterations induced by infection, such as changes in the cytoskeleton structure and multimembrane vesicles abundance. Taken together, to the best of our knowledge, these results revealed for the first-time ultrastructural aspects of different steps of the MPXVcycle.

Azadirachtin-based insecticide impairs testis morphology and spermatogenesis of the southern armyworm Spodoptera eridania (Lepidoptera: Noctuidae).

In the search for alternative tools for integrated pest management, azadirachtin, a botanical insecticide, has been used with the most promising activity against Spodoptera spp., but the mechanism of cytotoxicity on reproductive organs remains unclear. Spodoptera eridania (Stoll, 1782) is a polyphagous pest with great economic importance that has become an important target to elucidate the action of azadirachtin on the reproductive organs of insect pests, helping to understand the deleterious effects caused by its exposure. This study evaluated the effects of chronic exposure to azadirachtin on the morphology and ultrastructure of S. eridania larval testes as well as larval development. Azadirachtin exposure (6 or 18 mg a.i.L-1 ) caused a progressive increase in cumulative mortality and reduced gain in body mass after 5 days. Testicular structure indicated a reduction in their size with internal morphological changes such as spermatogonia, spermatogonial, spermatocytes and spermatid cysts in degeneration. The occurrence of cell death in germ and somatic cells was evidenced by the TUNEL technique. Electron microscopy revealed changes in cystic cells, such as cytoplasmic membrane rupture and cytoplasmic vacuolization. Chromatin compaction, changes in the rough endoplasmic reticulum and Golgi complex cisternae were observed in germ cells. Apoptotic bodies occurred between germ cell cysts. Azadirachtin damaged the testes of S. eridania larvae, and these changes compromised spermatogenesis and consequently the development of the reproductive potential of this specimen, making azadirachtin a promising botanical insecticide for application in integrated pest management programs. © 2022 Society of Chemical Industry.

Ultrastructural and Immunohistochemical Characterization of Maternal Myofibroblasts in the Bovine Placenta around Parturition

Myofibroblasts are contractile cells that exhibit features of both fibroblasts and smooth muscle cells. In the synepitheliochorial placenta of the cow myofibroblasts are found in the maternal stroma. However, a deeper understanding of the structure and function of the stromal myofibroblasts in the developed bovine placenta is still missing. Thus, immunohistochemical and ultrastructural analyses in bovine term placentomes, compared to non-pregnant caruncle samples, were conducted. To investigate functional aspects, contractility of placentomal caruncle slices was assessed in an in vitro contraction assay. Additionally, a three-dimensional reconstruction of a bovine placental myofibroblast was created. Immunofluorescent staining revealed a characteristic pattern, including cytoplasmic expression of α-smooth muscle actin, strong perinuclear signal for the intermediate filament vimentin and nuclear progesterone receptor staining. Ultrastructurally, stress fibers, extended cisternae of the rough endoplasmic reticulum and perinuclear intermediate filaments were observed. Moreover, in vitro stimulation with angiotensin-II, but not with prostaglandin F2α, induced contraction of placental caruncle tissue. Altogether, these results indicate that progesterone-responsive myofibroblasts represent a mesenchymal phenotype that is involved in the contractile properties of bovine placental stroma. Therefore, the present findings suggest a potential involvement of myofibroblasts in post-partum events of cattle, i.e., expulsion of fetal membranes and uterine involution.

Increased interaction between endoplasmic reticulum and mitochondria following sleep deprivation

BackgroundProlonged cellular activity may overload cell function, leading to high rates of protein synthesis and accumulation of misfolded or unassembled proteins, which cause endoplasmic reticulum (ER) stress and activate the unfolded protein response (UPR) to re-establish normal protein homeostasis. Previous molecular work has demonstrated that sleep deprivation (SD) leads to ER stress in neurons, with a number of ER-specific proteins being upregulated to maintain optimal cellular proteostasis. It is still not clear which cellular processes activated by sleep deprivation lead to ER- stress, but increased cellular metabolism, higher request for protein synthesis, and over production of oxygen radicals have been proposed as potential contributing factors. Here, we investigate the transcriptional and ultrastructural ER and mitochondrial modifications induced by sleep loss.ResultsWe used gene expression analysis in mouse forebrains to show that SD was associated with significant transcriptional modifications of genes involved in ER stress but also in ER-mitochondria interaction, calcium homeostasis, and mitochondrial respiratory activity. Using electron microscopy, we also showed that SD was associated with a general increase in the density of ER cisternae in pyramidal neurons of the motor cortex. Moreover, ER cisternae established new contact sites with mitochondria, the so-called mitochondria associated membranes (MAMs), important hubs for molecule shuttling, such as calcium and lipids, and for the modulation of ATP production and redox state. Finally, we demonstrated that Drosophila male mutant flies (elav > linker), in which the number of MAMs had been genetically increased, showed a reduction in the amount and consolidation of sleep without alterations in the homeostatic sleep response to SD.ConclusionsWe provide evidence that sleep loss induces ER stress characterized by increased crosstalk between ER and mitochondria. MAMs formation associated with SD could represent a key phenomenon for the modulation of multiple cellular processes that ensure appropriate responses to increased cell metabolism. In addition, MAMs establishment may play a role in the regulation of sleep under baseline conditions.