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Acta Histochemica Jul 2021Iron deficiency anemia (IDA) is a global health problem affecting various body systems and tissues including the cardiovascular system. Several literatures described the...
Iron deficiency anemia (IDA) is a global health problem affecting various body systems and tissues including the cardiovascular system. Several literatures described the associated physiological and clinical changes in the cardiovascular system and heart. However, the associated structural changes were poorly investigated. Therefore, the main aim of the present work was to elucidate whether IDA induces structural changes and alterations in the VEGF, CD34 and ASMA immunoexpression in the myocardium of albino rats. Thirty adult male albino rats were divided into two groups (fifteen rats each); control and anemic. Hematological data for all animals were assessed weekly and statistically analyzed. Three weeks later, animals were sacrificed, and heart specimens were obtained and processed for light and electron microscopy. All hematological parameters showed a statistically significant decrease in the anemic group. Structurally, the anemic group showed markedly degenerated, disrupted and disorganized cardiomyocytes in addition to markedly congested blood vessels, fibroblasts, collagen fibers deposition and perivascular cellular infiltration were noted. Also, positive immunostaining for VEGF, CD34 and ASMA was observed. Ultra-structurally, the myocardium of the anemic group showed disrupted and degenerated myofibrils with degenerated nuclei, perinuclear edema, widened interstitial spaces and marked collagen deposition. Mitochondria markedly increased with abnormal shapes. IDA induced myocardial injury that may propagate to regeneration through activated CD34 progenitor cells and increased VEGF or to degeneration and fibrosis through collagen fibers deposition and enhanced ASMA. So, early diagnosis and treatment of IDA is mandatory to avoid the associated myocardial structural changes.
Topics: Actins; Anemia, Iron-Deficiency; Animals; Antigens, CD34; Cell Differentiation; Collagen; Male; Mitochondria; Muscle, Smooth; Myocardium; Rats; Rats, Sprague-Dawley; Regeneration; Vascular Endothelial Growth Factor A
PubMed: 34052675
DOI: 10.1016/j.acthis.2021.151731 -
Genetics Jul 2021The chromatin landscape defines cellular identity in multicellular organisms with unique patterns of DNA accessibility and histone marks decorating the genome of each...
The chromatin landscape defines cellular identity in multicellular organisms with unique patterns of DNA accessibility and histone marks decorating the genome of each cell type. Thus, profiling the chromatin state of different cell types in an intact organism under disease or physiological conditions can provide insight into how chromatin regulates cell homeostasis in vivo. To overcome the many challenges associated with characterizing chromatin state in specific cell types, we developed an improved approach to isolate Drosophila melanogaster nuclei tagged with a GFPKASH protein. The perinuclear space-localized KASH domain anchors GFP to the outer nuclear membrane, and expression of UAS-GFPKASH can be controlled by tissue-specific Gal4 drivers. Using this protocol, we profiled chromatin accessibility using an improved version of Assay for Transposable Accessible Chromatin followed by sequencing (ATAC-seq), called Omni-ATAC. In addition, we examined the distribution of histone marks using Chromatin immunoprecipitation followed by sequencing (ChIP-seq) and Cleavage Under Targets and Tagmentation (CUT&Tag) in adult photoreceptor neurons. We show that the chromatin landscape of photoreceptors reflects the transcriptional state of these cells, demonstrating the quality and reproducibility of our approach for profiling the transcriptome and epigenome of specific cell types in Drosophila.
Topics: Animals; Cell Nucleus; Chromatin; Chromatin Immunoprecipitation Sequencing; Drosophila melanogaster; Green Fluorescent Proteins; Histone Code; Organ Specificity
PubMed: 34022041
DOI: 10.1093/genetics/iyab079 -
Cells Apr 2021Retinal degeneration is a leading cause of blindness. The unfolded protein response (UPR) is an endoplasmic reticulum (ER) stress response that affects cell survival and...
Retinal degeneration is a leading cause of blindness. The unfolded protein response (UPR) is an endoplasmic reticulum (ER) stress response that affects cell survival and death and GRP78 forms a representative protective response. We aimed to determine the exact localization of GRP78 in an animal model of light-induced retinal degeneration. Dark-adapted mice were exposed to blue light-emitting diodes and retinas were obtained at 24 h and 72 h after exposure. In the normal retina, we found that GRP78 was rarely detected in the photoreceptor cells while it was expressed in the perinuclear space of the cell bodies in the inner nuclear and ganglion cell layers. After injury, the expression of GRP78 in the outer nuclear and inner plexiform layers increased in a time-dependent manner. However, an increased GRP78 expression was not observed in damaged photoreceptor cells in the outer nuclear layer. GRP78 was located in the perinuclear space and ER lumen of glial cells and the ER developed in glial cells during retinal degeneration. These findings suggest that GRP78 and the ER response are important for glial cell activation in the retina during photoreceptor degeneration.
Topics: Animals; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Heat-Shock Proteins; Light; Male; Mice; Mice, Inbred BALB C; Retina; Retinal Degeneration
PubMed: 33922686
DOI: 10.3390/cells10050995 -
Biology of the Cell Jun 2021Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection induces an alteration in the endomembrane system of the mammalian cells. In this study, we used...
BACKGROUND INFORMATION
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection induces an alteration in the endomembrane system of the mammalian cells. In this study, we used transmission electron microscopy and electron tomography to investigate the main structural alterations in the cytoplasm of Vero cells infected with a SARS-CoV-2 isolate from São Paulo state (Brazil).
RESULTS
Different membranous structures derived from the zippered endoplasmic reticulum were observed along with virus assembly through membrane budding. Also, we demonstrated the occurrence of annulate lamellae in the cytoplasm of infected cells and the presence of virus particles in the perinuclear space.
CONCLUSIONS AND SIGNIFICANCE
This study contributes to a better understanding of the cell biology of SARS-CoV-2 and the mechanisms of the interaction of the virus with the host cell that promote morphological changes, recruitment of organelles and cell components, in a context of a virus-induced membrane remodelling.
Topics: Animals; COVID-19; Chlorocebus aethiops; Electron Microscope Tomography; Endoplasmic Reticulum; Humans; Intracellular Membranes; Microscopy, Electron, Transmission; Nuclear Envelope; SARS-CoV-2; Vero Cells; Virus Assembly; Virus Replication
PubMed: 33600624
DOI: 10.1111/boc.202000146 -
Rheumatology (Oxford, England) Aug 2021To evaluate the prevalence and meaning of antineutrophil cytoplasmic antibodies (ANCA) positivity in a cohort of IgG4-related disease (IgG4-RD).
OBJECTIVES
To evaluate the prevalence and meaning of antineutrophil cytoplasmic antibodies (ANCA) positivity in a cohort of IgG4-related disease (IgG4-RD).
METHODS
We identified patients with ANCA determination from a retrospective cohort of 69 patients with IgG4-RD. ANCA were measured by indirect immunofluorescence microscopy (IIF) and/or proteinase 3 (PR3)-ANCA and MPO-ANCA by ELISA. IIF patterns were classified as perinuclear (P-ANCA), cytoplasmic (C-ANCA) and atypical (X-ANCA). We compared the ANCA-positive vs the ANCA-negative IgG4-RD group.
RESULTS
Out of 69 patients, 31 IgG4-RD patients had an ANCA determination. Four patients with concomitant systemic autoimmune diseases were excluded. We found positive ANCA by IIF in 14 (56%) of 25 patients tested. The most common IIF pattern was C-ANCA in eight (57.1%), followed by dual C-ANCA/X-ANCA in four (28.6%) and P-ANCA and dual C-ANCA/P-ANCA in one each (7.1%). Of the 20 patients with ANCA determination by both IIF and ELISA, four have positive ANCA by ELISA (three for MPO-ANCA and one for PR3-ANCA). Of the two patients with only ELISA determination, one was positive for MPO-ANCA. The prevalence of ANCA positivity by ELISA was 22.7% (5 out of 22 patients). ANCA was more frequent in the Mikulizc/systemic phenotype (42.9%) compared with other phenotypes (P = 0.04). ANCA-positive IgG4-RD patients had more frequently lymph node and kidney involvement, high IgG1 levels and erythrocyte sedimentation rate, and positive antinuclear antibodies.
CONCLUSION
ANCA are found in a significant number of patients with IgG4-RD and differed from the ANCA-negative group in terms of clinical and serological features.
Topics: Adult; Aged; Antibodies, Antineutrophil Cytoplasmic; Aortic Diseases; Biliary Tract Diseases; Case-Control Studies; Female; Humans; Immunoglobulin G4-Related Disease; Kidney Diseases; Lacrimal Apparatus Diseases; Liver Diseases; Lymph Nodes; Male; Microscopy, Fluorescence; Middle Aged; Myeloblastin; Pancreatic Diseases; Peroxidase; Retroperitoneal Space; Retrospective Studies; Salivary Gland Diseases
PubMed: 33547775
DOI: 10.1093/rheumatology/keab124 -
Journal of Cell Communication and... Jun 2021Glutamine (gln) metabolism has emerged as a cancer therapeutic target in past few years, however, the effect of gln-deprivation of bCSCs remains elusive in breast...
Glutamine (gln) metabolism has emerged as a cancer therapeutic target in past few years, however, the effect of gln-deprivation of bCSCs remains elusive in breast cancer. In this study, effect of glutamine on stemness and differentiation potential of bCSCs isolated from MCF-7 and MDAMB-231 were studied. We have shown that bCSCs differentiate into CD24 epithelial population under gln-deprivation and demonstrated increased expression of epithelial markers such as e-cadherin, claudin-1 and decreased expression of mesenchymal protein n-cadherin. MCF-7-bCSCs showed a decrease in EpCAM population whereas MDAMB-231-bCSCs increased CD44 population in response to gln-deprivation. The expression of intracellular stem cell markers such sox-2, oct-4 and nanog showed a drastic decrease in gene expression under gln-deprived MDAMB-231-bCSCs. Finally, localization of β-catenin in MCF-7 and MDAMB-231 cells showed its accumulation in cytosol or perinuclear space reducing its efficiency to transcribe downstream genes. Conclusively, our study demonstrated that gln-deprivation induces differentiation of bCSCs into epithelial subtypes and also reduces stemness of bCSCs mediated by reduced nuclear localization of β-catenin. It also suggests that basal and luminal bCSCs respond differentially towards changes in extracellular and intracellular gln. This study could significantly affect the gln targeting regimen of breast cancer therapeutics.
PubMed: 33511560
DOI: 10.1007/s12079-020-00603-1 -
Cell and Tissue Research May 2021Inhibitors of sodium/glucose co-transporter 2 (SGLT2) are currently in clinical use for type 2 diabetes (T2D) treatment due to their anti-hyperglycemic effect exerted by...
Inhibitors of sodium/glucose co-transporter 2 (SGLT2) are currently in clinical use for type 2 diabetes (T2D) treatment due to their anti-hyperglycemic effect exerted by the inhibition of glucose reabsorption in the kidney. Inhibition of SGLT2 is associated with improvement of renal outcomes in chronic kidney disease associated with T2D. Our study aimed to describe the renal-specific phenotypic consequences of the SGLT2-loss of function "Jimbee" mutation within the Slc5a2 mouse gene in a non-diabetic/non-obese background. The Jimbee mice displayed reduced body weight, glucosuria, polyuria, polydipsia, and hyperphagia but were normoglycemic, with no signs of baseline insulin resistance or renal dysfunction. Histomorphological analysis of the kidneys revealed a normal architecture and morphology of the renal cortex, but shrinkage of the glomerular and tubular apparatus, including Bowman's space, glomerular tuft, mesangial matrix fraction, and proximal convoluted tubule (PCT). Immunofluorescent analysis of renal sections showed that SGLT2 was absent from the apical membrane of PCT of the Jimbee mice but remnant positive vesicles were detected within the cytosol or at the perinuclear interface. Renal localization and abundance of GLUT1, GLUT2, and SGLT1 were unchanged in the Jimbee genotype. Intriguingly, the mutation did not induce hepatic gluconeogenic gene expression in overnight fasted mice despite a high glucose excretion rate. The Jimbee phenotype is remarkably similar to humans with SLC5A2 mutations and provides a useful model for the study of SGLT2-loss of function effects on renal architecture and physiology, as well as for identifying possible novel roles for the kidneys in glucose homeostasis and metabolic reprogramming.
Topics: Animals; Diabetes Mellitus, Type 2; Female; Glucose; Homeostasis; Humans; Kidney; Loss of Function Mutation; Male; Mice; Sodium-Glucose Transporter 2
PubMed: 33409652
DOI: 10.1007/s00441-020-03358-8 -
Redox Biology Jan 2021Mitochondria are strategically trafficked throughout the cell by the action of microtubule motors, the actin cytoskeleton and adapter proteins. The intracellular...
Mitochondria are strategically trafficked throughout the cell by the action of microtubule motors, the actin cytoskeleton and adapter proteins. The intracellular positioning of mitochondria supports subcellular levels of ATP, Ca and reactive oxygen species (ROS, i.e. hydrogen peroxide, HO). Previous work from our group showed that deletion of the mitochondrial adapter protein Miro1 leads to perinuclear clustering of mitochondria, leaving the cell periphery devoid of mitochondria which compromises peripheral energy status. Herein, we report that deletion of Miro1 significantly restricts subcellular HO levels to the perinuclear space which directly affects intracellular responses to elevated mitochondrial ROS. Using the genetically encoded HO-responsive fluorescent biosensor HyPer7, we show that the highest levels of subcellular HO map to sites of increased mitochondrial density. Deletion of Miro1 or disruption of microtubule dynamics with Taxol significantly reduces peripheral HO levels. Following inhibition of mitochondrial complex 1 with rotenone we observe elevated spikes of HO in the cell periphery and complementary oxidation of mitochondrial peroxiredoxin 3 (PRX3) and cytosolic peroxiredoxin 2 (PRX2). Conversely, in cells lacking Miro1, rotenone did not increase peripheral HO or PRX2 oxidation but rather lead to increased nuclear HO and an elevated DNA-damage response. Lastly, local levels of HyPer7 oxidation correlate with the size and abundance of focal adhesions (FAs) in MEFs and cells lacking Miro1 have significantly smaller focal adhesions and reduced phosphorylation levels of vinculin and p130Cas compared to Miro1 MEFs. Together, we present evidence that the intracellular distribution of mitochondria influences subcellular HO levels and local cellular responses dependent on mitochondrial ROS.
Topics: Hydrogen Peroxide; Mitochondria; Mitochondrial Proteins; Oxidation-Reduction; Reactive Oxygen Species
PubMed: 33341544
DOI: 10.1016/j.redox.2020.101818 -
ELife Dec 2020The inner nuclear membrane is functionalized by diverse transmembrane proteins that associate with nuclear lamins and/or chromatin. When cells enter mitosis,...
The inner nuclear membrane is functionalized by diverse transmembrane proteins that associate with nuclear lamins and/or chromatin. When cells enter mitosis, membrane-chromatin contacts must be broken to allow for proper chromosome segregation; yet how this occurs remains ill-understood. Unexpectedly, we observed that an imbalance in the levels of the lamina-associated polypeptide 1 (LAP1), an activator of ER-resident Torsin AAA+-ATPases, causes a failure in membrane removal from mitotic chromatin, accompanied by chromosome segregation errors and changes in post-mitotic nuclear morphology. These defects are dependent on a hitherto unknown chromatin-binding region of LAP1 that we have delineated. LAP1-induced NE abnormalities are efficiently suppressed by expression of wild-type but not ATPase-deficient Torsins. Furthermore, a dominant-negative Torsin induces chromosome segregation defects in a LAP1-dependent manner. These results indicate that association of LAP1 with chromatin in the nucleus can be modulated by Torsins in the perinuclear space, shedding new light on the LAP1-Torsin interplay.
Topics: Adenosine Triphosphatases; Carrier Proteins; Cell Line, Tumor; Chromatin; Chromosome Segregation; Gene Knockout Techniques; HCT116 Cells; HSC70 Heat-Shock Proteins; HeLa Cells; Hep G2 Cells; Humans; Mitosis; Molecular Chaperones; Nuclear Envelope
PubMed: 33320087
DOI: 10.7554/eLife.63614 -
Journal of Microscopy and Ultrastructure 2020The damage of the adrenal gland by snake venoms needs to be clarified. Lethality (LD) of () venom was established by intraperitoneally mice injections. Preparation of...
The damage of the adrenal gland by snake venoms needs to be clarified. Lethality (LD) of () venom was established by intraperitoneally mice injections. Preparation of specimens for transmission electron microscopy samples from cortex adrenal gland biopsies at 3, 6, and 24 h was processed. The quantitative description by the principal component analysis (PCA) of the adrenal gland was as follows: thickening of the capillary endothelium, area of the capillary lumen, cell nucleus area, enlargement of the perinuclear space, number of mitochondria, area of the mitochondria, number of mitochondrial cristae, number of cristae per mitochondrial unit, and tubular diameter of the smooth endoplasmic reticulum (SER). Sections of the adrenal cortex, after 3 h postinjection with venom showed in the cortical cells: mitochondria with tubular cristae and slightly swollen SER cisternae, nucleus with variable heterochromatin content, irregular edges, and swollen nuclear envelope. After 6 h, cells with swollen nucleus envelope, electron dense lipids and mitochondria with loss of their cristae were observed. Myelin figures, close to the microvilli of the cortical cell, multivesicular bodies, swollen profiles of the SER, and electron dense lipid drops were noticed. After 24 h, thickening of the endothelial wall, fenestrae and projections into the capillary lumen, loss of the mitochondrial cristae, destruction of the capillary and the plasma membrane of the cortical cell, multivesicular body, SER loss, and an enlargement of the perinuclear space were detected. In the quantitative PCA, there were significant changes after the venom treatments.
PubMed: 33282685
DOI: 10.4103/JMAU.JMAU_49_19