Malformation of the endoplasmic reticulum system evolving into giant inclusions and Auer bodies in acute promyelocytic leukemia: an ultrastructural study of 6 cases

The endoplasmic reticulum（ER）is the largest membranous network serving as a region for protein, lipid and steroid synthesis, transport and storage. Detailed information about ER-cisternae, ER-tubules and rough endoplasmic reticulum (rER) is scarce in human blood cells. This study describes a series of giant inclusions and Auer bodies in promyeloblasts in six patients with acute promyelocytic leukemia (APL), by light microscopy, transmission electron microscopy (TEM) and cytochemical stains. TEM revealed that giant inclusions and pro-Auer bodies were associated with rER and surrounded by tubular structures composed of degenerated or redundant membrane in promyeloblasts, which corresponded with elements of the ER system. This paper reveals that in the promyeloblasts of APL, ER is the source of and transforms progressively into giant inclusions and Auer bodies.

The Cryo-EM Effect: Structural Biology of Neurodegenerative Disease Aggregates

Neurogenerative diseases are characterized by diverse protein aggregates with a variety of microscopic morphologic features. Although ultrastructural studies of human neurodegenerative disease tissues have been conducted since the 1960s, only recently have near-atomic resolution structures of neurodegenerative disease aggregates been described. Solid-state nuclear magnetic resonance spectroscopy and X-ray crystallography have provided near-atomic resolution information about in vitro aggregates but pose logistical challenges to resolving the structure of aggregates derived from human tissues. Recent advances in cryo-electron microscopy (cryo-EM) have provided the means for near-atomic resolution structures of tau, amyloid-β (Aβ), α-synuclein (α-syn), and transactive response element DNA-binding protein of 43 kDa (TDP-43) aggregates from a variety of diseases. Importantly, in vitro aggregate structures do not recapitulate ex vivo aggregate structures. Ex vivo tau aggregate structures indicate individual tauopathies have a consistent aggregate structure unique from other tauopathies. α-syn structures show that even within a disease, aggregate heterogeneity may correlate to disease course. Ex vivo structures have also provided insight into how posttranslational modifications may relate to aggregate structure. Though there is less cryo-EM data for human tissue-derived TDP-43 and Aβ, initial structural studies provide a basis for future endeavors. This review highlights structural variations across neurodegenerative diseases and reveals fundamental differences between experimental systems and human tissue derived protein inclusions.

An 80-Year-Old Woman With a Solitary Pulmonary Nodule

CASE PRESENTATION

An 80-year-old-woman was referred for evaluation of chest pain that appeared after providing care at home for her sick husband, which included helping him to get up and move about. The pain was initially triggered by lifting heavy objects but then became constant, without exacerbating or relieving factors. The pain was located in the left hemithorax and was not associated with shortness of breath or cough. Because the patient did not feel any better after a month, her general practitioner ordered a radiograph, which revealed a suspicious pulmonary nodule in the left upper lobe. She was a lifelong nonsmoker and denied any drug abuse. She had not been professionally exposed to lung carcinogens. She had a medical history of type 2 diabetes, ischemic cardiomyopathy, and renal artery stenosis. Her father died of lung cancer. She resided in Lille, France, and did not report any recent travel.

Globoids and Phytase: The Mineral Storage and Release System in Seeds

Phytate and phytases in seeds are the subjects of numerous studies, dating back as far as the early 20th century. Most of these studies concern the anti-nutritional properties of phytate, and the prospect of alleviating the effects of phytate with phytase. As reasonable as this may be, it has led to a fragmentation of knowledge, which hampers the appreciation of the physiological system at hand. In this review, we integrate the existing knowledge on the chemistry and biosynthesis of phytate, the globoid cellular structure, and recent advances on plant phytases. We highlight that these components make up a system that serves to store and-in due time-release the seed's reserves of the mineral nutrients phosphorous, potassium, magnesium, and others, as well as inositol and protein. The central component of the system, the phytate anion, is inherently rich in phosphorous and inositol. The chemical properties of phytate enable it to sequester additional cationic nutrients. Compartmentalization and membrane transport processes regulate the buildup of phytate and its associated nutrients, resulting in globoid storage structures. We suggest, based on the current evidence, that the degradation of the globoid and the mobilization of the nutrients also depend on membrane transport processes, as well as the enzymatic action of phytase.

Structures of α-synuclein filaments from multiple system atrophy

Synucleinopathies, which include multiple system atrophy (MSA), Parkinson's disease, Parkinson's disease with dementia and dementia with Lewy bodies (DLB), are human neurodegenerative diseases1. Existing treatments are at best symptomatic. These diseases are characterized by the presence of, and believed to be caused by the formation of, filamentous inclusions of α-synuclein in brain cells2,3. However, the structures of α-synuclein filaments from the human brain are unknown. Here, using cryo-electron microscopy, we show that α-synuclein inclusions from the brains of individuals with MSA are made of two types of filament, each of which consists of two different protofilaments. In each type of filament, non-proteinaceous molecules are present at the interface of the two protofilaments. Using two-dimensional class averaging, we show that α-synuclein filaments from the brains of individuals with MSA differ from those of individuals with DLB, which suggests that distinct conformers or strains characterize specific synucleinopathies. As is the case with tau assemblies4-9, the structures of α-synuclein filaments extracted from the brains of individuals with MSA differ from those formed in vitro using recombinant proteins, which has implications for understanding the mechanisms of aggregate propagation and neurodegeneration in the human brain. These findings have diagnostic and potential therapeutic relevance, especially because of the unmet clinical need to be able to image filamentous α-synuclein inclusions in the human brain.

Rethinking fibrinogen storage disease of the liver: ground glass and globular inclusions do not represent a congenital metabolic disorder but acquired collective retention of proteins

Three types of intracytoplasmic inclusions immunoreactive to fibrinogen are collectively diagnosed as hepatic fibrinogen storage disease. This study aimed to better characterize ground glass (type II) and globular (type III) fibrinogen inclusions by the pathological examination of 3 cases and a literature review. Three adults (age: 32-64 years; male/female = 2:1) were unexpectedly found to have fibrinogen-positive ground glass changes (type II inclusions) by liver needle biopsy, against a background of acute hepatitis E, resolving acute cholangitis, or severe lobular hepatitis of unknown etiology. One patient also had fibrinogen-positive intracytoplasmic globules (type III inclusions) in the first biopsy, but they were not present in a second biopsy. None had coagulation abnormalities or hypofibrinogenemia. On immunostaining, both inclusions were strongly positive for not only fibrinogen but also C-reactive protein and C4d. Ultrastructurally, ground glass changes corresponded to membrane-bound cytoplasmic inclusions containing amorphous, granular material. The pathological features of type II fibrinogen inclusions were identical to those of pale bodies in hepatocellular carcinoma. The literature review suggested that type I fibrinogen inclusions characterized by a polygonal appearance are strongly associated with mutations in fibrinogen genes, coagulopathy, and family history, whereas type II/III inclusions are immunoreactive to multiple proteins and typically develop in cases of other unrelated liver diseases. In conclusion, type II and III fibrinogen inclusions do not represent a true hereditary storage disease but instead the collective retention of multiple proteins. Given the lack of clinical significance, a less specific name (e.g., pale body) may be more appropriate for those inclusions.

Polyglucosan body structure in Lafora disease

Abnormal carbohydrate structures known as polyglucosan bodies (PGBs) are associated with neurological disorders, glycogen storage diseases (GSDs), and aging. A hallmark of the GSD Lafora disease (LD), a fatal childhood epilepsy caused by recessive mutations in the EPM2A or EPM2B genes, are cytoplasmic PGBs known as Lafora bodies (LBs). LBs result from aberrant glycogen metabolism and drive disease progression. They are abundant in brain, muscle and heart of LD patients and Epm2a^-/- and Epm2b^-/- mice. LBs and PGBs are histologically reminiscent of starch, semicrystalline carbohydrates synthesized for glucose storage in plants. In this study, we define LB architecture, tissue-specific differences, and dynamics. We propose a model for how small polyglucosans aggregate to form LBs. LBs are very similar to PGBs of aging and other neurological disorders, and so these studies have direct relevance to the general understanding of PGB structure and formation.

Characterization of multilamellar bodies and telocytes within the testicular interstitium of naked mole rat Heterocephalus glabe

Multilamellar bodies (MLBs) are produced and secreted by many cell types. In this study, we report the existence and ultrastructure of MLBs that are produced by Leydig cells and identification of telocytes in the testicular interstitium of naked mole rat. This study was performed on both breeder and non-breeder male naked mole rats using light microscopy, transmission electron microscopy, and morphometric approaches. In the testicular interstitium, the most prominent cells were Leydig cells, which contained numerous lipid droplets (LDs) in the cytoplasm. We found that MLBs were associated with the LDs of Leydig cells and were secreted into the extracellular or interstitial environment via exocytosis. After their release from Leydig cells, MLBs localized to the space between Leydig cells near blood vessels and attached to telocytes. We also identified telocytes in the testicular interstitium, and their cellular extensions were distributed throughout the interstitium. MLBs were aligned along the cellular extensions of telocytes, and membrane-to-membrane contact was observed between the cellular extensions of telocytes and MLBs, suggesting that telocytes may play a role in the transport of MLBs within the interstitial space. No ultrastructural differences were found in Leydig cells, telocytes, or MLBs between breeder and non-breeder testes. However, morphometric analysis revealed a significant difference in the number of MLBs between the breeder and non-breeder animals. Furthermore, both selective autophagy of LDs and non-selective autophagy were observed in Leydig cells. Typical features of macrolipophagy were also observed, as a few LDs were entirely enclosed by a limiting membrane. Remarkably, autophagy may be a key factor in the biogenesis of MLBs and steroid hormone production. The appearance of MLBs in the testicular interstitium of naked mole rats could thus be related to lipid storage and trafficking.

Proteasome-Rich PaCS as an Oncofetal UPS Structure Handling Cytosolic Polyubiquitinated Proteins. In Vivo Occurrence, in Vitro Induction, and Biological Role

In this article, we outline and discuss available information on the cellular site and mechanism of proteasome interaction with cytosolic polyubiquitinated proteins and heat-shock molecules. The particulate cytoplasmic structure (PaCS) formed by barrel-like particles, closely reproducing in vivo the high-resolution structure of 26S proteasome as isolated in vitro, has been detected in a variety of fetal and neoplastic cells, from living tissue or cultured cell lines. Specific trophic factors and interleukins were found to induce PaCS during in vitro differentiation of dendritic, natural killer (NK), or megakaryoblastic cells, apparently through activation of the MAPK-ERK pathway. Direct interaction of CagA bacterial oncoprotein with proteasome was shown inside the PaCSs of a Helicobacter pylori-infected gastric epithelium, a finding suggesting a role for PaCS in CagA-mediated gastric carcinogenesis. PaCS dissolution and autophagy were seen after withdrawal of inducing factors. PaCS-filled cell blebs and ectosomes were found in some cells and may represent a potential intercellular discharge and transport system of polyubiquitinated antigenic proteins. PaCS differs substantially from the inclusion bodies, sequestosomes, and aggresomes reported in proteinopathies like Huntington or Parkinson diseases, which usually lack PaCS. The latter seems more linked to conditions of increased cell proliferation/differentiation, implying an increased functional demand to the ubiquitin–proteasome system.

Digestive gland inclusion bodies in queen conch (Lobatus gigas) are non-parasitic

Unusual inclusion bodies occur within the epithelial cells of the digestive gland of queen conch, Lobatus gigas, and have previously been described as apicomplexan parasites. The aim of this study was to investigate the parasitic features of these inclusion bodies in queen conch. L. gigas from St. Kitts (Caribbean Sea) consistently (100% of n = 61) showed large numbers of ovoid to tri-bulbous dark brown inclusion bodies (15 × 30 µm) within vacuolar cells. Histochemical stains demonstrated iron, melanin, and glycoprotein and/or mucopolysaccharide within the inclusion bodies. Microscopic features indicative of a host response to injury were lacking in every case, as were consistent morphological forms to indicate distinct parasitic stages. Transmission electron microscopy failed to reveal cellular organelles of parasitic organisms and DNA extractions of purified inclusion bodies did not yield sufficient concentrations for successful PCR amplification. Scanning electron microscopy with energy dispersive X-ray analysis revealed a number of elements, particularly iron, within the inclusion bodies. We conclude that the inclusion bodies are not an infectious agent, and hypothesize that they represent a storage form for iron, and potentially other elements, within a protein matrix. Similar structures have been described in the digestive glands of other invertebrates, including prosobranchs.

Dropped Head Syndrome and the Presence of Rimmed Vacuoles in a Muscle Biopsy in Scleroderma-polymyositis Overlap Syndrome Associated with Anti-Ku Antibody

A 66-year-old woman with a history of interstitial lung disease presented with a 3-month history of dropped head syndrome (DHS), followed by camptocormia and extremity weakness. A clinical examination revealed Raynaud phenomenon, arthralgia, distal skin sclerosis, and microbleeds in the nailfold capillaries. An anti-Ku antibody test was positive. A muscle biopsy revealed inflammatory myopathy with rimmed vacuoles (RVs). The diagnosis of scleroderma-polymyositis (SSc-PM) overlap syndrome was made. RVs on a muscle biopsy in a patient with inflammatory myositis involving axial muscles may be seen either in inclusion body myositis or SSc-PM overlap syndrome. The examination of the skin and autoantibody testing help determine the diagnosis and treatment strategy.

Abnormal neurofilament inclusions and segregations in dorsal root ganglia of a Charcot-Marie-Tooth type 2E mouse model

Charcot-Marie-Tooth (CMT) disease or hereditary motor and sensory neuropathy is the most prevalent inherited peripheral neuropathy and is associated with over 90 causative genes. Mutations in neurofilament light polypeptide gene, NEFL cause CMT2E, an axonal form of CMT that results in abnormal structures and/or functions of peripheral axons in spinal cord motor neurons and dorsal root ganglion neurons. We have previously generated and characterized a knock-in mouse model of CMT2E with the N98S mutation in Nefl that presented with multiple inclusions in spinal cord neurons. In this report, we conduct immunofluorescence studies of cultured dorsal root ganglia (DRG) from Nefl^N98S/+ mice, and show that inclusions found in DRG neurites can occur in embryonic stages. Ultrastructural analyses reveal that the inclusions are disordered neurofilaments packed in high density, segregated from other organelles. Immunochemical studies show decreased NFL protein levels in DRG, cerebellum and spinal cord in Nefl^N98S/+ mice, and total NFL protein pool is shifted toward the triton-insoluble fraction. Our findings reveal the nature of the inclusions in Nefl^N98S/+ mice, provide useful information to understand mechanisms of CMT2E disease, and identify DRG from Nefl^N98S/+ mice as a useful cell line model for therapeutic discoveries.

Identification and characterization of GRA6/GRA7 of Neospora caninum in MDBK cells

Neospora caninum, an apicomplexan parasite, is recognized as a major bovine abortifacient. Dense granule antigens (GRAs) play important roles in the formation and modification of parasitophorous vacuoles (PVs) in Toxoplasma gondii. However, a few studies investigating GRAs have been reported in N. caninum. The aim of the present study was to characterize the dense GRA6/GRA7 of N. caninum in PVs using MDBK cells as a host cell model. Neospora caninum was inoculated into MDBK cells, and changes were observed using a transmission electron microscope (TEM). Neospora caninum GRA6/GRA7 were identified and characterized using bioinformatics, cell fractionation, and immunofluorescence. The TEM results revealed that integrated PVs were present in MDBK cells after N. caninum infection. Bioinformatics analysis showed that NcGRA6/NcGRA7 shared 28.76% and 29.66% homology with T. gondii GRA6/GRA7 (TgGRA6/TgGRA7) but had similar signal peptides, transmembrane domains, and motifs. Cell fractionation and subcellular localization analyses both showed that NcGRA6 was distributed in the lumen and intravacuolar network in soluble and transmembrane forms. The transmembrane form of NcGRA7 was observed in the PV membrane. These data lay a foundation for further study on bovine neosporosis and NcGRA6/NcGRA7 function during PV formation.

Chromatoid Bodies: Aggresome-like Characteristics and Degradation Sites for Organelles of Spermiogenic Cells

We investigated the localization of several markers for lysosomes and aggresomes in the chromatoid bodies (CBs) by immunoelectron microscopy. We found so-called aggresomal markers such as Hsp70 and ubiquitin in the core of the CBs and vimentin and proteasome subunit around the CBs. Ubiquitin-conjugating enzyme (E2) was also found in the CBs. In tubulovesicular structures surrounding the CBs, lysosomal markers were detected but an endoplasmic reticulum retention signal (KDEL) was not. Moreover, proteins located in each subcellular compartment, including the cytosol, mitochondria, and nucleus, were detected in the CBs. Signals for cytochrome oxidase I (COXI) coded on mitochondrial DNA were also found in the CBs. Quantitative analysis of labeling density showed that all proteins examined were concentrated in the CBs to some extent. These results show that the CBs have some aggresomal features, suggesting that they are not a synthetic site as proposed previously but a degradation site where unnecessary DNA, RNA, and proteins are digested.

Differential Translocation of Host Cellular Materials into the Chlamydia trachomatis Inclusion Lumen during Chemical Fixation

Chlamydia trachomatis manipulates host cellular pathways to ensure its proliferation and survival. Translocation of host materials into the pathogenic vacuole (termed 'inclusion') may facilitate nutrient acquisition and various organelles have been observed within the inclusion, including lipid droplets, peroxisomes, multivesicular body components, and membranes of the endoplasmic reticulum (ER). However, few of these processes have been documented in living cells. Here, we survey the localization of a broad panel of subcellular elements and find ER, mitochondria, and inclusion membranes within the inclusion lumen of fixed cells. However, we see little evidence of intraluminal localization of these organelles in live inclusions. Using time-lapse video microscopy we document ER marker translocation into the inclusion lumen during chemical fixation. These intra-inclusion ER elements resist a variety of post-fixation manipulations and are detectable via immunofluorescence microscopy. We speculate that the localization of a subset of organelles may be exaggerated during fixation. Finally, we find similar structures within the pathogenic vacuole of Coxiella burnetti infected cells, suggesting that fixation-induced translocation of cellular materials may occur into the vacuole of a range of intracellular pathogens.

[CME. Fabry disease: rare but not to be missed]

Beim Morbus Fabry handelt es sich um eine X-chromosomal-rezessiv vererbbare lysosomale Speicherkrankheit, die durch einen Enzymdefekt der α-Galaktosidase A entsteht. Es kommt zu einer Anreicherung der Sphingolipide in den Lysosomen des Gefässendothels sowie verschiedener Organe. Am häufigsten involviert sind Niere, Herz, Nervensystem, Gastrointestinum sowie die Augen. Nicht selten wird ein schwerer progredienter Krankheitsverlauf beobachtet, mit ersten Symptomen bereits in der Kindheit. Aufgrund der unspezifischen Krankheitssymptome ist es nicht einfach, die Erkrankung zu diagnostizieren, sodass sie häufig erst im Erwachsenenalter erkannt wird. Die ersten Symptome in der Kindheit beginnen oft mit schmerzhaften Akroparästhesien im Rahmen von peripheren Neuropathien. Hinzu kommen Müdigkeit, Fieberschmerzkrisen, gastrointestinale Symptome. Im fortgeschrittenen Stadium kann Morbus Fabry aufgrund von Endorganschäden wie Niereninsuffizienz, Schlaganfall oder Herzrhythmussstörungen bei Kardiomyopathie tödlich enden. Meistens sind Männer schwerer von der Krankheit betroffen. Die Prävalenz in der Gesamtbevölkerung wird mit 1:40 000 bis 1:70 000 geschätzt. Die einzige kausale Therapie stellt aktuell der Enzymersatz dar.

Pathological actin in vestibular hair cells of the waltzing guinea pig

Vestibular type 1 hair cells in the waltzing guinea pig contain needle-shaped inclusion bodies which grow in an uncontrolled fashion associated with the destruction of the cell. The needles are shown to be composed by filaments of actin, a protein identified in the electron microscope by its ability to bind subfragment 1 of myosin. Whereas actin filaments in stereocilia are oriented down towards the cell body, filaments in the needles point up towards the cuticular plate. The hereditary lesion appears to be associated with a defective control of polymerization of actin into filaments.

Hyaline Body Myopathy: Adulthood Manifestations

Background:

Hyaline body myopathy (HBM) is a rare chronic nonprogressive congenital myopathy, with variable patterns of inheritance.

Methods:

We describe a patient with congenital HBM with progression of weakness and increasing muscle pain in adulthood. Three muscle biopsies, done at various times in her life, are reported.

Results:

Symptoms started during childhood; however, as an adult, following a period of stability with no progression of the disease, the patient became symptomatic with worsening proximal limb weakness, severe aching pain and hypertrophy of calves. Moderate elevations of serum creatine kinase and myopathic features were noted on electrophysiologic testing. Muscle pathology showed significant fatty infiltration of skeletal muscle and increased number of fibers with internal nuclei. Histology demonstrated the presence of subsarcolemmal, well-delineated hyaline areas, which on histochemical studies was shown to be limited to type1 fibers. The hyaline bodies were dark with pH 4.2 ATPase and with immunohistochemical studies reacted only with myosin heavy chain slow. Electron microscopy showed the hyaline bodies to be composed of nonmembrane bound, fairly even sized granular material, which merged with the adjacent myofibrils. Earlier muscle biopsies, done during childhood, also revealed presence of similar subsarcolemmal hyaline deposits.

Conclusion:

There appears to be a pattern of presentation with adulthood progression in HBM, which has not been described before. Further case studies are required to understand the clinical progression in HBM.

Casein kinase II induced polymerization of soluble TDP-43 into filaments is inhibited by heat shock proteins

Background

Trans-activation Response DNA-binding Protein-43 (TDP-43) lesions are observed in Amyotrophic Lateral Sclerosis (ALS), Frontotemporal Lobar Degeneration with ubiquitin inclusions (FTLD-TDP) and 25–50% of Alzheimer's Disease (AD) cases. These abnormal protein inclusions are composed of either amorphous TDP-43 aggregates or highly ordered filaments. The filamentous TDP-43 accumulations typically contain clean 10–12 nm filaments though wider 18–20 nm coated filaments may be observed. The TDP-43 present within these lesions is phosphorylated, truncated and ubiquitinated, and these modifications appear to be abnormal as they are linked to both a cellular heat shock response and microglial activation. The mechanisms associated with this abnormal TDP-43 accumulation are believed to result in a loss of TDP-43 function, perhaps due to the post-translational modifications or resulting from physical sequestration of the TDP-43. The formation of TDP-43 inclusions involves cellular translocation and conversion of TDP-43 into fibrillogenic forms, but the ability of these accumulations to sequester normal TDP-43 and propagate this behavior between neurons pathologically is mostly inferred. The lack of methodology to produce soluble full length TDP-43 and recapitulate this polymerization into filaments as observed in disease has limited our understanding of these pathogenic cascades.

Results

The protocols described here generate soluble, full-length and untagged TDP-43 allowing for a direct assessment of the impact of various posttranslational modifications on TDP-43 function. We demonstrate that Casein Kinase II (CKII) promotes the polymerization of this soluble TDP-43 into 10 nm diameter filaments that resemble the most common TDP-43 structures observed in disease. Furthermore, these filaments are recognized as abnormal by Heat Shock Proteins (HSPs) which can inhibit TDP-43 polymerization or directly promote TDP-43 filament depolymerization.

Conclusion

These findings demonstrate CKII induces polymerization of soluble TDP-43 into filaments and Hsp90 promotes TDP-43 filament depolymerization. These findings provide rational for potential therapeutic intervention at these points in TDP-43 proteinopathies.

Autophagy-lysosome pathway associated neuropathology and axonal degeneration in the brains of alpha-galactosidase A-deficient mice

BACKGROUND

Mutations in the gene for alpha-galactosidase A result in Fabry disease, a rare, X-linked lysosomal storage disorder characterized by a loss of alpha-galactosidase A enzymatic activity. The resultant accumulation of glycosphingolipids throughout the body leads to widespread vasculopathy with particular detriment to the kidneys, heart and nervous system. Disruption in the autophagy-lysosome pathway has been documented previously in Fabry disease but its relative contribution to nervous system pathology in Fabry disease is unknown. Using an experimental mouse model of Fabry disease, alpha-galactosidase A deficiency, we examined brain pathology in 20-24 month old mice with particular emphasis on the autophagy-lysosome pathway.

RESULTS

Alpha-galactosidase A-deficient mouse brains exhibited enhanced punctate perinuclear immunoreactivity for the autophagy marker microtubule-associated protein light-chain 3 (LC3) in the parenchyma of several brain regions, as well as enhanced parenchymal and vascular immunoreactivity for lysosome-associated membrane protein-1 (LAMP-1). Ultrastructural analysis revealed endothelial cell inclusions with electron densities and a pronounced accumulation of electron-dense lipopigment. The pons of alpha-galactosidase A-deficient mice in particular exhibited a striking neuropathological phenotype, including the presence of large, swollen axonal spheroids indicating axonal degeneration, in addition to large interstitial aggregates positive for phosphorylated alpha-synuclein that co-localized with the axonal spheroids. Double-label immunofluorescence revealed co-localization of phosphorylated alpha-synuclein aggregates with ubiquitin and LC3.

CONCLUSION

Together these findings indicate widespread neuropathology and focused axonal neurodegeneration in alpha-galactosidase A-deficient mouse brain in association with disruption of the autophagy-lysosome pathway, and provide the basis for future mechanistic assessment of the contribution of the autophagy-lysosome pathway to this histologic phenotype.

TDP-43 inclusion bodies formed in bacteria are structurally amorphous, non-amyloid and inherently toxic to neuroblastoma cells

Accumulation of ubiquitin-positive, tau- and α-synuclein-negative intracellular inclusions of TDP-43 in the central nervous system represents the major hallmark correlated to amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. Such inclusions have variably been described as amorphous aggregates or more structured deposits having an amyloid structure. Following the observations that bacterial inclusion bodies generally consist of amyloid aggregates, we have overexpressed full-length TDP-43 and C-terminal TDP-43 in E. coli, purified the resulting full-length and C-terminal TDP-43 containing inclusion bodies (FL and Ct TDP-43 IBs) and subjected them to biophysical analyses to assess their structure/morphology. We show that both FL and Ct TDP-43 aggregates contained in the bacterial IBs do not bind amyloid dyes such as thioflavin T and Congo red, possess a disordered secondary structure, as inferred using circular dichroism and infrared spectroscopies, and are susceptible to proteinase K digestion, thus possessing none of the hallmarks for amyloid. Moreover, atomic force microscopy revealed an irregular structure for both types of TDP-43 IBs and confirmed the absence of amyloid-like species after proteinase K treatment. Cell biology experiments showed that FL TDP-43 IBs were able to impair the viability of cultured neuroblastoma cells when added to their extracellular medium and, more markedly, when transfected into their cytosol, where they are at least in part ubiquitinated and phosphorylated. These data reveal an inherently high propensity of TDP-43 to form amorphous aggregates, which possess, however, an inherently high ability to cause cell dysfunction. This indicates that a gain of toxic function caused by TDP-43 deposits is effective in TDP-43 pathologies, in addition to possible loss of function mechanisms originating from the cellular mistrafficking of the protein.

Unusual intracytoplasmic crystalline inclusions in chronic myelomonocytic leukemia with double minute chromosomes and MYC amplification: a rare case

Chronic myelomonocytic leukemia (CMML) is a clonal hematological disease characterized by the presence of peripheral blood monocytosis and bone marrow dysplasia. Double minute chromosomes (dmin) are rare and intracytoplasmic crystalline inclusions are very rare in hematologic malignancies. We present a case of CMML with dmin and unusual intracytoplasmic crystalline inclusions. To our knowledge, no such case has previously been reported.

'Cand. Actinochlamydia clariae' gen. nov., sp. nov., a unique intracellular bacterium causing epitheliocystis in catfish (Clarias gariepinus) in Uganda

Background and Objectives

Epitheliocystis, caused by bacteria infecting gill epithelial cells in fish, is common among a large range of fish species in both fresh- and seawater. The aquaculture industry considers epitheliocystis an important problem. It affects the welfare of the fish and the resulting gill disease may lead to mortalities. In a culture facility in Kampala, Uganda, juveniles of the African sharptooth catfish (Clarias gariepinus) was observed swimming in the surface, sometimes belly up, showing signs of respiratory problems. Histological examination of gill tissues from this fish revealed large amounts of epitheliocysts, and also presence of a few Ichthyobodo sp. and Trichodina sp.

Methods and Results

Sequencing of the epitheliocystis bacterium 16S rRNA gene shows 86.3% similarity with Candidatus Piscichlamydia salmonis causing epitheliocystis in Atlantic salmon (Salmo salar). Transmission electron microscopy showed that the morphology of the developmental stages of the bacterium is similar to that of members of the family Chlamydiaceae. The similarity of the bacterium rRNA gene sequences compared with other chlamydia-like bacteria ranged between 80.5% and 86.3%. Inclusions containing this new bacterium have tubules/channels (termed actinae) that are radiating from the inclusion membrane and opening on the cell surface or in neighbouring cells.

Conclusions

Radiation of tubules/channels (actinae) from the inclusion membrane has never been described in any of the other members of Chlamydiales. It seems to be a completely new character and an apomorphy. We propose the name Candidatus Actinochlamydia clariae gen. nov., sp. nov. (Actinochlamydiaceae fam. nov., order Chlamydiales, phylum Chlamydiae) for this new agent causing epitheliocystis in African sharptooth catfish.

Supramolecular organization of protein-releasing functional amyloids solved in bacterial inclusion bodies

Slow protein release from amyloidal materials is a molecular platform used by nature to control protein hormone secretion in the endocrine system. The molecular mechanics of the sustained protein release from amyloids remains essentially unexplored. Inclusion bodies (IBs) are natural amyloids that occur as discrete protein nanoparticles in recombinant bacteria. These protein clusters have been recently explored as protein-based functional biomaterials with diverse biomedical applications, and adapted as nanopills to deliver recombinant protein drugs into mammalian cells. Interestingly, the slow protein release from IBs does not significantly affect the particulate organization and morphology of the material, suggesting the occurrence of a tight scaffold. Here, we have determined, by using a combined set of analytical approaches, a sponge-like supramolecular organization of IBs combining differently folded protein versions (amyloid and native-like), which supports both mechanical stability and sustained protein delivery. Apart from offering structural clues about how amyloid materials release their monomeric protein components, these findings open exciting possibilities for the tailored development of smart biofunctional materials, adapted to mimic the functions of amyloid-based secretory glands of higher organisms.

Vascular occlusions in grapevines with Pierce's disease make disease symptom development worse

Vascular occlusions are common structural modifications made by many plant species in response to pathogen infection. However, the functional role(s) of occlusions in host plant disease resistance/susceptibility remains controversial. This study focuses on vascular occlusions that form in stem secondary xylem of grapevines (Vitis vinifera) infected with Pierce's disease (PD) and the impact of occlusions on the hosts' water transport and the systemic spread of the causal bacterium Xylella fastidiosa in infected vines. Tyloses are the predominant type of occlusion that forms in grapevine genotypes with differing PD resistances. Tyloses form throughout PD-susceptible grapevines with over 60% of the vessels in transverse sections of all examined internodes becoming fully blocked. By contrast, tylose development was mainly limited to a few internodes close to the point of inoculation in PD-resistant grapevines, impacting only 20% or less of the vessels. The extensive vessel blockage in PD-susceptible grapevines was correlated to a greater than 90% decrease in stem hydraulic conductivity, compared with an approximately 30% reduction in the stems of PD-resistant vines. Despite the systemic spread of X. fastidiosa in PD-susceptible grapevines, the pathogen colonized only 15% or less of the vessels in any internode and occurred in relatively small numbers, amounts much too small to directly block the vessels. Therefore, we concluded that the extensive formation of vascular occlusions in PD-susceptible grapevines does not prevent the pathogen's systemic spread in them, but may significantly suppress the vines' water conduction, contributing to PD symptom development and the vines' eventual death.

Pale body-like inclusion formation and neurodegeneration following depletion of 26S proteasomes in mouse brain neurones are independent of α-synuclein

Parkinson's disease (PD) is characterized by the progressive degeneration of substantia nigra pars compacta (SNpc) dopaminergic neurones and the formation of Lewy bodies (LB) in a proportion of the remaining neurones. α-synuclein is the main component of LB, but the pathological mechanisms that lead to neurodegeneration associated with LB formation remain unclear. Three pivotal elements have emerged in the development of PD: α-synuclein, mitochondria and protein degradation systems. We previously reported a unique model, created by conditional genetic depletion of 26S proteasomes in the SNpc of mice, which mechanistically links these three elements with the neuropathology of PD: progressive neurodegeneration and intraneuronal inclusion formation. Using this model, we tested the hypothesis that α-synuclein was essential for the formation of inclusions and neurodegeneration caused by 26S proteasomal depletion. We found that both of these processes were independent of α-synuclein. This provides an important insight into the relationship between the proteasome, α-synuclein, inclusion formation and neurodegeneration. We also show that the autophagy-lysosomal pathway is not activated in 26S proteasome-depleted neurones. This leads us to suggest that the paranuclear accumulation of mitochondria in inclusions in our model may reflect a role for the ubiquitin proteasome system in mitochondrial homeostasis and that neurodegeneration may be mediated through mitochondrial factors linked to inclusion biogenesis.

GM2 gangliosidosis in an adult pet rabbit

A 1.5-year-old neutered male rabbit was presented with chronic nasal discharge and ataxia. Rapid progression of neurological signs was noted subsequent to general anaesthesia and the rabbit was humanely destroyed due to the poor prognosis. At necropsy examination there were no gross changes affecting the brain or spinal cord. Microscopical examination revealed that the perikarya of numerous neurons in the brain and spinal cord were distended by the intracytoplasmic accumulation of pale, finely granular to vacuolar material. Transmission electron microscopy showed this to be composed of concentric membranous cytoplasmic bodies. Thin layer chromatography revealed elevation of GM2 ganglioside in the brain of this rabbit compared with that of an unaffected control rabbit. Enzymatically, there was markedly reduced activity of tissue β-hexosaminidase A in brain and liver tissue from the rabbit. This was a result of an almost complete absence of the enzymatic activity of the α-subunit of that enzyme. These findings are consistent with sphingolipidosis comparable with human GM2 gangliosidosis variant B1.

Accumulation of lipid inclusions in astrocytes of aging human optic nerve

We examined age-related changes in the human optic nerve (ON) from 10 postmortem donor eye samples (age: 21- to 94-year-old). In aged ON, many axons showed paucity of cytoskeleton, and possessed disorganized myelin that remained in the extracellular space. Lipid inclusions were detected in glia, as stained by oil red O, and these accumulated with aging. To identify and confirm which glial cell type possessed lipid inclusions, we performed immunohistochemistry (IHC) and transmission electron microscopy (TEM). Comparisons were made from TEM features and size of the glia immunolabeled with glial fibrillary acidic protein and glutamine synthetase (markers for astrocytes) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (a marker for oligodendrocytes). It was found that lipid inclusions were restricted to the astrocytes having larger perikarya than the oligodendrocytes (IHC) and possessing filaments in cytoplasm (TEM). These astrocytes also possessed myelin debris and it is thus likely that those inclusions originated from degenerated myelin of the ON axons. These data indicate that astrocytes play a role in phagocytosis and clearance of disorganized myelin in aging human ON.

Kinetics of inclusion body formation and its correlation with the characteristics of protein aggregates in Escherichia coli

The objective of the research was to understand the structural determinants governing protein aggregation into inclusion bodies during expression of recombinant proteins in Escherichia coli. Recombinant human growth hormone (hGH) and asparaginase were expressed as inclusion bodies in E.coli and the kinetics of aggregate formation was analyzed in details. Asparaginase inclusion bodies were of smaller size (200 nm) and the size of the aggregates did not increase with induction time. In contrast, the seeding and growth behavior of hGH inclusion bodies were found to be sequential, kinetically stable and the aggregate size increased from 200 to 800 nm with induction time. Human growth hormone inclusion bodies showed higher resistance to denaturants and proteinase K degradation in comparison to those of asparaginase inclusion bodies. Asparaginase inclusion bodies were completely solubilized at 2–3 M urea concentration and could be refolded into active protein, whereas 7 M urea was required for complete solubilization of hGH inclusion bodies. Both hGH and asparaginase inclusion bodies showed binding with amyloid specific dyes. In spite of its low β-sheet content, binding with dyes was more prominent in case of hGH inclusion bodies than that of asparaginase. Arrangements of protein molecules present in the surface as well as in the core of inclusion bodies were similar. Hydrophobic interactions between partially folded amphiphillic and hydrophobic alpha-helices were found to be one of the main determinants of hGH inclusion body formation. Aggregation behavior of the protein molecules decides the nature and properties of inclusion bodies.

Macrophages sequester clofazimine in an intracellular liquid crystal-like supramolecular organization

Clofazimine is a poorly-soluble but orally-bioavailable small molecule drug that massively accumulates in macrophages when administered over prolonged periods of time. To determine whether crystal-like drug inclusions (CLDIs) that form in subcellular spaces correspond to pure clofazimine crystals, macrophages of clofazimine-fed mice were elicited with an intraperitoneal thioglycollate injection. Inside these cells, CLDIs appeared uniform in size and shape, but were sensitive to illumination. Once removed from cells, CLDIs were unstable. Unlike pure clofazimine crystals, isolated CLDIs placed in distilled water burst into small birefringent globules, which aggregated into larger clusters. Also unlike pure clofazimine crystals, CLDIs fragmented when heated, and disintegrated in alkaline media. In contrast to all other organelles, CLDIs were relatively resistant to sonication and trypsin digestion, which facilitated their biochemical isolation. The powder x-ray diffraction pattern obtained from isolated CLDIs was consistent with the diffraction pattern of liquid crystals and inconsistent with the expected molecular diffraction pattern of solid, three dimensional crystals. Observed with the transmission electron microscope (TEM), CLDIs were bounded by an atypical double-layered membrane, approximately 20 nanometers thick. CLDIs were polymorphic, but generally exhibited an internal multilayered organization, comprised of stacks of membranes 5 to 15 nanometers thick. Deep-etch, freeze-fracture electron microscopy of unfixed snap-frozen tissue samples confirmed this supramolecular organization. These results suggest that clofazimine accumulates in macrophages by forming a membrane-bound, multilayered, liquid crystal-like, semi-synthetic cytoplasmic structure.

Structural and metabolic correlation for Bacillus megaterium ACBT03 in response to colchicine biotransformation

This study aims to evaluate the effects of colchicine on metabolic and structural changes in Bacillus megaterium ACBT03, enduring colchicine bioconversion. Electron microscopy examination of cells adapted to different concentrations of colchicine for its bioconversion to pharmacologically active 3-demethylated colchicine, endowed changes in cell shape, decreased cell wall and plasma membrane thickness. In line with microscopic studies, lipid and membrane protein contents were drastically reduced in bacterial cells adapted to higher concentrations of colchicine and resulting into decrease in cell membrane thickness. More numbers of polyhydroxybutyrate (PHB) rich inclusion bodies were found inside the colchicine adapted cells and presence of higher amount of PHB, a carbon source for generation of redox potential, indicates that it might be responsible for activation of P450 BM-3 enzyme and plays significant role in colchicine demethylation. The presence of dense ribosome like bodies in colchicine adapted cells showed higher biosynthesis of P450 BM-3. Reduction in cell wall and cell membrane thickness, presence of more inclusion bodies and ribosome like masses in colchicine adapted cells were some of the key interlinked phenomena responsible for colchicine bioconversion. This is the first study which reports that colchicine demethylation process severely affects the structural and metabolic functions of the bacteria.

Viral basophilic inclusions in the digestive gland of razor clams Ensis arcuatus (Pharidae) in Galicia (NW Spain)

During a histological survey of razor clam Ensis arcuatus (Jeffreys, 1865) from Galicia (NW Spain), basophilic inclusion bodies were observed in epithelial cells of the digestive gland. Transmission electron microscopy revealed the intranuclear position of these inclusions containing viral particles with icosahedral symmetry. Size and symmetry of these unenveloped virus particles suggest similarities to the families Papillomaviridae and Polyomaviridae which have been described as causing a viral gametocytic hypertrophy in oysters Crassostrea virginica and C. gigas. This is the first report of viral particles in E. arcuatus.

Undifferentiated (embryonal) liver sarcoma: synchronous and metachronous occurrence with neoplasms other than mesenchymal liver hamartoma

Undifferentiated (embryonal) liver sarcoma (UELS) is a rare tumor that typically occurs in children. The association of UELS with neoplasm other than mesenchymal liver hamartoma is exceedingly rare. The aim of the study was to report 3 cases of UELS, 2 of them being interesting because of their association with another neoplasm, vaginal embryonal rhabdomyosarcoma in a teenage girl and B-acute lymphoblastic leukemia in a middle-aged woman. Besides, one of our cases of UELS, in a 58-year-old woman, is an extremely rare presentation of such a tumor in a middle-aged adult. The patient's clinical features, therapy, and pathologic results were reviewed; immunohistochemical analysis and, in 2 cases, electron microscopy were performed. In this study, all 3 patients were females aged 13, 13, and 58 years. Histopathologic evaluation of resected liver tumors confirmed the diagnosis of UELS in all of them. In 2 of the cases, metachronous occurrence of UELS with vaginal embryonal rhabdomyosarcoma in a teenage girl and B-acute lymphoblastic leukemia in a middle-aged woman is described. Careful clinical analysis, histologic studies, and immunohistochemistry are mandatory to distinguish UELS from other hepatic malignancies with similar or overlapping features and to exclude the possibility of other tumors that may be considered in the differential diagnosis. The association of UELS with another neoplasm is exceedingly rare.

Chlamydia species-dependent differences in the growth requirement for lysosomes

Genome reduction is a hallmark of obligate intracellular pathogens such as Chlamydia, where adaptation to intracellular growth has resulted in the elimination of genes encoding biosynthetic enzymes. Accordingly, chlamydiae rely heavily on the host cell for nutrients yet their specific source is unclear. Interestingly, chlamydiae grow within a pathogen-defined vacuole that is in close apposition to lysosomes. Metabolically-labeled uninfected host cell proteins were provided as an exogenous nutrient source to chlamydiae-infected cells, and uptake and subsequent labeling of chlamydiae suggested lysosomal degradation as a source of amino acids for the pathogen. Indeed, Bafilomycin A1 (BafA1), an inhibitor of the vacuolar H⁺/ATPase that blocks lysosomal acidification and functions, impairs the growth of C. trachomatis and C. pneumoniae, and these effects are especially profound in C. pneumoniae. BafA1 induced the marked accumulation of material within the lysosomal lumen, which was due to the inhibition of proteolytic activities, and this response inhibits chlamydiae rather than changes in lysosomal acidification per se, as cathepsin inhibitors also inhibit the growth of chlamydiae. Finally, the addition of cycloheximide, an inhibitor of eukaryotic protein synthesis, compromises the ability of lysosomal inhibitors to block chlamydial growth, suggesting chlamydiae directly access free amino acids in the host cytosol as a preferred source of these nutrients. Thus, chlamydiae co-opt the functions of lysosomes to acquire essential amino acids.

Imaging internal features of whole, unfixed bacteria

Wet scanning-transmission electron microscopy (STEM) is a technique that allows high-resolution transmission imaging of biological samples in a hydrated state, with minimal sample preparation. However, it has barely been used for the study of bacterial cells. In this study, we present an analysis of the advantages and disadvantages of wet STEM compared with standard transmission electron microscopy (TEM). To investigate the potential applications of wet STEM, we studied the growth of polyhydroxyalkanoate and triacylglycerol carbon storage inclusions. These were easily visible inside cells, even in the early stages of accumulation. Although TEM produces higher resolution images, wet STEM is useful when preservation of the sample is important or when studying the relative sizes of different features, since samples do not need to be sectioned. Furthermore, under carefully selected conditions, it may be possible to maintain cell viability, enabling new types of experiments to be carried out. To our knowledge, internal features of bacterial cells have not been imaged previously by this technique.

Proteasome inhibition drives HDAC6-dependent recruitment of tau to aggresomes

Lesions containing aggregated and hyperphosphorylated tau protein are characteristic of neurodegenerative tauopathies. We have developed a cellular model of pathological tau deposition and clearance by overexpressing wild type human tau in HEK293 cells. When proteasome activity is inhibited, HEK293/tau cells accumulate tau protein in structures that bear many of the hallmarks of aggresomes. These include recruitment of tau into large spherical inclusions, accumulation of the retrograde motor protein dynein at the centrosome, formation of an intermediate filament cage around inclusions, and clustering of mitochondria at the aggresome. Tau aggresomes form rapidly and can be cleared upon relief of proteasome inhibition. We observe recruitment of pathological misfolded phospho-tau species to aggresomes. Immunoblotting reveals accumulation of detergent insoluble aggregated tau species. Knockdown of histone deacetylase 6, a protein known to interact with tau, reveals a requirement for HDAC6 activity in tau aggresome formation. Direct observation of the accumulation and clearance of abnormal tau species will allow us to dissect the cellular and molecular mechanisms at work in clearing aggresomal tau and its similarity to disease relevant pathological tau clearance mechanisms.

The lipid peroxidation products 4-oxo-2-nonenal and 4-hydroxy-2-nonenal promote the formation of α-synuclein oligomers with distinct biochemical, morphological, and functional properties

Oxidative stress has been implicated in the etiology of neurodegenerative disorders with α-synuclein pathology. Lipid peroxidation products such as 4-oxo-2-nonenal (ONE) and 4-hydroxy-2-nonenal (HNE) can covalently modify and structurally alter proteins. Herein, we have characterized ONE- or HNE-induced α-synuclein oligomers. Our results demonstrate that both oligomers are rich in β-sheet structure and have a molecular weight of about 2000 kDa. Atomic force microscopy analysis revealed that ONE-induced α-synuclein oligomers were relatively amorphous, with a diameter of 40-80 nm and a height of 4-8 nm. In contrast, the HNE-induced α-synuclein oligomers had a protofibril-like morphology with a width of 100-200 nm and a height of 2-4 nm. Furthermore, neither oligomer type polymerized into amyloid-like fibrils despite prolonged incubation. Although more SDS and urea stable, because of a higher degree of cross-linking, ONE-induced α-synuclein oligomers were less compact and more sensitive to proteinase K treatment. Finally, both ONE- and HNE-induced α-synuclein oligomers were cytotoxic when added exogenously to a neuroblastoma cell line, but HNE-induced α-synuclein oligomers were taken up by the cells to a significantly higher degree. Despite nearly identical chemical structures, ONE and HNE induce the formation of off-pathway α-synuclein oligomers with distinct biochemical, morphological, and functional properties.

Atypical (symplastic) leiomyoma of the uterus--a case report

A 30-year-old, nulliparous woman presented with a history of subfertility. On examination she was found to have uterine fibroid of 28 weeks size of gravid uterus and subsequently laporatomy myomectomy was performed. Multilobulated masses, with diameters ranging from 22 mm to 160 mm were found. Cut sections of the lobulated masses showed whitish whorled cut surface. One of the multilobulated masses had a cystic cavity, measuring 60x50x35 mm(3). Light microscopic findings of the mass with the cystic cavity showed a well-circumscribed cellular tumour composed of cells exhibiting moderate nuclear atypia which were enlarged, nuclei with prominent chromatin clumping and were distributed in areas. Some tumour cells showed large nuclear pseudoinclusions, multinucleated or multilobated tumour giant cells, smudging and few enlarged nucleoli. Mitotic activity was 4 MFs per 10 HPFs. Occasional cells with intracytoplasmic inclusions resembling rhabdoid - like features were seen. There were no atypical mitoses or tumour necroses were noted. Diagnosis of atypical leiomyoma or symplastic leiomyoma was made. Atypical or symplastic leiomyomas are rare in the region of Malaysia and the present case discusses its incidence in younger age, its morphological features along with diagnosis and clinical outcome.

Ultrastructure of granular osmiophilic material deposits (GOM) in arterioles of CADASIL patients

Granular osmiophilic material (GOM) is a pathognomonic feature of CADASIL that may be a consequence of pathological processes triggered by Notch3 mutations. Since knowledge of the effects of CADASIL-associated GOM deposits is important to understand the molecular pathogenesis of this disorder, we performed a thorough ultrastructural analysis of GOM morphology in the skin and muscle arterioles in CADASIL patients. Electron microscopy revealed numerous GOM deposits with different morphology including size, shape and osmiophilic density. Osmiophilic granular material of high density was frequently observed in part of GOM deposits located near vascular smooth muscle cells (VSMC) while a part localized distally from the cell body was less dense and loose. On the basis of our observations we postulate that GOM can be formed on the surface of VSMC in the arteriolar wall and penetrate from these cells into the basement membrane and/or extracellular matrix. The dispersion of granules, which form GOM deposits, may be one of the factors triggering the thickening and changes in the basement membrane and/or extracellular matrix.

Chlamydia trachomatis intercepts Golgi-derived sphingolipids through a Rab14-mediated transport required for bacterial development and replication

Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation.

Neuronal ceroid lipofuscinosis diagnosed via skin biopsy

We aim to report that skin biopsy, a non-invasive test by neurological standards, may lead to a diagnosis. A 4-year-old male presented with a 2-year history of epilepsy and progressive developmental regression. The patient had a mildly elevated ammonia level; however, evaluation for the accumulation of excess serum amino acids and evaluation of urine for organic acids was negative. MRI revealed cerebral atrophy, and an electroencephalogram demonstrated multifocal sharp and slow waves. Due to the progressive degenerative neurologic presentation, a neurologic storage disease was favored. An axillary skin biopsy was performed, revealing eosinophilic intra-cytoplasmic inclusions within the eccrine glands. A periodic acid-Schiff stain also highlighted these inclusions. Electron microscopic studies demonstrated characteristic multiple membrane-bound inclusions within the eccrine epithelial cells, containing curvilinear inclusion material characteristic of neuronal ceroid lipofuscinosis. The clinical, histological, electron microscopic and enzymatic studies were diagnostic of late-infantile onset neuronal ceroid lipofuscinosis.

Hereditary diffuse leukoencephalopathy with spheroids: ultrastructural and immunoelectron microscopic studies

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is a rare autosomal dominant disorder characterized by cerebral white matter degeneration with myelin loss and axonal swellings (spheroids) leading to progressive cognitive and motor dysfunction. Histopathology of HDLS has been well characterized, but ultrastructural details are lacking. Here we report ultrastructural and immunoelectron microscopic characterization of spheroids and capillary basal lamina in white matter of HDLS brains. Spheroids had thin or discontinuous or no myelin sheaths. They contained various combinations of aggregated neurofilaments (NF), cytoplasmic organelles, dense bodies, and laminated figures. Aggregated filaments labeled with antibodies to phosphorylated NF (pNF), non-pNF and amyloid precursor protein. The gliotic white matter had many reactive astrocytes, and lipid-laden macrophages with membranous and fingerprint-like bodies. The basal laminas (BL) of many capillaries were dilated, and the enlarged space was heavily deposited with banded collagen type I and III. Some BL had focal thickenings and duplications. Fibronectin, not collagen IV, was found associated with banded collagen. The various types of axonal spheroids and changes in capillary basal lamina have not been emphasized previously. It remains to be determined if they are a reactive process or a primary mechanism of white matter degeneration in HDLS.

Characterization of anthocyanic vacuolar inclusions in Vitis vinifera L. cell suspension cultures

Anthocyanic vacuolar inclusions (AVIs) are intra-vacuolar structures capable of concentrating anthocyanins and are present in over 50 of the highest anthocyanin-accumulating plant species. Presence of AVIs alters pigment intensity, total anthocyanin levels, pigment hue and causes bathochromic shifts in a spatio-temporal manner within various flowers, vegetables and fruits. A year-long study on Vitis vinifera cell suspension cultures found a strong correlation between AVI prevalence and anthocyanin content, but not the number of pigmented cells, growth rate or stilbene content. Furthermore, enhancement of the prevalence of AVIs and anthocyanins was achieved by treatment of V. vinifera cell suspension cultures with sucrose, jasmonic acid and white light. A unique autofluorescence of anthocyanins was used to demonstrate microscopically that AVIs proceed from the cytosol across the tonoplast and were able to coalesce intravacuolarly, with fewer, larger AVIs predominating as cells mature. Purification and characterisation of these bodies were performed, showing that they were dense, highly organic structures, with a lipid component indicative of membrane-encasement. These purified AVIs were also shown to comprise long-chain tannins and possessed an increased affinity for binding acylated anthocyanins, though no unique protein component was detected.