The lack of the cell division protein FtsZ induced generation of giant cells under acidic stress in cyanobacterium Synechocystis sp. PCC6803

Bacteria exposed to environmental stresses often exhibit superior acclimation abilities to environmental change. Acid treatment causes an increase in the cell length of the cyanobacterium Synechocystis sp. PCC6803 under light conditions. We aimed to elucidate the relationship between acidic stress and cell enlargement. After being synchronized under dark conditions, the cells were cultivated at different pH (pH 8.0 or pH 6.0) levels under light conditions. Synechocystis 6803 cells exhibited only cell growth occurred (cell volume expansion) and slow proliferation under the acidic condition. In the recovery experiment of the enlarged cells, they proliferated normally at pH 8.0, and the cell lengths decreased to the normal cell size under light conditions. Inhibition of cell division might be caused by acidic stress. To understand the effect of acidic stress on cell division, we evaluated the expression of FtsZ via Western blotting. The FtsZ concentration in cells was lower at pH 6.0 than at pH 8.0 and was not sufficient for cell division in the photoautotrophic conditions. ClpXP is well known as a regulator of the Z-ring dynamics in E. coli. The transcriptional level of four clpXP genes was upregulated approximately threefold at pH 6.0 after 24 h compared with that in cells grown at pH 8.0. The lack of FtsZ may be caused by the upregulation of clpXP expression under acidic condition. Therefore, ClpXP may participate in the degradation of FtsZ and be involved in the regulation of cell division via FtsZ under acidic stress in Synechocystis 6803.

The resting membrane potential of hSC-CM in a syncytium is more hyperpolarised than that of isolated cells

Human-induced pluripotent stem cell (hiPSC) and stem cell (hSC) derived cardiomyocytes (CM) are gaining popularity as in vitro model for cardiology and pharmacology studies. A remaining flaw of these cells, as shown by single-cell electrophysiological characterization, is a more depolarized resting membrane potential (RMP) compared to native CM. Most reports attribute this to a lower expression of the Kir2.1 potassium channel that generates the IK1 current. However, most RMP recordings are obtained from isolated hSC/hiPSC-CMs whereas in a more native setting these cells are interconnected with neighboring cells by connexin-based gap junctions, forming a syncytium. Hereby, these cells are electrically connected and the total pool of IK1 increases. Therefore, the input resistance (Ri) of interconnected cells is lower than that of isolated cells. During patch clamp experiments pipettes need to be well attached or sealed to the cell, which is reflected in the seal resistance (Rs), because a nonspecific ionic current can leak through this pipette-cell contact or seal and balance out small currents within the cell such as IK1. By recording the action potential of isolated hSC-CMs and that of hSC-CMs cultured in small monolayers, we show that the RMP of hSC-CMs in monolayer is approximately -20 mV more hyperpolarized compared to isolated cells. Accordingly, adding carbenoxolone, a connexin channel blocker, isolates the cell that is patch clamped from its neighboring cells of the monolayer and depolarizes the RMP. The presented data show that the recorded RMP of hSC-CMs in a syncytium is more negative than that determined from isolated hSC/hiPSC-CMs, most likely because the active pool of Kir2.1 channels increased.

Furin cleavage of the SARS-CoV-2 spike is modulated by O-glycosylation

The SARS-CoV-2 coronavirus responsible for the global pandemic contains a novel furin cleavage site in the spike protein (S) that increases viral infectivity and syncytia formation in cells. Here, we show that O-glycosylation near the furin cleavage site is mediated by members of the GALNT enzyme family, resulting in decreased furin cleavage and decreased syncytia formation. Moreover, we show that O-glycosylation is dependent on the novel proline at position 681 (P681). Mutations of P681 seen in the highly transmissible alpha and delta variants abrogate O-glycosylation, increase furin cleavage, and increase syncytia formation. Finally, we show that GALNT family members capable of glycosylating S are expressed in human respiratory cells that are targets for SARS-CoV-2 infection. Our results suggest that host O-glycosylation may influence viral infectivity/tropism by modulating furin cleavage of S and provide mechanistic insight into the role of the P681 mutations found in the highly transmissible alpha and delta variants.

[Osteoclast-Like giant cell bladder carcinoma: Case report]

BACKGROUND

Osteoclast-like giant cell bladder carcinomas are an extremely unusual and aggressive histological subtype of urothelial carcinomas. Only 30 cases are reported in the international literature.

CLINICAL CASE

A 79-year-old male patient attended our Urology department for a six-month history of macroscopic hematuria. As part of its diagnostic protocol, a CT scan of the abdomen and pelvis with elimination phase was performed, finding a 12-mm filling defect at the level of the posterior wall of the bladder; subsequently, a cystoscopy was performed confirming the presence of a 1.5 cm bladder tumor, which was completely resected. Pathology analysis with hematoxylin and eosin staining revealed a composition of mononuclear cells and osteoclast-like giant cells; immunohistochemistry was positive for epithelial markers CK AE-1 / AE-3, EMA, P53 and CD68.

CONCLUSIONS

These tumors are extremely unusual and aggressive. The only diagnostic method is through immunohistochemistry where the presence of epithelial markers for urothelium in neoplastic cells is confirmed. Radical surgical treatment is recommended and to date there is no proven effective adjuvant treatment. Its median overall survival is 15 months.

Multiple versus solitary giant cell lesions of the jaw: Similar or distinct entities?

The majority of giant cell lesions of the jaw present as a solitary focus of disease in bones of the maxillofacial skeleton. Less frequently they occur as multifocal lesions. This raises the clinical dilemma if these should be considered distinct entities and therefore each need a specific therapeutic approach. Solitary giant cell lesions of the jaw present with a great diversity of symptoms. Recent molecular analysis revealed that these are associated with somatic gain-of-function mutations in KRAS, FGFR1 or TRPV4 in a large component of the mononuclear stromal cells which all act on the RAS/MAPK pathway. For multifocal lesions, a small group of neoplastic multifocal giant cell lesions of the jaw remain after ruling out hyperparathyroidism. Strikingly, most of these patients are diagnosed with jaw lesions before the age of 20 years, thus before the completion of dental and jaw development. These multifocal lesions are often accompanied by a diagnosis or strong clinical suspicion of a syndrome. Many of the frequently reported syndromes belong to the so-called RASopathies, with germline or mosaic mutations leading to downstream upregulation of the RAS/MAPK pathway. The other frequently reported syndrome is cherubism, with gain-of-function mutations in the SH3BP2 gene leading through assumed and unknown signaling to an autoinflammatory bone disorder with hyperactive osteoclasts and defective osteoblastogenesis. Based on this extensive literature review, a RAS/MAPK pathway activation is hypothesized in all giant cell lesions of the jaw. The different interaction between and contribution of deregulated signaling in individual cell lineages and crosstalk with other pathways among the different germline- and non-germline-based alterations causing giant cell lesions of the jaw can be explanatory for the characteristic clinical features. As such, this might also aid in the understanding of the age-dependent symptomatology of syndrome associated giant cell lesions of the jaw; hopefully guiding ideal timing when installing treatment strategies in the future.

VEGF Maintains Maternal Vascular Space Homeostasis in the Mouse Placenta through Modulation of Trophoblast Giant Cell Functions

Vascular endothelial growth factor (VEGF) is an angiogenic growth factor that acts primarily on endothelial cells, but numerous studies suggest that VEGF also acts on non-endothelial cells, including trophoblast cells. Inhibition of VEGF signaling by excess production of the endogenous soluble VEGF receptor sFlt1 in trophoblast cells has been implicated in several pregnancy complications. Our previous studies and other reports have shown that VEGF directly regulates placental vascular development and functions and that excess VEGF production adversely affects placental vascular development. Trophoblast giant cells (TGCs) line the maternal side of the placental vasculature in mice and function like endothelial cells. In this study, we specifically examined the effect of excess VEGF signaling on TGC development associated with defective placental vascular development using two mouse models an endometrial VEGF overexpression model and a placenta-specific sFlt1 knockdown model. Placentas of endometrial VEGF-overexpressing dams at embryonic days (E) 11.5 and 14.5 showed dramatic enlargement of the venous maternal spaces in junctional zones. The size and number of the parietal TGCs that line these venous spaces in the placenta were also significantly increased. Although junctional zone venous blood spaces from control and VEGF-overexpressing dams were not markedly different in size at E17.5, the number and size of P-TGCs were both significantly increased in the placentas from VEGF-overexpressing dams. In sFlt1 knockdown placentas, however, there was a significant increase in the size of the sinusoidal TGC-lined, alkaline phosphatase-positive maternal blood spaces in the labyrinth. These results suggest that VEGF signaling plays an important role in maintaining the homeostasis of the maternal vascular space in the mouse placenta through modulation of TGC development and differentiation, similar to the effect of VEGF on endothelial cells in other vascular beds.

Progesterone depletion results in Lamin B1 loss and induction of cell death in mouse trophoblast giant cells

Trophoblast giant cells (TGCs), a mouse trophoblast subtype, have large amounts of cytoplasm and high ploidy levels via endocycles. The diverse functions and gene expression profiles of TGCs have been studied well, but their nuclear structures remain unknown. In this study, we focus on Lamin B1, a nuclear lamina, and clarify its expression dynamics, regulation and roles in TGC functions. TGCs that differentiated from trophoblast stem cells were used. From days 0 to 9 after differentiation, the number of TGCs gradually increased, but the amount of LMNB1 peaked at day 3 and then slightly decreased. An immunostaining experiment showed that LMNB1-depleted TGCs increased after day 6 of differentiation. These LMNB1-depleted TGCs diffused peripheral localization of the heterochromatin marker H3K9me2 in the nuclei. However, LMINB1-knock down was not affected TGCs specific gene expression. We found that the death of TGCs also increased after day 6 of differentiation. Moreover, Lamin B1 loss and the cell death in TGCs were protected by 10-6 M progesterone. Our results conclude that progesterone protects against Lamin B1 loss and prolongs the life and function of TGCs.

Macrophage-specific responses to human- and animal-adapted tubercle bacilli reveal pathogen and host factors driving multinucleated cell formation

The Mycobacterium tuberculosis complex (MTBC) is a group of related pathogens that cause tuberculosis (TB) in mammals. MTBC species are distinguished by their ability to sustain in distinct host populations. While Mycobacterium bovis (Mbv) sustains transmission cycles in cattle and wild animals and causes zoonotic TB, M. tuberculosis (Mtb) affects human populations and seldom causes disease in cattle. The host and pathogen determinants underlying host tropism between MTBC species are still unknown. Macrophages are the main host cell that encounters mycobacteria upon initial infection, and we hypothesised that early interactions between the macrophage and mycobacteria influence species-specific disease outcome. To identify factors that contribute to host tropism, we analysed blood-derived primary human and bovine macrophages (hMϕ or bMϕ, respectively) infected with Mbv and Mtb. We show that Mbv and Mtb reside in different cellular compartments and differentially replicate in hMϕ whereas both Mbv and Mtb efficiently replicate in bMϕ. Specifically, we show that out of the four infection combinations, only the infection of bMϕ with Mbv promoted the formation of multinucleated giant cells (MNGCs), a hallmark of tuberculous granulomas. Mechanistically, we demonstrate that both MPB70 from Mbv and extracellular vesicles released by Mbv-infected bMϕ promote macrophage multinucleation. Importantly, we extended our in vitro studies to show that granulomas from Mbv-infected but not Mtb-infected cattle contained higher numbers of MNGCs. Our findings implicate MNGC formation in the contrasting pathology between Mtb and Mbv for the bovine host and identify MPB70 from Mbv and extracellular vesicles from bMϕ as mediators of this process.

The identification of host and pathogen factors contributing to host-pathogen interaction is crucial to understand the pathogenesis and dissemination of tuberculosis. This is particularly the case in deciphering the mechanistic basis for host-tropism across the MTBC. Here, we show that in vitro, M. bovis but not M. tuberculosis induces multinucleated cell formation in bovine macrophages. We identified host and pathogen mechanistic drivers of multinucleated cell formation: MPB70 as the M. bovis factor and bovine macrophage extracellular vesicles. Using a cattle experimental infection model, we confirmed differential multinucleated cell formation in vivo. Thus, we have identified host and pathogen factors that contribute to host tropism in human/bovine tuberculosis. Additionally, this work provides an explanation for the long-standing association of multinucleated cells with tuberculosis pathogenesis.

Polyploidy formation in cancer cells: How a Trojan horse is born

Ploidy increase has been shown to occur in different type of tumors and participate in tumor initiation and resistance to the treatment. Polyploid giant cancer cells (PGCCs) are cells with multiple nuclei or a single giant nucleus containing multiple complete sets of chromosomes. The mechanism leading to formation of PGCCs may depend on: endoreplication, mitotic slippage, cytokinesis failure, cell fusion or cell cannibalism. Polyploidy formation might be triggered in response to various genotoxic stresses including: chemotherapeutics, radiation, hypoxia, oxidative stress or environmental factors like: air pollution, UV light or hyperthermia. A fundamental feature of polyploid cancer cells is the generation of progeny during the reversal of the polyploid state (depolyploidization) that may show high aggressiveness resulting in the formation of resistant disease and tumor recurrence. Therefore, we propose that modern anti-cancer therapies should be designed taking under consideration polyploidization/ depolyploidization processes, which confer the polyploidization a hidden potential similar to a Trojan horse delayed aggressiveness. Various mechanisms and stress factors leading to polyploidy formation in cancer cells are discussed in this review.

The root-knot nematode effector MiEFF18 interacts with the plant core spliceosomal protein SmD1 required for giant cell formation

The root-knot nematode Meloidogyne incognita secretes specific effectors (MiEFF) and induces the redifferentiation of plant root cells into enlarged multinucleate feeding 'giant cells' essential for nematode development. Immunolocalizations revealed the presence of the MiEFF18 protein in the salivary glands of M. incognita juveniles. In planta, MiEFF18 localizes to the nuclei of giant cells demonstrating its secretion during plant-nematode interactions. A yeast two-hybrid approach identified the nuclear ribonucleoprotein SmD1 as a MiEFF18 partner in tomato and Arabidopsis. SmD1 is an essential component of the spliceosome, a complex involved in pre-mRNA splicing and alternative splicing. RNA-seq analyses of Arabidopsis roots ectopically expressing MiEFF18 or partially impaired in SmD1 function (smd1b mutant) revealed the contribution of the effector and its target to alternative splicing and proteome diversity. The comparison with Arabidopsis galls data showed that MiEFF18 modifies the expression of genes important for giant cell ontogenesis, indicating that MiEFF18 modulates SmD1 functions to facilitate giant cell formation. Finally, Arabidopsis smd1b mutants exhibited less susceptibility to M. incognita infection, and the giant cells formed on these mutants displayed developmental defects, suggesting that SmD1 plays an important role in the formation of giant cells and is required for successful nematode infection.

Giant cell myocarditis in young woman diagnosed at the autopsy: a case report

Giant cell myocarditis (GCM) is a rare inflammatory disease of the heart that often affects younger patients. The clinical course is typically rapid with fulminant congestive heart failure. Prognosis is poor; the proper diagnosis is often rendered at the autopsy. Herein, we present a prototypical case of this rare type of myocarditis, affecting a 44-year-old previously healthy woman who was referred to the intensive care department due to an acute onset cardiac arrest followed by resuscitation. The heart ultrasound and imaging examinations revealed a severe dysfunction and dilatation of both ventricles, without any significant finding in the coronary arteries. Twelve days after the initial presentation, the patient died due to congestive heart failure refractory to intensive therapy. The post-mortem histology of the heart revealed multiple small necrotic foci in the myocardium in both ventricles, with dense inflammatory infiltration with abundant multinucleated giant histiocytes, in line with a diagnosis of GCM. The natural history, pathophysiology, and histological differential diagnosis is discussed, together with review of the relevant literature including uncommon and emerging units.

Zoledronic Acid in a Mouse Model of Human Fibrous Dysplasia: Ineffectiveness on Tissue Pathology, Formation of "Giant Osteoclasts" and Pathogenetic Implications

We compared the effects of a nitrogen-containing bisphosphonate (N-BP), zoledronic acid (ZA), and an anti-mouse RANKL antibody (anti-mRANKL Ab) on the bone tissue pathology of a transgenic mouse model of human fibrous dysplasia (FD). For comparison, we also reviewed the histological samples of a child with McCune-Albright syndrome (MAS) treated with Pamidronate for 3 years. EF1α-Gsα^R201C mice with FD-like lesions in the tail vertebrae were treated with either 0.2 mg/kg of ZA at day 0, 7, and 14 or with 300 μg/mouse of anti-mRANKL Ab at day 0 and 21. All mice were monitored by Faxitron and histological analysis was performed at day 42. ZA did not affect the progression of the radiographic phenotype in EF1α-Gsα^R201C mice. FD-like lesions in the ZA group showed the persistence of osteoclasts, easily detectable osteoclast apoptotic activity and numerous "giant osteoclasts". In contrast, in the anti-mRANKL Ab-treated mice, osteoclasts were markedly reduced/absent, the radiographic phenotype reverted and the FD-like lesions were extensively replaced by newly formed bone. Numerous "giant osteoclasts" were also detected in the samples of the child with MAS. This study supports the hypothesis that osteoclasts per se, independently of their resorptive activity, are essential for development and expansion of FD lesions.

A rare case of a metastatic giant cell-rich osteosarcoma of the mandible: Update and differential diagnostic considerations

A metastatic giant cell-rich osteosarcoma (GCRO) to the jaws is an exceedingly rare neoplasm. To date, fewer than 10 cases have been reported in the English language literature. In this article, we describe an additional case of a metastatic GCRO that presented the diagnostic challenge of a painless mass in the posterior mandible of a 19-year-old girl who exhibited rapid and aggressive local growth. The lesion was confirmed radiologically as an ill-defined expansive osteolytic mass showing cortical perforation. Microscopically, the presence of osteoclast-like giant cells permeated with atypical oval and rounded mesenchymal cells in a fibrovascular stroma, cellular atypia, and scarce osteoid formation were observed. Immunohistochemistry revealed the Ki-67 proliferative index in 50% of positive cells, positivity for vimentin and CD68, as well as scarce positivity for CDK4. The patient's medical history involved a GCRO in the proximal ulna. This report highlights the aggressive behavior of GCRO and its high capacity for metastasis to different parts of the body. Clinicians, pathologists, and surgeons should be aware of the giant cell-rich variant of osteosarcoma of the jaws, an imminent "wolf in a sheep's skin", because its indolent but unrelenting growth and dissemination, with radiographic and histologic characteristics that may represent a diagnostic pitfall regarding aggressive central giant cell lesions of the jaws.

Intralesional injection of triamcinolone hexacetonide as an alternative treatment for central giant cell lesions: a prospective study

The aim of this prospective study was to report on the response to treatment of central giant cell lesions (CGCL) with intralesional corticosteroid injections. Consecutive cases of CGCL were treated with a biweekly intralesional injection of 20mg/ml triamcinolone hexacetonide diluted in an anaesthetic solution of 2% lidocaine/epinephrine 1:200 000 at the proportion 1:1. All patients were monitored using cone beam computed tomography. Eleven patients were treated; their ages ranged from 15-34 (mean 22 years); and eight lesions were in the mandible, and three in the maxilla. Three cases were diagnosed as non-aggressive, and eight as aggressive. Six cases presented good results (four aggressive and two non-aggressive); three cases presented a moderate response (two aggressive and one non-aggressive); and two had a poor response to treatment (both aggressive). In four cases with a good response, osteoplasty was done. In all cases with a moderate response, the remaining lesion was curetted. Cases with a poor response were submitted to either curettage or denosumab injections. Corticotherapy, as main or neoadjuvant therapy, may be an option for treatment of CGCL.

Macromolecular and electrical coupling between inner hair cells in the rodent cochlea

Inner hair cells (IHCs) are the primary receptors for hearing. They are housed in the cochlea and convey sound information to the brain via synapses with the auditory nerve. IHCs have been thought to be electrically and metabolically independent from each other. We report that, upon developmental maturation, in mice 30% of the IHCs are electrochemically coupled in 'mini-syncytia'. This coupling permits transfer of fluorescently-labeled metabolites and macromolecular tracers. The membrane capacitance, Ca2+-current, and resting current increase with the number of dye-coupled IHCs. Dual voltage-clamp experiments substantiate low resistance electrical coupling. Pharmacology and tracer permeability rule out coupling by gap junctions and purinoceptors. 3D electron microscopy indicates instead that IHCs are coupled by membrane fusion sites. Consequently, depolarization of one IHC triggers presynaptic Ca2+-influx at active zones in the entire mini-syncytium. Based on our findings and modeling, we propose that IHC-mini-syncytia enhance sensitivity and reliability of cochlear sound encoding.

[Prevalence in Mexico of giant cell tumor, osteosarcoma and chondrosarcoma (2013-2017)]

INTRODUCTION

Primary bone tumors make up 1% of cancers in adults, the most common being osteosarcoma and chondrosarcoma. Giant cell tumor (GCT) is a locally aggressive benign neoplasm, accounting for 4-10% of all primary bone tumors, but in certain populations it accounts for up to 20%. The main objective of this work was to determine the proportion of GCTs, osteosarcomas and chondrosarcomas in a period of five years, and describe the characteristics of the patients from whom they come. Clinical implications: More information about the epidemiology of bone tumors is required to know their epidemiology in the Mexican population.

MATERIAL AND METHODS

Descriptive observational study of a retrospective cross section including all patients who underwent surgery for tumoral resection, in public hospitals at national level, and whose histopathological pieces were processed and resulted in tissue compatible with a) GCT, b) osteosarcomas and c) chondrosarcomas.

RESULTS

Between 2013 and 2017, 138 cases of the three primary bone tumors studied were reported, giant cell tumor (50%), osteosarcoma (25.36%) and chondrosarcoma (24.64%). The states with the highest number of cases were the state of Mexico (45.65%) and Mexico City (26.81%). Women had a higher prevalence (57.25%) than men (42.75%). The average age of presentation of the tumors was 36.80 years.

CONCLUSIONS

GCT is not an uncommon tumor in the Mexican population, since it has its own characteristics.

[A Case of Anaplastic Carcinoma with Osteoclastlike Giant Cells of the Pancreas Concomitant with Lung Recurrence of Solitary Fibrous Tumor]

A 32-year-old woman presented with epigastric pain and an abdominal mass. Abdominal CT showed a 130mm pancreatic tail mass with an enhanced rim, central necrosis, and small calcification. A 6mm lung tumor was also found via chest CT. Her medical history included surgical resection of cerebral solitary fibrous tumor when she was 24 years old. When she was 31 years old, it had recurred but was cured by gamma knife radiosurgery. We performed distal pancreatectomy and splenectomy with lymph node dissection. According to pathological and immunohistochemical findings, it was diagnosed as an anaplastic carcinoma with osteoclast-like giant cells. She underwent surgical resection of the lung tumor 2 months after pancreatic resection and was diagnosed with metastasis from the solitary fibrous tumor. Fourteen months since undergoing pancreatectomy, the patient experienced no recurrence from both diseases. We report a rare resected case of anaplastic carcinoma of pancreas concomitant with recurrent solitary fibrous tumor.

Burkholderia pseudomallei invades the olfactory nerve and bulb after epithelial injury in mice and causes the formation of multinucleated giant glial cells in vitro

The infectious disease melioidosis is caused by the bacterium Burkholderia pseudomallei. Melioidosis is characterised by high mortality and morbidity and can involve the central nervous system (CNS). We have previously discovered that B. pseudomallei can infect the CNS via the olfactory and trigeminal nerves in mice. We have shown that the nerve path is dependent on mouse strain, with outbred mice showing resistance to olfactory nerve infection. Damage to the nasal epithelium by environmental factors is common, and we hypothesised that injury to the olfactory epithelium may increase the vulnerability of the olfactory nerve to microbial insult. We therefore investigated this, using outbred mice that were intranasally inoculated with B. pseudomallei, with or without methimazole-induced injury to the olfactory neuroepithelium. Methimazole-mediated injury resulted in increased B. pseudomallei invasion of the olfactory epithelium, and only in pre-injured animals were bacteria found in the olfactory nerve and bulb. In vitro assays demonstrated that B. pseudomallei readily infected glial cells isolated from the olfactory and trigeminal nerves (olfactory ensheathing cells and trigeminal Schwann cells, respectively). Bacteria were degraded by some cells but persisted in other cells, which led to the formation of multinucleated giant cells (MNGCs), with olfactory ensheathing cells less likely to form MNGCs than Schwann cells. Double Cap mutant bacteria, lacking the protein BimA, did not form MNGCs. These data suggest that injuries to the olfactory epithelium expose the primary olfactory nervous system to bacterial invasion, which can then result in CNS infection with potential pathogenic consequences for the glial cells.

Infections of the central nervous system (CNS), though uncommon, are associated with severe morbidity and mortality. Burkholderia pseudomallei, the causative agent of melioidosis, can infect the CNS. We have shown that B. pseudomallei can enter the CNS via peripheral nerves extending between the nasal cavity and the brain (bypassing the blood-brain/blood-cerebrospinal fluid barriers). In the current study, we show that prior injury to the olfactory epithelium can increase B. pseudomallei invasion of the olfactory nerve and bulb, highlighting a novel risk factor for CNS infections. We also demonstrate the ability of peripheral nerve glia to internalise B. pseudomallei, resulting in the formation of multinucleated giant cells (MNGCs), dependent on the bacterial protein BimA. These findings provide important new insights into the pathogenesis of B. pseudomallei.

Complex patterns of cell growth in the placenta in normal pregnancy and as adaptations to maternal diet restriction

The major milestones in mouse placental development are well described, but our understanding is limited to how the placenta can adapt to damage or changes in the environment. By using stereology and expression of cell cycle markers, we found that the placenta grows under normal conditions not just by hyperplasia of trophoblast cells but also through extensive polyploidy and cell hypertrophy. In response to feeding a low protein diet to mothers prior to and during pregnancy, to mimic chronic malnutrition, we found that this normal program was altered and that it was influenced by the sex of the conceptus. Male fetuses showed intrauterine growth restriction (IUGR) by embryonic day (E) 18.5, just before term, whereas female fetuses showed IUGR as early as E16.5. This difference was correlated with differences in the size of the labyrinth layer of the placenta, the site of nutrient and gas exchange. Functional changes were implied based on up-regulation of nutrient transporter genes. The junctional zone was also affected, with a reduction in both glycogen trophoblast and spongiotrophoblast cells. These changes were associated with increased expression of Phlda2 and reduced expression of Egfr. Polyploidy, which results from endoreduplication, is a normal feature of trophoblast giant cells (TGC) but also spongiotrophoblast cells. Ploidy was increased in sinusoidal-TGCs and spongiotrophoblast cells, but not parietal-TGCs, in low protein placentas. These results indicate that the placenta undergoes a range of changes in development and function in response to poor maternal diet, many of which we interpret are aimed at mitigating the impacts on fetal and maternal health.

Giant Cell Lesions of the Jaws:A Review and Comparative Histopathological Study

BACKGROUND AND OBJECTIVES

Giant cell lesions (GCLs) are rare lesions which prominently feature multinucleated giant cells in their histology. They include central giant cell granuloma (CGCG), giant cell tumour of bone (GCT), peripheral giant cell granuloma (PGCG), Cherubism (CHB), e.t.c. This study reviewed the clinico-demographic parameters of GCLs of the jaws and assessed the giant cells.

METHODS

This was a retrospective study examining the histopathology records of which part of the body of two tertiary institutions. All entries of cases diagnosed as GCLs were retrieved and data were extracted. Also, the giant cells in tissue sections were assessed. Data were analysed using SPSS Inc. version 20 while Chi square test was used to test for association. This was considered significant quand p < 0.05.

RESULTS

Over the study period, 2,862 biopsy reports were reviewed. GCLs constituted 48(1.7%) and M: F ratio was 1:1.6 while majority occurred in the 2nd and 3rd decades. The mandible was the most common site recording 27(56.3%) cases and CGCG was the most frequently diagnosed GCL constituting 22(45.8%). Assessment of the giant cells revealed CGCG had predominantly large giant cells, a dense dispersal of giant cells and irregularly shaped giant cells, while CHB mainly had large giant cells with dense dispersal, but round shaped giant cells.

CONCLUSION

GCLs are rare lesions commonly seen in females in the 2nd and 3rd decades of life with preference for the mandible. CGCG was the most commonly encountered lesion, while the giant cells in CGCG and CHB were similar in size as well as dispersal.

Pharmacological Therapy for Treatment of Recurrent Central Giant Cell Lesion in a Child

A central giant cell lesion (CGCL) is a reactive lesion that causes destruction of bone and soft tissues and has a high recurrence rate. Only 16 percent of CGCLs are observed in children. Treatment is determined by the aggressiveness and size of the lesion and it usually involves curettage or resection. Alternative treatments, such as nasal calcitonin and intralesional corticosteroid injections, are also used. The purposes of this paper are: (1) to report the case of a nine-year-old patient who presented with a CGCL; (2) to describe its pharmacological management; and (3) to review the literature about the clinical, radiographic, and histological features of CGCL.

The Multiple Ways Nuclei Scale on a Multinucleated Muscle Cell Scale

In mononucleated cells, nuclear size scales with cell size, but does this relationship extend to multinucleated cells? In this issue of Developmental Cell,Windner et al. (2019) examine scaling of nuclei in multinucleated Drosophila muscle fibers and identify global and local cellular inputs that contribute to nuclear size regulation.

Arabidopsis tonoplast intrinsic protein and vacuolar H+-adenosinetriphosphatase reflect vacuole dynamics during development of syncytia induced by the beet cyst nematode Heterodera schachtii

Plant parasitic cyst nematodes induce specific hypermetabolic syncytial nurse cell structures in host roots. A characteristic feature of syncytia is the lack of the central vacuole and the formation of numerous small and larger vesicles. We show that these structures are formed de novo via widening of ER cisternae during the entire development of syncytium, whereas in advanced stages of syncytium development, larger vacuoles are also formed via fusion of vesicles/tubules surrounding organelle-free pre-vacuole regions. Immunogold transmission electron microscopy of syncytia localised the vacuolar markers E subunit of vacuolar H⁺-adenosinetriphosphatase (V-ATPase) complex and tonoplast intrinsic protein (γ-TIP1;1) mostly in membranes surrounding syncytial vesicles, thus indicating that these structures are vacuoles and that some of them have a lytic character. To study the function of syncytial vacuoles, changes in expression of AtVHA-B1, AtVHA-B2 and AtVHA-B3 (coding for isoforms of subunit B of V-ATPase), and TIP1;1 and TIP1;2 (coding for γ-TIP proteins) genes were analysed. RT-qPCR revealed significant downregulation of AtVHA-B2, TIP1;1 and TIP1;2 at the examined stages of syncytium development compared to uninfected roots. Expression of VHA-B1 and VHA-B3 decreased at 3 dpi but reached the level of control at 7 dpi. These results were confirmed for TIP1;1 by monitoring At-γ-TIP-YFP reporter construct expression. Infection test conducted on tip1;1 mutant plants showed formation of larger syncytia and higher numbers of females in comparison to wild-type plants indicating that reduced levels or lack of TIP1;1 protein promote nematode development.

Parasitic worms hijack key plant protein to build their nest

Parasitic nematode worms infect a variety of crop plants worldwide. Roots infected by these worms start to look rather unsavory - with knot like tumors (galls) developing all over them. At the core of each gall, a worm matures and lays its eggs. Olmo et al. (2018) looked into the developmental reprogramming that leads to gall formation and found an Arabidopsis protein to be a necessary component in this process.

[Advances in diagnosis and treatment of undifferentiated pancreatic carcinoma with osteoclast-like giant cells]

Undifferentiated pancreatic carcinoma with osteoclast-like giant cell(UOC) published to date, and most have been in Asia, is a rare occurrence making up 1% of all pancreatic malignancies.With the increasing number of reported cases of the disease, the degree of awareness of the disease also gradually deepened, but there are few summary articles for the clinical features, imaging features, pathological features, treatment programs, prognosis and other aspects of UOC.Hence, this article is going to introduce pathological features, clinical manifestations, diagnosis and treatment of adjuvant advances of UOC in detail.