Multinucleated Research Articles

IRAK4 inhibition: an effective strategy for immunomodulating peri-implant osseointegration via reciprocally-shifted polarization in the monocyte-macrophage lineage cells

BackgroundThe biomaterial integration depends on its interaction with the host immune system. Monocyte-macrophage lineage cells are immediately recruited to the implant site, polarized into different phenotypes, and fused into multinucleated cells, thus playing roles in tissue regeneration. IL-1R-associated kinase 4 (IRAK4) inhibition was reported to antagonize inflammatory osteolysis and regulate osteoclasts and foreign body giant cells (FBGCs), which may be a potential target in implant osseointegration.MethodsIn in-vitro experiments, we established simulated physiological and inflammatory circumstances in which bone-marrow-derived macrophages were cultured on sand-blasted and acid-etched (SLA) titanium surfaces to evaluate the induced macrophage polarization, multinucleated cells formation, and biological behaviors in the presence or absence of IRAK4i. Then, bone marrow stromal stem cells (BMSCs) were cultured in the conditioned media collected from the aforementioned induced osteoclasts or FBGCs cultures to clarify the indirect coupling effect of multinucleated cells on BMSCs. We further established a rat implantation model, which integrates IRAK4i treatment with implant placement, to verify the positive effect of IRAK4 inhibition on the macrophage polarization, osteoclast differentiation, and ultimately the early peri-implant osseointegration in vivo.ResultsUnder inflammatory conditions, by transforming the monocyte-macrophage lineage cells from M1 to M2, IRAK4i treatment could down-regulate the formation and activity of osteoclast and relieve the inhibition of FBGC generation, thus promoting osteogenic differentiation in BMSCs and improve the osseointegration.ConclusionThis study may improve our understanding of the function of multinucleated cells and offer IRAK4i as a therapeutic strategy to improve early implant osseointegration and help to eliminate the initial implant failure.

Cd13 controls myeloid cell-cell fusion

Abstract Macrophages have the ability to undergo phenotypic and functional changes in response to microenvironmental cues. One such change is the formation of multinucleated giant cells (MGCs) via intercellular fusion triggered by certain bacterial or parasitic infections or implantation of medical devices that induces deleterious MGC formation in response to the foreign body. Despite advances in biomaterials, implants ultimately corrode to produce particles that initiate a foreign body response characterized by macrophage fusion into pro-inflammatory, Foreign Body Giant Cells that directly define the pathology of loosening of medical implants. We have shown that the transmembrane protein CD13 is a multifunctional molecule that regulates diverse processes such as cell-cell adhesion, receptor endocytosis and recycling and organization of the actin cytoskeleton, all of which are critical in cell-cell fusion. We demonstrate that subcutaneous foreign implants in CD13 KOmice produce significantly more MGCs with increased levels of plasma pro-inflammatory cytokines. In vitro induction of fusion in CD13-deficient myeloid progenitors generated from bone marrow resulted in hyperfusion to generate MGCs that were considerably larger in size and contained many more nuclei than those from wild type progenitors, suggesting that CD13 regulates MGC formation at the stage of fusion. While expression of the key fusion proteins are typically downregulated in mature cells post-fusion, expression of these proteins is sustained at high levels in multinucleated cells lacking CD13. Thus, CD13 acts as a brake to prevent aberrant myeloid cell-cell fusion and may be a novel therapeutic target in pathological conditions mediated by abnormal cell fusion. Supported by grants from NIH (1R21 AI15 )

Muscle fusogens go viral for gene delivery to skeletal muscle

Viruses and multinucleated cells rely on fusogens to facilitate the fusion of their membranes. In this issue of Cell, Millay and colleagues demonstrate that replacing viral fusogens with mammalian skeletal muscle fusogens leads to the specific transduction of skeletal muscle and the ability to deliver gene therapy constructs in a therapeutically relevant muscle disease.

Abstract 291: Thrombin-activated Platelet Releasate Reduces Myoblast Fusion Capacity In Muscle Cells Affected By Peripheral Artery Disease

Introduction: In the absence of injury, direct interactions between platelets (Plt) and skeletal muscle myoblasts (Mb) are limited. However, ischemic muscle injury increases vascular permeability resulting in potential interactions between Mb and Plt. In PAD, Mb have poor differentiation capacity and Plt have increased activation. We hypothesize that Plt activation directly deters myogenic potential of ischemic Mb in PAD. Methods: Ischemic and perfused muscle was obtained during amputations for PAD. Mb were isolated using sequential plating and cell sorting. Mb from healthy donors (PAD-) were purchased. Isolated Plt from healthy donors without PAD were resuspended in physiologic and supraphysiologic concentrations, with some being thrombin-activated (TA) under shear conditions. Acellular Plt releasate (PR) from resting or TA Plt were added to proliferation or differentiation media (10% volume) and incubated 5 days with Mb. Proliferation was measured by CellTiter Glo. Multinucleated cells positive for myosin heavy chain were counted to obtain myocyte fusion index (MFI), a surrogate for differentiation. Resting and TA Plt were aggregated with Mb under shear conditions and their binding was measured by immunofluorescence. Results: Proliferation was higher in ischemic PAD Mb exposed to supraphysiologic TAPR compared to those in proliferation media (p=0.0022) or physiologic TAPR (p=0.0005) (Fig 1A - N=4). However, TAPR treatment also significantly and consistently decreased MFI across cell groups in a dose-dependent manner (Fig 1B). In the presence of thrombin and shear stress, Plt-Mb were prominently expressed (Fig 1C). Conclusion: Released mediators from TA Plt enhance Mb proliferation at the expense of terminal differentiation, potentially leading to defective muscle repair. Inhibiting the interactions between Plt and Mb is a potential target to improve response to ischemic injury, reduce myopathy and a consideration for best medical therapy for PAD.

Determination of Disease Severity of Rhizoctonia solani Kühn (Telemorph: Thanatephorus cucumeris (Frank) Donk) Isolates from Bean, Sugar Beet and Potato Planting Areas in Konya

This study was carried out to determine the disease severity of Rhizoctonia solani isolates isolated from plant samples collected from bean, sugar beet and potato cultivation areas in Konya in 2020 and the anastomosis groups of the most virulent isolates. A total of 40 R. solani isolates were obtained as a result of the isolations made from 86 plant samples (36 beans, 25 sugar beets and 25 potatoes) showing root rot symptoms in general appearance. The number of R. solani isolates obtained from these plants, respectively; 10 isolates from beans, 15 from potatoes and 15 from sugar beets. Nine of the bean isolates and 14 of the potato and sugar beet isolates were determined as multinucleic. One isolate each isolated from the bean, sugar beet and potato was determined as binucleic. As a result, a total of 37 multinucleate (MN) and 3 binucleate (BN) isolates were obtained from all plants. As a result of pathogenicity tests, 3 R. solani isolates with the highest disease severity for each plant were amplified using ITS1F and ITS4B primers and anastomosis groups were determined. Accordingly, the anastomosis groups of Fa 3.2 (97%), Fa 2.2 (89%) and Fa 1 (86%) in beans were characterized as AG 4HGI. The isolates with the highest disease severity in potatoes (Pa 10, Pa 12.1 and Pa 15.2) were determined as AG 3 group. Disease severity was determined as 50% of Pa 15.2, 44% of Pa 10 and 42% of Pa 12.1. The disease severity of 9 of the isolates obtained from sugar beet was determined as 100%. The anastomosis group of 3 randomly selected isolates from these isolates was characterized as AG 2-2.

Tonian carbonaceous compressions indicate that Horodyskia is one of the oldest multicellular and coenocytic macro-organisms

Macrofossils with unambiguous biogenic origin and predating the one-billion-year-old multicellular fossils Bangiomorpha and Proterocladus interpreted as crown-group eukaryotes are quite rare. Horodyskia is one of these few macrofossils, and it extends from the early Mesoproterozoic Era to the terminal Ediacaran Period. The biological interpretation of this enigmatic fossil, however, has been a matter of controversy since its discovery in 1982, largely because there was no evidence for the preservation of organic walls. Here we report new carbonaceous compressions of Horodyskia from the Tonian successions (~950–720 Ma) in North China. The macrofossils herein with bona fide organic walls reinforce the biogenicity of Horodyskia. Aided by the new material, we reconstruct Horodyskia as a colonial organism composed of a chain of organic-walled vesicles that likely represent multinucleated (coenocytic) cells of early eukaryotes. Two species of Horodyskia are differentiated on the basis of vesicle sizes, and their co-existence in the Tonian assemblage provides a link between the Mesoproterozoic (H. moniliformis) and the Ediacaran (H. minor) species. Our study thus provides evidence that eukaryotes have acquired macroscopic size through the combination of coenocytism and colonial multicellularity at least ~1.48 Ga, and highlights an exceptionally long range and morphological stasis of this Proterozoic macrofossils.

Protocol Optimization for Direct Reprogramming of Primary Human Fibroblast into Induced Striatal Neurons.

The modeling of neuropathology on induced neurons obtained by cell reprogramming technologies can fill a gap between clinical trials and studies on model organisms for the development of treatment strategies for neurodegenerative diseases. Patient-specific models based on patients' cells play an important role in such studies. There are two ways to obtain induced neuronal cells. One is based on induced pluripotent stem cells. The other is based on direct reprogramming, which allows us to obtain mature neuronal cells from adult somatic cells, such as dermal fibroblasts. Moreover, the latter method makes it possible to better preserve the age-related aspects of neuropathology, which is valuable for diseases that occur with age. However, direct methods of reprogramming have a significant drawback associated with low cell viability during procedures. Furthermore, the number of reprogrammable neurons available for morphological and functional studies is limited by the initial number of somatic cells. In this article, we propose modifications of a previously developed direct reprogramming method, based on the combination of microRNA and transcription factors, which allowed us to obtain a population of functionally active induced striatal neurons (iSNs) with a high efficiency. We also overcame the problem of the presence of multinucleated neurons associated with the cellular division of starting fibroblasts. Synchronization cells in the G1 phase increased the homogeneity of the fibroblast population, increased the survival rate of induced neurons, and eliminated the presence of multinucleated cells at the end of the reprogramming procedure. We have demonstrated that iSNs are functionally active and able to form synaptic connections in co-cultures with mouse cortical neurons. The proposed modifications can also be used to obtain a population of other induced neuronal types, such as motor and dopaminergic ones, by selecting transcription factors that determine differentiation into a region-specific neuron.

CD30 stimulation induces multinucleation and chromosomal instability in HTLV-1-infected cell lines.

A recent report indicated involvement of CD30 in progression of human leukemia virus type 1 (HTLV-1) infection, but the exact roles of CD30 in this process remain unclear. This study was conducted to determine the role of CD30 by stimulating CD30 expressed on HTLV-1-infected cell lines with CD30 ligand and observing its effects. CD30 stimulation increased multinucleated cells and inhibited proliferation of HTLV-1-infected cells. This inhibition was recovered by interruption of CD30 stimulation. Chromatin bridges found in multinucleated cells suggested DNA damage. CD30 stimulation triggered DNA double-strand breaks (DSBs) and chromosomal imbalances. CD30 stimulation induced reactive oxygen species (ROS), which induced DSBs. Generation of ROS and multinucleated cells by CD30 was dependent on phosphoinositide 3-kinase. RNA sequencing showed that CD30 stimulation produced significant changes in gene expression profiles, including upregulation of programmed death ligand 1 (PD-L1). Tax, which has also been shown to induce multinucleation and chromosomal instability, failed to induce CD30. These results suggest that induction of CD30, independent of Tax, triggers morphological abnormalities, chromosomal instability, and alteration of gene expression in HTLV-1-infected cells.

Immunohistochemical characterization of the mandibular condyle for type I and II collagen, aggrecan, MMP-9, and MMP-13 in MMP-2-deficient mice.

Mice devoid of matrix metalloproteinase (MMP)-2 due to gene targeting have been reported to show articular cartilage destruction in the knee joint; however, the phenotype of the mandibular condylar cartilage remains unknown. Thus, in the present study, we investigated the mandibular condyle in Mmp2-/- mice. We obtained and bred Mmp2-/- mice from the same source as the previous study, and performed genotyping using genomic DNA extracted from finger snips. The mandibular condyle of Mmp2-/- mice and wild-type (WT) mice was immunohistochemically examined for the localization of extracellular matrix (ECM) proteins (type I and II collagen, and aggrecan), and MMP-9 and MMP-13. No cartilage destruction was observed in the mandibular condyle of Mmp2-/- mice, and no difference was found in the localization of the ECM proteins between the Mmp2-/- mice and WT mice. However, the bone marrow cavity in the subchondral bone of the mandibular condyle was more distinct in Mmp2-/- mice than in WT mice at the age of 50 weeks. Of note, MMP-9 characteristically localized in multinucleated cells in the mandibular condyle in 50-week-old Mmp2-/- mice. MMP-2 may be involved in the regulation of osteoclast differentiation and the formation of the bone marrow cavity in aged mice.

Diagnostic Significance of Targeted Next-Generation Sequencing in Central Nervous System Infections in Neurosurgery of Pediatrics.

Cerebrospinal fluid (CSF) pathogen culture suffers from the drawbacks of prolonged cycle time and a low positivity rate in diagnosing intracranial infections in children. This study aims to investigate the diagnostic potential of targeted next-generation sequencing (tNGS) in pediatric neurosurgery for central nervous system (CNS) infections. A retrospective study was conducted on children under 14 with suspected intracranial infections following craniocerebral trauma or surgery between November 2018 and August 2020. Routine, biochemical, smear, and pathogen culture tests were performed on CSF during treatment. The main parameters of CSF analysis encompassed white blood cells (WBC, ×106/L) count, percentage of multinucleated cells (%), protein levels (g/L), glucose concentration (GLU, mmol/L), chloride levels (mmol/L), and pressure (mmH2O). The outcomes of tNGS were assessed through the Receiver Operating Characteristic (ROC) curve and pertinent diagnostic parameters. Among the 35 included pediatric patients, 22 were clinically diagnosed with CNS infection in neurosurgery, tNGS was confirmed in 18 cases. The sensitivity and specificity of tNGS were 81.8% and 76.9%, respectively, while the traditional method of CSF cultures and smears exhibited a sensitivity of 13.6% and a specificity of 100%. ROC curve analysis indicated an area under the curve (AUC) of 0.794 for tNGS and 0.568 for the CSF cultures and smears. CSF analysis indicated that the two groups exhibited statistically significant differences in terms of WBC count [330.0 (110.00-2639.75) vs 14.00 (4.50-26.50), P<0.001] and percentage of multinuclear cells (%) [87.50 (39.75-90.00) vs 0 (0-10.00), P<0.001]. However, the remaining parameters did not statistically significant differences between the groups (all P>0.05). tNGS demonstrates a high degree of diagnostic accuracy when detecting infections within the CNS of pediatric neurosurgery patients. tNGS can effectively establish for diagnosing CNS infections by detecting pathogenic microorganisms and their corresponding virulence and/or resistance genes within the test samples.

380 The kinesin-like protein Kif11 is essential for the survival of TP53 mutant triple-negative breast cancer cells

OBJECTIVES/GOALS: While mutant TP53 is an attractive therapeutic target in TNBC, attempts to target the mutant p53 protein directly have failed. Thus, we aim to identify pathways critical for the survival of TP53 mutant cells that can be targeted in TNBC. We have identified Kif11 as one such target and aim to further investigate its function in TP53 mutant TNBC. METHODS/STUDY POPULATION: We conducted a dual in silico/in vivo screen that identified Kif11 inhibition as preferentially inhibiting the growth of TP53 mutant TNBC. We obtained data on TP53 mutational status, KIF11 mRNA expression levels, and clinical characteristics from TCGA, METABRIC, and CCLE datasets. We treated breast cancer cell lines with the KIF11 inhibitor SB-743921. Cell counts were obtained through staining with DAPI or Hoechst and imaging on the ImageXPress PICO. We detected cell death by DRAQ7 staining and flow cytometry analysis following Annexin V-PI staining. To investigate mitotic spindle organization, we performed immunofluorescent staining with an anti-tubulin antibody and DAPI co-staining. Cell cycle analysis was performed through flow cytometry. RESULTS/ANTICIPATED RESULTS: KIF11 is highly expressed in TP53 mutant and TNBC clinical samples. High KIF11 expression is associated with poorer clinical outcomes. Kif11 inhibition suppresses growth of both TP53 mutant and wild-type breast cancer cells, but preferentially induces the death of TP53 mutant cells as detected by DRAQ7 and Annexin V/PI staining. Kif11 inhibition induces a G2-M block and growth inhibition in TP53 wild-type cells. On the other hand, following treatment with the Kif11 inhibitor SB-743921, TP53 mutant cells undergo mitotic spindle dysfunction leading to the formation of multinucleated cells and cell death. DISCUSSION/SIGNIFICANCE: These results demonstrate that Kif11 is a promising therapeutic target in aggressive, TP53 mutant TNBCs. Kif11 inhibitors, including SB-743921, have been tested in human trials, and are well tolerated, but it is unclear which patients would most benefit. Our studies show that Kif11 inhibitors may be most useful in patients with TP53 mutant TNBCs.

Routine red bone marrow smear in local breed claves at Basrah, Iraq

The state of the peripheral blood reflects on bone marrow activity. Therefore, we need to know the normal red bone marrow, and it can be a reference for those interested in hematology. Calves of apparently healthy local breeds were used to examine the state of the bone marrow, take a sample of peripheral blood before slaughter, and then a bone marrow biopsy that was immediately after slaughter. The calves that showed typical values for the parameters of red blood cells and total and differential white blood cells were included in the study. The result of bone marrow smears for nine normal calves appeared to have a faint coloration of granulated myelocytic than erythroid cells. As well as the myeloid was less than the erythroid, and that M: E ratio was 0.91±0.03. The erythroid series, Rubriblast, and Rubricyte were present as the most common progenitor red cell, including basophilic, polychromic, and normochromic cytoplasm, metarubricyte as a reduced nucleus. The myeloid series: Myeloblast, myelocyte was the most common progenitor white cells with granulation as basophilic, eosinophilic and neutrophilic within their cytoplasm, metamyelocyte with shrunken nuclei and band cell with horseshoe nucleus. They rarely found the megakaryocyte, enormous multinucleate cell.

Roles and heterogeneity of mesenchymal progenitors in muscle homeostasis, hypertrophy, and disease.

Skeletal muscle is mainly composed of multinucleated cells called myofibers, and has excellent regenerative and adaptive abilities. These abilities are granted by muscle satellite cells (MuSCs), which are anatomically defined cells located between myofibers and basal lamina. In addition to myofibers and MuSCs, skeletal muscle contains several types of cells located in interstitial areas, such as mesenchymal progenitors. These cells are positive for platelet-derived growth factor receptor alpha and are called fibro/adipogenic progenitors (FAPs) or mesenchymal stromal cells. Although mesenchymal progenitors were originally identified as the causative cells of ectopic fat accumulation in skeletal muscles, recent studies have shed light on their beneficial roles in homeostasis, regeneration, and hypertrophy. Furthermore, the heterogeneity of mesenchymal progenitors is of great interest in understanding skeletal muscle development, homeostasis, regeneration, aging, and diseases. In this concise review, we summarize recent findings on the physiological roles of mesenchymal progenitors and their heterogeneity and discuss the remaining critical concerns.

Acute myocardial calcification in a patient with fulminant myocarditis.

Relationship with Industry: None A 38-year-old man was admitted with a 3-week history of rapid clinical deterioration. The patient presented with multisystem inflammatory syndrome associated with multi-organ failure (white blood and polynuclear cells counts at respectively 54.40 and 51.60 *109/L; C-reactive protein, Ferritin and Fibrinogen levels at respectively, 214 mg/L, 1624 μg/L, and 8.31 g/L; and creatinine and bilirubin levels at respectively 397 μmol/L (4,49 mg/dL) and 57 μMol/L (3,33 mg/dL)). Large screening and multiple testing for bacterial and viral infections remained negative in a patient with Covid-19 infection 3-months earlier without vaccination. The patient was transferred to the Intensive Care Unit necessitating mechanical ventilation, hemodialysis, and inotropic support. Rapidly, diffuse ST elevation on electrocardiogram and increased levels of high-sensitivity cardiac I troponin (hs-cTnI = 135000 ng/L) and natriuretic peptide (NT-ProBNP = 72114 ng/L) were found. Coronary angiogram showed no significant coronary disease and transthoracic echocardiography (TTE) showed reduced left ventricular ejection fraction (LVEF = 40%). Cardiac magnetic resonance imaging confirmed diffuse and extensive gadolinium uptake. Despite negative cardiac biopsies, the diagnosis of fulminant myocarditis was made and the patient underwent corticosteroids bolus and intravenous immunoglobulin therapies. Clinical evolution was deemed favourable with a progressive decrease in systemic inflammatory process associated with a decrease in cardiac biomarkers levels. However, 2 weeks later, chest X-ray (Panel A) and TTE (Panel B) showed acute and impressive left ventricular calcified remodelling process with diffuse epicardial calcification and septal patchy fibrosis (whites triangles). The positron emission tomography (PET-CT) confirmed the diffuse FDG uptakes suggesting persistent local inflammatory process (Panel C) associated with large epicardial calcified remodelling (Panel D). The patient was discharged 1 month after the index admission with optimized heart-failure therapy and planned follow-up at the Heart Failure Clinic.

Ketoprofen-Based Polymer-Drug Nanoparticles Provide Anti-Inflammatory Properties to HA/Collagen Hydrogels.

Current limitations of wound dressings for treating chronic wounds require the development of novel approaches. One of these is the immune-centered approach, which aims to restore the pro-regenerative and anti-inflammatory properties of macrophages. Under inflammatory conditions, ketoprofen nanoparticles (KT NPs) can reduce pro-inflammatory markers of macrophages and increase anti-inflammatory cytokines. To assess their suitability as part of wound dressings, these NPs were combined with hyaluronan (HA)/collagen-based hydro- (HGs) and cryogels (CGs). Different HA and NP concentrations and loading techniques for NP incorporation were used. The NP release, gel morphology, and mechanical properties were studied. Generally, colonialization of the gels with macrophages resulted in high cell viability and proliferation. Furthermore, direct contact of the NPs to the cells reduced the level of nitric oxide (NO). The formation of multinucleated cells on the gels was low and further decreased by the NPs. For the HGs that produced the highest reduction in NO, extended ELISA studies showed reduced levels of the pro-inflammatory markers PGE2, IL-12 p40, TNF-α, and IL-6. Thus, HA/collagen-based gels containing KT NPs may represent a novel therapeutic approach for treating chronic wounds. Whether effects observed in vitro translate into a favorable profile on skin regeneration in vivo will require rigorous testing.

Treatment Options for Multinucleate Cell Angiohistiocytoma: A Case Series and Review of the Literature.

Multinucleate cell angiohistiocytoma (MCAH) is an unusual fibrohistiocytic proliferation in the dermis with vascular hyperplasia. Numerous clinicopathological studies of MCAH have been published, but little has been written in relation to treatment. The aim of the present study is to review the therapeutical approaches for MCAH in the literature and to report the results of the different therapies followed at our institution. A literature review was conducted including all MCAH published cases that followed any therapy. Search terms included "multinucleate cell angiohistiocytoma" or "MCAH" and "treatment" or "therapy". Also, all cases of MCAH treated at our institution from 2010 to 2020 are reported. The literature search revealed 16 cases of MCAH treated with any of the therapeutic options. At our institution, 9 patients have been treated of MCAH between 2010 and 2020. Over 75% of them were female, and the median age was 56 years (range 47-73). More than 50% had lesions on the dorsum of the hands. Surgical excision was indicated in 2 patients, ablative CO2 laser was used in 1 patient and the 6 remaining ones followed vascular-targeted therapies (PDL and IPL). A satisfactory cosmetic result was achieved in all of them. We propose PDL therapy as a first-line treatment for MCAH since it achieves satisfactory esthetic results, while being well-tolerated. Selecting those amenable patients according to morphologic characteristics may be useful to avoid unsuccessful therapies. In MCAH with predominant fibrous stroma, surgery or CO2 laser may be the best option.

Cell cycle-dependent palmitoylation of protocadherin 7 by ZDHHC5 promotes successful cytokinesis.

Cell division requires dramatic reorganization of the cell cortex, which is primarily driven by the actomyosin network. We previously reported that protocadherin 7 (PCDH7) gets enriched at the cell surface during mitosis, which is required to build up the full mitotic rounding pressure. Here, we report that PCDH7 interacts with and is palmitoylated by the palmitoyltransferase, ZDHHC5. PCDH7 and ZDHHC5 colocalize at the mitotic cell surface and translocate to the cleavage furrow during cytokinesis. The localization of PCDH7 depends on the palmitoylation activity of ZDHHC5. Silencing PCDH7 increases the percentage of multinucleated cells and the duration of mitosis. Loss of PCDH7 expression correlates with reduced levels of active RhoA and phospho-myosin at the cleavage furrow. This work uncovers a palmitoylation-dependent translocation mechanism for PCDH7, which contributes to the reorganization of the cortical cytoskeleton during cell division.

A novel process for the production of Chromochloris zofingiensis through dark-induced multi-nuclei formation

Chromochloris zofingiensis is an astaxanthin- and lipid-producing green microalga. In this study, we examined the effect of transitioning cultures between light and dark conditions on biomass productivity. In general, cell proliferation was observed when cultures were transferred from dark heterotrophic conditions (12 d) to irradiated autotrophic conditions; these cells were multinucleated and showed rapid division. Specific growth rates of 1.85 and 0.36 d−1 were observed in heterotrophically precultured and autotrophically precultured cells, respectively. Under subsequent dark conditions, the autotrophically precultured cells became larger and the number of nuclei per cell increased from 1–2 to 6–12 within 8 d, indicating that the dark conditions blocked cytokinesis while allowing DNA replication through nuclear division. Our study also defined a relative nuclear division rate by comparing the specific growth rate of nuclei per cell with that of cell division. The unique coordination of multinucleated cells cultured in the dark and cellular division triggered by environmental light can improve the biomass productivity of this valuable alga. Our study reported the multinucleation mechanisms in C. zofingiensis which was accompanied by a rapid cellular division.

Induced membrane technique using bone cement with or without cefazolin in chicken segmental radius defect.

The utilization of antibiotic-loaded cement spacer in the induced membrane development has been a debate topic in human medicine. To the best of the author's knowledge, these combinations have not yet been evaluated in birds. Therefore, this study assessed induced membrane formation using radiography and histology, in a segmental defect of a chicken radius, with or without the addition of cefazolin. Thirty 18-month-old healthy chickens were divided into two equal groups: G1-bone defect filled with bone cement; G2-bone defect filled with cefazolin powder-loaded bone cement. Radiographic examinations of the left forearm were taken immediately after surgery and at 7, 15, and 21 postoperative days. For the collection of the induced membranes, five chickens in each group were euthanized at 7, 15, and 21 days after surgery. Radiographically, the bone cement was identified as a radiopaque structure occupying the bone defect in both groups. Mild new bone formation in at least one of the fractured extremities of the bone defect was seen only 21 days after surgery in most chickens. Histologically, there was no difference in the mean thickness of the induced membrane between groups at all time points. Multifocal multinucleated cells differed between groups at 7 (G1 > G2) and 21 (G2 > G1) days after surgery. Mononuclear inflammatory infiltrate differed between groups only on day 21 (G1 > G2). Fibrous tissue proliferation did not differ between groups at all evaluation times. Blood vessel density differed only at 21 days postoperatively (G2 < G1). Multifocal areas of cartilage differed between groups at all time points (G1 > G2). In conclusion, cefazolin mixed with bone cement did not affect thickness of the induced membrane, but did result in a negative effect on some histological aspects, such as fewer vessels, less multifocal areas of cartilage, and persistence of inflammation.

Morphological and Functional Characteristics of the Microenvironment After Pleural Implantation of Biosynthetic Materials

The objective: to study morphological changes in tissues after implantation of a bioresorbable material synthesized on the basis of polylactide (PLA) and polycaprolactone (PCL) in various ratios.Subjects and Methods. Laboratory animals Chinchilla lanigera (n = 12) underwent intrapleural implantation with 2% PLA/PCL 1/1 and 4% PLA/PCL 1/3 materials. Morphometric assessment was carried out in14 and 28 weeks, the animals were withdrawn from the experiment by an anesthetic overdosing.Results. When studying tissues adjacent to the implant regardless of differences in its composition, similar morphological signs were observed. A fibrous capsule formed around the implants, and it was more pronounced in 4% of PLA/PCL 1/3. In the structure of the implants, we noted the growth of loose and dense unformed fibrous connective tissue with blood vessels with a significant replacement of the bioresorbable polymer material (by 2/3). Lymphocytes, plasma cells, single macrophages, and multinucleated cells were predominantly located at the implant/tissue interface. In all studied samples, no necrosis was observed in the implantation bed and surrounding tissue.Conclusion. The data obtained confirm the biosafety of biomaterials and demonstrate the potential for their use in surgical treatment of humans.