Multiple Cell Layers Research Articles

Breast cancers originating from the major lactiferous ducts and the process of neoductgenesis: Ductal Adenocarcinoma of the Breast, DAB

PurposeTo call attention to a highly fatal breast cancer subtype arising from the major lactiferous ducts that is currently underdiagnosed as ductal carcinoma in situ (DCIS) with or without microinvasion. MethodAll breast cancers diagnosed at the Department of Mammography, Falun Central Hospital, Sweden, since 1977 have been classified according to their mammographic tumour features (imaging biomarkers) and followed up at regular intervals for the past four decades. The imaging biomarkers characteristic of breast cancers apparently arising from the major lactiferous ducts have been correlated with large format thin and thick section histopathology and long-term patient outcome. ResultsBreast cancers arising within the major lactiferous ducts propagate intraductally and produce continuously branching neoducts through epithelial-mesenchymal transformation (EMT), an invasive process termed neoductgenesis, which eventually forms a massive tumour burden. The high fatality of this breast cancer subtype indicates its truly invasive nature, although it is conventionally termed ductal carcinoma in situ, DCIS, terminology which is at odds with its poor long-term patient outcome. The neoducts are filled with multiple layers of malignant cells, have no attached lobules, and propagate by forming multiple invasive side branches. These newly formed duct-like structures are surrounded by a desmoplastic reaction (cancer associated fibroblasts, CAFs) and periductal lymphocytic infiltration. The neoducts are tightly packed together in irregular formations bearing no resemblance to the paniculate branching structure of normal lactiferous ducts. Cancers originating from the major ducts have six imaging biomarkers which can be easily recognized at breast imaging. These are described in detail in an accompanying article. ConclusionsNeoductgenesis in the breast, DAB, is similar in appearance and prognosis to ductal adenocarcinoma of the prostate, DAP. We propose the term ductal adenocarcinoma of the breast, DAB, to facilitate its recognition as a distinct invasive breast cancer subtype. The high fatality rates associated with neoductgenesis reflect the failure of current histopathologic diagnostic criteria to effectively guide therapeutic practice. When the neoducts are associated with small stellate/spiculated or spherical/oval-shaped invasive cancers arising from the terminal ductal lobular units (TDLUs), the prognosis and management are erroneously estimated according to the smaller invasive tumour(s), giving a false sense of security often resulting in undertreatment. Recognition that neoductgenesis is an invasive malignancy is a prerequisite for preventing treatment failure.

Structure of the nectary in Chaenomeles japonica (Thunb.) Lindl. ex Spach. in different stages of flowering with focus on nectar secretion.

Chaenomeles japonica is an attractive ornamental shrub flowering in spring. It is also a valuable source of nectar and pollen for entomofauna. The study was carried out to investigate the structure of hypanthial nectaries present in the flowers of this species with the use of light and scanning electron microscopy. Nectary tissues were examined in three stages of flowering, with special focus placed on changes occurring in the epidermisand nectariferous parnechyma. Long-styled flowers, which produce nectar abundantly, were selected for the study. The nectary parenchyma was shown to consist of multiple cell layers (up to 20). The epidermis was initially single-layered, but the number of layers gradually increased to 2-3 during the following days of flowering. The outer walls of epidermis cells were covered by a strongly undulating cuticle with massive striae. Cracks and perforations, which are probably nectar release sites, were visible between the striae. The presence of the secretion in the intercellular spaces between the parenchyma layer and the epidermis may indicate apoplastic nectar transport. The presence of stomata, as well as pores in the cuticle layer of the nectary epidermis, suggests that C. japonica nectar is secreted in two ways: (i) through the nectarostomata and (ii) ordinary epidermis cells with the involvement of the cuticle.

Fabrication of an align-random distinct, heterogeneous nanofiber mat endowed with bifunctional properties for engineered 3D cardiac anisotropy

The development of multilayered anisotropic scaffolds with a 3D anisotropy similar to that of native cardiac tissue with layer-specific oriented multiple cell layers is a major challenge in the reconstruction of engineered cardiac tissue in vitro. Herein, we present an electrospun align-random distinct, heterogeneous nanofiber (NF) mat to facilitate the construction of a multilayered anisotropic scaffold with different orientations, which recreates the cardiac anisotropy via hollow patterned electrolyte-assisted electrospinning (HP-ELES). Based on the HP-ELES process, a distinct but heterogeneous polycaprolactone (PCL) NF mat, which comprised an ultra-thin (<10 μm) aligned NF membrane at the core and a thick random NF mat at the peripheral rim, was readily fabricated. The fabricated heterogeneous NF mat was endowed with bifunctional properties of not only uniaxially aligned topographical cues to align the cardiomyocytes (CMs) followed by creating a uniaxial contractile motion but also mechanical stability to enable manual manipulation provided by the aligned NF membrane and random NF mat, respectively. Intriguingly, the in vitro cell culture of CMs possessing spontaneous contraction on the heterogeneous NF mat demonstrated cell alignment and subsequent uniaxial contraction along with aligned NFs. The stacking triple layers also exhibited multiaxial contraction, which potentially simulates the squeezing force of the heart tissue. HP-ELES is highly expected to increase the use of ultra-thin aligned NF membranes for the development of in vitro anisotropic organ models and for in vivo tissue regeneration requiring multilayered anisotropic scaffolds owing to the ease of the manual manipulation of the membrane.

Six Shades of Vascular Smooth Muscle Cells Illuminated by KLF4 (Krüppel-Like Factor 4).

Multiple layers of vascular smooth muscle cells (vSMCs) are present in blood vessels forming the media of the vessel wall. vSMCs provide a vessel wall structure, enabling it to contract and relax, thus modulating blood flow. They also play a crucial role in the development of vascular diseases, such as atherosclerosis and aortic aneurysm formation. vSMCs display a remarkable high degree of plasticity. At present, the number of different vSMC phenotypes has only partially been characterized. By mapping vSMC phenotypes in detail and identifying triggers for phenotype switching, the relevance of the different phenotypes in vascular disease may be identified. Up until recently, vSMCs were classified as either contractile or dedifferentiated (ie, synthetic). However, single-cell RNA sequencing studies revealed such dedifferentiated arterial vSMCs to be highly diverse. Currently, no consensus exist about the number of vSMC phenotypes. Therefore, we reviewed the data from relevant single-cell RNA sequencing studies, and classified a total of 6 vSMC phenotypes. The central dedifferentiated vSMC type that we classified is the mesenchymal-like phenotype. Mesenchymal-like vSMCs subsequently seem to differentiate into fibroblast-like, macrophage-like, osteogenic-like, and adipocyte-like vSMCs, which contribute differentially to vascular disease. This phenotype switching between vSMCs requires the transcription factor KLF4 (Krüppel-like factor 4). Here, we performed an integrated analysis of the data about the recently identified vSMC phenotypes, their associated gene expression profiles, and previous vSMC knowledge to better understand the role of vSMC phenotype transitions in vascular pathology.

PD11-09 CELLULAR MECHANISMS OF 5-ALPHA REDUCTASE INHIBITOR TREATMENT RESISTANCE IN BENIGN PROSTATIC HYPERPLASIA

You have accessJournal of UrologyBenign Prostatic Hyperplasia: Basic Research & Pathophysiology (PD11)1 Sep 2021PD11-09 CELLULAR MECHANISMS OF 5-ALPHA REDUCTASE INHIBITOR TREATMENT RESISTANCE IN BENIGN PROSTATIC HYPERPLASIA Diya Binoy Joseph, Gervaise Henry, Alicia Malewska, Jeffrey Reese, Ryan Mauck, Jeffrey Gahan, Ryan Hutchinson, James Mohler, Claus Roehrborn, and Douglas Strand Diya Binoy JosephDiya Binoy Joseph More articles by this author , Gervaise HenryGervaise Henry More articles by this author , Alicia MalewskaAlicia Malewska More articles by this author , Jeffrey ReeseJeffrey Reese More articles by this author , Ryan MauckRyan Mauck More articles by this author , Jeffrey GahanJeffrey Gahan More articles by this author , Ryan HutchinsonRyan Hutchinson More articles by this author , James MohlerJames Mohler More articles by this author , Claus RoehrbornClaus Roehrborn More articles by this author , and Douglas StrandDouglas Strand More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001986.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: 5-alpha reductase inhibitors (5ARIs) are prescribed to reduce prostate volume and alleviate lower urinary tract symptoms due to Benign Prostatic Hyperplasia (BPH). In some patients, prostate shrinkage is focal and does not result in improved urinary symptoms. We examined the phenotypic changes in glandular acini accompanying 5ARI treatment to determine the cellular mechanisms of treatment resistance. METHODS: Mass spectrometry was performed to measure 5ARI drug and hormone levels in prostate tissue from BPH patients. Patients with confirmed presence of 5ARI drug, low DHT and histological response were selected for spatial transcriptomics. Visium spatial transcriptomics was performed on histologically-responsive and non-responsive regions. Primary prostate epithelial cells were treated with TNF-α to activate NF-κB and qPCR was used to measure lineage-specific gene expression. RESULTS: We observed that patients with detectable levels of 5ARI drug display reduced DHT and increased testosterone regardless of phenotypic response. In 5ARI treated patients, regions of normal prostate glandular architecture can often be seen adjacent to regions of smaller acini with multiple cell layers, defined as histologically-resistant and -responsive, respectively. Spatial transcriptomics performed on histologically-resistant vs. -responsive regions revealed a urethral club-like molecular signature in small acini. These regions displayed increased TNF-α expression and nuclear localization and phosphorylation of p65. Treatment of primary prostate epithelial cells with TNF-α activated NF-κB and upregulated club cell genes, recapitulating the in vivo expression of these genes in responsive regions. CONCLUSIONS: We conclude that 5ARI treatment results in small ducts of androgen-independent club cells. It is unclear whether 5ARI treatment is inducing direct lineage switching of prostate luminal cells to club-like cells for survival or whether 5ARI-induced apoptosis of prostate luminal cells is indirectly driving altered differentiation of basal epithelia to club epithelia. Alternatively, androgen-independent club cells may be expanded during BPH and survive 5ARI treatment and repopulate prostate glands after 5ARI withdrawal. Further studies are required to determine how adjacent, histologically normal prostate glands maintain AR-dependent signaling despite low levels of tissue DHT and whether club cells can act as progenitors during androgen replenishment and prostate regrowth. Source of Funding: AUA Research Scholar Award 659333 to DBJ, R01 DK115477 to DWS and NCI P30CA016056 to Roswell Park Comprehensive Cancer Center for support of the Bioanalytical, Metabolomics, and Pharmacokinetics Shared Resource © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e201-e201 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Diya Binoy Joseph More articles by this author Gervaise Henry More articles by this author Alicia Malewska More articles by this author Jeffrey Reese More articles by this author Ryan Mauck More articles by this author Jeffrey Gahan More articles by this author Ryan Hutchinson More articles by this author James Mohler More articles by this author Claus Roehrborn More articles by this author Douglas Strand More articles by this author Expand All Advertisement Loading ...

Vessel- and ray-specific monolignol biosynthesis as an approach to engineer fiber-hypolignification and enhanced saccharification in poplar.

Lignin is one of the main factors determining recalcitrance to processing of lignocellulosic biomass towards bio-based materials and fuels. Consequently, wood of plants engineered for low lignin content is typically more amenable to processing. However, lignin-modified plants often exhibit collapsed vessels and associated growth defects. Vessel-specific reintroduction of lignin biosynthesis in dwarfed low-lignin cinnamoyl-CoA reductase1 (ccr1) Arabidopsis mutants using the ProSNBE:AtCCR1 construct overcame the yield penalty while maintaining high saccharification yields, and showed that monolignols can be transported between the different xylem cells acting as 'good neighbors' in Arabidopsis. Here, we translated this research into the bio-energy crop poplar. By expressing ProSNBE:AtCCR1 into CRISPR/Cas9-generated ccr2 poplars, we aimed for vessel-specific lignin biosynthesis to: (i) achieve growth restoration while maintaining high saccharification yields; and (ii) study the existence of 'good neighbors' in poplar wood. Analyzing the resulting ccr2 ProSNBE:AtCCR1 poplars showed that vessels and rays act as good neighbors for lignification in poplar. If sufficient monolignols are produced by these cells, monolignols migrate over multiple cell layers, resulting in a restoration of the lignin amount to wild-type levels. If the supply of monolignols is limited, the monolignols are incorporated into the cell walls of the vessels and rays producing them and their adjoining cells resulting in fiber hypolignification. One such fiber-hypolignified line had 18% less lignin and, despite its small yield penalty, had an increase of up to 71% in sugar release on a plant base upon saccharification.

Oral Versus Gastrointestinal Mucosal Immune Niches in Homeostasis and Allostasis

Different body systems (epidermis, respiratory tract, cornea, oral cavity, and gastrointestinal tract) are in continuous direct contact with innocuous and/or potentially harmful external agents, exhibiting dynamic and highly selective interaction throughout the epithelia, which function as both a physical and chemical protective barrier. Resident immune cells in the epithelia are constantly challenged and must distinguish among antigens that must be either tolerated or those to which a response must be mounted for. When such a decision begins to take place in lymphoid foci and/or mucosa-associated lymphoid tissues, the epithelia network of immune surveillance actively dominates both oral and gastrointestinal compartments, which are thought to operate in the same immune continuum. However, anatomical variations clearly differentiate immune processes in both the mouth and gastrointestinal tract that demonstrate a wide array of independent immune responses. From single vs. multiple epithelia cell layers, widespread cell-to-cell junction types, microbial-associated recognition receptors, dendritic cell function as well as related signaling, the objective of this review is to specifically contrast the current knowledge of oral versus gut immune niches in the context of epithelia/lymphoid foci/MALT local immunity and systemic output. Related differences in 1) anatomy 2) cell-to-cell communication 3) antigen capture/processing/presentation 4) signaling in regulatory vs. proinflammatory responses and 5) systemic output consequences and its relations to disease pathogenesis are discussed.

Desmosomes polarize and integrate chemical and mechanical signaling to govern epidermal tissue form and function

The epidermis is a stratified epithelium in which structural and functional features are polarized across multiple cell layers. This type of polarity is essential for establishing the epidermal barrier, but how it is created and sustained is poorly understood. Previous work identified a role for the classic cadherin/filamentous-actin network in establishment of epidermal polarity. However, little is known about potential roles of the most prominent epidermal intercellular junction, the desmosome, in establishing epidermal polarity, in spite of the fact that desmosome constituents are patterned across the apical to basal cell layers. Here, we show that desmosomes and their associated intermediate filaments (IFs) are key regulators of mechanical polarization in epidermis, whereby basal and suprabasal cells experience different forces that drive layer-specific functions. Uncoupling desmosomes and IF or specific targeting of apical desmosomes through depletion of the superficial desmosomal cadherin, desmoglein 1, impedes basal stratification in an invitro competition assay and suprabasal tight junction barrier functions in 3D reconstructed epidermis. Surprisingly, disengaging desmosomes from IF also accelerated the expression of differentiation markers, through precocious activation of the mechanosensitive transcriptional regulator serum response factor (SRF) and downstream activation of epidermal growth factor receptor family member ErbB2 by Src family kinase (SFK)-mediated phosphorylation. This Dsg1-SFK-ErbB2 axis also helps maintain tight junctions and barrier function later in differentiation. Together, these data demonstrate that the desmosome-IF network is a critical contributor to the cytoskeletal-adhesive machinery that supports the polarized function of the epidermis.

Venous malformation vessels are improperly specified and hyperproliferative.

Venous malformations (VMs) are slow-flow malformations of the venous vasculature and are the most common type of vascular malformation with a prevalence of 1%. Germline and somatic mutations have been shown to contribute to VM pathogenesis, but how these mutations affect VM pathobiology is not well understood. The goal of this study was to characterize VM endothelial and mural cell expression by performing a comprehensive expression analysis of VM vasculature. VM specimens (n = 16) were stained for pan-endothelial, arterial, venous, and endothelial progenitor cell proteins; proliferation was assessed with KI67. Endothelial cells in the VM vessels were abnormally orientated and improperly specified, as seen by the misexpression of both arterial and endothelial cell progenitor proteins not observed in control vessels. Consistent with arterialization of the endothelial cells, VM vessels were often surrounded by multiple layers of disorganized mural cells. VM endothelium also had a significant increase in proliferative endothelial cells, which may contribute to the dilated channels seen in VMs. Together the expression analysis indicates that the VM endothelium is misspecified and hyperproliferative, suggesting that VMs are biologically active lesions, consistent with clinical observations of VM progression over time.

A Fast 3D Electrochemical/Thermal Model for Large-Format Li-Ion Pouch Cells

Ever since the first commercial Li-ion battery launched in 1991, Li-ion batteries have been the best available energy storage systems for consumer electronics [1]. With recent advances in cell capacity, cycle time and battery management systems, they have become even more popular as an ideal candidate for grid-scale energy storage and electric vehicles [2].When a battery is being charged or discharged, there is inevitable heat generation due to electrochemical reactions, ohmic resistance and entropy changes [3]. If the amount of heat generated is not sufficiently dissipated from the battery, it could substantially increase the cell temperature which leads to severe cell degradation and even catastrophic thermal runaway. Furthermore, large temperature inhomogeneity is commonly observed in large-format pouch cells due to the non-uniform local current density and reaction rate. Therefore, in order to maintain stable and durable performance, it is vital to understand the irregular heat generation and temperature distribution associated with cell geometry and properties, and design appropriate cooling techniques accordingly.Battery modeling is a useful tool to investigate the electrochemical reactions and consequent heat generation during charging and discharging. An experimentally validated battery model has the ability to accurately predict the cell response under different test conditions, eliminating the need for repeated lengthy experiments. Among all the existing Li-ion battery models, the Doyle-Fuller-Newman (DFN) model [4-6], originally proposed by John Newman and his students, is the most widely accepted electrochemical model for Li-ion batteries. Based on this, a few battery thermal models have been established by coupling a pseudo-2D electrochemical model with a 3D heat transfer model [7-9]. The electric and concentration fields are solved in a 1D unit-cell and are extracted to calculate the heat generation rates in a 3D battery geometry. However, such a method would introduce large errors in large-format pouch cells in temperature predictions as the assumption of uniform current density and reaction rate is not valid.Therefore, in this study, we would like to propose a pseudo-4D (P4D) battery model, which extends the original DFN model from 1D to 3D battery geometry. The charge balance, mass balance and reaction kinetics, as well as energy balance, are spatially resolved for the entire battery geometry, considering the inhomogeneity of battery state properties. Furthermore, a scaling analysis is carried out via non-dimensionalization of the model equations to demonstrate that a single-layer cell would be sufficient to simulate the overall electrical and thermal performance of the battery which actually contains multiple cell layers. The complexity of the model can thereby be reduced to make the model more time-efficient for fast simulations.

Congenital goiter with areas of signet ring cell differentiation in a juvenile giraffe: a very rare entity

BackgroundCongenital goiter is a common thyroid metabolic disorder characterized by low levels of thyroid hormone, subsequent secretion of excess thyroid-stimulating hormone (TSH) from the pituitary gland, and compensatory hyperplasia of the glands. The presence of signet ring cells (SRCs) does not provide sufficient evidence for the diagnosis of a thyroid tumor, making histopathological diagnosis challenging. In addition, SRCs can also appear in congenital goiter. Therefore, a comprehensive diagnosis of congenital goiter is warranted based on clinical symptoms, autopsy, histopathology, and laboratory examination.Case presentationA juvenile giraffe at the Ordos Zoo in Ordos presented with symptoms of loss of appetite, serious salivation, and slow growth rate since birth. Its height and weight were significantly lower than those of other giraffes of the same age. The animal ultimately died at 17 months of age. Autopsy revelaed that the thyroids were hard, with an uneven surface and with the presence of many small raised follicles, and dense in cross-section. Other organs were visibly atrophic. Histopathologically, diffuse follicles were irregular in size and shape in the hyperplastic goiter. Some follicles were collapsed due to lack of colloids. The follicles were lined by single or multiple layers of hyperplastic follicular cells (HFCs), some of which were exfoliated in the lumen. The HFCs were either cuboidal with eosinophilic cytoplasm and many red small granules or showed SRC differentiation, with nuclei pressed to one edge of the cell and distorted by cytoplasmic mucin that appeared as a single clear vacuole HFCs and as a foamy, multivesicular cytoplasmic material in others. Scattered necrosis of myocardial cells and hepatocytes, cerebral hemorrhage, necrosis of intestinal villi, and obvious atrophy of organs were also observed. Immunohistochemical tests were strongly positive for thyroglobulin and thyroid transcription factor-1 (TTF-1) in the cytoplasm of HFCs.ConclusionsHere we present a case of congenital goiter with areas of SRC differentiation in the thyroid of a juvenile giraffe.

Plant Morphogenesis: Mechanical Feedback Position Is Crucial in Organ Flattening

A new study presents a three-dimensional mechanical model with multiple cell layers to interrogate the flattening of organs during development. This model shows the importance of initial asymmetry and its reinforcement by mechanical feedback within the inner cell walls, not the outer epidermal wall, in guiding organ flattening of organ primordia.

Rhizobium etli CE3-DsRed pMP604: a useful biological tool to study initial infection steps in Phaseolus vulgaris nodulation.

Rhizobium etli CE3-DsRed pMP604 drives infection 12-24 h earlier than R. etli CE3-DsRed and it is an excellent tool in live-cell imaging studies of IT developement in P. vulgaris roots. The study of the cellular dynamics of nodulation has frequently been limited by the difficulty of performing live-cell imaging in nodule primordia and legume roots, which are constituted by multiple cell layers, such is the case of Phaseolus vulgaris. Seeking conditions to reduce the time it takes for rhizobia to infect P. vulgaris root, we decided to explore the nodulation properties of Rhizobium etli CE3 pMP604, a strain that constitutively produces Nod factors through a flavonoids-independent transcriptional activation which is often used to purify Nod factors. Even though the strain infects 12-24h earlier than the parental R. etli CE3 strain, infection thread (IT) formation, nodule organogenesis processes and N2-fixation activity are similar for both strains. Additionally, we have confirmed that R. etli CE3-DsRed pMP604 is an excellent tool to trace IT development in P. vulgaris roots.

Microscopic anatomy and ultrastructure of the resin ducts of Ferula ferulaeoides (Steud.) Korov. in Xinjiang.

Ferula ferulaeoides (Steud.) Korov. is a perennial herb that belongs to Umbelliferae (Apiaceae). Its resin and roots have extensive commercial and medicinal value in the Xinjiang region. However, the resin-secreting resin ducts (RDs) of F. ferulaeoides have not been studied in detail. This study used optical and transmission electron microscopy to explore the anatomical features, including the distribution, size, and structure, of the RDs among different organs of F. ferulaeoides. The microstructure data revealed that the RDs consisted of a round lumen, a layer of secretory cells, and multiple layers of sheath cells. Notably, the RDs in stem were arranged alternatively in a multilayered ring with vascular bundles of three distinct sizes. The ultrastructural analysis revealed that organelles in the secretory cells potentially play important roles in resin secretion. Those data may be of great significance to understanding the anatomy of the RDs in Ferula L. and Umbelliferae.

MTOR plays a pivotal role in multiple processes of enamel organ development principally through the mTORC1 pathway and in part via regulating cytoskeleton dynamics

We herein report that deletion of mTOR in dental epithelia caused defective development of multiple cell layers of the enamel organ, which culminated in tooth malformation and cystogenesis. Specifically, cells of the stellate reticulum and stratum intermedium were poorly formed, resulting in cystic changes. The pre-ameloblasts failed to elongate along the apical-basal axis and persisted vigorous expression of Sox2 and P63, which are normally downregulated during cytodifferentiation. Expression of amelogenic markers was also attenuated in mutants. Cell proliferation and cell sizes in mutants were significantly reduced over time. Importantly, we found reduced amounts and aberrant aggregations of cytoskeletal components in mutants, along with attenuated expression of cytoskeleton regulator Cdc42, whose epithelial deletion causes a similar phenotype. Moreover, disruption of actin assembly in an organ culture system affected cell proliferation and cytodifferentiation of tooth germs, supporting a causative role of mTOR-regulated cytoskeleton dynamics for the observed phenotype of mTOR mutant mice. In further support of this view, we showed that mTOR overactivation caused increased cytoskeletal component synthesis and assembly, along with accelerated cytodifferentiation in the enamel organ. Finally, we demonstrated that mTOR regulated enamel organ development principally through the mTORC1 pathway.

Osteogenic and angiogenic lineage differentiated adipose-derived stem cells for bone regeneration of calvarial defects in rabbits.

Cell sheet techniques are widely used in bone engineering. However, vascularization remains a challenge in fabricating vascularized engineered bone. The goal of this study was to induce adipose-derived stem cell (ADSC) osteogenic and angiogenic lineage differentiation and investigate the use of bidiretionally differentiated ADSCs for bone regeneration. ADSCs were cultured to form an osteogenic cell sheet. Other ADSCs were induced to differentiate into endothelial progenitor cells (EPCs), which were identified and characterized by morphological observation and CD31 immunofluorescent staining. Then, the ADSC sheet-EPC complexes were implanted subcutaneously into nude mice, while ADSC sheets alone were implanted as a control. After 8 weeks of transplantation, microcomputed tomography (micro-CT) and histological observation were used to assess bone formation. We then implanted the complexes in calvarial defects in rabbits and assessed bone repair by micro-CT and histological analysis. The ADSC sheets consisted of multiple layers of cells and extracellular matrix. The obtained EPCs formed capillary-like structures and expressed the specific antigen marker CD31. The osteogenic ADSC sheet-EPC complexes formed dense and well-vascularized new bone tissue at 8 weeks after implantation. Bone density was significantly lower in the control group than in the complex group (p < .05). In addition, the reconstruction of calvarial defects in rabbits in complex group was obviously greater than that in the control group (p < .05). These results suggested that the approach of engineering bone tissue with bidiretionally differentiated ADSCs enabled bone regeneration, thus offering a promising strategy for repairing bone defects.

Reproductive Responses to Wounding and Heat Stress in Gametophytic Thalli of the Red Alga Pyropia yezoensis

The timing of the transition from growth to reproduction is essential for the regulation of the seaweed life cycle. Variable environmental conditions can stress seaweeds and promote trade-offs between their growth and reproduction. Here, we demonstrate that reproductive responses can be induced by environmental stresses in the gametophytic thalli of the marine red alga Pyropia yezoensis. Excision of explants accelerated release of asexual monospores and sexual carpospores. The algal sensitivity to wounding was enhanced by a 3-day dark treatment prior to the excision of the explants. By contrast, heat stress at 25°C stimulated the production of a callus, a three-dimensional aggregation of randomly divided cells with multiple cell layers. This callus produced new gametophytic thalli with a normal shape; therefore, callus formation is thought to be one of the asexual reproductive strategies used by the alga to increase the number of thalli under heat stress conditions. Our results demonstrate that wounding and heat stress can reset the timing of reproduction and that gametophytic thalli therefore use a variety of distinct reproductive strategies under different stress conditions. These findings provide insights into the induction of reproduction by environmental stresses as a life cycle trade-off in seaweeds.

A Simplified Single-Layer Pseudo-4D Electrochemical/Thermal Model for Large-Format Li-Ion Pouch Cells

Ever since the first commercial Li-ion battery launched in 1991, Li-ion batteries have been the best available energy storage systems for consumer electronics [1]. With recent advances in cell capacity, cycle time and battery management systems, they have become even more popular as an ideal candidate for grid-scale energy storage and electric vehicles [2].When a battery is being charged or discharged, there is inevitable heat generation due to electrochemical reactions, ohmic resistance and entropy changes [3]. If the amount of heat generated is not sufficiently dissipated from the battery, it could substantially increase the cell temperature which leads to severe cell degradation and even catastrophic thermal runaway. Furthermore, large temperature inhomogeneity is commonly observed in large-format pouch cells due to the non-uniform local current density and reaction rate. Therefore, in order to maintain stable and durable performance, it is vital to understand the irregular heat generation and temperature distribution associated with cell geometry and properties, and design appropriate cooling techniques accordingly.Battery modeling is a useful tool to investigate the electrochemical reactions and consequent heat generation during charging and discharging. An experimentally validated battery model has the ability to accurately predict the cell response under different test conditions, eliminating the need for repeated lengthy experiments. Among all the existing Li-ion battery models, the pseudo-2D (P2D) model, originally proposed by John Newman and his students [4-6], is the most widely accepted electrochemical model for Li-ion batteries. Based on this, a few battery thermal models have been established by coupling a P2D electrochemical model with a 3D heat transfer model [7-9]. The electric and concentration fields are solved in a 1D unit-cell and are extracted to calculate the heat generation rates in a 3D battery geometry. However, such a method would introduce large errors in large-format pouch cells as the assumption of uniform current density and reaction rate is not valid.Therefore, in this study, we would like to propose a pseudo-4D (P4D) battery model, which extends the original P2D model from 1D to 3D battery geometry. The charge balance, mass balance and reaction kinetics, as well as energy balance, are spatially resolved for the entire battery geometry, considering the inhomogeneity of battery state properties. Furthermore, a scaling analysis is carried out via non-dimensionalization of the model equations to demonstrate that a single-layer cell would be sufficient to simulate the overall electrical and thermal performance of the battery which actually contains multiple cell layers. The complexity of the model can thereby be reduced to make the model more time-efficient.

Impact Of Continuous Treatment With Propylthiouracil On Renal And Hepatic Functions In Rabbits

This study was designed to investigate the effect of continuous treatment with the anti-thyroid drug, propylthiouracil (PTU), on renal and hepatic functions in rabbits as an experimental animal model. Animals were randomly divided into four different isolated groups (n = 10); Group I received normal saline. Group II, III, and IV were daily administrated with PTU in oral dosing of 50, 75, and 150 mg/kg, BWT, respectively, for three successive weeks. Serum T3 and T4 levels were measured in all groups. Increased serum creatinine and blood urea nitrogen levels (P<0.05) were also associated. Moreover, liver enzymes levels, aspartate aminotransferase, alanine aminotransferase, and total serum cholesterol levels showed a significant increase in a dose and time decedent manner. Thyroid glands of PTU-treated rabbits showed variable sized-follicles lined by multiple layers of follicular cells, which displayed signs of hyperactivity as the average follicular cell height. The diameter of its width was significantly increased compared with that in the control group. Besides, follicles were filled with a variable quantity of low-dense vacuolated colloids. Kidneys of such animals showed tubulointerstitial nephritis, glomerular atrophy, and multiple focal areas of mononuclear cell reaction. While the observed hepatic lesions were in the form of severe congestion in central vein and hepatic artery, hepatocellular necrosis, and granulocytic lymphoid cellular responses around portal areas associated with peri-portal fibrosis. Such lesions were dependent on doses of PTU. This study referred to that continuous treatment with an antithyroid drug PTU induced a hypothyroid state that was associated with impaired renal and hepatic functions in rabbits.

Inactivation of Wt1 causes pre-granulosa cell to steroidogenic cell transformation and defect of ovary development†.

Wt1 gene encodes a nuclear transcription factor which is specifically expressed in ovarian granulosa cells and testicular Sertoli cells. Our previous studies demonstrated that Wt1 is required for the lineage specification of supporting cells and inactivation of Wt1 results in Sertoli cells to Leydig-like cells transformation. To test whether Wt1 is also involved in lineage maintenance of granulosa cells during ovary development, Wt1 was specifically deleted in pre-granulosa cells using Foxl2-cre. We found that the female Wt1-/flox; Foxl2-cre mice were infertile with atrophic ovaries and no growing follicles with multiple layers of granulosa cells were observed. A large number of 3β-HSD-positive steroidogenic cells were detected in ovaries of Wt1-/flox; Foxl2-cre mice during embryonic stage and these cells were derived from Foxl2-expressing pre-granulosa cells. The quantitative results showed the expression of granulosa cell marker genes (Foxl2, Follistatin) was downregulated and steroidogenic cell marker genes (3β-HSD, Cyp11a1, Star and Sf1) was dramatically increased in Wt1-/flox; Foxl2-cre ovaries. We also found that the meiosis of germ cells in Wt1-/flox; Foxl2-cre ovaries was delayed but not arrested. This study demonstrates that Wt1 is required for lineage maintenance of granulosa cells and inactivation of Wt1 results in pre-granulosa cells to steroidogenic cells transformation which in turn causes the defect of ovary development.