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1.
Biophys J ; 123(1): 68-79, 2024 01 02.
Article in English | MEDLINE | ID: mdl-37978799

ABSTRACT

Measuring protein thermostability provides valuable information on the biophysical rules that govern the structure-energy relationships of proteins. However, such measurements remain a challenge for membrane proteins. Here, we introduce a new experimental system to evaluate membrane protein thermostability. This system leverages a recently developed nonfluorescent membrane scaffold protein to reconstitute proteins into nanodiscs and is coupled with a nano-format of differential scanning fluorimetry (nanoDSF). This approach offers a label-free and direct measurement of the intrinsic tryptophan fluorescence of the membrane protein as it unfolds in solution without signal interference from the "dark" nanodisc. In this work, we demonstrate the application of this method using the disulfide bond formation protein B (DsbB) as a test membrane protein. NanoDSF measurements of DsbB reconstituted in dark nanodiscs loaded with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphorylglycerol (DMPG) lipids show a complex biphasic thermal unfolding pattern with a minor unfolding transition followed by a major transition. The inflection points of the thermal denaturation curve reveal two distinct unfolding midpoint melting temperatures (Tm) of 70.5°C and 77.5°C, consistent with a three-state unfolding model. Further, we show that the catalytically conserved disulfide bond between residues C41 and C130 drives the intermediate state of the unfolding pathway for DsbB in a DMPC and DMPG nanodisc. To extend the utility of this method, we evaluate and compare the thermostability of DsbB in different lipid environments. We introduce this method as a new tool that can be used to understand how compositionally and biophysically complex lipid environments drive membrane protein stability.


Subject(s)
Dimyristoylphosphatidylcholine , Membrane Proteins , Dimyristoylphosphatidylcholine/chemistry , Temperature , Fluorometry , Disulfides , Lipid Bilayers/chemistry
2.
Nat Cell Biol ; 25(12): 1821-1832, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38049604

ABSTRACT

Lineage transitions are a central feature of prostate development, tumourigenesis and treatment resistance. While epigenetic changes are well known to drive prostate lineage transitions, it remains unclear how upstream metabolic signalling contributes to the regulation of prostate epithelial identity. To fill this gap, we developed an approach to perform metabolomics on primary prostate epithelial cells. Using this approach, we discovered that the basal and luminal cells of the prostate exhibit distinct metabolomes and nutrient utilization patterns. Furthermore, basal-to-luminal differentiation is accompanied by increased pyruvate oxidation. We establish the mitochondrial pyruvate carrier and subsequent lactate accumulation as regulators of prostate luminal identity. Inhibition of the mitochondrial pyruvate carrier or supplementation with exogenous lactate results in large-scale chromatin remodelling, influencing both lineage-specific transcription factors and response to antiandrogen treatment. These results establish reciprocal regulation of metabolism and prostate epithelial lineage identity.


Subject(s)
Monocarboxylic Acid Transporters , Prostate , Male , Humans , Prostate/metabolism , Monocarboxylic Acid Transporters/metabolism , Cell Differentiation/physiology , Epithelial Cells/metabolism , Androgen Antagonists/pharmacology , Androgen Antagonists/metabolism , Lactates/metabolism
3.
Cell Rep ; 42(10): 113221, 2023 10 31.
Article in English | MEDLINE | ID: mdl-37815914

ABSTRACT

Advanced prostate cancers are treated with therapies targeting the androgen receptor (AR) signaling pathway. While many tumors initially respond to AR inhibition, nearly all develop resistance. It is critical to understand how prostate tumor cells respond to AR inhibition in order to exploit therapy-induced phenotypes prior to the outgrowth of treatment-resistant disease. Here, we comprehensively characterize the effects of AR blockade on prostate cancer metabolism using transcriptomics, metabolomics, and bioenergetics approaches. The metabolic response to AR inhibition is defined by reduced glycolysis, robust elongation of mitochondria, and increased reliance on mitochondrial oxidative metabolism. We establish DRP1 activity and MYC signaling as mediators of AR-blockade-induced metabolic phenotypes. Rescuing DRP1 phosphorylation after AR inhibition restores mitochondrial fission, while rescuing MYC restores glycolytic activity and prevents sensitivity to complex I inhibition. Our study provides insight into the regulation of treatment-induced metabolic phenotypes and vulnerabilities in prostate cancer.


Subject(s)
Prostatic Neoplasms, Castration-Resistant , Prostatic Neoplasms , Humans , Male , Androgens/metabolism , Cell Line, Tumor , Prostatic Neoplasms/genetics , Prostatic Neoplasms, Castration-Resistant/genetics , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Receptors, Androgen/drug effects , Receptors, Androgen/metabolism , Signal Transduction
4.
J Microbiol Methods ; 212: 106808, 2023 09.
Article in English | MEDLINE | ID: mdl-37595876

ABSTRACT

Bacterial biofilms are critical to pathogenesis and infection. They are associated with rising rates of antimicrobial resistance. Biofilms are correlated with worse clinical outcomes, making them important to infectious diseases research. There is a gap in knowledge surrounding biofilm kinetics and dynamics which makes biofilm research difficult to translate from bench to bedside. To address this gap, this work employs a well-characterized crystal violet biomass accrual and planktonic cell density assay across a clinically relevant time course and expands statistical analysis to include kinetic information in a protocol termed the TMBL (Temporal Mapping of the Biofilm Lifecycle) assay. TMBL's statistical framework quantitatively compares biofilm communities across time, species, and media conditions in a 96-well format. Measurements from TMBL can reliably be condensed into response features that inform the time-dependent behavior of adherent biomass and planktonic cell populations. Staphylococcus aureus and Pseudomonas aeruginosa biofilms were grown in conditions of metal starvation in nutrient-variable media to demonstrate the rigor and translational potential of this strategy. Significant differences in single-species biofilm formation are seen in metal-deplete conditions as compared to their controls which is consistent with the consensus literature on nutritional immunity that metal availability drives transcriptomic and metabolomic changes in numerous pathogens. Taken together, these results suggest that kinetic analysis of biofilm by TMBL represents a statistically and biologically rigorous approach to studying the biofilm lifecycle as a time-dependent process. In addition to current methods to study the impact of microbe and environmental factors on the biofilm lifecycle, this kinetic assay can inform biological discovery in biofilm formation and maintenance.


Subject(s)
Biofilms , Biological Assay , Kinetics , Biomass , Gene Expression Profiling
5.
Article in English | MEDLINE | ID: mdl-37326232

ABSTRACT

BACKGROUND: Regenerative approaches performed in periodontics seems to be efficient in treating intrabony defects. There are, however, many factors that may affect the predictability of the regenerative procedures. The present article aimed to propose a new risk assessment tool for treating periodontal intrabony defects by regenerative therapy. METHODS: Different variables that could affect the success of a regenerative procedure were considered based on their impact on (i) the wound healing potential, promoting wound stability, cells, and angiogenesis, or (ii) the ability to clean the root surface and maintain an optimal plaque control or (iii) aesthetics (risk for gingival recession). RESULTS: The risk assessment variables were divided into a patient, tooth, defect, and operator level. Patient-related factors included medical conditions such as diabetes, smoking habit, plaque control, compliance with supportive care, and expectations. Tooth-related factors included prognosis, traumatic occlusal forces or mobility, endodontic status, root surface topography, soft tissue anatomy, and gingival phenotype. Defect-associated factors included local anatomy (number of residual bone walls, width, and depth), furcation involvement, cleansability, and number of sides of the root involved. Operator-related factors should not be neglected and included the clinician's level of experience, the presence of environmental stress factors, and the use of checklists in the daily routine. CONCLUSIONS: Using a risk assessment comprised of patient-, tooth-, defect- and operator-level factors can aid the clinician in identifying challenging characteristics and in the treatment decision process.

6.
Compend Contin Educ Dent ; 44(1): 18-24; quiz 25, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36696274

ABSTRACT

Periodontitis is a chronic, multifactorial inflammatory disease characterized by progressive destruction of the tooth-supporting apparatus. Determining tooth prognosis is of central importance in clinical practice to help both the clinician and patient understand the risks and benefits of treatment while shedding light on the patient's long-term periodontal prognosis and aiding in the development of an individualized treatment plan. Several indexing-type systems have been proposed for determining the prognosis of periodontally involved teeth. The periodontal risk score (PRS) is a simple, evidence-based, motivational tool that can be used in daily clinical practice in both healthy and periodontally involved patients. The PRS incorporates systemic and lifestyle prognostic factors to achieve superior predictive accuracy. With the PRS, patients are encouraged to achieve a target score (representing an "excellent" prognosis) that can be realistically attained through compliance with a periodontal maintenance plan. The purpose of this article is to present to clinicians how to implement this evidence-based tool into their daily practices and thus help patients improve their long-term periodontal prognosis.


Subject(s)
Periodontitis , Tooth Loss , Humans , Periodontitis/therapy , Prognosis , Risk Factors , Chronic Disease
7.
Plant Cell Environ ; 46(3): 736-746, 2023 03.
Article in English | MEDLINE | ID: mdl-36564901

ABSTRACT

Within vascular plants, the partitioning of hydraulic resistance along the soil-to-leaf continuum affects transpiration and its response to environmental conditions. In trees, the fractional contribution of leaf hydraulic resistance (Rleaf ) to total soil-to-leaf hydraulic resistance (Rtotal ), or fRleaf (=Rleaf /Rtotal ), is thought to be large, but this has not been tested comprehensively. We compiled a multibiome data set of fRleaf using new and previously published measurements of pressure differences within trees in situ. Across 80 samples, fRleaf averaged 0.51 (95% confidence interval [CI] = 0.46-0.57) and it declined with tree height. We also used the allometric relationship between field-based measurements of soil-to-leaf hydraulic conductance and laboratory-based measurements of leaf hydraulic conductance to compute the average fRleaf for 19 tree samples, which was 0.40 (95% CI = 0.29-0.56). The in situ technique produces a more accurate descriptor of fRleaf because it accounts for dynamic leaf hydraulic conductance. Both approaches demonstrate the outsized role of leaves in controlling tree hydrodynamics. A larger fRleaf may help stems from loss of hydraulic conductance. Thus, the decline in fRleaf with tree height would contribute to greater drought vulnerability in taller trees and potentially to their observed disproportionate drought mortality.


Subject(s)
Soil , Trees , Trees/physiology , Water/physiology , Plant Transpiration/physiology , Plant Leaves/physiology
8.
J Neural Eng ; 20(1)2023 01 18.
Article in English | MEDLINE | ID: mdl-36548995

ABSTRACT

Objective:Flexible Electrocorticography (ECoG) electrode arrays that conform to the cortical surface and record surface field potentials from multiple brain regions provide unique insights into how computations occurring in distributed brain regions mediate behavior. Specialized microfabrication methods are required to produce flexible ECoG devices with high-density electrode arrays. However, these fabrication methods are challenging for scientists without access to cleanroom fabrication equipment.Results:Here we present a fully desktop fabricated flexible graphene ECoG array. First, we synthesized a stable, conductive ink via liquid exfoliation of Graphene in Cyrene. Next, we established a stencil-printing process for patterning the graphene ink via laser-cut stencils on flexible polyimide substrates. Benchtop tests indicate that the graphene electrodes have good conductivity of ∼1.1 × 103S cm-1, flexibility to maintain their electrical connection under static bending, and electrochemical stability in a 15 d accelerated corrosion test. Chronically implanted graphene ECoG devices remain fully functional for up to 180 d, with averagein vivoimpedances of 24.72 ± 95.23 kΩ at 1 kHz. The ECoG device can measure spontaneous surface field potentials from mice under awake and anesthetized states and sensory stimulus-evoked responses.Significance:The stencil-printing fabrication process can be used to create Graphene ECoG devices with customized electrode layouts within 24 h using commonly available laboratory equipment.


Subject(s)
Electrocorticography , Graphite , Mice , Animals , Electrocorticography/methods , Electrodes, Implanted , Brain/physiology , Brain Mapping/methods
9.
J Periodontol ; 94(4): 459-466, 2023 04.
Article in English | MEDLINE | ID: mdl-36117424

ABSTRACT

BACKGROUND: Tooth-level prognostic systems are valuable tools for treatment planning and risk assessment of periodontally involved teeth. Recently the Miller-McEntire prognosis index was found to outperform comparable systems. However, it had some limitations. The present study aimed to develop and evaluate the prognostic performance of a modified version that addresses most limitations of the previous model called the periodontal risk score (PRS). METHODS: Data were retrieved retrospectively from patients who received surgical and non-surgical periodontal treatment at a university setting. Data on medical history and smoking status at baseline and the last maintenance visit were collected. Both univariate and multivariate Cox proportional hazard regression models were used to analyze the prognostic capability for predicting tooth loss due to periodontitis (TLP) risk. RESULTS: A total of 6762 teeth (281 patients) were followed up for a mean period of 22.6 ± 6.34 (10-47.6y) years. The PRS was successfully able to stratify the risk of TLP at baseline when the three different classes of association were compared for anterior and/or posterior tooth loss. After controlling for maintenance, age, and sex, the index showed an excellent predictive capacity for TLP with a Harrell C-index of 0.947. CONCLUSIONS: The periodontal risk score (PRS) displayed excellent predictive capability for anterior as well as posterior tooth loss due to periodontitis. This system was able to predict long-term tooth loss with a very high accuracy  in a population treated mainly by dental students and periodontics residents. The use of this/similar prognosis system is advisable as a means to establish tooth prognosis.


Subject(s)
Periodontitis , Tooth Loss , Humans , Tooth Loss/epidemiology , Retrospective Studies , Periodontitis/therapy , Risk Factors , Prognosis
10.
Adv Healthc Mater ; 11(18): e2200626, 2022 09.
Article in English | MEDLINE | ID: mdl-35869830

ABSTRACT

Electrophysiology and optical imaging provide complementary neural sensing capabilities - electrophysiological recordings have high temporal resolution, while optical imaging allows recording of genetically-defined populations at high spatial resolution. Combining these two modalities for simultaneous large-scale, multimodal sensing of neural activity across multiple brain regions can be very powerful. Here, transparent, inkjet-printed electrode arrays with outstanding optical and electrical properties are seamlessly integrated with morphologically conformant transparent polymer skulls. Implanted on transgenic mice expressing the Calcium (Ca2+ ) indicator GCaMP6f in excitatory neurons, these "eSee-Shells" provide a robust opto-electrophysiological interface for over 100 days. eSee-Shells enable simultaneous mesoscale Ca2+ imaging and electrocorticography (ECoG) acquisition from multiple brain regions covering 45 mm2 of cortex under anesthesia and in awake animals. The clarity and transparency of eSee-Shells allow recording single-cell Ca2+ signals directly below the electrodes and interconnects. Simultaneous multimodal measurement of cortical dynamics reveals changes in both ECoG and Ca2+ signals that depend on the behavioral state.


Subject(s)
Calcium , Polymers , Animals , Electrodes, Implanted , Electrophysiological Phenomena , Mice , Mice, Transgenic , Skull
11.
Radiat Res ; 197(5): 491-508, 2022 05 01.
Article in English | MEDLINE | ID: mdl-35213725

ABSTRACT

Recent analysis of all solid cancer incidence (1958-2009) in the Life Span Study (LSS) revealed evidence of upward curvature in the radiation dose response among males but not females. Upward curvature in sex-averaged excess relative risk (ERR) for all solid cancer mortality (1950-2003) was also observed in the 0-2 Gy dose range. As reasons for non-linearity in the LSS are not completely understood, we conducted dose-response analyses for all solid cancer mortality and incidence applying similar methods [1958-2009 follow-up, DS02R1 doses, including subjects not-in-city (NIC) at the time of the bombing] and statistical models. Incident cancers were ascertained from Hiroshima and Nagasaki cancer registries, while cause of death was ascertained from death certificates throughout Japan. The study included 105,444 LSS subjects who were alive and not known to have cancer before January 1, 1958 (80,205 with dose estimates and 25,239 NIC subjects). Between 1958 and 2009, there were 3.1 million person-years (PY) and 22,538 solid cancers for incidence analysis and 3.8 million PY and 15,419 solid cancer deaths for mortality analysis. We fitted sex-specific ERR models adjusted for smoking to both types of data. Over the entire range of doses, solid cancer mortality dose-response exhibited a borderline significant upward curvature among males (P = 0.062) and significant upward curvature among females (P = 0.010); for solid cancer incidence, as before, we found a significant upward curvature among males (P = 0.001) but not among females (P = 0.624). The sex difference in magnitude of dose-response curvature was statistically significant for cancer incidence (P = 0.017) but not for cancer mortality (P = 0.781). The results of analyses in the 0-2 Gy range and restricted lower dose ranges generally supported inferences made about the sex-specific dose-response shape over the entire range of doses for each outcome. Patterns of sex-specific curvature by calendar period (1958-1987 vs. 1988-2009) and age at exposure (0-19 vs. 20-83) varied between mortality and incidence data, particularly among females, although for each outcome there was an indication of curvature among 0-19-year-old male survivors in both calendar periods and among 0-19-year-old female survivors in the recent period. Collectively, our findings indicate that the upward curvature in all solid cancer dose response in the LSS is neither specific to males nor to incidence data; its evidence appears to depend on the composition of sites comprising all solid cancer group and age at exposure or time. Further follow up and site-specific analyses of cancer mortality and incidence will be important to confirm the emerging trend in dose-response curvature among young survivors and unveil the contributing factors and sites.


Subject(s)
Neoplasms, Radiation-Induced , Nuclear Warfare , Nuclear Weapons , Adolescent , Adult , Atomic Bomb Survivors , Child , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Japan/epidemiology , Longevity , Male , Neoplasms, Radiation-Induced/etiology , Young Adult
12.
Article in English | MEDLINE | ID: mdl-37641661

ABSTRACT

Transparent microelectrodes that facilitate simultaneous optical and electrophysiological interfacing are desirable tools for neuroscience. Electrodes made from transparent conductors such as graphene and indium tin oxide (ITO) show promise but are often limited by poor interfacial charge-transfer properties. Here, microelectrodes are demonstrated that take advantage of the transparency and volumetric capacitance of the mixed ion-electron conductor Poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). Ring-shaped microelectrodes are fabricated by inkjet-printing PEDOT:PSS, encapsulating with Parylene-C, and then exposing a contact site that is much smaller than the microelectrode outer diameter. This unique structure allows the encapsulated portion of the microelectrode volume surrounding the contact site to participate in signal transduction, which reduces impedance and enhances charge storage capacity. While using the same 100 µm diameter contact site, increasing the outer diameter of the encapsulated electrode from 300 to 550 µm reduces the impedance from 294±21 to 98±2 kΩ, respectively, at 1 Hz. Similarly, the charge storage capacity is enhanced from 6 to 21 mC cm-2. The PEDOT:PSS microelectrodes provide a low-haze, high-transmittance optical interface, demonstrating their suitability for optical neuroscience applications. They remain functional after a million 1 V stimulation cycles, up to 600 µA of stimulation current, and more than 1000 mechanical bending cycles.

13.
Cancer Lett ; 515: 28-35, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34052326

ABSTRACT

Many organs experience a loss of tissue mass and a decline in regenerative capacity during aging. In contrast, the prostate continues to grow in volume. In fact, age is the most important risk factor for prostate cancer. However, the age-related factors that influence the composition, morphology and molecular features of prostate epithelial progenitor cells, the cells-of-origin for prostate cancer, are poorly understood. Here, we review the evidence that prostate luminal progenitor cells are expanded with age. We explore the age-related changes to the microenvironment that may influence prostate epithelial cells and risk of transformation. Finally, we raise a series of questions about models of aging and regulators of prostate aging which need to be addressed. A fundamental understanding of aging in the prostate will yield critical insights into mechanisms that promote the development of age-related prostatic disease.


Subject(s)
Aging/pathology , Prostatic Neoplasms/pathology , Stem Cells/pathology , Animals , Epithelial Cells/pathology , Humans , Male , Tumor Microenvironment/physiology
14.
Am J Clin Exp Urol ; 8(4): 140-151, 2020.
Article in English | MEDLINE | ID: mdl-32929410

ABSTRACT

Age is a significant risk factor for disease of the prostate. However, the mechanisms by which age increases disease risk have not been well described. We previously reported age-related changes within the inflammatory and luminal compartments of the mouse prostate. Old mouse prostates exhibit an expansion of the population of Trop2+ luminal progenitor cells and a reduction in the frequency and functional capacity of Trop2- luminal cells, indicating that different cell-types have distinct responses to aging. Whether distinct cell-types in the prostate share a common signature of aging has not been established. We transcriptionally profiled four distinct cell-types in young adult and old mouse prostates: stromal, basal, Trop2+ luminal progenitor and Trop2- luminal cells. Motif analysis of genes upregulated in old prostate cell-types pointed to transcriptional regulators of inflammatory and hypoxia-related signaling. Glutathione metabolism and the antioxidant response emerged as a common signature of aging across prostatic lineages. Expression of genes implicated in mouse prostate aging, including the antioxidant response gene Hmox1, correlates with age of diagnosis in primary prostate tumors from the TCGA cohort. These findings reveal a common signature shared by distinct cell-types in the old prostate reflective of age-associated metabolic reprogramming.

15.
Surg Open Sci ; 2(4): 25-31, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32954245

ABSTRACT

BACKGROUND: Treatment paradigms for borderline resectable pancreatic cancer are evolving with increasing use of neoadjuvant chemotherapy and neoadjuvant chemoradiation. Variations in the definition of borderline resectable pancreatic cancer and neoadjuvant approaches have made standardizing care for borderline resectable pancreatic cancer difficult. We report an effort to standardize management of borderline resectable pancreatic cancer throughout Sanford Health, a large community oncology network. METHODS: Starting in October 2013, cases of pancreatic adenocarcinoma without known metastatic disease were categorized as borderline resectable pancreatic cancer if they met ≥ 1 of the following criteria: (1) abutment of superior mesenteric, common hepatic, or celiac arteries with < 180° involvement, (2) venous involvement deemed potentially suitable for reconstruction, and/or (3) biopsy-proven lymph node involvement. Patients with borderline resectable pancreatic cancer were treated with neoadjuvant chemotherapy followed by reimaging and surgery if venous involvement had improved; if disease remained borderline resectable, patients underwent neoadjuvant chemoradiation and surgical exploration as long as reimaging did not reveal evidence of progressive disease. RESULTS: Forty-three patients from October 2013 to April 2017 were diagnosed with borderline resectable pancreatic cancer. Twelve of 42 (29%) patients proceeded to surgical exploration directly after neoadjuvant chemotherapy; 23 (55%) received neoadjuvant chemoradiation. Overall, 28/43 (65%) underwent exploration with 19 (44%) able to undergo resection. Of those, 14/19 (74%) attained R0 resection and 11/19 (58%) were pathologic N0. No pretreatment or treatment variables were associated with resection rates; resection was the only variable associated with survival. CONCLUSION: This report demonstrates the feasibility of implementing a standardized approach to borderline resectable pancreatic cancer across multiple sites over a wide geographic area. Adherence to protocol therapies was good and surgical outcomes are similar to many reported series.

16.
Int J Obstet Anesth ; 44: 74-76, 2020 11.
Article in English | MEDLINE | ID: mdl-32805470

ABSTRACT

Congenital complete heart block is a rare phenomenon that may be discovered during pregnancy in patients who were previously asymptomatic. Peripartum management of these patients mandates a multidisciplinary approach with careful planning regarding indications for pacing, appropriate anesthetic technique, and contingency planning. Approaches to anesthetic management for congenital complete heart block have been described, but management in association with severe pre-eclampsia has not been reported. We describe the anesthetic management of a parturient with complete heart block who presented with severe pre-eclampsia requiring urgent cesarean section.


Subject(s)
Anesthesia, Epidural/methods , Anesthesia, Obstetrical/methods , Anesthesia, Spinal/methods , Cesarean Section , Heart Block/congenital , Pre-Eclampsia/physiopathology , Pregnancy Complications, Cardiovascular/physiopathology , Adult , Female , Heart Block/complications , Heart Block/physiopathology , Humans , Pregnancy
17.
PLoS One ; 15(1): e0226725, 2020.
Article in English | MEDLINE | ID: mdl-31929545

ABSTRACT

The cell cycle regulator p27Kip1 is a critical factor controlling cell number in many lineages. While its anti-proliferative effects are well-established, the extent to which this is a result of its function as a cyclin-dependent kinase (CDK) inhibitor or through other known molecular interactions is not clear. To genetically dissect its role in the developing corneal endothelium, we examined mice harboring two loss-of-function alleles, a null allele (p27-) that abrogates all protein function and a knockin allele (p27CK-) that targets only its interaction with cyclins and CDKs. Whole-animal mutants, in which all cells are either homozygous knockout or knockin, exhibit identical proliferative increases (~0.6-fold) compared with wild-type tissues. On the other hand, use of mosaic analysis with double markers (MADM) to produce infrequently-occurring clones of wild-type and mutant cells within the same tissue environment uncovers a roughly three- and six-fold expansion of individual p27CK-/CK- and p27-/- cells, respectively. Mosaicism also reveals distinct migration phenotypes, with p27-/- cells being highly restricted to their site of production and p27CK-/CK- cells more widely scattered within the endothelium. Using a density-based clustering algorithm to quantify dispersal of MADM-generated clones, a four-fold difference in aggregation is seen between the two types of mutant cells. Overall, our analysis reveals that, in developing mouse corneal endothelium, p27 regulates cell number by acting cell autonomously, both through its interactions with cyclins and CDKs and through a cyclin-CDK-independent mechanism(s). Combined with its parallel influence on cell motility, it constitutes a potent multi-functional effector mechanism with major impact on tissue organization.


Subject(s)
Cell Movement , Cell Proliferation , Cyclin-Dependent Kinase Inhibitor p27/physiology , Endothelium, Corneal/cytology , Animals , Cell Cycle , Cells, Cultured , Endothelium, Corneal/metabolism , Female , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Phenotype
18.
RSC Adv ; 10(24): 14403-14409, 2020 Apr 06.
Article in English | MEDLINE | ID: mdl-35498500

ABSTRACT

Iodine containing oxidizers are especially effective for neutralizing spore forming bacteria by generating iodine gas as a long-lived bactericide. Metal iodates have been shown to be strong oxidizers when combined with aluminum fuel particles for energy generating applications. One method to produce metal iodates in situ is by using metal oxides and an energetic salt: aluminum iodate hexahydrate (Al(H2O)6(IO3)3(HIO3)2), which is called AIH. In this study, the thermal stability and reactivity of AIH with metal oxides commonly used in energetic formulations was investigated. Three metal oxides: bismuth(iii) oxide (Bi2O3), copper(ii) oxide (CuO), and iron(iii) oxide (Fe2O3) were investigated because of their different oxygen release properties. Each metal oxide powder was combined with AIH powder. Thermal stability and reactivity were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) and reactive properties calculated to supplement experimental observations. Powder X-ray diffraction (XRD) was also used to identify the product species at various stages of heating corresponding to exothermic activity. Results show that AIH decomposition is entirely endothermic but, with the addition of metal oxide powder to AIH, exothermic reactions transform metal oxides into more stable metal iodates. This analysis provides an understanding of the compatibility of AIH with metal oxides and contributes to the development of novel energetic composites that have the advantages of both thermal and biocidal mechanisms for spore neutralization.

19.
J Vis Exp ; (153)2019 11 22.
Article in English | MEDLINE | ID: mdl-31814611

ABSTRACT

The prostate epithelium is comprised predominantly of basal and luminal cells. In vivo lineage tracing has been utilized to define the differentiation capacity of mouse prostate basal and luminal cells during development, tissue-regeneration and transformation. However, evaluating cell-intrinsic and extrinsic regulators of prostate epithelial differentiation capacity using a lineage tracing approach often requires extensive breeding and can be cost-prohibitive. In the prostate organoid assay, basal and luminal cells generate prostatic epithelium ex vivo. Importantly, primary epithelial cells can be isolated from mice of any genetic background or mice treated with any number of small molecules prior to, or after, plating into three-dimensional (3D) culture. Sufficient material for evaluation of differentiation capacity is generated after 7-10 days. Collection of basal-derived and luminal-derived organoids for (1) protein analysis by Western blot and (2) immunohistochemical analysis of intact organoids by whole-mount confocal microscopy enables researchers to evaluate the ex vivo differentiation capacity of prostate epithelial cells. When used in combination, these two approaches provide complementary information about the differentiation capacity of prostate basal and luminal cells in response to genetic or pharmacological manipulation.


Subject(s)
Cell Differentiation , Epithelial Cells/cytology , Prostate/cytology , Animals , Cell Count , Humans , Male , Mice , Organoids/cytology
20.
Am J Orthod Dentofacial Orthop ; 156(6): 846-857, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31784019

ABSTRACT

Orthodontic treatment to upright an inclined molar adjacent to an edentulous space is often necessary before implant placement. The implant site may also require a ridge augmentation if the bony volume is not sufficient. The time required for both treatment steps can be lengthy and can discourage patients from accepting dental implants. This case report presents a novel interdisciplinary approach to implant site development. Selective osteotomy and simultaneous ridge augmentation were performed on the bilateral mesially inclined second molars before orthodontic uprighting. The severely inclined second molars were uprighted in 5 months, and the enhanced implant sites were ready for implant placement without complications. A finite element analysis revealed that the osteotomy partially affected the biomechanical responses of the dentoalveolar structures during molar uprighting.


Subject(s)
Alveolar Ridge Augmentation , Dental Implants , Osteotomy , Dental Implantation, Endosseous , Humans , Molar
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