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1.
J Neurosci ; 44(14)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38360746

RESUMO

An increasing number of pathogenic variants in presynaptic proteins involved in the synaptic vesicle cycle are being discovered in neurodevelopmental disorders. The clinical features of these synaptic vesicle cycle disorders are diverse, but the most prevalent phenotypes include intellectual disability, epilepsy, movement disorders, cerebral visual impairment, and psychiatric symptoms ( Verhage and Sørensen, 2020; Bonnycastle et al., 2021; John et al., 2021; Melland et al., 2021). Among this growing list of synaptic vesicle cycle disorders, the most frequent is STXBP1 encephalopathy caused by de novo heterozygous pathogenic variants in syntaxin-binding protein 1 (STXBP1, also known as MUNC18-1; Verhage and Sørensen, 2020; John et al., 2021). STXBP1 is an essential protein for presynaptic neurotransmitter release. Its haploinsufficiency is the main disease mechanism and impairs both excitatory and inhibitory neurotransmitter release. However, the disease pathogenesis and cellular origins of the broad spectrum of neurological phenotypes are poorly understood. Here we generate cell type-specific Stxbp1 haploinsufficient male and female mice and show that Stxbp1 haploinsufficiency in GABAergic/glycinergic neurons causes developmental delay, epilepsy, and motor, cognitive, and psychiatric deficits, recapitulating majority of the phenotypes observed in the constitutive Stxbp1 haploinsufficient mice and STXBP1 encephalopathy. In contrast, Stxbp1 haploinsufficiency in glutamatergic neurons results in a small subset of cognitive and seizure phenotypes distinct from those caused by Stxbp1 haploinsufficiency in GABAergic/glycinergic neurons. Thus, the contrasting roles of excitatory and inhibitory signaling reveal GABAergic/glycinergic dysfunction as a key disease mechanism of STXBP1 encephalopathy and suggest the possibility to selectively modulate disease phenotypes by targeting specific neurotransmitter systems.


Assuntos
Encefalopatias , Epilepsia , Transtornos do Neurodesenvolvimento , Animais , Feminino , Masculino , Camundongos , Encefalopatias/genética , Epilepsia/genética , Neurônios GABAérgicos/metabolismo , Proteínas Munc18/genética , Proteínas Munc18/metabolismo , Transtornos do Neurodesenvolvimento/genética , Neurotransmissores
2.
Dig Dis Sci ; 69(8): 3061-3068, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38782854

RESUMO

INTRODUCTION: Patients with cirrhosis are at risk for cardiac complications such as heart failure, particularly heart failure with preserved ejection fraction (HFpEF) due to left ventricular diastolic dysfunction (LVDD). The H2FPEF score is a predictive model used to identify patients with HFpEF. Our primary aim was to assess the H2FPEF score in patients with cirrhosis and determine its potential to identify patients at risk for heart failure after liver transplant. METHODS: This was a cohort study of patients undergoing liver transplant for cirrhosis from January 2010 and October 2018 who had a pre-transplant transthoracic echocardiogram. RESULTS: 166 cirrhosis subjects were included in the study. The majority were men (65%) and Caucasian (85%); NASH was the most common cause of cirrhosis (41%) followed by alcohol (34%). The median H2FPEF score was 2.0 (1.0-4.0). Patients with NASH cirrhosis had higher H2FPEF scores (3.22, 2.79-3.64) than those with alcohol induced cirrhosis (1.89, 1.5-2.29, p < 0.001) and other causes of cirrhosis (1.73, 1.28-2.18, p < 0.001). All subjects with a H2FPEF score > 6 had NASH cirrhosis. There was no association between the H2FPEF scores and measures of severity of liver disease (bilirubin, INR, or MELD score). Patients with heart failure after liver transplant had higher H2FPEF scores than those without heart failure (4.0, 3.1-4.9 vs. 2.3, 2.1-2.6, respectively; p = 0.015), but the score did not predict post-transplant mortality. CONCLUSION: H2FPEF scores are higher in cirrhosis patients with NASH and appear to be associated with post-transplant heart failure, but not death.


Assuntos
Insuficiência Cardíaca , Cirrose Hepática , Transplante de Fígado , Hepatopatia Gordurosa não Alcoólica , Humanos , Masculino , Transplante de Fígado/efeitos adversos , Feminino , Pessoa de Meia-Idade , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/diagnóstico , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Cirrose Hepática/complicações , Cirrose Hepática/cirurgia , Idoso , Volume Sistólico , Estudos Retrospectivos , Ecocardiografia , Fatores de Risco , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia , Medição de Risco/métodos
3.
J Autoimmun ; 140: 103125, 2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37844543

RESUMO

Interleukin-2 (IL-2) therapies targeting the high affinity IL-2 receptor expressed on regulatory T cells (Tregs) have shown promising therapeutic benefit in autoimmune diseases through nonselective expansion of pre-existing Treg populations, but are potentially limited by the inability to induce antigen-specific Tregs, as well as by dose-limiting activation of effector immune cells in settings of inflammation. We recently developed biodegradable nanoparticles encapsulating rapamycin, called ImmTOR, which induce selective immune tolerance to co-administered antigens but do not increase total Treg numbers. Here we demonstrate that the combination of ImmTOR and an engineered Treg-selective IL-2 variant (termed IL-2 mutein) increases the number and durability of total Tregs, as well as inducing a profound synergistic increase in antigen-specific Tregs when combined with a target antigen. We demonstrate that the combination of ImmTOR and an IL-2 mutein leads to durable inhibition of antibody responses to co-administered AAV gene therapy capsid, even at sub-optimal doses of ImmTOR, and provides protection in autoimmune models of type 1 diabetes and primary biliary cholangitis. Importantly, ImmTOR also increases the therapeutic window of engineered IL-2 molecules by mitigating effector immune cell expansion and preventing exacerbation of disease in a model of graft-versus-host-disease. At the same time, IL-2 mutein shows potential for dose-sparing of ImmTOR. Overall, these results establish that the combination of ImmTOR and an IL-2 mutein show synergistic benefit on both safety and efficacy to provide durable antigen-specific immune tolerance to mitigate drug immunogenicity and to treat autoimmune diseases.

4.
Environ Sci Technol ; 56(21): 14972-14981, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35839145

RESUMO

Compared to surface application, manure subsurface injection reduces surface runoff of nutrients, antibiotic resistant microorganisms, and emerging contaminants. Less is known regarding the impact of both manure application methods on surface transport of antibiotic resistance genes (ARGs) in manure-amended fields. We applied liquid dairy manure to field plots by surface application and subsurface injection and simulated rainfall on the first or seventh day following application. The ARG richness, relative abundance (normalized to 16s rRNA), and ARG profiles in soil and surface runoff were monitored using shotgun metagenomic sequencing. Within 1 day of manure application, compared to unamended soils, soils treated with manure had 32.5-70.5% greater ARG richness and higher relative abundances of sulfonamide (6.5-129%) and tetracycline (752-3766%) resistance genes (p ≤ 0.05). On day 7, soil ARG profiles in the surface-applied plots were similar to, whereas subsurface injection profiles were different from, that of the unamended soils. Forty-six days after manure application, the soil ARG profiles in manure injection slits were 37% more diverse than that of the unamended plots. The abundance of manure-associated ARGs were lower in surface runoff from manure subsurface injected plots and carried a lower resistome risk score in comparison to surface-applied plots. This study demonstrated, for the first time, that although manure subsurface injection reduces ARGs in the runoff, it can create potential long-term hotspots for elevated ARGs within injection slits.


Assuntos
Esterco , Solo , Antibacterianos/farmacologia , RNA Ribossômico 16S/genética , Microbiologia do Solo , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos
5.
Int J Mol Sci ; 23(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36077335

RESUMO

The retina and RPE cells are regularly exposed to chronic oxidative stress as a tissue with high metabolic demand and ROS generation. DJ-1 is a multifunctional protein in the retina and RPE that has been shown to protect cells from oxidative stress in several cell types robustly. Oxidation of DJ-1 cysteine (C) residues is important for its function under oxidative conditions. The present study was conducted to analyze the impact of DJ-1 expression changes and oxidation of its C residues on RPE function. Monolayers of the ARPE-19 cell line and primary human fetal RPE (hfRPE) cultures were infected with replication-deficient adenoviruses to investigate the effects of increased levels of DJ-1 in these monolayers. Adenoviruses carried the full-length human DJ-1 cDNA (hDJ) and mutant constructs of DJ-1, which had all or each of its three C residues individually mutated to serine (S). Alternatively, endogenous DJ-1 levels were decreased by transfection and transduction with shPARK7 lentivirus. These monolayers were then assayed under baseline and low oxidative stress conditions. The results were analyzed by immunofluorescence, Western blot, RT-PCR, mitochondrial membrane potential, and viability assays. We determined that decreased levels of endogenous DJ-1 levels resulted in increased levels of ROS. Furthermore, we observed morphological changes in the mitochondria structure of all the RPE monolayers transduced with all the DJ-1 constructs. The mitochondrial membrane potential of ARPE-19 monolayers overexpressing all DJ-1 constructs displayed a significant decrease, while hfRPE monolayers only displayed a significant decrease in their ΔΨm when overexpressing the C2S mutation. Viability significantly decreased in ARPE-19 cells transduced with the C53S construct. Our data suggest that the oxidation of C53 is crucial for regulating endogenous levels of ROS and viability in RPE cells.


Assuntos
Cisteína , Epitélio Pigmentado da Retina , Cisteína/metabolismo , Humanos , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Epitélio Pigmentado da Retina/metabolismo
6.
J Am Soc Nephrol ; 31(7): 1539-1554, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32487559

RESUMO

BACKGROUND: Aberrant microRNA (miRNA) expression affects biologic processes and downstream genes that are crucial to CKD initiation or progression. The miRNA miR-204-5p is highly expressed in the kidney but whether miR-204-5p plays any role in the development of chronic renal injury is unknown. METHODS: We used real-time PCR to determine levels of miR-204 in human kidney biopsies and animal models. We generated Mir204 knockout mice and used locked nucleic acid-modified anti-miR to knock down miR-204-5p in mice and rats. We used a number of physiologic, histologic, and molecular techniques to analyze the potential role of miR-204-5p in three models of renal injury. RESULTS: Kidneys of patients with hypertension, hypertensive nephrosclerosis, or diabetic nephropathy exhibited a significant decrease in miR-204-5p compared with controls. Dahl salt-sensitive rats displayed lower levels of renal miR-204-5p compared with partially protected congenic SS.13BN26 rats. Administering anti-miR-204-5p to SS.13BN26 rats exacerbated interlobular artery thickening and renal interstitial fibrosis. In a mouse model of hypertensive renal injury induced by uninephrectomy, angiotensin II, and a high-salt diet, Mir204 gene knockout significantly exacerbated albuminuria, renal interstitial fibrosis, and interlobular artery thickening, despite attenuation of hypertension. In diabetic db/db mice, administering anti-miR-204-5p exacerbated albuminuria and cortical fibrosis without influencing blood glucose levels. In all three models, inhibiting miR-204-5p or deleting Mir204 led to upregulation of protein tyrosine phosphatase SHP2, a target gene of miR-204-5p, and increased phosphorylation of signal transducer and activator of transcription 3, or STAT3, which is an injury-promoting effector of SHP2. CONCLUSIONS: These findings indicate that the highly expressed miR-204-5p plays a prominent role in safeguarding the kidneys against common causes of chronic renal injury.


Assuntos
Nefropatias Diabéticas/metabolismo , Hipertensão/metabolismo , Rim/metabolismo , Rim/patologia , MicroRNAs/metabolismo , Nefroesclerose/metabolismo , Adulto , Albuminúria/genética , Animais , Artérias/patologia , Pressão Sanguínea/efeitos dos fármacos , Nefropatias Diabéticas/patologia , Feminino , Fibrose , Técnicas de Silenciamento de Genes , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia , Masculino , Camundongos , Camundongos Knockout , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Pessoa de Meia-Idade , Nefroesclerose/etiologia , Nefroesclerose/patologia , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Cloreto de Sódio na Dieta/administração & dosagem , Regulação para Cima
7.
Phys Rev Lett ; 122(17): 173603, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31107076

RESUMO

A strong optical nonlinearity arises when coherent light is scattered by a semiconductor quantum dot coupled to a nanophotonic waveguide. We exploit the Fano effect in such a waveguide to control the phase of the quantum interference underpinning the nonlinearity, experimentally demonstrating a tunable quantum optical filter which converts a coherent input state into either a bunched or an antibunched nonclassical output state. We show theoretically that the generation of nonclassical light is predicated on the formation of a two-photon bound state due to the interaction of the input coherent state with the quantum dot. Our model demonstrates that the tunable photon statistics arise from the dependence of the sign of two-photon interference (either constructive or destructive) on the detuning of the input relative to the Fano resonance.

9.
Mol Pharmacol ; 90(2): 80-95, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27193582

RESUMO

The increasing prevalence of influenza viruses with resistance to approved antivirals highlights the need for new anti-influenza therapeutics. Here we describe the functional properties of hexamethylene amiloride (HMA)-derived compounds that inhibit the wild-type and adamantane-resistant forms of the influenza A M2 ion channel. For example, 6-(azepan-1-yl)-N-carbamimidoylnicotinamide ( 9: ) inhibits amantadine-sensitive M2 currents with 3- to 6-fold greater potency than amantadine or HMA (IC50 = 0.2 vs. 0.6 and 1.3 µM, respectively). Compound 9: competes with amantadine for M2 inhibition, and molecular docking simulations suggest that 9: binds at site(s) that overlap with amantadine binding. In addition, tert-butyl 4'-(carbamimidoylcarbamoyl)-2',3-dinitro-[1,1'-biphenyl]-4-carboxylate ( 27: ) acts both on adamantane-sensitive and a resistant M2 variant encoding a serine to asparagine 31 mutation (S31N) with improved efficacy over amantadine and HMA (IC50 = 0.6 µM and 4.4 µM, respectively). Whereas 9: inhibited in vitro replication of influenza virus encoding wild-type M2 (EC50 = 2.3 µM), both 27: and tert-butyl 4'-(carbamimidoylcarbamoyl)-2',3-dinitro-[1,1'-biphenyl]-4-carboxylate ( 26: ) preferentially inhibited viruses encoding M2(S31N) (respective EC50 = 18.0 and 1.5 µM). This finding indicates that HMA derivatives can be designed to inhibit viruses with resistance to amantadine. Our study highlights the potential of HMA derivatives as inhibitors of drug-resistant influenza M2 ion channels.


Assuntos
Amilorida/análogos & derivados , Antivirais/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/metabolismo , Proteínas da Matriz Viral/antagonistas & inibidores , Amantadina/farmacologia , Amilorida/síntese química , Amilorida/química , Amilorida/farmacologia , Animais , Antivirais/química , Morte Celular/efeitos dos fármacos , Linhagem Celular , Guanidinas/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Vírus da Influenza A Subtipo H9N2/efeitos dos fármacos , Ativação do Canal Iônico/efeitos dos fármacos , Camundongos , Simulação de Acoplamento Molecular , Técnicas de Patch-Clamp , Proteínas da Matriz Viral/metabolismo
11.
Pharm Res ; 31(7): 1823-33, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24464271

RESUMO

PURPOSE: The purpose of this study was to validate the approach of serial sampling from one mouse through ligand binding assay (LBA) quantification of dosed biotherapeutic in diluted whole blood to derive a pharmacokinetic (PK) profile. METHODS: This investigation compared PK parameters obtained using serial and composite sampling methods following administration of human IgG monoclonal antibody. The serial sampling technique was established by collecting 10 µL of blood via tail vein at each time point following drug administration. Blood was immediately diluted into buffer followed by analyte quantitation using Gyrolab to derive plasma concentrations. Additional studies were conducted to understand matrix and sampling site effects on drug concentrations. RESULTS: The drug concentration profiles, irrespective of biological matrix, and PK parameters using both sampling methods were not significantly different. There were no sampling site effects on drug concentration measurements except that concentrations were slightly lower in sodium citrated plasma than other matrices. CONCLUSIONS: We recommend the application of mouse serial sampling, particularly with limiting drug supply or specialized animal models. Overall the efficiencies gained by serial sampling were 40-80% savings in study cost, animal usage, study length and drug conservation while inter-subject variability across PK parameters was less than 30%.


Assuntos
Anticorpos Monoclonais/sangue , Imunoglobulina G/sangue , Animais , Anticorpos Monoclonais/administração & dosagem , Coleta de Amostras Sanguíneas/economia , Coleta de Amostras Sanguíneas/métodos , Imunoglobulina G/administração & dosagem , Injeções Intravenosas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais
12.
Phys Rev Lett ; 111(4): 044801, 2013 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-23931374

RESUMO

In Compton scattering light sources, a laser pulse is scattered by a relativistic electron beam to generate tunable x and gamma rays. Because of the inhomogeneous nature of the incident radiation, the relativistic Lorentz boost of the electrons is modulated by the ponderomotive force during the interaction, leading to intrinsic spectral broadening and brightness limitations. These effects are discussed, along with an optimization strategy to properly balance the laser bandwidth, diffraction, and nonlinear ponderomotive force.

13.
PNAS Nexus ; 2(11): pgad394, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38024395

RESUMO

Tolerogenic ImmTOR nanoparticles encapsulating rapamycin have been demonstrated to mitigate immunogenicity of adeno-associated virus (AAV) gene therapy vectors, enhance levels of transgene expression, and enable redosing of AAV at moderate vector doses of 2 to 5E12 vg/kg. However, recent clinical trials have often pushed AAV vector doses 10-fold to 50-fold higher, with serious adverse events observed at the upper range. Here, we assessed combination therapy of ImmTOR with B cell-targeting drugs for the ability to increase the efficiency of redosing at high vector doses. The combination of ImmTOR with a monoclonal antibody against B cell activation factor (aBAFF) exhibited strong synergy leading to more than a 5-fold to 10-fold reduction of splenic mature B cells and plasmablasts while increasing the fraction of pre-/pro-B cells. In addition, this combination dramatically reduced anti-AAV IgM and IgG antibodies, thus enabling four successive AAV administrations at doses up to 5E12 vg/kg and at least two AAV doses at 5E13 vg/kg, with the transgene expression level in the latter case being equal to that observed in control animals receiving a single vector dose of 1E14 vg/kg. Similar synergistic effects were seen with a combination of ImmTOR and a Bruton's tyrosine kinase inhibitor, ibrutinib. These results suggest that ImmTOR could be combined with B cell-targeting agents to enable repeated vector administrations as a potential strategy to avoid toxicities associated with vector doses above 1E14 vg/kg.

14.
Rheumatol Ther ; 10(4): 825-847, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37069364

RESUMO

INTRODUCTION: SEL-212 is a developmental treatment for uncontrolled gout characterized by serum uric acid (sUA) levels ≥ 6 mg/dl despite treatment. It comprises a novel PEGylated uricase (SEL-037; also called pegadricase) co-administered with tolerogenic nanoparticles containing sirolimus (rapamycin) (SEL-110; also called ImmTOR®), which mitigates the formation of anti-drug antibodies (ADAs) against uricase and SEL-037 (PEGylated uricase), thereby enabling sustained sUA control (sUA < 6 mg/dl). The aim of this study was to identify appropriate dosing for SEL-037 and SEL-110 for use in phase 3 clinical trials. METHODS: This open-label phase 2 study was conducted in adults with symptomatic gout and sUA ≥ 6 mg/dl. Participants received five monthly infusions of SEL-037 (0.2 or 0.4 mg/kg) alone or in combination with three or five monthly infusions of SEL-110 (0.05-0.15 mg/kg). Safety, tolerability, sUA, ADAs, and tophi were monitored for 6 months. RESULTS: A total of 152 adults completed the study. SEL-037 alone resulted in rapid sUA reductions that were not sustained beyond 30 days in most participants due to ADA formation and loss of uricase activity. Levels of ADAs decreased with increasing doses of SEL-110 up to 0.1 mg/kg, with anti-uricase titers < 1080 correlating with sustained sUA control and reductions in tophi. Overall, 66% of evaluable participants achieved sUA control at week 20 following five monthly doses of SEL-037 0.2 mg/kg + SEL-110 0.1-0.15 mg/kg, whereas only 26% achieved sUA control at week 20 when SEL-110 was withdrawn after week 12. Compared to other dose combinations, SEL-037 0.2 mg/kg + SEL-110 0.15 mg/kg achieved the greatest sUA control at week 12 and was well-tolerated with no safety concerns. CONCLUSION: Results provide continued support for the use of multiple monthly administrations of SEL-037 0.2 mg/kg + SEL-110 0.1-0.15 mg/kg in clinical trials for SEL-212. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02959918.

15.
Foot Ankle Int ; 44(3): 232-242, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36859796

RESUMO

BACKGROUND: Prophylactic vancomycin treatment decreases the prevalence of surgical site and deep infections by >70% in diabetic patients undergoing reconstructive foot and ankle surgery. Thus, determining whether clinically relevant local vancomycin doses affect diabetic fracture healing is of medical interest. We hypothesized that application of vancomycin powder to the fracture site during surgery would not affect healing outcomes, but continuous exposure of vancomycin would inhibit differentiation of osteoblast precursor cells and their osteogenic activity in vitro. METHODS: The vancomycin dose used to treat the diabetic rats was a modest increase to routine surgical site vancomycin application of 1 to 2 g for a 70-kg adult (21 mg/kg). After femur fracture in BB-Wistar type 1 diabetic rats, powdered vancomycin (25 mg/kg) was administered to the fracture site. Bone marrow and periosteal cells isolated from diabetic bones were cultured and treated with increasing levels of vancomycin (0, 5, 50, 500, or 5000 µg/mL). RESULTS: Radiographic scoring, micro-computed tomography (µCT) analysis, and torsion mechanical testing failed to identify any statistical difference between the vancomycin-treated and the untreated fractured femurs 6 weeks postfracture. Low to moderate levels of vancomycin treatment (5 and 50 µg/mL) did not impair cell viability, osteoblast differentiation, or calcium deposition in either the periosteum or bone marrow-derived cell cultures. In contrast, high doses of vancomycin (5000 µg/mL) did impair viability, differentiation, and calcium deposition. CLINICAL RELEVANCE: In this diabetic rodent fracture model, vancomycin powder application at clinically relevant doses did not affect fracture healing or osteogenesis.


Assuntos
Diabetes Mellitus Experimental , Fraturas do Fêmur , Ratos , Animais , Vancomicina/farmacologia , Consolidação da Fratura , Pós , Cálcio/farmacologia , Cálcio/uso terapêutico , Microtomografia por Raio-X , Ratos Wistar , Fraturas do Fêmur/tratamento farmacológico , Fraturas do Fêmur/cirurgia
16.
J Orthop Res ; 41(7): 1494-1504, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36515300

RESUMO

The effects of locally applied zinc chloride (ZnCl2 ) on early and late-stage parameters of fracture healing were evaluated in a diabetic rat model. Type 1 Diabetes has been shown to negatively impact mechanical parameters of bone as well as biologic markers associated with bone healing. Zinc treatments have been shown to reverse those outcomes in tests of nondiabetic and diabetic animals. This study is the first to assess the efficacy of a noncarrier mediated ZnCl2 on bony healing in diabetic animals. This is a promising basic science approach which may lead to benefits for diabetic patients in the future. Treatment and healing were assessed through quantification of callus zinc, radiographic scoring, microcomputed tomography (µCT), histomorphometry, and mechanical testing. Local ZnCl2 treatment increased callus zinc levels at 1 and 3 days after fracture (p ≤ 0.025). Femur fractures treated with ZnCl2 showed increased mechanical properties after 4 and 6 weeks of healing. Histomorphometry of the ZnCl2 -treated fractures found increased callus cartilage area at Day 7 (p = 0.033) and increased callus bone area at Day 10 (p = 0.038). In contrast, callus cartilage area was decreased (p < 0.01) after 14 days in the ZnCl2 -treated rats. µCT analysis showed increased bone volume in the fracture callus of ZnCl2 -treated rats at 6 weeks (p = 0.0012) with an associated increase in the proportion of µCT voxel axial projections (Z-rays) spanning the fracture site. The results suggest that local ZnCl2 administration improves callus chondrogenesis leading to greater callus bone formation and improved fracture healing in diabetic rats.


Assuntos
Diabetes Mellitus Experimental , Fraturas do Fêmur , Ratos , Animais , Zinco/farmacologia , Diabetes Mellitus Experimental/complicações , Microtomografia por Raio-X , Calo Ósseo , Consolidação da Fratura , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/tratamento farmacológico , Fraturas do Fêmur/complicações
17.
bioRxiv ; 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37398366

RESUMO

The retinal pigmented epithelium (RPE) constitutes the outer blood-retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age-related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of exosomes that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral exosomes from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal-side sub-RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of exosome release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in exosome content, including basal-side specific desmosome and hemidesmosome shedding via exosomes. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age-related retinal diseases, (e.g., AMD) and broadly from blood-CNS barriers in other neurodegenerative diseases.

18.
J Extracell Biol ; 2(10)2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-38108061

RESUMO

The retinal pigmented epithelium (RPE) constitutes the outer blood-retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age-related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles (EVs) from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of small EVs (sEVs) including exosomes, that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral sEVs from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal-side sub-RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of sEV release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in sEV content, including basal-side specific desmosome and hemidesmosome shedding via sEVs. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age-related retinal diseases (e.g., AMD).

19.
Sci Rep ; 12(1): 4261, 2022 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-35277572

RESUMO

Preferential flow reduces water residence times and allows rapid transport of pollutants such as organic contaminants. Thus, preferential flow is considered to reduce the influence of soil matrix-solute interactions during solute transport. While this claim may be true when rainfall directly follows solute application, forcing rapid chemical and physical disequilibrium, it has been perpetuated as a general feature of solute transport-regardless of the magnitude preferential flow. A small number of studies have alternatively shown that preferential transport of strongly sorbing solutes is reduced when solutes have time to diffuse and equilibrate within the soil matrix. Here we expand this inference by allowing solute sorption equilibrium to occur and exploring how physiochemical properties affect solute transport across a vast range of preferential flow. We applied deuterium-labeled rainfall to field plots containing manure spiked with eight common antibiotics with a range of affinity for the soil after 7 days of equilibration with the soil matrix and quantified preferential flow and solute transport using 48 soil pore water samplers spread along a hillslope. Based on > 700 measurements, our data showed that solute transport to lysimeters was similar-regardless of antibiotic affinity for soil-when preferential flow represented less than 15% of the total water flow. When preferential flow exceeded 15%, however, concentrations were higher for compounds with relatively low affinity for soil. We provide evidence that (1) bypassing water flow can select for compounds that are more easily released from the soil matrix, and (2) this phenomenon becomes more evident as the magnitude of preferential flow increases. We argue that considering the natural spectrum preferential flow as an explanatory variable to gauge the influence of soil matrix-solute interactions may improve parsimonious transport models.


Assuntos
Poluentes do Solo , Solo , Solo/química , Poluentes do Solo/análise , Soluções , Água/química , Movimentos da Água
20.
Nat Commun ; 13(1): 272, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-35022448

RESUMO

Biologic drugs have transformed the standard of care for many diseases. However, many biologics induce the formation of anti-drug antibodies (ADAs), which can compromise their safety and efficacy. Preclinical studies demonstrate that biodegradable nanoparticles-encapsulating rapamycin (ImmTOR), but not free rapamycin, mitigate the immunogenicity of co-administered biologic drugs. Here we report the outcomes from two clinical trials for ImmTOR. In the first ascending dose, open-label study (NCT02464605), pegadricase, an immunogenic, pegylated uricase enzyme derived from Candida utilis, is assessed for safety and tolerability (primary endpoint) as well as activity and immunogenicity (secondary endpoint); in the second single ascending dose Phase 1b trial (NCT02648269) composed of both a double-blind and open-label parts, we evaluate the safety of ImmTOR (primary endpoint) and its ability to prevent the formation of anti-drug antibodies against pegadricase and enhance its pharmacodynamic activity (secondary endpoint) in patients with hyperuricemia. The combination of ImmTOR and pegadricase is well tolerated. ImmTOR inhibits the development of uricase-specific ADAs in a dose-dependent manner, thus enabling sustained enzyme activity and reduction in serum uric acid levels. ImmTOR may thus represent a feasible approach for preventing the formation of ADAs to a broad range of immunogenic biologic therapies.


Assuntos
Anticorpos/uso terapêutico , Hiperuricemia/tratamento farmacológico , Nanopartículas/química , Nanopartículas/uso terapêutico , Polietilenoglicóis/farmacologia , Urato Oxidase/uso terapêutico , Adulto , Idoso , Anticorpos/química , Terapia Biológica , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Orgânicos/química , Urato Oxidase/farmacologia , Ácido Úrico , Adulto Jovem
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