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1.
Cell Death Dis ; 15(6): 400, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849380

RESUMO

Emerging evidence demonstrates that pyroptosis has been implicated in the pathogenesis of asthma. Gasdermin D (GSDMD) is the pyroptosis executioner. The mechanism of GSDMD in asthma remains unclear. The aim of this study was to elucidate the potential role of GSDMD in asthmatic airway inflammation and remodeling. Immunofluorescence staining was conducted on airway epithelial tissues obtained from both asthma patients and healthy controls (HCs) to evaluate the expression level of N-GSDMD. ELISA was used to measure concentrations of cytokines (IL-1ß, IL-18, IL-17A, and IL-10) in serum samples collected from asthma patients and healthy individuals. We demonstrated that N-GSDMD, IL-18, and IL-1ß were significantly increased in samples with mild asthma compared with those from the controls. Then, wild type and Gsdmd-knockout (Gsdmd-/-) mice were used to establish asthma model. We performed histopathological staining, ELISA, and flow cytometry to explore the function of GSDMD in allergic airway inflammation and tissue remodeling in vivo. We observed that the expression of N-GSDMD, IL-18, and IL-1ß was enhanced in OVA-induced asthma mouse model. Gsdmd knockout resulted in attenuated IL-18, and IL-1ß production in both bronchoalveolar lavage fluid (BALF) and lung tissue in asthmatic mice. In addition, Gsdmd-/- mice exhibit a significant reduction in airway inflammation and remodeling, which might be associated with reduced Th17 inflammatory response and M2 polarization of macrophages. Further, we found that GSDMD knockout may improve asthmatic airway inflammation and remodeling through regulating macrophage adhesion, migration, and macrophage M2 polarization by targeting Notch signaling pathway. These findings demonstrate that GSDMD deficiency profoundly alleviates allergic inflammation and tissue remodeling. Therefore, GSDMD may serve as a potential therapeutic target against asthma.


Assuntos
Asma , Modelos Animais de Doenças , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos Knockout , Ovalbumina , Proteínas de Ligação a Fosfato , Animais , Asma/genética , Asma/patologia , Asma/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Proteínas de Ligação a Fosfato/genética , Camundongos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Humanos , Remodelação das Vias Aéreas , Feminino , Inflamação/patologia , Inflamação/metabolismo , Inflamação/genética , Camundongos Endogâmicos C57BL , Masculino , Citocinas/metabolismo , Piroptose , Pulmão/patologia , Pulmão/metabolismo , Gasderminas
2.
Sci Adv ; 10(26): eadm8454, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941462

RESUMO

The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of peripheral nerve repair remain unclear. Netrin-1 (NTN1) was found up-regulated in nerve stump after peripheral nerve injury (PNI). Herein, we demonstrated that NTN1-high endothelial cells (NTN1+ECs) were the critical component of vascular niche, fostering angiogenesis, axon regeneration, and repair-related phenotypes. We also found that NTN1+EC-derived exosomes (NTN1 EC-EXO) were involved in the formation of vascular niche as a critical role. Multi-omics analysis further verified that NTN1 EC-EXO carried a low-level expression of let7a-5p and activated key pathways associated with niche formation including focal adhesion, axon guidance, phosphatidylinositol 3-kinase-AKT, and mammalian target of rapamycin signaling pathway. Together, our study suggested that the construction of a pre-regenerative niche induced by NTN1 EC-EXO could establish a beneficial microenvironment for nerve repair and facilitate functional recovery after PNI.


Assuntos
Células Endoteliais , Exossomos , Regeneração Nervosa , Netrina-1 , Traumatismos dos Nervos Periféricos , Netrina-1/metabolismo , Netrina-1/genética , Exossomos/metabolismo , Regeneração Nervosa/genética , Animais , Células Endoteliais/metabolismo , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/terapia , Traumatismos dos Nervos Periféricos/patologia , Camundongos , Neovascularização Fisiológica , Transdução de Sinais , Humanos , Nervos Periféricos/metabolismo
3.
Mater Today Bio ; 26: 101084, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38757055

RESUMO

Neuroanatomical tract tracers are important for studying axoplasmic transport and the complex interconnections of the nervous system. Though traditional fluorescent tracers are widely used, they have several prominent drawbacks when imaging, including low resolutions and low tissue penetrations and inability to be supervised dynamically within a long peripheral nerve during the long term. Here, we explored the potential of ICG as a neural tracer for axoplasmic transport and for the first time demonstrated that ICG could be used to detect transport function within peripheral nerve by near-infrared region II (NIR-II) imaging. On basis of this finding, a novel bi-directional neural tracer biotinylated dextran amine-indocyanine green (BDA-ICG) was prepared and characterized with better long-term stability and higher nerve-to-background ratio than ICG in vivo, and successfully imaged the injured peripheral nerve from the healthy one within 24 h. Our results show that BDA-ICG are promising neural tracers and clinically available dyes with NIR-II emission tail characteristics as ICG.

4.
Exp Neurol ; 377: 114783, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38688418

RESUMO

The structural and functional features of lymphatic vessels in the peripheral nervous system (pLVs) is still unclear. Here, we clarify the existence of pLVs in rats, PROX1-EGFP transgenic mice and human, and exhibit a clear three-dimensional structure for helping understand its structural features. Moreover, two specific phenotypes of lymphatics endothelial cells (Rnd1Hi LECs and Ccl21Hi LECs) in peripheral nerves are well characterized by single-cell sequencing. Subsequently, the ability of trans-lymphatic delivery to peripheral nerves via pLVs has been dynamically demonstrated. After peripheral nerve injury (PNI), extensive lymphangiogenesis occurs in the lesion area and further enhances the efficiency of retrograde lymphatic-nerve transport. In PNI animal models, subcutaneously footpad-injected exosomes are efficiently delivered to sciatic nerve via pLVs which can promote nerve regeneration. The trans-lymphatic delivery to peripheral nerves via pLVs can subtly bypass BNB which provides an easy and alternative delivery route for PNI treatment.


Assuntos
Vasos Linfáticos , Camundongos Transgênicos , Regeneração Nervosa , Traumatismos dos Nervos Periféricos , Animais , Regeneração Nervosa/fisiologia , Vasos Linfáticos/fisiologia , Camundongos , Traumatismos dos Nervos Periféricos/patologia , Ratos , Humanos , Sistema Nervoso Periférico , Ratos Sprague-Dawley , Masculino , Nervo Isquiático/fisiologia , Nervo Isquiático/lesões , Linfangiogênese/fisiologia , Células Endoteliais/fisiologia , Exossomos/metabolismo
5.
Front Pharmacol ; 15: 1359954, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38495103

RESUMO

Introduction: The purpose of this study was to identify the chemical components of Massa Medicata Fermentata (MMF) in different fermentation methods, analyze its regulatory effects on gastrointestinal propulsion and intestinal flora in mice with food accumulation, and further explore its mechanism of action in the treatment of dyspepsia. Methods: The chemical compositions of three kinds of MMF were identified using the UPLC-Q- Exactive Orbitrap mass spectrometer. A model of spleen deficiency and food accumulation in mice was established. The gastric emptying rate and intestinal propulsion rate were calculated, serum gastrin concentration and cholinesterase activity were measured, and 16S rRNA microbial detection was performed in different groups of mouse feces. Results: The results showed that a total of 95 chemical components were identified from the three MMF extracts, 62 of which were the same, but there were differences in flavonoids and their glycosides, organic acids, and esters. MMF, PFMMF, and commercial MMF could all significantly improve the gastric emptying rate, intestinal propulsion rate, and GAS concentration in the serum of model mice; PFMMF has a better effect, while there was no significant difference in cholinesterase activity among the groups (p > 0.05). The 16S rRNA sequencing results showed that the MMF and PFMMF could increase the content of beneficial bacteria Bacteroidetes and decrease the pathogenic bacteria Verrucomicrobia in the intestines of model mice, while the commercial MMF could not. Discussion: Studies suggest that MMF has a variety of possible mechanisms for improving food accumulation and treating gastrointestinal dyspepsia, which provides reference value for the quality evaluation and clinical application of MMF.

6.
ACS Appl Mater Interfaces ; 16(10): 12117-12148, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38421602

RESUMO

Acute kidney injury (AKI) is a serious clinical syndrome with high morbidity, elevated mortality, and poor prognosis, commonly considered a "sword of Damocles" for hospitalized patients, especially those in intensive care units. Oxidative stress, inflammation, and apoptosis, caused by the excessive production of reactive oxygen species (ROS), play a key role in AKI progression. Hence, the investigation of effective and safe antioxidants and inflammatory regulators to scavenge overexpressed ROS and regulate excessive inflammation has become a promising therapeutic option. However, the unique physiological structure and complex pathological alterations in the kidneys render traditional therapies ineffective, impeding the residence and efficacy of most antioxidant and anti-inflammatory small molecule drugs within the renal milieu. Recently, nanotherapeutic interventions have emerged as a promising and prospective strategy for AKI, overcoming traditional treatment dilemmas through alterations in size, shape, charge, and surface modifications. This Review succinctly summarizes the latest advancements in nanotherapeutic approaches for AKI, encompassing nanozymes, ROS scavenger nanomaterials, MSC-EVs, and nanomaterials loaded with antioxidants and inflammatory regulator. Following this, strategies aimed at enhancing biocompatibility and kidney targeting are introduced. Furthermore, a brief discussion on the current challenges and future prospects in this research field is presented, providing a comprehensive overview of the evolving landscape of nanotherapeutic interventions for AKI.


Assuntos
Injúria Renal Aguda , Humanos , Espécies Reativas de Oxigênio/metabolismo , Injúria Renal Aguda/tratamento farmacológico , Rim/metabolismo , Estresse Oxidativo , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Inflamação/tratamento farmacológico
7.
Bioorg Chem ; 144: 107067, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38232683

RESUMO

Due to the antibiotics abuse, bacterial infection has become one of the leading causes of human death worldwide. Novel selective antimicrobial agents are urgently needed, with the hope of maintaining the balance of the microbial environment. Photo-activated chemotherapeutics have shown great potential to eliminate bacteria with appealing spatiotemporal selectivity. In this work, we reported the structural modification to enhance the triplet excited state property of Rhodamine B, synthesizing a rhodamine-based photosensitizer RBPy. Upon light activation, RBPy exhibited much stronger photosensitization ability than the parent compound Rhodamine B both in solution and in bacteria. Importantly, RBPy can selectively inactivate Staphylococcus aureus and inhibit biofilm formation with high biocompatibility. This work provides a new strategy to develop rhodamine-based photoactive chemotherapeutics for antimicrobial photodynamic therapy.


Assuntos
Fotoquimioterapia , Infecções Estafilocócicas , Humanos , Fármacos Fotossensibilizantes/farmacologia , Superóxidos , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Infecções Estafilocócicas/tratamento farmacológico , Rodaminas/farmacologia
8.
Hum Vaccin Immunother ; 20(1): 2303226, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38251677

RESUMO

Immunoglobulin A (IgA) is the most abundant antibody (Ab) in human mucosae, with secretory form (sIgA) being dominant and uniquely stable. sIgA is challenging to produce recombinantly but is naturally found in human milk, which could be considered a global resource for this biologic, justifying its development as a mucosal therapeutic. Presently, SARS-CoV-2 was utilized as a model mucosal pathogen, and methods were developed to efficiently extract human milk sIgA from donors who were naïve to SARS-CoV-2 or had recovered from infection that elicited high-titer anti-SARS-CoV-2 Spike sIgA in their milk (pooled to make LCTG-002). Mass spectrometry determined that proteins with a relative abundance of 1% or greater were all associated with sIgA. Western blot demonstrated that all batches consisted predominantly of sIgA. Compared to control IgA, LCTG-002 demonstrated significantly higher Spike binding (mean endpoint of 0.87 versus 5.87). LCTG-002 was capable of blocking the Spike receptor-binding domain - angiotensin-converting enzyme 2 (ACE2) interaction with significantly greater potency compared to control (mean LCTG-002 IC50 154ug/mL versus 50% inhibition not achieved for control), and exhibited significant neutralization activity against Spike-pseudotyped virus infection (mean LCTG-002 IC50 49.8ug/mL versus 114.5ug/mL for control). LCTG-002 was tested for its capacity to reduce viral lung burden in K18+hACE2 transgenic mice inoculated with SARS-CoV-2. LCTG-002 significantly reduced SARS-CoV-2 titers compared to control when administered at 0.25 mg/day or 1 mg/day, with a maximum TCID50 reduction of 4.9 logs. This innovative study demonstrates that LCTG-002 is highly pure and efficacious in vivo, supporting further development of milk-derived, polyclonal sIgA therapeutics.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Camundongos , Animais , Leite Humano , Imunoglobulina A Secretora , Modelos Animais de Doenças , Imunoglobulina A , Camundongos Transgênicos , Antivirais
9.
Nanomedicine (Lond) ; 18(21): 1421-1439, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37933634

RESUMO

Background: Excessive reactive oxygen species (ROS) and subsequent mitochondrial dysfunction are pivotal in initiating cardiac hypertrophy. To explore nano-selenium's (SeNP's) preventive potential against this condition, the authors evaluated chemically synthesized chitosan-SeNPs and biosynthesized Bacillus cereus YC-3-SeNPs in an angiotensin II (Ang II)-induced cardiac hypertrophy model. Methods: This investigation encompassed ROS measurement, mitochondrial membrane potential analysis, transmission electron microscopy, gene and protein expression analyses, protein carbonylation assays, serum antioxidant quantification and histological staining. Results: SeNPs effectively countered Ang II-induced cardiac hypertrophy by reducing ROS, restoring mitochondrial and protein kinase 2α (CK2-α) function, activating antioxidant pathways and enhancing serum antioxidant levels. Conclusion: This finding underscores SeNPs' role in attenuating Ang II-induced myocardial hypertrophy both in vitro and in vivo.


Enlargement of the heart is called cardiac hypertrophy; this is caused by too many reactive oxygen species, which are compounds that damage the mitochondria of cells. The mitochondria provide energy to cells and their disruption can cause a significantly negative effect on cells and the tissues and organs cells make up. Selenium is a type of metal that must be consumed in small amounts to stay healthy; it has antioxidant effects, meaning it can stop reactive oxygen species and potentially prevent cardiac hypertrophy. Nano-selenium (SeNP), consisting of tiny, spherical particles containing selenium, may be a more effective way of delivering selenium as an antioxidant to prevent cardiac hypertrophy. SeNPs were made synthetically and from a type of bacterium called Bacillus cereus; both SeNPs demonstrated antioxidant effects in heart cells taken from chicken embryos and live chickens. These results suggest that SeNPs could be developed into medication to combat cardiac hypertrophy.


Assuntos
Nanopartículas , Selênio , Selênio/farmacologia , Antioxidantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo , Mitocôndrias/metabolismo
10.
Adv Mater ; : e2305072, 2023 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-37867201

RESUMO

Twistronics, an emerging field focused on exploring the unique electrical properties induced by twist interface in graphene multilayers, has garnered significant attention in recent years. The general manipulation of twist angle depends on the assembly of van der Waals (vdW) layered materials, which has led to the discovery of unconventional superconductivity, ferroelectricity, and nonlinear optics, thereby expanding the realm of twistronics. Recently, in situ tuning of interlayer conductivity in vdW layered materials has been achieved based on scanning probe microscope. In this Perspective, the advancements in in situ twistronics are focused on by reviewing the state-of-the-art in situ manipulating technology, discussing the underlying mechanism based on the concept of structural superlubricity, and exploiting the real-time twistronic tests under scanning electron microscope (SEM). It is shown that the real-time manipulation under SEM allows for visualizing and monitoring the interface status during in situ twistronic testing. By harnessing the unique tribological properties of vdW layered materials, this novel platform not only enhances the fabrication of twistronic devices but also facilitates the fundamental understanding of interface phenomena in vdW layered materials. Moreover, this platform holds great promise for the application of twistronic-mechanical systems, providing avenues for the integration of twistronics into various mechanical frameworks.

11.
J Mater Chem B ; 11(42): 10052-10071, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37846619

RESUMO

Peripheral nerve injuries are common and can cause catastrophic consequences. Although peripheral nerves have notable regenerative capacity, full functional recovery is often challenging due to a number of factors, including age, the type of injury, and delayed healing, resulting in chronic disorders that cause lifelong miseries and significant financial burdens. Fluorescence imaging, among the various techniques, may be the key to overcome these restrictions and improve the prognosis because of its feasibility and dynamic real-time imaging. Intraoperative dynamic fluorescence imaging allows the visualization of the morphological structure of the nerve so that surgeons can reduce the incidence of medically induced injury. Axoplasmic transport-based neuroimaging allows the visualization of the internal transport function of the nerve, facilitating early, objective, and accurate assessment of the degree of regenerative repair, allowing early intervention in patients with poor recovery, thereby improving prognosis. This review briefly discusses peripheral nerve fluorescent dyes that have been reported or could potentially be employed, with a focus on their role in visualizing the nerve's function and anatomy.


Assuntos
Traumatismos dos Nervos Periféricos , Nervos Periféricos , Humanos , Nervos Periféricos/diagnóstico por imagem , Traumatismos dos Nervos Periféricos/diagnóstico por imagem , Imagem Óptica/métodos
12.
Microorganisms ; 11(10)2023 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-37894163

RESUMO

In order to deepen the understanding of the role and regulation mechanisms of prokaryotic global transcription regulators in complex processes, including virulence, the associations between the affinity and binding sequences of Mycobacterium tuberculosis MtrA have been explored extensively. Analysis of MtrA 294 diversified 26 bp binding sequences revealed that the sequence similarity of fragments was not simply associated with affinity. The unique variation patterns of GC content and periodical and sequential fluctuation of affinity contribution curves were observed along the sequence in this study. Furthermore, docking analysis demonstrated that the structure of the dimer MtrA-DNA (high affinity) was generally consistent with other OmpR family members, while Arg 219 and Gly 220 of the wing domain interacted with the minor groove. The results of the binding box replacement experiment proved that box 2 was essential for binding, which implied the differential roles of the two boxes in the binding process. Furthermore, the results of the substitution of the nucleotide at the 20th and/or 21st positions indicated that the affinity was negatively associated with the value of minor groove width precisely at the 21st position. The dimerization of the unphosphorylated MtrA facilitated by a low-affinity DNA fragment was observed for the first time. However, the proportion of the dimer was associated with the affinity of substrate DNA, which further suggested that the affinity was actually one characteristic of the stability of dimers. Based on the finding of 17 inter-molecule hydrogen bonds identified in the interface of the MtrA dimer, including 8 symmetric complementary ones in the conserved α4-ß5-α5 face, we propose that hydrogen bonds should be considered just as important as salt bridges and the hydrophobic patch in the dimerization. Our comprehensive study on a large number of binding fragments with quantitative affinity values provided new insight into the molecular mechanism of dimerization, binding specificity and affinity determination of MtrA and clues for solving the puzzle of how global transcription factors regulate a large quantity of target genes.

13.
Cell Signal ; 112: 110887, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37717713

RESUMO

Sirtuin1 (Sirt1) activation significantly attenuated calcium oxalate (CaOx) crystal deposition and renal inflammatory injury by regulating renal immune microenvironment. Here, to elucidate the molecular mechanism underlying the therapeutic effects of Sirt1 on macrophage related inflammation and tubular epithelial cells (TECs) necrosis, we constructed a macrophage and CaOx monohydrate (COM)-stimulated tubular cell co-culture system to mimic immune microenvironment in kidney and established a mouse model of CaOx nephrocalcinosis in wild-type and myeloid-specific Sirt1 knockout mice. Target prediction analyses of Gene Expression Omnibus Datasets showed that only miR-34b-5p is regulated by lipopolysaccharides and upregulated by SRT1720 and targets the TLR4 3'-untranslated region. In vitro, SRT1720 suppressed TLR4 expression and M1 macrophage polarization and decreased reactive oxygen species (ROS) production and mitochondrial damage in COM-stimulated TECs by targeting miR-34b-5p. Mechanically, Sirt1 promoted miR-34b-5p expression by suppressing the tri-methylation of H3K27, which directly bound to the miR-34b-5p promoter and abolished the miR-34b-5p transcription. Furthermore, loss of Sirt1 aggravated CaOx nephrocalcinosis-induced inflammatory and oxidative kidney injury, while AgomiR-34b reversed these effects. Therefore, our data suggested that Sirt1 inhibited TLR4 signaling and M1 macrophage polarization and decreased inflammatory and oxidative injury of TECs in vitro and in vivo.


Assuntos
MicroRNAs , Nefrocalcinose , Camundongos , Animais , Oxalato de Cálcio/metabolismo , Oxalato de Cálcio/farmacologia , Nefrocalcinose/metabolismo , Sirtuína 1/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Rim/metabolismo , Macrófagos/metabolismo
14.
Front Bioeng Biotechnol ; 11: 1258036, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37711455

RESUMO

Protein-protected metal nanomaterials are becoming the most promising fluorescent nanomaterials for biosensing, bioimaging, and therapeutic applications due to their obvious fluorescent molecular properties, favorable biocompatibility and excellent physicochemical properties. Herein, we pioneeringly prepared a cellulase protected fluorescent gold nanoclusters (Cel-Au NCs) exhibiting red fluorescence under the excitation wavelength of 560 nm via a facile and green one-step method. Based on the fluorescence turn-off mechanism, the Cel-Au NCs were used as a biosensor for specificity determination of ascorbic acid (AA) at the emission of 680 nm, which exhibited satisfactory linearity over the range of 10-400 µM and the detection limit of 2.5 µM. Further, the actual sample application of the Au NCs was successfully established by evaluating AA in serum with good recoveries of 98.76%-104.83%. Additionally, the bacteria, including gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and gram-negative bacteria (Escherichia coli), were obviously stained by Cel-Au NCs with strong red emission. Thereby, as dual-functional nanoclusters, the prepared Cel-Au NCs have been proven to be an excellent fluorescent bioprobe for the detection of AA and bacterial labeling in medical diagnosis and human health maintenance.

15.
bioRxiv ; 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37693438

RESUMO

Immunoglobulin A (IgA) is the most abundant antibody (Ab) in human mucosal compartments including the respiratory tract, with the secretory form of IgA (sIgA) being dominant and uniquely stable in these environments. sIgA is naturally found in human milk, which could be considered a global resource for this biologic, justifying the development of human milk sIgA as a dedicated airway therapeutic for respiratory infections such as SARS-CoV-2. In the present study, methods were therefore developed to efficiently extract human milk sIgA from donors who were either immunologically naïve to SARS-CoV-2 (pooled as a control IgA) or had recovered from a PCR-confirmed SARS-CoV-2 infection that elicited high-titer anti-SARS-CoV-2 Spike sIgA Abs in their milk (pooled together to make LCTG-002). Mass spectrometry determined that proteins with a relative abundance of 1.0% or greater were all associated with sIgA. None of the proteins exhibited statistically significant differences between batches. Western blot demonstrated all batches consisted predominantly of sIgA. Compared to control IgA, LCTG-002 demonstrated significantly higher binding to Spike, and was also capable of blocking the Spike - ACE2 interaction in vitro with 6.3x greater potency compared to control IgA (58% inhibition at ∼240ug/mL). LCTG-002 was then tested in vivo for its capacity to reduce viral burden in the lungs of K18+hACE2 transgenic mice inoculated with SARS-CoV-2. LCTG-002 was demonstrated to significantly reduce SARS-CoV-2 titers in the lungs compared to control IgA when administered at either 250ug/day or 1 mg/day, as measured by TCID50, plaque forming units (PFU), and qRT-PCR, with a maximum reduction of 4.9 logs. This innovative study demonstrates that LCTG-002 is highly pure, efficacious, and well tolerated in vivo, supporting further development of milk-derived, polyclonal sIgA therapeutics against SARS-CoV-2 and other mucosal infections.

16.
Breastfeed Med ; 18(8): 602-611, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37615565

RESUMO

Background: Although in the early pandemic period COVID-19 pathology among young children and infants was typically less severe compared with that observed among adults, this has not remained entirely consistent as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have emerged. There is an enormous body of evidence demonstrating the benefits of human milk antibodies (Abs) in protecting infants against a wide range of enteric and respiratory infections. It is highly plausible that the same holds true for protection against SARS-CoV-2 as this virus infects cells of the gastrointestinal and respiratory mucosae. Understanding the durability of a human milk Ab response over time after infection is critical. Objective: Previously, we examined the Abs present in milk of those recently infected with SARS-CoV-2 and concluded that the response was secretory immunoglobulin A (sIgA) dominant and that these titers were highly correlated with neutralization potency. The present study aimed to monitor the durability of the SARS-CoV-2 IgA and secretory Ab (sAb) response in milk from COVID-19-recovered lactating individuals over 12 months in the absence of vaccination or reinfection. Results: This analysis revealed a robust and durable spike-specific milk sIgA response, and at 9-12 months after infection, 88% of the samples exhibited titers above the positive cutoff for IgA and 94% were above the cutoff for sAb. Fifty percent of participants exhibited less than twofold reduction of spike-specific IgA through 12 months. A strong, significant positive correlation between IgA and sAb against spike persisted throughout the study period. Nucleocapsid-specific Abs were also assessed, which revealed significant background or cross-reactivity of milk IgA against this immunogen, as well as limited/inconsistent durability compared with Spike titers. Conclusion: These data suggest that lactating individuals are likely to continue producing spike-specific Abs in their milk for 1 year or more, which may provide critical passive immunity to infants against SARS-CoV-2 throughout the lactation period.


Assuntos
COVID-19 , Leite Humano , Adulto , Criança , Lactente , Feminino , Humanos , Pré-Escolar , Lactação , Aleitamento Materno , SARS-CoV-2 , Imunoglobulina A Secretora
17.
Proc Natl Acad Sci U S A ; 120(31): e2303675120, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37494395

RESUMO

Anti-CRISPR (Acr) proteins are encoded by phages and other mobile genetic elements and inhibit host CRISPR-Cas immunity using versatile strategies. AcrIIC4 is a broad-spectrum Acr that inhibits the type II-C CRISPR-Cas9 system in several species by an unknown mechanism. Here, we determined a series of structures of Haemophilus parainfluenzae Cas9 (HpaCas9)-sgRNA in complex with AcrIIC4 and/or target DNA, as well as the crystal structure of AcrIIC4 alone. We found that AcrIIC4 resides in the crevice between the REC1 and REC2 domains of HpaCas9, where its extensive interactions restrict the mobility of the REC2 domain and prevent the unwinding of target double-stranded (ds) DNA at the PAM-distal end. Therefore, the full-length guide RNA:target DNA heteroduplex fails to form in the presence of AcrIIC4, preventing Cas9 nuclease activation. Altogether, our structural and biochemical studies illuminate a unique Acr mechanism that allows DNA binding to the Cas9 effector complex but blocks its cleavage by preventing R-loop formation, a key step supporting DNA cleavage by Cas9.


Assuntos
Bacteriófagos , Sistemas CRISPR-Cas , Estruturas R-Loop , RNA Guia de Sistemas CRISPR-Cas , DNA/metabolismo , Bacteriófagos/genética , Edição de Genes
18.
Sci Rep ; 13(1): 10956, 2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37414830

RESUMO

Head and neck squamous cell carcinoma (HNSC) is the most common malignant tumor of head and neck. Due to the insidious nature of HNSC and the lack of effective early diagnostic indicators, the development of novel biomarkers to improve patient prognosis is particularly urgent. In this study, we explored and validated the correlation between cytochrome P450 family 4 subfamily F member 12 (CYP4F12) expression levels and HNSC progression using data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) datasets and collected patient samples. We analyzed the association of CYP4F12 expression with clinicopathological features, immune correlation and prognosis. Finally, we analyzed the correlation between CYP4F12 and pathways, and verified by experiments. The results showed that CYP4F12 was low expressed in tumor tissues, participated in a variety of phenotypic changes of HNSC and affected immune cell infiltration. Pathway analysis indicated that CYP4F12 may play a key role in tumor cell migration and apoptosis. Experimental results showed that over-expression of CYP4F12 inhibited cell migration and enhanced the adhesion between cells and matrix by inhibiting epithelial-mesenchymal transition (EMT) pathway in HNSC cells. In conclusion, our study provided insights into the role of CYP4F12 in HNSC and revealed that CYP4F12 may be a potential therapeutic target for HNSC.


Assuntos
Hidrocarboneto de Aril Hidroxilases , Neoplasias de Cabeça e Pescoço , Humanos , Transição Epitelial-Mesenquimal/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Movimento Celular/genética , Biomarcadores , Neoplasias de Cabeça e Pescoço/genética , Prognóstico , Biomarcadores Tumorais/genética
19.
Front Immunol ; 14: 1154782, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37325620

RESUMO

Introduction: Influenza (flu) vaccination prevented over 100,000 hospitalizations and 7000 deaths from flu over the 2019-2020 season in the USA. Infants <6 months are the most likely to die from flu, though flu vaccines are only licensed for infants >6 months old. Therefore, it is recommended that flu vaccination occur during pregnancy, as this reduces severe complications; however, vaccination rates are suboptimal, and vaccination is also recommended postpartum. For breast/chest-fed infants, the vaccine is believed to elicit protective and robust seasonally-specific milk antibody (Ab). Few comprehensive studies exist examining Ab responses in milk after vaccination, with none measuring secretory Ab (sAb). Determining whether sAbs are elicited is critical, as this Ab class is highly stable in milk and mucosae. Methods: In the present study, our aim was to determine to what extent specific Ab titers in the milk of lactating people were boosted after seasonal influenza vaccination. Over the 2019-2020 and 2020-2021 seasons, milk was obtained pre- and post-vaccination and assessed for specific IgA, IgG, and sAb against relevant hemagglutinin (HA) antigens by a Luminex immunoassay. Results: IgA and sAb were not found to be significantly boosted, while only IgG titers against B/Phuket/3073/2013, included in vaccines since 2015, exhibited an increase. Across the 7 immunogens examined, as many as 54% of samples exhibited no sAb boost. No significant differences for IgA, sAb, or IgG boosting were measured between seasonally-matched versus mismatched milk groups, indicating boosting was not seasonally-specific. No correlations between IgA and sAb increases were found for 6/8 HA antigens. No boost in IgG- or IgA-mediated neutralization post vaccination was observed. Discussion: This study highlights the critical need to redesign influenza vaccines with the lactating population in mind, wherein the aim should be to elicit a potent seasonally-specific sAb response in milk. As such, this population must be included in clinical studies.


Assuntos
Vacinas contra Influenza , Influenza Humana , Feminino , Lactente , Gravidez , Humanos , Influenza Humana/prevenção & controle , Hemaglutininas , Leite Humano , Lactação , Anticorpos Antivirais , Imunoglobulina G , Vacinação , Imunoglobulina A
20.
medRxiv ; 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37293109

RESUMO

Although in the early pandemic period, COVID-19 pathology among young children and infants was typically less severe compared to that observed among adults, this has not remained entirely consistent as SARS-CoV-2 variants have emerged. There is an enormous body of evidence demonstrating the benefits of human milk antibodies (Abs) in protecting infants against a wide range of enteric and respiratory infections. It is highly plausible that the same holds true for protection against SARS-CoV-2, as this virus infects cells of the gastrointestinal and respiratory mucosae. Understanding the durability of a human milk Ab response over time after infection is critical. Previously, we examined the Abs present in milk of those recently infected with SARS-CoV-2, and concluded that the response was secretory IgA (sIgA)-dominant and that these titers were highly correlated with neutralization potency. The present study aimed to monitor the durability of the SARS-CoV-2 IgA and secretory Ab (sAb) response in milk from COVID-19-recovered lactating individuals over 12 months, in the absence of vaccination or re-infection. This analysis revealed a robust and durable Spike-specific milk sIgA response, that at 9-12 months after infection, 88% of the samples exhibited titers above the positive cutoff for IgA and 94% were above cutoff for sAb. Fifty percent of participants exhibited less than a 2-fold reduction of Spike-specific IgA through 12 months. A strong significant positive correlation between IgA and sAb against Spike persisted throughout the study period. Nucleocapsid-specific Abs were also assessed, which revealed significant background or cross reactivity of milk IgA against this immunogen, as well as limited/inconsistent durability compared to Spike titers. These data suggests that lactating individuals are likely to continue producing Spike-specific Abs in their milk for 1 year or more, which may provide critical passive immunity to infants against SARS-CoV-2 throughout the lactation period.

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