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1.
Mol Ther Nucleic Acids ; 35(3): 102228, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-38975000

RESUMO

Duchenne muscular dystrophy (DMD) is a progressive muscle disease caused by the absence of dystrophin protein. One current DMD therapeutic strategy, exon skipping, produces a truncated dystrophin isoform using phosphorodiamidate morpholino oligomers (PMOs). However, the potential of exon skipping therapeutics has not been fully realized as increases in dystrophin protein have been minimal in clinical trials. Here, we investigate how miR-146a-5p, which is highly elevated in dystrophic muscle, impacts dystrophin protein levels. We find inflammation strongly induces miR-146a in dystrophic, but not wild-type myotubes. Bioinformatics analysis reveals that the dystrophin 3' UTR harbors a miR-146a binding site, and subsequent luciferase assays demonstrate miR-146a binding inhibits dystrophin translation. In dystrophin-null mdx52 mice, co-injection of miR-146a reduces dystrophin restoration by an exon 51 skipping PMO. To directly investigate how miR-146a impacts therapeutic dystrophin rescue, we generated mdx52 with body-wide miR-146a deletion (146aX). Administration of an exon skipping PMO via intramuscular or intravenous injection markedly increases dystrophin protein levels in 146aX vs. mdx52 muscles while skipped dystrophin transcript levels are unchanged supporting a post-transcriptional mechanism of action. Together, these data show that miR-146a expression opposes therapeutic dystrophin restoration, suggesting miR-146a inhibition warrants further research as a potential DMD exon skipping co-therapy.

2.
Educ Res Rev ; 432024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38854741

RESUMO

Morphemes are the smallest meaningful unit of language (e.g., affixes, base words) that express grammatical and semantic information. Additionally, morphological knowledge is significantly related to children's word reading and reading comprehension skills. Researchers have broadly assessed morphological knowledge by using a wide range of tasks and stimuli, which has influenced the interpretation of the relations between morphological knowledge and reading outcomes. This review of 103 studies used meta-analytic structural equation modeling (MASEM) to investigate the relations between commonly occurring morphological knowledge assessment features (e.g., written versus oral, spelling versus no spelling) in the literature to reading outcomes, including word reading and reading comprehension. Meta-regression techniques were used to examine moderators of age and reading ability. Morphological assessments that used a written modality (e.g., reading, writing) were more predictive of word reading outcomes than those administered orally. Assessments of morphological spelling were more predictive of both word reading and reading comprehension outcomes than those that did not examine spelling accuracy. Age was a significant moderator of the relation between morphology and word reading, such that the relation was stronger for the younger than the older children. Younger children also demonstrated higher relations between multiple task dimensions and reading comprehension, including oral tasks, tasks without decoding, and tasks that provided context clues. These findings have important implications for future morphological intervention studies aimed to improve children's reading outcomes, in particular the use of orthography and spelling within the context of teaching morphology.

3.
Nicotine Tob Res ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38826068

RESUMO

INTRODUCTION: Many surgeons require patients to quit smoking prior to elective surgeries to reduce the risk of postoperative complications. Our aim was to qualitatively evaluate the communication and care experiences of patients and clinicians involved in conversations about quitting smoking prior to elective orthopaedic surgery. METHODS: A qualitative interview study of rural-residing Veterans, primary care providers (PCPs), and Veterans Administration (VA) orthopaedic surgery staff and pharmacists, who care for rural Veterans. We performed a combination of deductive and inductive approaches to support conventional content analysis using a Patient-Centered Care framework. RESULTS: Patients appreciated a shared approach with their PCP on the plan and reasons for cessation. Despite not knowing if the motivation for elective surgeries served as a teachable moment to facilitate long-term abstinence, almost all clinicians believed it typically helped in the short-term. There was a lack of standardized workflow between primary care and surgery, especially when patients used care delivered outside of VA. CONCLUSIONS: While clinician-provided information about the reasons behind the requirement to quit smoking preoperatively was beneficial, patients appreciated the opportunity to collaborate with their care teams on developing a plan for cessation and abstinence. Other aspects of patient-centered care need to be leveraged, such as the therapeutic alliance or patient-as-person, to build trust and improve communication surrounding tobacco use treatment. System-level changes may need to be made to improve coordination and connection of clinicians within and across disciplines. IMPLICATIONS: This study included perspectives from patients, primary care teams, and surgical teams and found that, in addition to providing information, clinicians need to address other aspects of patient-centered care such as the therapeutic alliance and patient-as-person domains to promote patient engagement in tobacco use treatment. This, in turn, could enhance the potential of surgery as a teachable moment and patient success in quitting smoking.

4.
Dis Model Mech ; 17(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38770680

RESUMO

Absence of dystrophin results in muscular weakness, chronic inflammation and cardiomyopathy in Duchenne muscular dystrophy (DMD). Pharmacological corticosteroids are the DMD standard of care; however, they have harsh side effects and unclear molecular benefits. It is uncertain whether signaling by physiological corticosteroids and their receptors plays a modifying role in the natural etiology of DMD. Here, we knocked out the glucocorticoid receptor (GR, encoded by Nr3c1) specifically in myofibers and cardiomyocytes within wild-type and mdx52 mice to dissect its role in muscular dystrophy. Double-knockout mice showed significantly worse phenotypes than mdx52 littermate controls in measures of grip strength, hang time, inflammatory pathology and gene expression. In the heart, GR deletion acted additively with dystrophin loss to exacerbate cardiomyopathy, resulting in enlarged hearts, pathological gene expression and systolic dysfunction, consistent with imbalanced mineralocorticoid signaling. The results show that physiological GR functions provide a protective role during muscular dystrophy, directly contrasting its degenerative role in other disease states. These data provide new insights into corticosteroids in disease pathophysiology and establish a new model to investigate cell-autonomous roles of nuclear receptors and mechanisms of pharmacological corticosteroids.


Assuntos
Distrofina , Camundongos Endogâmicos mdx , Camundongos Knockout , Receptores de Glucocorticoides , Animais , Receptores de Glucocorticoides/metabolismo , Distrofina/metabolismo , Distrofina/genética , Distrofina/deficiência , Miocárdio/patologia , Miocárdio/metabolismo , Distrofia Muscular de Duchenne/patologia , Distrofia Muscular de Duchenne/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Miócitos Cardíacos/efeitos dos fármacos , Camundongos , Cardiomiopatias/patologia , Cardiomiopatias/metabolismo , Camundongos Endogâmicos C57BL , Distrofia Muscular Animal/patologia , Distrofia Muscular Animal/metabolismo , Fenótipo , Sístole/efeitos dos fármacos
6.
J Smok Cessat ; 2023: 3399001, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38077280

RESUMO

Introduction: Some medical centers and surgeons require patients to stop smoking cigarettes prior to elective orthopaedic surgeries in an effort to decrease surgical complications. Given higher rates of smoking among rural individuals, rural patients may be disproportionately impacted by these requirements. We assessed the perceptions and experiences of rural-residing Veterans and clinicians related to this requirement. Methods: We conducted qualitative semistructured one-on-one interviews of 26 rural-residing veterans, 10 VA orthopaedic surgery staff (from two Veterans Integrated Services Networks), 24 PCPs who serve rural veterans (14 VA; 10 non-VA), and 4 VA pharmacists. Using the knowledge, attitudes, and behavior framework, we performed conventional content analysis. Results: We found three primary themes across respondents: (1) knowledge of and the evidence base for the requirement varied widely; (2) strong personal attitudes toward the requirement; and (3) implementation and possible implications of this requirement. All surgery staff reported knowledge of requirements at their institution. VA PCPs reported knowledge of requirements but typically could not recall specifics. Most patients were unaware. The majority of respondents felt this requirement could increase motivation to quit smoking. Some PCPs felt a more thorough explanation of smoking-related complications would result in increased quit attempts. About half of all patients reported belief that the requirement was reasonable regardless of initial awareness. Respondents expressed little concern that the requirement might increase rural-urban disparities. Most PCPs and patients felt that there should be exceptions for allowing surgery, while surgical staff disagreed. Discussion. Most respondents thought elective surgery was a good motivator to quit smoking; but patients, PCPs, and surgical staff differed on whether there should be exceptions to the requirement that patients quit preoperatively. Future efforts to augment perioperative smoking cessation may benefit from improving coordination across services and educating patients more about the benefits of quitting.

7.
World J Cardiol ; 15(10): 531-541, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37900903

RESUMO

BACKGROUND: Cardiac arrest is a leading cause of mortality in America and has increased in the incidence of cases over the last several years. Cardiopulmonary resuscitation (CPR) increases survival outcomes in cases of cardiac arrest; however, healthcare workers often do not perform CPR within recommended guidelines. Real-time audiovisual feedback (RTAVF) devices improve the quality of CPR performed. This systematic review and meta-analysis aims to compare the effect of RTAVF-assisted CPR with conventional CPR and to evaluate whether the use of these devices improved outcomes in both in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) patients. AIM: To identify the effect of RTAVF-assisted CPR on patient outcomes and CPR quality with in- and OHCA. METHODS: We searched PubMed, SCOPUS, the Cochrane Library, and EMBASE from inception to July 27, 2020, for studies comparing patient outcomes and/or CPR quality metrics between RTAVF-assisted CPR and conventional CPR in cases of IHCA or OHCA. The primary outcomes of interest were return of spontaneous circulation (ROSC) and survival to hospital discharge (SHD), with secondary outcomes of chest compression rate and chest compression depth. The methodological quality of the included studies was assessed using the Newcastle-Ottawa scale and Cochrane Collaboration's "risk of bias" tool. Data was analyzed using R statistical software 4.2.0. results were statistically significant if P < 0.05. RESULTS: Thirteen studies (n = 17600) were included. Patients were on average 69 ± 17.5 years old, with 7022 (39.8%) female patients. Overall pooled ROSC in patients in this study was 37% (95% confidence interval = 23%-54%). RTAVF-assisted CPR significantly improved ROSC, both overall [risk ratio (RR) 1.17 (1.001-1.362); P = 0.048] and in cases of IHCA [RR 1.36 (1.06-1.80); P = 0.002]. There was no significant improvement in ROSC for OHCA (RR 1.04; 0.91-1.19; P = 0.47). No significant effect was seen in SHD [RR 1.04 (0.91-1.19); P = 0.47] or chest compression rate [standardized mean difference (SMD) -2.1; (-4.6-0.5)]; P = 0.09]. A significant improvement was seen in chest compression depth [SMD 1.6; (0.02-3.1); P = 0.047]. CONCLUSION: RTAVF-assisted CPR increases ROSC in cases of IHCA and chest compression depth but has no significant effect on ROSC in cases of OHCA, SHD, or chest compression rate.

8.
J Med Virol ; 95(9): e29067, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37675796

RESUMO

The COVID-19 pandemic had a profound impact on global health, but rapid vaccine administration resulted in a significant decline in morbidity and mortality rates worldwide. In this study, we sought to explore the temporal changes in the humoral immune response against SARS-CoV-2 healthcare workers (HCWs) in Augusta, GA, USA, and investigate any potential associations with ethno-demographic features. Specifically, we aimed to compare the naturally infected individuals with naïve individuals to understand the immune response dynamics after SARS-CoV-2 vaccination. A total of 290 HCWs were included and assessed prospectively in this study. COVID status was determined using a saliva-based COVID assay. Neutralizing antibody (NAb) levels were quantified using a chemiluminescent immunoassay system, and IgG levels were measured using an enzyme-linked immunosorbent assay method. We examined the changes in antibody levels among participants using different statistical tests including logistic regression and multiple correspondence analysis. Our findings revealed a significant decline in NAb and IgG levels at 8-12 months postvaccination. Furthermore, a multivariable analysis indicated that this decline was more pronounced in White HCWs (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.07-4.08, p = 0.02) and IgG (OR = 2.07, 95% CI = 1.04-4.11, p = 0.03) among the whole cohort. Booster doses significantly increased IgG and NAb levels, while a decline in antibody levels was observed in participants without booster doses at 12 months postvaccination. Our results highlight the importance of understanding the dynamics of immune response and the potential influence of demographic factors on waning immunity to SARS-CoV-2. In addition, our findings emphasize the value of booster doses to ensure durable immunity.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , COVID-19/prevenção & controle , Pandemias , SARS-CoV-2 , Anticorpos Neutralizantes , Pessoal de Saúde , Imunoglobulina G
9.
Ann Behav Med ; 57(7): 530-540, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37232548

RESUMO

BACKGROUND: Despite the elevated prevalence of smoking among gender minority adults, little is known about the factors that influence their tobacco use and cessation. PURPOSE: We identified and examined factors that influence tobacco use and cessation for gender minority adults, using a conceptual framework based on the Model of Gender Affirmation and Gender Minority Stress Model. METHODS: Nineteen qualitative, semi-structured in-depth interviews were conducted with gender minority adults who smoke or no longer smoke and were recruited from the Portland, OR metropolitan area. Interviews were audio-recorded, professionally transcribed, and analyzed utilizing thematic analysis. RESULTS: Four main themes were generated. Gender minority adults smoke to cope with general and gender minority-specific stressors. Smoking was described as a social behavior that was influenced and sustained by community and interpersonal relationships. Smoking cessation was motivated by health concerns (both general and gender minority-specific) and moderated by conducive life circumstances. Recommendations for tobacco cessation interventions highlighted the importance and role of social support. Participants expressed a strong desire for gender minority-specific tobacco cessation programs. There are unique and complex factors that contribute to the higher prevalence of smoking observed among gender minority adults. CONCLUSIONS: Tobacco cessation interventions are urgently needed for this population and should be tailored to address the unique factors that impact tobacco use and cessation among gender minority people to increase the likelihood of success.


Tobacco use is the leading cause of preventable death in the U.S. Smoking rates among gender minority people (people whose gender identity and/or gender expression do not align with the cultural expectations of their sex assigned at birth) are higher than in the general population. As a result, for developing smoking cessation interventions, it is important to understand what influences tobacco use and cessation among gender minority adults; however, little is known about these specific influencing factors. By conducting 19 interviews with gender minority adults who smoke or no longer smoke, we found gender minority adults smoke to cope with general and gender minority-specific stressors. In addition, smoking was described as a social behavior that was influenced and sustained by community and interpersonal relationships. Furthermore, smoking cessation was motivated by health concerns (both general and gender minority-specific) and moderated by conducive life circumstances. In sum, to encourage tobacco cessation, these findings suggest interventions across multiple contexts. Gender-affirming smoking cessation programs may prove more acceptable, satisfactory, and successful when (a) tailored to gender minority persons' needs, motivators, and experienced barriers and (b) aligned with significant and meaningful life changes, such as gender-affirming hormone therapy and surgery.


Assuntos
Minorias Sexuais e de Gênero , Abandono do Hábito de Fumar , Adulto , Humanos , Relações Interpessoais , Apoio Social , Uso de Tabaco/epidemiologia
12.
bioRxiv ; 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37214870

RESUMO

Duchenne muscular dystrophy (DMD) is a progressive muscle disease caused by the absence of dystrophin protein. One current DMD therapeutic strategy, exon skipping, produces a truncated dystrophin isoform using phosphorodiamidate morpholino oligomers (PMOs). However, the potential of exon skipping therapeutics has not been fully realized as increases in dystrophin protein have been minimal in clinical trials. Here, we investigate how miR-146a-5p, which is highly elevated in dystrophic muscle, impacts dystrophin protein levels. We find inflammation strongly induces miR-146a in dystrophic, but not wild-type myotubes. Bioinformatics analysis reveals that the dystrophin 3'UTR harbors a miR-146a binding site, and subsequent luciferase assays demonstrate miR-146a binding inhibits dystrophin translation. In dystrophin-null mdx52 mice, co-injection of miR-146a reduces dystrophin restoration by an exon 51 skipping PMO. To directly investigate how miR-146a impacts therapeutic dystrophin rescue, we generated mdx52 with body-wide miR-146a deletion (146aX). Administration of an exon skipping PMO via intramuscular or intravenous injection markedly increases dystrophin protein levels in 146aX versus mdx52 muscles; skipped dystrophin transcript levels are unchanged, suggesting a post-transcriptional mechanism-of-action. Together, these data show that miR-146a expression opposes therapeutic dystrophin restoration, suggesting miR-146a inhibition warrants further research as a potential DMD exon skipping co-therapy.

13.
Assessment ; 30(8): 2364-2372, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36707917

RESUMO

A programmatic series of studies developed and evaluated the Attitudes toward Transactional Sex Scale (ATTS) to measure adolescents' attitudes toward engaging in a sexual encounter initiated by an older adult offering desired objects such as cell phone, clothes, cash, or car rides in exchange for sex. Qualitative interviews informed the initial item generation followed by a series of studies assessing the psychometric properties of the measure. Study 1 evaluated the ATTS in a sample of 186 Batswana adolescents and assessed the factor structure, item-to-whole correlations, internal consistency, and convergent validity. In Study 2, the ATTS was administered to a cross-validation sample (N = 387). Confirmatory factor analysis, convergent validity, and internal consistency were consistent with the findings from the original sample. Discriminant validity was also assessed in Study 2. A subset of the sample (N = 119) completed the measure on two occasions and yielded satisfactory test-retest reliability. The resulting instrument appears to have sound psychometric properties and can be used to measure adolescents' attitudes toward accepting such adult sexual initiation that are implicated in the disproportionate burden of HIV among adolescents and young adults in sub-Saharan Africa. No existing measure with known psychometric properties has previously been available.


Assuntos
Atitude , Comportamento Sexual , Adulto Jovem , Humanos , Adolescente , Idoso , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários
14.
AIDS Care ; 35(1): 7-15, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35156485

RESUMO

Antiretroviral therapy (ART) adherence is suboptimal among gay, bisexual, and other men who have sex with men (GBMSM). Online interventions that incorporate social support represent new opportunities to improve adherence. This study focused on how social support was provided and sought within a technology-based ART adherence intervention. We coded and analyzed 1,751 messages. Within the social support messages, half of the time participants sought social support and half of the time they provided social support. Emotional and informational support were the most frequently exchanged forms. The most frequent topic that participants sought support around was interpersonal relationships (29%), followed by HIV care and treatment (28%). Similarly, 31% and 27% of messages in which participants provided support was related to HIV treatment and care and interpersonal relationships, respectively. HIV treatment and care issues most salient were ART adherence, lab results and upcoming tests, ART side effects, changes in ART regimens, and relationships with healthcare providers. Participants used the messaging feature in this intervention to spontaneously discuss and exchange support around HIV treatment and care. This analysis provided an opportunity to understand how participants informally interact with one another, how they seek and provide social support online, and their salient personal issues.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Masculino , Humanos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/psicologia , Homossexualidade Masculina , Antirretrovirais/uso terapêutico , Apoio Social , Adesão à Medicação/psicologia
15.
J Fam Theory Rev ; 15(4): 662-676, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38351982

RESUMO

In this paper, the authors introduce the Triadic Model of Pediatric Care, an innovative conceptual framework for pediatric practice with transgender and gender diverse children. The Triadic Model of Pediatric Care consists of three experts-pediatricians, primary caregiver(s), and children-who each possess unique insights, knowledge, and decision-making power. This model guides pediatricians to provide gender-affirming care that acknowledges children as experts of their own experience and worthy of bodily autonomy, while also working to ensure primary caregiver(s) have the information and support necessary to provide a safe and nurturing developmental environment for their child. The authors provide a recommendation for how the Triadic Model of Pediatric Care might be applied in a pediatric healthcare setting and conclude with a summary of the model's implications, limitations, and future directions.

16.
AIDS Educ Prev ; 34(4): 325-332, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35994581

RESUMO

The COVID-19 pandemic and resulting public health response has disrupted the lives of adolescents and their families worldwide. We evaluated the impact of the pandemic on attitudes, beliefs, and sexual risk behavior among adolescents in Botswana. Participants were recruited using household-based sampling across residential districts (blocks) in and around Gaborone, Botswana, and completed surveys on laptop computers at a private, central location. We compared baseline survey data from 380 adolescents who completed the survey pre-pandemic (n = 139) to those who completed the survey intra-pandemic (n = 241). Participants had a mean age of 15.2 years; 58.6% were girls and 41.4% were boys. Intra-pandemic, participants reported greater engagement in transactional sex (38.1% compared to 13.6% pre-pandemic, p <. 05), more favorable attitudes toward transactional sex with sugar daddies and sugar mommies (p <. 05), greater intentions to remain sexually active in the future (29.2% vs.13.6%, respectively, p <.05), and lower self-efficacy in handling risky sexual situations (p < .01). Public health interventions that lessen these concerning shifts in attitudes and behaviors will be key to protecting the sexual health of adolescents and to supporting their safe transition to adulthood.


Assuntos
COVID-19 , Infecções por HIV , Adolescente , Adulto , Botsuana/epidemiologia , COVID-19/epidemiologia , Estudos Transversais , Feminino , Infecções por HIV/prevenção & controle , Humanos , Masculino , Pandemias , Assunção de Riscos , Comportamento Sexual , Açúcares
17.
Cureus ; 14(3): e23253, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35449677

RESUMO

Erythropoietic protoporphyria is a rare skin condition that commonly presents in childhood. We report a case of a 35-year-old Hispanic male with a history of sun sensitivity, presenting with complaints of immediate burning and itching of the skin on his face and upper extremities upon sun exposure. On examination, there was minimal face erythema and calluses over the knuckles. Laboratory workup demonstrated substantially increased protoporphyrin (over 10 times the upper limit of normal) along with elevated liver enzyme levels. Liver biopsy confirmed stage 4 cirrhosis. Our patient's cutaneous manifestations were the primary complaint that led to the diagnosis of his terminal hepatic illness. We recommend screening for erythropoietic protoporphyria in patients who present with a life-long history of non-blistering, burning and itching of the skin, which begins immediately upon sun exposure.

18.
Antibiotics (Basel) ; 10(11)2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34827318

RESUMO

(1) Background: The aim of this study was to test whether matrix-bound zoledronate (zol) molecules enhanced the oral biofilm colonization of a mineralized matrix, rendering the alveolar bone more susceptible to medication-related osteonecrosis of the jaw (MRONJ) following invasive dental procedures. (2) Methods: We tested the effect of matrix-bound zol on the growth and attachment of Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn) and Actinomyces israelii (Ai), and whether the nitrogen-containing component of zol contributed to such effect. The role of oral bacteria in the induction of osteonecrosis was then tested using an extra-oral bone defect model. (3) Results: The attachment of biofilm to hydroxyapatite discs increased when the discs were pre-treated with zol. Bacterial proliferation was not affected. Matrix-bound zol was more potent than non-nitrogen-containing etidronate in enhancing the colonization. Stimulation was dampened by pre-treating the bacteria with histidine. The delivery of oral biofilm to a tibial defect caused osteonecrosis in zol-treated rats. (4) Conclusions: We conclude that matrix-bound zol enhances the oral biofilm colonization of hydroxyapatite. This enhancement depended on the presence of the nitrogen-containing group. The oral biofilm rendered the extra-oral bone susceptible to medication-related osteonecrosis, suggesting that it has an important role in the induction of MRONJ.

19.
J Neurosci ; 41(41): 8508-8531, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34417332

RESUMO

Axon regenerative failure in the mature CNS contributes to functional deficits following many traumatic injuries, ischemic injuries, and neurodegenerative diseases. The complement cascade of the innate immune system responds to pathogen threat through inflammatory cell activation, pathogen opsonization, and pathogen lysis, and complement is also involved in CNS development, neuroplasticity, injury, and disease. Here, we investigated the involvement of the classical complement cascade and microglia/monocytes in CNS repair using the mouse optic nerve injury (ONI) model, in which axons arising from retinal ganglion cells (RGCs) are disrupted. We report that central complement C3 protein and mRNA, classical complement C1q protein and mRNA, and microglia/monocyte phagocytic complement receptor CR3 all increase in response to ONI, especially within the optic nerve itself. Importantly, genetic deletion of C1q, C3, or CR3 attenuates RGC axon regeneration induced by several distinct methods, with minimal effects on RGC survival. Local injections of C1q function-blocking antibody revealed that complement acts primarily within the optic nerve, not retina, to support regeneration. Moreover, C1q opsonizes and CR3+ microglia/monocytes phagocytose growth-inhibitory myelin debris after ONI, a likely mechanism through which complement and myeloid cells support axon regeneration. Collectively, these results indicate that local optic nerve complement-myeloid phagocytic signaling is required for CNS axon regrowth, emphasizing the axonal compartment and highlighting a beneficial neuroimmune role for complement and microglia/monocytes in CNS repair.SIGNIFICANCE STATEMENT Despite the importance of achieving axon regeneration after CNS injury and the inevitability of inflammation after such injury, the contributions of complement and microglia to CNS axon regeneration are largely unknown. Whereas inflammation is commonly thought to exacerbate the effects of CNS injury, we find that complement proteins C1q and C3 and microglia/monocyte phagocytic complement receptor CR3 are each required for retinal ganglion cell axon regeneration through the injured mouse optic nerve. Also, whereas studies of optic nerve regeneration generally focus on the retina, we show that the regeneration-relevant role of complement and microglia/monocytes likely involves myelin phagocytosis within the optic nerve. Thus, our results point to the importance of the innate immune response for CNS repair.


Assuntos
Axônios/metabolismo , Complemento C1q/metabolismo , Complemento C3/metabolismo , Células Mieloides/metabolismo , Traumatismos do Nervo Óptico/metabolismo , Células Ganglionares da Retina/metabolismo , Animais , Axônios/imunologia , Complemento C1q/imunologia , Complemento C3/imunologia , Feminino , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/imunologia , Regeneração Nervosa/fisiologia , Traumatismos do Nervo Óptico/imunologia , Traumatismos do Nervo Óptico/patologia , Células Ganglionares da Retina/imunologia
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