Acute Inflammatory Profiles Differ with Sex and Age After Spinal Cord Injury

Background Sex and age are emerging as influential variables that affect spinal cord injury (SCI) recovery. Despite a changing demographic towards older age at the time of SCI, the effects of sex or age on inflammation remain to be elucidated. This study determined the sex- and age-dependency of the innate immune response acutely after SCI. Methods Male and female mice of ages 4- and 14-month-old received T9 contusion SCI and the proportion of microglia, monocyte-derived macrophages (MDM), and neutrophils surrounding the lesion were determined at 3- and 7-day post-injury (DPI) using flow cytometry. Cell counts of microglia and MDMs were obtained using immunohistochemistry to verify flow cytometry results at 3-DPI. Microglia and MDMs were separately isolated using fluorescence-activated cell sorting (FACS) at 3-day post-injury (DPI) to assess RNA expression of 27 genes associated with activation, redox, and debris metabolism/clearance. Results Flow cytometry revealed that being female and older at the time of injury significantly increased MDMs relative to other phagocytes, specifically increasing the ratio of MDMs to microglia at 3-DPI. Cell counts using immunohistochemistry revealed that male mice have more total microglia within SCI lesions that can account for a lower MDM/microglia ratio. With NanoString analyses of 27 genes, only 1 was differentially expressed between sexes in MDMs; specifically, complement protein C1qa was increased in males. No genes were affected by age in MDMs. Only 2 genes were differentially regulated in microglia between sexes after controlling for false discovery rate, specifically CYBB (NOX2) as a reactive oxygen species (ROS)-associated marker as well as MRC1 (CD206), a gene associated with reparative phenotypes. Both genes were increased in female microglia. No microglial genes were differentially regulated between ages. Differences between microglia and MDMs were found in 26 of 27 genes analyzed, all expressed higher in MDMs with three exceptions. Specifically, C1qa, cPLA2, and CD86 were expressed higher in microglia. Conclusions These findings indicate that inflammatory responses to SCI are sex-dependent at both the level of cellular recruitment and gene expression

Binge-Pattern Alcohol Exposure during Puberty Induces Long-Term Changes in HPA Axis Reactivity

Adolescence is a dynamic and important period of brain development however, little is known about the long-term neurobiological consequences of alcohol consumption during puberty. Our previous studies showed that binge-pattern ethanol (EtOH) treatment during pubertal development negatively dysregulated the responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis, as manifested by alterations in corticotrophin-releasing hormone (CRH), arginine vasopressin (AVP), and corticosterone (CORT) during this time period. Thus, the primary goal of this study was to determine whether these observed changes in important central regulators of the stress response were permanent or transient. In this study, juvenile male Wistar rats were treated with a binge-pattern EtOH treatment paradigm or saline alone for 8 days. The animals were left undisturbed until adulthood when they received a second round of treatments consisting of saline alone, a single dose of EtOH, or a second binge-pattern treatment paradigm. The results showed that pubertal binge-pattern EtOH exposure induced striking long-lasting alterations of many HPA axis parameters. Overall, our data provide strong evidence that binge-pattern EtOH exposure during pubertal maturation has long-term detrimental effects for the healthy development of the HPA axis

Effects of pubertal binge ethanol pre-treatments on AVP gene expression in the SON of ethanol exposed adult rats.

<p>AVP mRNA expression 1.0 h post-injection of 3 g/kg EtOH in adult animals. Animals were treated during puberty with either saline (EtOH Naïve) or binge EtOH (EtOH pre-exposed). Adult animals were then treated with saline (open bars), acute EtOH (hatched bars) or binge EtOH (solid bars). Data are expressed as mean ± SEM AVP mRNA copies/µg total RNA. Dissimilar letters indicate a statistically significant difference between groups for all pairwise comparisons (P<0.05).</p

Effects of pubertal binge ethanol pre-treatments on plasma CORT levels in EtOH exposed adult animals.

<p>Plasma corticosterone (CORT) levels 1.0 h post-injection of 3 g/kg EtOH in adult animals. Animals were treated during puberty with either saline (EtOH Naïve) or binge EtOH (EtOH pre-exposed). Adult animals were then treated with saline (open bars), acute EtOH (hatched bars) or binge EtOH (solid bars). Data are expressed as mean ± SEM CORT ng/ml. Dissimilar letters indicate a statistically significant difference between groups for all pairwise comparisons (P<0.05).</p

Effects of pubertal binge ethanol pre-treatments on CRH gene expression in the PVN of ethanol exposed adult rats.

<p>CRH mRNA expression 1.0 h post-injection of 3 g/kg EtOH in adult animals. Animals were treated during puberty with either saline (EtOH Naïve) or binge EtOH (EtOH pre-exposed). Adult animals were then treated with saline (open bars), acute EtOH (hatched bars) or binge EtOH (solid bars). Data are expressed as mean ± SEM CRH mRNA copies/µg total RNA. Dissimilar letters indicate a statistically significant difference between groups for all pairwise comparisons (P<0.05).</p

Experimental Design.

<p>Diagram describing the animal treatment groups. Left column indicates treatment the animals received during puberty (saline  =  EtOH naïve, or Binge EtOH  =  EtOH pre-exposed). Left column indicates the subsequent treatments the same animals received as adult (saline, acute EtOH, Binge EtOH). PND  =  post natal day.</p

Effects of pubertal binge ethanol pre-treatments on AVP gene expression in the PVN of ethanol exposed adult rats.

<p>AVP mRNA expression 1.0 h post-injection of 3 g/kg EtOH in adult animals. Animals were treated during puberty with either saline (EtOH Naïve) or binge EtOH (EtOH pre-exposed). Adult animals were then treated with saline (open bars), acute EtOH (hatched bars) or binge EtOH (solid bars). Data are expressed as mean ± SEM AVP mRNA copies/µg total RNA. Dissimilar letters indicate a statistically significant difference between groups for all pairwise comparisons (P<0.05).</p

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health