Chronic social stress impairs virus specific adaptive immunity during acute Theiler's virus infection

Prenatal Stress Impairs Spinal Cord Oligodendrocyte Maturation via BDNF Signaling in the Experimental Autoimmune Encephalomyelitis Model of Multiple Sclerosis

One of the most substantial and established environmental risk factors for neurological and psychiatric disorders is stress exposure, whose detrimental consequences hinge on several variables including time. In this regard the gestational period is known to present an intrinsic vulnerability to environmental insults and thus stressful events during pregnancy can lead to severe consequences on the offspring's brain development with long-term repercussions throughout adulthood. On this basis, we investigated the long-lasting impact of prenatal stress exposure on the susceptibility to the experimental autoimmune encephalomyelitis (EAE), a well-established murine model of multiple sclerosis. Although stress is considered a triggering factor for this chronic, progressive, autoimmune disease, little is known about the underlying mechanisms. To this end, EAE was induced by immunization with MOG35-55/CFA and pertussis toxin administration in adult female C57BL/6 mice born from control or stressed dams exposed to restraint stress during the last days of gestation. Our results demonstrate that gestational stress induces a marked increase in the severity of EAE symptoms in adulthood. Further, we highlight an altered maturation of oligodendrocytes in the spinal cord of prenatally stressed EAE mice, as indicated by the higher levels of GPR17, a marker of immature oligodendrocyte precursor cells. These behavioral and molecular alterations are paralleled by changes in the expression and signaling of the neurotrophin BDNF, an important mediator of neural plasticity that may contribute to stress-induced impaired remyelination. Since several already marketed drugs are able to modulate BDNF levels, these results pave the way to the possibility of repositioning these drugs in multiple sclerosis.

The impact of social capital on patients with multiple sclerosis

OBJECTIVE

To evaluate the association between social capital (SC) and the physical and psychological impact of multiple sclerosis (MS).

MATERIALS & METHODS

A cross-sectional study was conducted among people with MS (pwMS) at The Royal London Hospital, London, UK. Participants completed a survey including the Multiple Sclerosis Impact Scale-29 (MSIS-29), the Hospital Anxiety and Depression Scale (HADS), the self-reported EDSS and a SC questionnaire (SCQ). The SCQ assessed personal relationships, social support networks, civic engagement, and trust and cooperative norms. Kendall's tau correlation test was performed to measure the correlation between SC and MSIS-29 scores, and multiple linear regressions were conducted to find the best outcome prediction model.

RESULTS

236 pwMS participated in the study. Median age was 43.5 years (IQR 35-52). Of the total, 168 (71.2%) were female and 180 (76.3%) had relapsing-remitting MS. Median MSIS-29 scores were 23.7 (IQR 8.8-57.5) for the physical scale and 38.9 (IQR 16.7-55.6) for the psychological scales. Total SC scores were significantly correlated with the MSIS-29 physical (τb = -0.09, P = .02) and psychological scores (τb = -0.23, P < .001). After adjusting for possible confounders, the "personal relationships" domain had a significant effect on the MSIS-29 physical scores (β = -2.70, SE = 1.34; P = .045). Total SC (β = -1.08, SE = 0.33; P = .001) and the "personal relationships" (β = -2.60, SE = 1.20; P = .031) and "trust and cooperative norms" (β = -1.40, SE = 0.61; P = .024) domains had a significant effect on the MSIS-29 psychological scores.

CONCLUSIONS

Higher levels of SC were associated with lower physical and psychological impact of MS. Emerging evidence on SC and its effects on MS should be translated into interventions designed to promote the health and well-being of pwMS.

Recommended housing densities for research mice: filling the gap in data-driven alternatives

Space recommendations for mice made in the Guide for Care and Use of Laboratory Animals have not changed since 1972, despite important improvements in husbandry and caging practices. The 1996 version of the Guide put forth a challenge to investigators to produce new data evaluating the effects of space allocation on the well-being of mice. In this review, we summarize many studies published in response to this challenge. We distinguish between studies using ventilated or nonventilated caging systems and those evaluating reproductive performance or general well-being of adult mice. We discuss how these studies might affect current housing density considerations in both production and research settings and consider gaps in mouse housing density research. Additionally, we discuss reliable methods used to monitor and quantify general well-being of research mice. Collectively, this large body of new data suggests that husbandry practices dictating optimal breeding schemes and space allocation per mouse can be reconsidered. Specifically, these data demonstrate that prewean culling of litters has no benefit, trio breeding is an effective production strategy without adversely affecting pup survival and well-being, and housing of adult mice at densities of up to twice current Guide recommendations does not compromise well-being for most strains.-Svenson, K. L., Paigen, B. Recommended housing densities for research mice: filling the gap in data-driven alternatives.

Social disruption alters pain and cognition in an animal model of multiple sclerosis

Although pain and cognitive deficits are widespread and debilitating symptoms of multiple sclerosis (MS), they remain poorly understood. Theiler's murine encephalomyelitis virus (TMEV) infection is an animal model of MS where disease course is exacerbated by prior stressors. Here chronic infection coupled with prior social stress increased pain behavior and impaired hippocampal-dependent memory consolidation during the demyelinating phase of disease in SJL mice. These results suggest that the TMEV model may be useful in investigating pain and cognitive impairments in MS. However, in contrast to prior Balb/cJ studies, stress failed to consistently alter behavioral and physiological indicators of disease course.

Social disruption induced priming of CNS inflammatory response to Theiler's virus is dependent upon stress induced IL-6 release

Chronic social disruption stress (SDR) exacerbates acute and chronic phase Theiler's murine encephalomyelitis virus (TMEV) infection, a mouse model of multiple sclerosis. However, the precise mechanism by which this occurs remains unknown. The present study suggests that SDR exacerbates TMEV disease course by priming virus-induced neuroinflammation. It was demonstrated that IL-1β mRNA expression increases following acute SDR; however, IL-6 mRNA expression, but not IL-1β, is upregulated in response to chronic SDR. Furthermore, this study demonstrated SDR prior to infection increases infection related central IL-6 and IL-1β mRNA expression, and administration of IL-6 neutralizing antibody during SDR reverses this increase in neuroinflammation.