Check out some of the papers that were recently published by DMCBH members:

Liisa Galea: Cellular and molecular signatures of motherhood in the adult and ageing rat brain

Journal: Open Biology

Pregnancy is marked by robust changes, including brain changes to volume, structure, connectivity and neuroplasticity. Although some brain changes are restricted to pregnancy and the postpartum, others are long-lasting. Few studies have examined possible mechanisms of these changes or the effects of multiple pregnancies.

The present study characterized various cellular and molecular signatures of parity (nulliparous, primiparous, biparous) in the rat hippocampus. The researchers investigated density of neural stems cells, microglia and levels of a synaptic protein, cell signalling pathways, neuroinflammation, and the tryptophan-kynurenine (TRP-KYN) pathway. The results concluded that previous parity has lasting effects on synaptic plasticity with fewer lasting effects on inflammation and cell signalling phosphoproteins in the whole hippocampus.


Khaled Abdelrahman: Sexual dimorphism of G protein-coupled receptor signaling in the brain

Journal: Neural Regeneration Research

G protein-coupled receptors (GPCRs) represent the most substantial family of membrane receptors that are targeted by U.S. Food and Drug Administration-approved drugs. Much of the preclinical research to understand the pharmacology of many membrane receptors including GPCRs is derived from studies in male animal models. Understanding the sex-specific disparities in GPCR pharmacological fingerprints can aid in developing targeted ligands that precisely correct GPCR signaling modalities in men and women and ultimately, enhance their effectiveness for certain pathophysiological conditions.

The researchers summarized the current evidence supporting the sex-biased signaling of GPCRs implicated in several brain disorders. They highlighted the importance of studying sex as a critical biological variable in GPCR signaling of the brain. Further work, however, is necessary to profile the sex-biased pharmacology of the rest of the GPCR candidates in the brain and provide a better understanding of the underlying biological causes behind these observed sex differences.


Helen Tremlett: Multiple sclerosis disease-modifying drug use by immigrants: a real-world study

Journal: Scientific Reports

Little is known about disease-modifying drug (DMD) initiation by immigrants with multiple sclerosis (MS) in countries with universal health coverage. The study assessed the association between immigration status and DMD use within 5-years after the first MS-related healthcare encounter.

The researchers identified 8762 MS cases (522 were immigrants). Among immigrants of lower SES, odds of filling any DMD prescription were reduced, whereas they did not differ between immigrants and long-term residents across SES quintiles. Overall use (odds) of a first DMD within 5 years after the first MS-related encounter was associated with immigration status.


Helen Tremlett: Disease-Modifying Therapies Used to Treat Multiple Sclerosis and the Gut Microbiome: A Systematic Review

Journal: Journal of Neurology

The gut microbiome may play a role in multiple sclerosis (MS). However, its relationship with the disease-modifying therapies (DMTs) remains unclear. The researchers systematically reviewed the literature to examine the relationship between DMTs and the gut microbiota among persons with MS (pwMS).

The results showed that no study found a difference in gut microbiota alpha-diversity between DMT exposed/unexposed. One study observed a difference in beta-diversity between interferon-beta users/DMT non-users. All studies examined taxa-level differences, but most (6) combined different DMTs. DMT users had lower relative abundances of carbohydrate degradation and reductive tricarboxylic acid cycle I pathway than non-users, but findings could not be attributed to a specific DMT. Overall, while DMT use was not associated with gut microbiota diversity differences, taxa-level differences were observed. Further work is warranted, as most studies were cross-sectional, few examined functionality, and DMTs were combined.


Helen Tremlett: Comorbidity in the multiple sclerosis and neuromyelitis optica spectrum disorders population: findings from an underserved, low income country, Zambia

Journal: Multiple Sclerosis and Related Disorders

Comorbidities are common in multiple sclerosis (MS); little is known in neuromyelitis optica spectrum disorders (NMOSD) or outside high-income regions. The objective of the study was to compare comorbidities in MS/NMOSD patients, Zambia.

Thirty-three were included (MS/NMOSD:17/16). Odds of any/any physical comorbidity was higher in MS versus NMOSD. The results showed physical comorbidity affected >2-in-5 MS/NMOSD patients and psychiatric disorders ∼1-in-5. Odds of any physical comorbidity were >five-fold higher in MS versus NMOSD.


Helen Tremlett: Risk of multiple sclerosis in people living with HIV: an international cohort study

Journal: Annals of Neurology

There has been interest in a possible negative association between HIV and multiple sclerosis (MS). The researchers aimed to compare the risk of MS in a cohort of individuals living with HIV to that in the general population. Population-based health data were accessed for 2 cohorts of HIV-positive persons from Sweden and British Columbia.

The combined Sweden-Canada cohort included 29,163 (75% men) HIV-positive persons. The standardized incidence ratio for MS following the first antiretroviral therapy exposure (ART) was also calculated. This international population-based study demonstrated a lower risk of MS among HIV-positive individuals, and HIV-positive ART-exposed individuals. These findings provide support for further exploration into the relationship among HIV, ART, and MS.


Helen Tremlett: Gastrointestinal Conditions in the Multiple Sclerosis Prodrome

Journal: Annals of Clinical and Translational Neurology

The current study investigated gastrointestinal (GI)-related physician visits and drug dispensations in the 5 years preceding a first recorded demyelinating event or multiple sclerosis (MS) onset. Results showed the administrative cohort MS cases had higher rates of physician visits related to gastritis, duodenitis, and diseases of the esophagus. MS cases also had greater risk of at least one dispensation for several drug classes. Men had a disproportionally higher relative risk for propulsives than women.

GI-related physician visits and drug dispensations were more common in the 5 years before the first demyelinating event versus matched controls. This concludes that GI symptoms are a measurable feature of the prodromal or early phase of MS, with a sex difference evident.


Helen Tremlett: A cross-sectional study of MRI features and the gut microbiome in pediatric-onset multiple sclerosis

Journal: Annals of Clinical and Translational Neurology

The purpose of this study was to identify gut microbiome features associated with MRI lesion burden in persons with pediatric-onset multiple sclerosis (symptom onset <18 years).

The results showed that T1- and T2-weighted lesion volumes were not significantly associated with alpha diversity. At the phylum level, high Tenericutes was associated with higher T1 and T2 volumes and high Firmicutes, Patescibacteria or Actinobacteria with lower lesion volumes. At the genus level, high Ruminiclostridium, whereas low Coprococcus 3 and low Erysipelatoclostridium were associated with higher lesion volumes.