Marisa Wexler, MS,  senior science writer—

Marisa holds a Master of Science in cellular and molecular pathology from the University of Pittsburgh, where she studied novel genetic drivers of ovarian cancer. Her areas of expertise include cancer biology, immunology, and genetics, and she has worked as a science writing and communications intern for the Genetics Society of America.

Articles by Marisa Wexler

MS Therapies Among Limited Offerings Through AllianceRx Walgreens Prime

Medications for treating certain rare and chronic conditions,  including multiple sclerosis (MS), are now available from the specialty and home delivery pharmacy AllianceRx Walgreens Prime, the company announced. The newly included specialty medications are all limited distribution drugs (LDDs), which means the drug manufacturers have signed agreements giving very…

Study Identifies Possible Genetic Causes of MS

Scientists are zeroing in on mutations in a few genes that appear to be major risk factors for developing multiple sclerosis (MS). The results of their research suggest there are common biological pathways that cause the disease. The study, “Exome sequencing in multiple sclerosis families identifies 12…

#AANAM – Ocrevus Effective in RRMS Patients with Poor Responses to Other DMTs, Early Trial Data Suggest

Early, one-year data from the Phase 3 CHORDS study show that Ocrevus effectively prevents relapses and disease progression in relapsing-remitting multiple sclerosis (RRMS) patients who have had poor responses to other disease-modifying therapies. These interim results were presented at the 2019 annual meeting of the American Academy of Neurology (AAN) in…

#AANAM – Research Suggests Extended Interval Dosing of Tysabri Can Decrease Risk of PML

New data suggests that treatment with Tysabri (natalizumab) in an extended interval dosing regimen is associated with a significantly lower risk of progressive multifocal leukoencephalopathy (PML) in patients with multiple sclerosis (MS), compared with the standard interval dosing. The data was presented by Lana Zhovtis Ryerson, MD, on May 7 at the 2019 …

#AANAM – Precision Innovative Network and Splice Machine Will Present Predictive Healthcare Application at AAN Meeting

A new clinical application prototype that uses machine learning to help physicians predict the best treatment options for patients with multiple sclerosis (MS) will be unveiled at the American Academy of Neurology’s 2019 annual meeting May 4–10, in Philadelphia, Pennsylvania. The prototype is called PIN Population Data Platform. It has been…

Excess Body Fat Spurs Disease Progression by Impact on Immune Cells, Study Suggests

A link between fat molecules called ceramides and worsening disease in overweight and obese people with multiple sclerosis appears to exist, a study reports, with its findings suggesting that ceramides prompt the growth of immune cells called monocytes, which in turn spurs disease progression. These results also strengthen the likelihood that lifestyle factors, like diet and weight, can act as disease modifiers, its researchers said. High body mass index has been linked to the risk of developing MS, but for reasons that aren't clear. One idea is that weight-induced differences in lipids (fat molecules) in the blood, because they are involved in several cellular signaling processes, may affect MS and its course in people with higher BMIs. To test this hypothesis, a team led by researchers at the Advanced Science Research Center (ASRC) at The Graduate Center and at the Icahn School of Medicine at Mount Sinai analyzed 54 patients with relapsing-remitting MS (MS), ages 18 to 60, and with normal or high BMIs (27 people in each group). Participants were followed for two years. BMI is a measure of body fat based on height and weight. A normal BMI is defined as one between 18.5 and 24.9, while a person is considered overweight with a BMI of 25–29.9, and obese it is 30 or higher. Researchers took blood samples, and looked for differences between the groups in terms of both immune cells and blood lipid profiles. They then validated their findings in a separate group of 91 RRMS patients. Patients with high BMIs tended to have more monocytes than those with normal BMIs. Monocytes can travel through the blood to tissues where they develop into macrophages, immune cells with various functions that are best known for "eating" invading bacteria. Monocytes can also travel to the brain and damage nerve fibers. Overweight and obese patients also had significantly higher levels of ceramides compared with normal-weight patients, and the researchers wondered if a link might exist between the two. Through a set of experiments in cells, they discovered that ceramides cause epigenetic changes in monocytes; that is, they alter the way their genomes are "read," so they alter gene activity. Specifically, ceramide-treated cells showed a type of epigenetic change called methylation — which generally turns genes "off" — in genes that normally help prevent cells from dividing. Conceptually, these genetic changes serve to unleash monocytes, leading them to grow more (proliferate) than they otherwise might. The researchers also found more methylation on the genomes of monocytes from high-BMI patients than those from low-BMI patients, and they noted that the overweight or obese patients also tended to have greater disease activity, worse disability progression, and more brain lesions on MRI (magnetic resonance imaging) scans on follow-up. Finally, the researchers tested a mouse model of MS, giving one group of mice a standard diet and another a high-fat diet. Mice fed the high-fat diet were found to have greater disease severity, more brain lesions, and more monocytes, confirming the findings seen in MS patients. "This study gives us a much-needed view into the environmental influences that can affect and change the behavior of cells in an individual's body," Kamilah Castro, the study's first author, said in a press release. "Our findings suggest that increased levels of saturated fat as a result of dietary habits are one likely cause of the epigenetic changes that advance MS, which gives us a starting point for a potential intervention." According to the team, the findings support the concept of nutri-epigenomics: that is, the ability of food to alter the way the genetic information is interpreted by each cell, and suggest that "weight management and dietary intervention" might affect MS prognosis. One limitation was the study's small size, its researchers noted. "While we consider our results … very exciting and mechanistic, we acknowledge that the potential consideration of ceramide levels as biomarkers for disease progression in MS would require validation ... using larger cohorts with a longitudinal and/or cross-sectional design," they concluded. "It will also be important to evaluate the effectiveness of dietary intervention (with an emphasis on the reduction of specific classes of saturated fats), as potential modulator of plasma ceramide levels and possibly of disease course in MS patients."