Mark Horowitz

Mark Horowitz

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Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 June 2021 in BMJ
Verified
Journal Article
Open access
PDF file
CRChristopher E Ramsden
Christopher E Ramsden
DZDaisy Zamora
Daisy Zamora
KFKeturah R Faurot
Keturah R Faurot
BMBeth MacIntosh
Beth MacIntosh
MHMark Horowitz
Mark Horowitz
JMJ Douglas Mann
J Douglas Mann
Objective To determine whether dietary interventions that increase n-3 fatty acids with and without reduction in n-6 linoleic acid can alter circulating lipid mediators implicated in headache pathogenesis, and decrease headache in adults with migraine. Design Three arm, parallel group, randomized, modified double blind, controlled trial. Setting Ambulatory, academic medical center in the United States over 16 weeks. Participants 182 participants (88% women, mean age 38 years) with migraines on 5-20 days per month (67% met criteria for chronic migraine). Interventions Three diets designed with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and linoleic acid altered as controlled variables: H3 diet (n=61)—increase EPA+DHA to 1.5 g/day and maintain linoleic acid at around 7% of energy; H3-L6 diet (n=61)—increase n-3 EPA+DHA to 1.5 g/day and decrease linoleic acid to ≤1.8% of energy; control diet (n=60)—maintain EPA+DHA at <150 mg/day and linoleic acid at around 7% of energy. All participants received foods accounting for two thirds of daily food energy and continued usual care. Main outcome measures The primary endpoints (week 16) were the antinociceptive mediator 17-hydroxydocosahexaenoic acid (17-HDHA) in blood and the headache impact test (HIT-6), a six item questionnaire assessing headache impact on quality of life. Headache frequency was assessed daily with an electronic diary. Results In intention-to-treat analyses (n=182), the H3-L6 and H3 diets increased circulating 17-HDHA (log ng/mL) compared with the control diet (baseline-adjusted mean difference 0.6, 95% confidence interval 0.2 to 0.9; 0.7, 0.4 to 1.1, respectively). The observed improvement in HIT-6 scores in the H3-L6 and H3 groups was not statistically significant (−1.6, −4.2 to 1.0, and −1.5, −4.2 to 1.2, respectively). Compared with the control diet, the H3-L6 and H3 diets decreased total headache hours per day (−1.7, −2.5 to −0.9, and −1.3, −2.1 to −0.5, respectively), moderate to severe headache hours per day (−0.8, −1.2 to −0.4, and −0.7, −1.1 to −0.3, respectively), and headache days per month (−4.0, −5.2 to −2.7, and −2.0, −3.3 to −0.7, respectively). The H3-L6 diet decreased headache days per month more than the H3 diet (−2.0, −3.2 to −0.8), suggesting additional benefit from lowering dietary linoleic acid. The H3-L6 and H3 diets altered n-3 and n-6 fatty acids and several of their nociceptive oxylipin derivatives in plasma, serum, erythrocytes or immune cells, but did not alter classic headache mediators calcitonin gene related peptide and prostaglandin E2. Conclusions The H3-L6 and H3 interventions altered bioactive mediators implicated in headache pathogenesis and decreased frequency and severity of headaches, but did not significantly improve quality of life. Trial registration ClinicalTrials.gov NCT02012790

6 October 2020 in The Journal of Pain
Verified
Journal Article
Closed access
ADAnthony Domenichiello
Anthony Domenichiello
MSMatthew R. Sapio
Matthew R. Sapio
ALAmelia J. Loydpierson
Amelia J. Loydpierson
DMDragan Maric
Dragan Maric
TGTaichi Goto
Taichi Goto
CRChristopher E. Ramsden
Christopher E. Ramsden

31 May 2022 in Journal of Alzheimer’s Disease
Verified
Journal Article
Closed access
PDF file
CRChristopher E. Ramsden
Christopher E. Ramsden
GKGregory S. Keyes
Gregory S. Keyes
ECElizabeth Calzada
Elizabeth Calzada
MHMark Horowitz
Mark Horowitz
DZDaisy Zamora
Daisy Zamora
DMDragan Maric
Dragan Maric
Background: Sporadic Alzheimer’s disease (sAD) lacks a unifying hypothesis that can account for the lipid peroxidation observed early in the disease, enrichment of ApoE in the core of neuritic plaques, hallmark plaques and tangles, and selective vulnerability of entorhinal-hippocampal structures. Objective: We hypothesized that 1) high expression of ApoER2 (receptor for ApoE and Reelin) helps explain this anatomical vulnerability; 2) lipid peroxidation of ApoE and ApoER2 contributes to sAD pathogenesis, by disrupting neuronal ApoE delivery and Reelin-ApoER2-Dab1 signaling cascades. Methods: In vitro biochemical experiments; Single-marker and multiplex fluorescence-immunohistochemistry (IHC) in postmortem specimens from 26 individuals who died cognitively normal, with mild cognitive impairment or with sAD. Results: ApoE and ApoER2 peptides and proteins were susceptible to attack by reactive lipid aldehydes, generating lipid-protein adducts and crosslinked ApoE-ApoER2 complexes. Using in situ hybridization alongside IHC, we observed that: 1) ApoER2 is strongly expressed in terminal zones of the entorhinal-hippocampal ‘perforant path’ projections that underlie memory; 2) ApoE, lipid aldehyde-modified ApoE, Reelin, ApoER2, and the downstream Reelin-ApoER2 cascade components Dab1 and Thr19-phosphorylated PSD95 accumulated in the vicinity of neuritic plaques in perforant path terminal zones in sAD cases; 3) several ApoE/Reelin-ApoER2-Dab1 pathway markers were higher in sAD cases and positively correlated with histological progression and cognitive deficits. Conclusion: Results demonstrate derangements in multiple ApoE/Reelin-ApoER2-Dab1 axis components in perforant path terminal zones in sAD and provide proof-of-concept that ApoE and ApoER2 are vulnerable to aldehyde-induced adduction and crosslinking. Findings provide the foundation for a unifying hypothesis implicating lipid peroxidation of ApoE and ApoE receptors in sAD.

18 August 2021 in Expert Opinion on Pharmacotherapy
Verified
Journal Article
Open access
JDJohn M Davis
John M Davis
DZDaisy Zamora
Daisy Zamora
MHMark Horowitz
Mark Horowitz
SLStefan Leucht
Stefan Leucht
Introduction: Pimavanserin is FDA-approved to treat hallucinations and delusions associated with Parkinson’s disease psychosis. As a potent 5-HT2A inverse agonist/antagonist, it could be efficacious in other psychiatric disorders. Recently, several studies have investigated this potential. Areas covered: The authors review the efficacy and adverse effects of pimavanserin for hallucinations in dementia, major depression, and schizophrenia. Expert opinion: Two controlled studies suggest pimavanserin has potential as a treatment for hallucinations in dementia. In patients with depression who did not respond to antidepressant treatment, pimavanserin augmentation was efficacious in a phase 2 study. Pimavanserin augmentation also alleviated sexual side effects of SSRI and SSNI. However, Acadia Pharmaceuticals stated in a press release that it does not plan further antidepressant trials based on its phase 3 trial, which showed a nonsignificant trend toward an antidepressant effect. Since almost all existing antipsychotics fail to substantially benefit negative symptoms, better treatments are needed. Pimavanserin augmentation of antipsychotics did benefit negative symptoms (effect size≈0.2) but failed to reduce the total PANSS score significantly in two large, well-controlled double-blind studies. Pimavanserin has a good safety profile.

12 May 2021 in Clinical Nutrition
Verified
Journal Article
Closed access
BMBeth MacIntosh
Beth MacIntosh
CRChristopher E. Ramsden
Christopher E. Ramsden
GHGilson Honvoh
Gilson Honvoh
KFKeturah R. Faurot
Keturah R. Faurot
OPOlafur S. Palsson
Olafur S. Palsson
JMJohn D. Mann
John D. Mann

1 December 2020 in Pain
Verified
Journal Article
Closed access
ADAnthony Domenichiello
Anthony Domenichiello
JJJennifer R. Jensen
Jennifer R. Jensen
DZDaisy Zamora
Daisy Zamora
MHMark Horowitz
Mark Horowitz
ZYZhi-Xin Yuan
Zhi-Xin Yuan
CRChristopher E. Ramsden
Christopher E. Ramsden
Chronic posttraumatic headache (PTH) is among the most common and disabling sequelae of traumatic brain injury (TBI). Current PTH treatments are often only partially effective and have problematic side effects. We previously showed in a small randomized trial of patients with chronic nontraumatic headaches that manipulation of dietary fatty acids decreased headache frequency, severity, and pain medication use. Pain reduction was associated with alterations in oxylipins derived from n-3 and n-6 fatty acids, suggesting that oxylipins could potentially mediate clinical pain reduction. The objective of this study was to investigate whether circulating oxylipins measured in the acute setting after TBI could serve as prognostic biomarkers for developing chronic PTH. Participants enrolled in the Traumatic Head Injury Neuroimaging Classification Protocol provided serum within 3 days of TBI and were followed up at 90 days postinjury with a neurobehavioral symptom inventory (NSI) and satisfaction with life survey. Liquid chromatography-tandem mass spectrometry methods profiled 39 oxylipins derived from n-3 docosahexaenoic acid (DHA), and n-6 arachidonic acid and linoleic acid. Statistical analyses assessed the association of oxylipins with headache severity (primary outcome, measured by headache question on NSI) as well as associations between oxylipins and total NSI or satisfaction with life survey scores. Among oxylipins, 4-hydroxy-DHA and 19,20-epoxy-docosapentaenoate (DHA derivatives) were inversely associated with headache severity, and 11-hydroxy-9-epoxy-octadecenoate (a linoleic acid derivative) was positively associated with headache severity. These findings support a potential for DHA-derived oxylipins as prognostic biomarkers for development of chronic PTH.