Analysis of NINDS Health Disparities and Health Equity Research Portfolio, 2016-2020: Results and a Process for Transparency, Accuracy, and Reliability.

BACKGROUND AND OBJECTIVES: As detailed throughout this special issue, the National Institute of Neurological Disorders and Stroke (NINDS) recently undertook a strategic planning effort to guide the Institute's efforts and priorities in health disparities and health equity (HD/HE) research. One input into this effort was to conduct a 5-year longitudinal, in-depth analysis of NINDS-supported HD/HE research newly funded between the years 2016 and 2020. The goals of this analysis were to describe NINDS's portfolio according to consistent, contemporary definitions and HD/HE disciplinary theory. This required the development of a novel, systematic, and validated analysis protocol. The portfolio analysis was designed to inform the recommendations of an expert working group convened by the NINDS and internal efforts to support high-priority research, training, and infrastructure efforts. METHODS: NINDS staff developed and validated this HD/HE research portfolio analysis protocol. Ultimately, HD/HE projects were characterized by their disease focus, populations of study, the health equity determinant(s) addressed, and the type and phase of research being conducted. For all interventional research, there was further assessment of the type and setting of intervention delivery as well as utilization of evidence-based community engagement and intervention sustainability approaches. RESULTS: A total of 58 new HD/HE research projects were funded from 2016 to 2020. The results of the descriptive analysis described here help provide a holistic picture of NINDS's HD/HE research portfolio, revealing strengths and gaps in the portfolio as well as opportunities ripe for future investment. DISCUSSION: NINDS developed a standardized HD/HE research categorization methodology with imbedded quality control checks that is intended to be transparent, accurate, and reproducible. The results of this HD/HE research portfolio analysis will serve as a baseline from which to assess the success of NINDS's research investments going forward.

Role of global public sector research in discovering new drugs and vaccines.

Analysis of international public-sector contributions to Food and Drug Administration (FDA)-approved drugs and vaccines allows for a more thorough examination of the global biomedical innovation ecosystem by institution of origin. Using new and existing methods, we have identified 364 FDA-approved drugs and vaccines approved from 1973 to 2016 discovered in whole or in part by Public Sector Research Institutions (PSRIs) worldwide. We identified product-specific intellectual property contributions to FDA-approved small molecule and biologic drugs and vaccines from the FDA Orange Book, our peer network, published studies, and three new sources: reports of medical product manufacturers' payments to physicians and teaching hospitals under The Sunshine Act of 2010, a paper by Kneller and 64 royalty monetization transactions by academic institutions and/or their faculty that one of us (AS) maintains. We include a total of 293 drugs discovered either wholly by a US PSRI or jointly by a U.S. and a non-U.S. PSRI. 119 FDA-approved drugs and vaccines were discovered by PSRIs outside the U.S. Of these, 71 were solely discovered outside the US, while 48 also involved intellectual property contributions by US PSRIs. In the context of the global public sector landscape, the US dominates drug discovery, accounting for two-thirds of these drugs and many of the important, innovative vaccines introduced over the past 30 years. Contributions by Canada, UK, Germany, Belgium, Japan, and others each amount to 5.4% or less of the total. Supplementary Information: The online version contains supplementary material available at 10.1007/s10961-023-10007-z.

A protocol for retrospective translational science case studies of health interventions.

The critical processes driving successful research translation remain understudied. We describe a mixed-method case study protocol for analyzing translational research that has led to the successful development and implementation of innovative health interventions. An overarching goal of these case studies is to describe systematically the chain of events between basic, fundamental scientific discoveries and the adoption of evidence-based health applications, including description of varied, long-term impacts. The case study approach isolates many of the key factors that enable the successful translation of research into practice and provides compelling evidence connecting the intervention to measurable changes in health and medical practice, public health outcomes, and other broader societal impacts. The goal of disseminating this protocol is to systematize a rigorous approach, which can enhance reproducibility, promote the development of a large collection of comparable studies, and enable cross-case analyses. This approach, an application of the "science of translational science," will lead to a better understanding of key research process markers, timelines, and potential points of leverage for intervention that may help facilitate decisions, processes, and policies to speed the sustainable translational process. Case studies are effective communication vehicles to demonstrate both accountability and the impacts of the public's investment in research.

Apolipoprotein E4 domain interaction mediates detrimental effects on mitochondria and is a potential therapeutic target for Alzheimer disease.

Apolipoprotein (apo) E4 is the major genetic risk factor for late-onset Alzheimer disease (AD). ApoE4 assumes a pathological conformation through an intramolecular interaction mediated by Arg-61 in the amino-terminal domain and Glu-255 in the carboxyl-terminal domain, referred to as apoE4 domain interaction. Because AD is associated with mitochondrial dysfunction, we examined the effect of apoE4 domain interaction on mitochondrial respiratory function. Steady-state amounts of mitochondrial respiratory complexes were examined in neurons cultured from brain cortices of neuron-specific enolase promoter-driven apoE3 (NSE-apoE3) or apoE4 (NSE-apoE4) transgenic mice. All subunits of mitochondrial respiratory complexes assessed were significantly lower in NSE-apoE4 neurons compared with NSE-apoE3 neurons. However, no significant differences in levels of mitochondrial complexes were detected between astrocytes expressing different apoE isoforms driven by the glial fibrillary acidic protein promoter, leading to our conclusion that the effect of apoE4 is neuron specific. In neuroblastoma Neuro-2A (N2A) cells, apoE4 expression reduced the levels of mitochondrial respiratory complexes I, IV, and V. Complex IV enzymatic activity was also decreased, lowering mitochondrial respiratory capacity. Mutant apoE4 (apoE4-Thr-61) lacking domain interaction did not induce mitochondrial dysfunction in N2A cells, indicating that the effect is specific to apoE4-expressing cells and dependent on domain interaction. Consistent with this finding, treatment of apoE4-expressing N2A cells with a small molecule that disrupts apoE4 domain interaction restored mitochondrial respiratory complex IV levels. These results suggest that pharmacological intervention with small molecules that disrupt apoE4 domain interaction is a potential therapeutic approach for apoE4-carrying AD subjects.

Loss of LR11/SORLA enhances early pathology in a mouse model of amyloidosis: evidence for a proximal role in Alzheimer's disease.

Alzheimer's disease (AD) is the most prevalent form of dementia, resulting in progressive neuronal death and debilitating damage to brain loci that mediate memory and higher cognitive function. While pathogenic genetic mutations have been implicated in approximately 2% of AD cases, the proximal events that underlie the common, sporadic form of the disease are incompletely understood. Converging lines of evidence from human neuropathology, basic biology, and genetics have implicated loss of the multifunctional receptor LR11 (also known as SORLA and SORL1) in AD pathogenesis. Cell-based studies suggest that LR11 reduces the formation of beta-amyloid (Abeta), the molecule believed to be a primary toxic species in AD. Recently, mutant mice deficient in LR11 were shown to upregulate murine Abeta in mouse brain. In the current study, LR11-deficient mice were crossed with transgenic mice expressing autosomal-dominant human AD genes, presenilin-1 (PS1DeltaE9) and amyloid precursor protein (APPswe). Here, we show that LR11 deficiency in this AD mouse model significantly increases Abeta levels and exacerbates early amyloid pathology in brain, causing a forward shift in disease onset that is LR11 gene dose-dependent. Loss of LR11 increases the processing of the APP holo-molecule into alpha-, beta-, and gamma-secretase derived metabolites. We propose that LR11 regulates APP processing and Abeta accumulation in vivo and is of proximal importance to the cascade of pathological amyloidosis. The results of the current study support the hypothesis that control of LR11 expression may exert critical effects on Alzheimer's disease susceptibility in humans.

Production of antisera using fusion proteins.

This unit details the use of bacterially produced fusion proteins for the production of antisera, allowing for the large-scale generation of affinity-purified antibodies to specific, targeted epitopes. The use of pET vectors containing a polyhistidine (His) or glutathione-S-transferase (GST) tag to construct bacterial expression plasmids are provided as prototypical examples of fusion protein methodology. The basic protocols provided in this unit describe: (1) transformation of E. coli for high-yield production of soluble fusion protein, (2) purification of soluble fusion proteins for use in immunization using chelated nickel or glutathione affinity chromatography (for His- and GST-tagged fusion proteins, respectively), (3) immunization of rabbits with purified fusion protein and collection of antisera, and (4) characterization of antisera for antibody specificity using immunoblotting techniques. Support protocols describe the purification of His-tagged insoluble fusion proteins for animal immunization and the construction and use of affinity columns for purifying antibodies using soluble fusion proteins.

LR11/SorLA expression is reduced in sporadic Alzheimer disease but not in familial Alzheimer disease.

LR11 is an ApoE receptor that is enriched in the brain. We have shown that LR11 is markedly downregulated in patients with sporadic Alzheimer disease (AD). This finding led us to explore whether reduced LR11 expression reflects a primary mechanism of disease or merely a secondary consequence of other AD-associated changes. Therefore, LR11 expression was assessed in a transgenic mouse model of AD and familial AD (FAD) brains. Immunohistochemistry and immunoblotting of LR11 in PS1/APP transgenic and wild-type mice indicated that LR11 levels are not affected by genotype or accumulation of amyloid pathology. LR11 expression was also evaluated based on immunoblotting and LR11 immunostaining intensity in human frontal cortex in controls, sporadic AD, and FAD, including cases with presenilin-1 (PS1) and presenilin-2 (PS2) mutations. Although LR11 was reduced in sporadic AD, there was no difference in protein level or staining intensity between control and FAD cases. The finding that LR11 expression is unaffected in both a mouse model of AD and autosomal-dominant forms of AD suggests that LR11 is not regulated by amyloid accumulation or other AD neuropathologic changes. We hypothesize that LR11 loss may be specific to sporadic AD and influence amyloid pathology through mechanisms independent of substrate-enzyme interactions regulated by FAD mutations.

The lipoprotein receptor LR11 regulates amyloid beta production and amyloid precursor protein traffic in endosomal compartments.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline and neuropathological changes, including the deposition of amyloid beta (Abeta) in senile plaques. The mechanisms causing the disease and Abeta accumulation are not well understood, but important genetic associations with apolipoprotein E genotype and involvement of lipoprotein receptors have become apparent. LR11 (also known as SorLA), a member of the low-density lipoprotein receptor family, has been identified previously as an altered transcript in microarray analyses of samples from human AD cases. Here, we show neuronal expression of the lipoprotein receptor LR11 in control brain in regions vulnerable to AD neuropathology and marked reduction of LR11 expression in these regions in AD brains before cell death. Overexpression of LR11 drastically reduces levels of extracellular Abeta and also lowers levels of total cellular amyloid precursor protein (APP). LR11 colocalizes with APP and regulates its trafficking in endocytic compartments, which are important intracellular sites for APP processing and Abeta generation. Endogenous LR11 localizes to neuronal multivesicular bodies in both rat and human brain. The robust correlation between reduced LR11 expression and AD neuropathology and its potent effects on extracellular Abeta levels suggest that this neuronal lipoprotein receptor could play an important role in AD pathogenesis.

Activity-dependent presynaptic regulation of quantal size at the mammalian neuromuscular junction in vivo.

Changes in synaptic activity alter quantal size, but the relative roles of presynaptic and postsynaptic cells in these changes are only beginning to be understood. We examined the mechanism underlying increased quantal size after block of synaptic activity at the mammalian neuromuscular junction in vivo. We found that changes in neither acetylcholinesterase activity nor acetylcholine receptor density could account for the increase. By elimination, it appears likely that the site of increased quantal size after chronic block of activity is presynaptic and involves increased release of acetylcholine. We used mice with muscle hyperexcitability caused by mutation of the ClC-1 muscle chloride channel to examine the role of postsynaptic activity in controlling quantal size. Surprisingly, quantal size was increased in ClC mice before block of synaptic activity. We examined the mechanism underlying increased quantal size in ClC mice and found that it also appeared to be located presynaptically. When presynaptic activity was completely blocked in both control and ClC mice, quantal size was large in both groups despite the higher level of postsynaptic activity in ClC mice. This suggests that postsynaptic activity does not regulate quantal size at the neuromuscular junction. We propose that presynaptic activity modulates quantal size at the neuromuscular junction by modulating the amount of acetylcholine released from vesicles.

Effects of gustatory nerve transection and regeneration on quinine-stimulated Fos-like immunoreactivity in the parabrachial nucleus of the rat.

The distribution of quinine-stimulated Fos-like immunoreactivity (FLI) in several subdivisions of the parabrachial nucleus (PBN) known to be responsive to gustatory stimulation was examined in rats in which the chorda tympani nerve (CT) and/or glossopharyngeal nerve (GL) was transected (Experiment 1) and in rats in which the GL was transected with regeneration promoted or prevented (Experiment 2). We confirmed previous findings in the literature by demonstrating that rats intraorally infused with 3 mM quinine showed a robust population of FLI in the waist area and the external lateral (EL) and external medial (EM) subdivisions of the PBN (Yamamoto et al. [1994] Physiol Behav 56:1197-1202; Travers et al., [ 1999] Am J Physiol 277:R384-R394). In the waist area, only GL transection significantly decreased the number of FLI-neurons elicited by intraoral infusion of quinine compared with water-stimulated controls. In the external subdivisions neither neurotomy affected the number of FLI-neurons. The effect of GL transection in the waist area was enduring for rats in which the GL did not regenerate (up to 94 days), but regeneration of the GL after 52 days restored quinine-stimulated FLI to control values. In these same GL-transected animals, there were parallel decreases in the number of gapes elicited by intraoral quinine stimulation that recovered, but only subsequent to regeneration of the GL. These data provide support for the role of the waist area in the brainstem processing that underlies oromotor rejection behaviors and also help substantiate the hypothesis that the CT and GL are relatively specialized with regard to function. Moreover, when the quinine-induced pattern of neural activity in the second central gustatory relay, as assessed by FLI, is substantially altered by the loss of peripheral gustatory input from the GL, it can be restored upon regeneration of the nerve.