ALS Finding a Cure Request for Proposals
To Develop and Validate ALS Organoid Models

Overview:

Organoids are a powerful new and compelling technology for studying disease biology. Several different and complementary organoid models currently exist with relevance to ALS, but none of these models has been tested across multiple ALS iPSC lines, and all have been created using different lines/genetic backgrounds making comparisons between/among them challenging.

The reagents and assays used to assess ALS phenotypes have likewise varied. This variability and limited scale make it challenging to interpret results and to establish methodologic robustness.

This targeted RFP aims to answer the question: are there reproducible ALS phenotypes (pathology, omics, biomarkers) that are detectable within and/or across organoid models created from human C9orf72 and TDP43 mutation-carrying lines that differ from organoids derived from healthy gender and age-matched controls.

We are specifically looking for reliable ALS-relevant phenotypes that are widely observed (regardless of which line was used), reproducible, easily measured, and appear as early as possible, so as to potentially enable humanized disease modeling and utility for future therapeutic development.

We are ideally looking for assembloid models incorporating corticospinal motor neurons, spinal motor neurons, and muscle cells, so as to form a true ALS “circuit”, but will also consider applications utilizing any two out of these three cell types/regions. In addition to the “required” cell types, groups are also encouraged to incorporate multiple additional cell types, including glial cells, into their organoid models so as to more faithfully recapitulate the full extent of disease biology.

At the end of the grant period, we plan to invite all the funded labs back together for a follow- up workshop to compare methodologies, share data, discuss technical challenges, and brainstorm ideas for next steps. We encourage collaborative proposals and are hoping to fund a

diverse range of models/methods so as to accelerate the field. Experience developing organoids and compelling preliminary data will be important criteria for the review committee.

Materials Provided:

We will provide funding for proposals to develop organoids from 5 male C9ORF72 ALS and 5 age-matched control iPSC lines from the Answer ALS cohort, 1 C9orf72 ALS and 1 matching revertant control line, and 1 M337V line and 1 matching wild type/revertant control line from the INDI cohort, all at similar passage numbers. This will allow everyone to compare the phenotypes in their models based on identical lines. All lines will be provided to groups in a blinded fashion to better enable validation of independent approaches.

Where possible, funded labs will also be provided with standardized antibodies for the following:

  • p-TDP43
  • C and N-terminal TDP43
  • DPR analysis will be performed at Mayo Clinic using the antibodies developed by Dr. Len Petrucelli’s group

Outcome Measures:

There are two key measures of success we would like the funded labs to address: maturational state and demonstration of ALS-relevant pathophysiology.

Cellular Maturation (proof of basic biology):

  • Transcriptomic signatures (groups are encouraged to perform both snSEQ and bulk RNA transcriptomic analyses if possible)
  • Please provide information as to the maturation state of the cells in your organoid models via at least 1 of the following immunohistochemical markers:
    1. ChAT expression
    2. UCHL1 expression
    3. GFAP expression
    4. Markers of NMJ maturation/innervation (for those organoid models that include muscle)
  • Please provide information as to the maturation state of the cells in your organoid models via at least 1 of the following functional assessments:
    1. Electrophysiologic measures of cellular activity
  1. Calcium imaging of cellular activity
  2. Ability to drive muscle fiber contraction via stimulation of connecting neurons (for those organoid models including muscle)
  3. Measures of synaptic density
  4. Other functional assessments

Recapitulation of ALS phenotypes (necessary for translation):

  1. Validation of DPR production in the C9 When do DPR’s appear? Which DPR’s?
  2. Accumulation of RNA foci in the C9 Which cell types do you see foci in? What % of cells show foci? How many foci on average are there per cell? What is the earliest timepoint for reliable detection of foci?
  3. Are you able to detect translocation of TDP43 out of the nucleus of corticospinal motor neurons and/or spinal motor neurons in your organoid models? If so, what is the earliest timepoint for reliable detection?
  4. Are you able to detect other signs of TDP43 dysfunction in your models (changes in transcriptomics, presence of cryptic exon inclusion/splicing defects, etc)? If so, what is the earliest timepoint for reliable detection?
  5. In those C9 and TDP43 derived organoids which include muscle, are you able to detect changes in NMJ’s? (numbers, size, innervation status, electrophysiological responses, etc) If so, what is the earliest timepoint for reliable detection?
  6. Are you able to detect other signs of neuropathology in your organoid models? (e.g. cell death, inflammation, synapse loss, axonal changes, etc) If so, what is the earliest timepoint for reliable detection? We suggest using both an NFL assay and an LDH release assay to measure differences between ALS and control

Funding Timelines:

Applications open: November 20th, 2023 Applications due: January 31st, 2024 Anticipated earliest start date: June, 2024 Submit to: https://app.box.com

Grants are for the support of 2-year proposals of up to $300,000 USD total (inclusive of a maximum of 15% in indirect costs). Costs for lines and antibodies will be contracted separately by ALS Finding a Cure (and do not need to be included in the requested budget). Support will not normally exceed 2 years and applicants should submit proposals that are compatible with a 2-year time frame. The continuation of funding within this period will be subject to the submission of satisfactory progress reports, which will be required at six-month intervals.

Application Process

  1. Please provide a cover letter addressed to ALS Finding a Cure and the Leandro Rizzuto Foundation including:
    1. Proposal Title
    2. Total costs (15% overhead cap)
    3. Number of milestones and related costs (to equal amount above)
    4. List of all investigators and institutions (and letters of collaboration if external to the PI’s lab and institution)
    5. Name and contact information for person(s) responsible for contracts
    6. Address for mailing of payments
  2. Provide a study plan including:
  • A brief abstract suitable for media release to the lay public if the application is successful
  • Project Plan, Background, and Timeline (max. 5 pages) including:
    • Study background and rationale/significance
    • Study objectives/specific aims (i.e. how you plan to address the success measures outlined above in the RFP)
    • Supporting/preliminary data;
    • Experimental design/research plan;
  • Detailed itemized budget and budget justification
  • Description of study milestones, including the costs associated and timeline of specific deliverables
  • Any research funding from other funding sources that relates to the proposed work
  1. Signed and dated investigator CVs
  2. Financial Disclosure Form: use either NIH form https://ethics.od.nih.gov/forms450, or an equivalent institutional form.