This Readme file was generated on 2023-06-09. GENERAL INFORMATION Title of Dataset: Dynamin Related Protein 1 (Drp1) is a critical regulator of mitochondrial calcium homeostasis during myocardial ischemia/reperfusion injury Description of Dataset: Dynamin related protein 1 (Drp1) is a cytosolic GTPase protein that when activated translocates to the mitochondria, meditating mitochondrial fission and increasing reactive oxygen species (ROS) in cardiomyocytes. Drp1 is thus a promising therapeutic target for reducing cardiac ischemia/reperfusion (IR) injury. Lack of specificity of Drp1 small molecule inhibitors and the reliance on the use of Drp1 haploinsufficient hearts in genetic approaches have left the role of Drp1 in IR in question. We address these concerns using two approaches: a) Mice with short-term (3-week) conditional, cardiomyocyte specific Drp1 knock out (KO) and b) a novel, highy specific Drp1 GTPase inhibitor, Drpitor1a. Short-term Drp1 KO mice did not exhibit decreased exercise capacity or heart contractility, but isolated cardiac mitochondria demonstrated increased mitochondrial complex 1 activity, respiratory coupling, calcium retention capacity compared to controls. When exposed to IR injury on a Langendorff persusion system, Drp1 KO hearts had preserved contractility, decreased ROS, enchanced mitochondrial calcium capacity, increased resistance to mitochondrial permeability transition pore (MPTP) opening, and decreased cardiac ryanodine receptor (RYR2) gene expression. Phamacological inhibition of Drp1 with Drpitor1a following ischemia but prior to reperfusion was similarly protective of cardiac function and mitochondrial calcium homeostasis. In contrast to the benefits of short-term Drp1 inhibition, prolonged Drp1 ablation (6weeks) resulted in cardiomyopathy. We conclude that Drp1 is a key regulator of myocardial mitochondrial calcium handling and ROS generation following IR injury. Short-term inhibiton of Drp1 is a promising strategy for limiting early myocardial IR injury which is relevant for acute myocardial infarction, cardiac arrest, and heart transplantation. Author Contact Information Name: Lin Piao Institution: University of Chicago Address: 5841 S. Maryland Avenue, MC 6080, Chicago, IL 60637 Email: lpiao@bsd.uchicago.edu Author/Alternate Contact Information Name: Willard Sharp ORCID: https://orcid.org/0000-0002-7175-3523 Institution: University of Chicago Address: 5841 S. Maryland Avenue, MC 6080, Chicago, IL 60637 Email: wsharp@uchicago.edu Author/Alternate Contact Information Name: Yonghu Fang Institution: University of Chicago Address: 5841 S. Maryland Avenue, MC 6080, Chicago, IL 60637 Email: yfang1@uchicago.edu Date of data collection: Geographic location of data collection: Information about funding sources that supported the collection of the data: SHARING/ACCESS INFORMATION Licenses/restrictions placed on the data: This dataset is made available under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). Links to publications that cite or use the data: Links to other publicly accessible locations of the data: Links/relationships to ancillary data sets: Was data derived from another source? If yes, list source(s): Recommended citation for this dataset: Piao, L., Sharp, W., & Fang, Y. (2023). Dynamin Related Protein 1 (Drp1) is a critical regulator of mitochondrial calcium homeostasis during myocardial ischemia/reperfusion injury. https://doi.org/10.6082/uchicago.6218 DATA & FILE OVERVIEW File List: WB cytochrome C and PARKIN.pzfx Complex I assay CA vs CA IR alla.pzfx Treadmill.pzfx calcium uptake retention capicity assay.pzfx complex I&III activity wt vs TG.pzfx complex I dipstick.pzfx DRP1 KO IR and FS%.pzfx protein expression of NTG vs DRP1KO.pzfx mito size and mitoSox.pzfx EM mito size and ROS production.pzfx NTG vs DRP1 KO mito PM IR OCR.pzfx mPTP CTR vs DRP1KO Ca and cyclosporine A.pzfx H2O2 production with Ca-mac.pzfx Relationship between files, if important: Additional related data collected that was not included in the current data package: Are there multiple versions of the dataset? If yes, name of file(s) that was updated: Why was the file updated? When was the file updated? METHODOLOGICAL INFORMATION Description of methods used for collection/generation of data: Methods for processing the data: Instrument- or software-specific information needed to interpret the data: Standards and calibration information, if appropriate: Environmental/experimental conditions: Describe any quality-assurance procedures performed on the data: People involved with sample collection, processing, analysis and/or submission: DATA-SPECIFIC INFORMATION FOR: Number of variables: Number of cases/rows: Variable List: Missing data codes: Specialized formats or other abbreviations used: