ABSTRACT
Two-dimensional ultrasound (2DUS) echocardiography is the main noninvasive method used to evaluate cardiac function in animal models of myocardial infarction (MI). However, 2DUS echocardiography does not capture regional differences in cardiac contractility since it relies on planar images to estimate left ventricular (LV) geometry and global function. Thus, the current study was designed to evaluate the efficacy of a newly developed 4-dimensional ultrasound (4DUS) method in detecting cardiac functional differences between two models of MI, permanent ligation (PL), and ischemia/reperfusion (I/R) in rats. We found that only 4DUS was able to detect LV global functional differences between the two models and that 4DUS-derived surface area strain accurately detected infarcted regions within the myocardium that correlated well with histological infarct size analysis. We also found that 4DUS-derived strain, which includes circumferential, longitudinal, and surface area strain, correlated with the peak positive of the first derivative of left ventricular pressure (+dP/dtmax). In conclusion, 4DUS strain echocardiography effectively assesses myocardial mechanics following experimentally induced ischemia in rats and accurately estimates infarct size as early as 1 day after injury. 4DUS also correlates well with +dP/dtmax, a widely used marker of cardiac contractility.
Subject(s)
Myocardial Infarction , Myocardial Reperfusion Injury , Rats, Sprague-Dawley , Animals , Male , Myocardial Infarction/diagnostic imaging , Myocardial Infarction/physiopathology , Myocardial Infarction/pathology , Rats , Myocardial Reperfusion Injury/diagnostic imaging , Myocardial Reperfusion Injury/physiopathology , Echocardiography, Four-Dimensional/methods , Myocardial Contraction , Ventricular Function, Left , Disease Models, AnimalABSTRACT
Glutamine is a critical amino acid that serves as an energy source, building block, and signaling molecule for the heart tissue and the immune system. However, the role of glutamine metabolism in regulating cardiac remodeling following myocardial infarction (MI) is unknown. In this study, we show in adult male mice that glutamine metabolism is altered both in the remote (contractile) area and in infiltrating macrophages in the infarct area after permanent left anterior descending artery occlusion. We found that metabolites related to glutamine metabolism were differentially altered in macrophages at days 1, 3, and 7 after MI using untargeted metabolomics. Glutamine metabolism in live cells was increased after MI relative to no MI controls. Gene expression in the remote area of the heart indicated a loss of glutamine metabolism. Glutamine administration improved LV function at days 1, 3, and 7 after MI, which was associated with improved contractile and metabolic gene expression. Conversely, administration of BPTES, a pharmacological inhibitor of glutaminase-1, worsened LV function after MI. Neither glutamine nor BPTES administration impacted gene expression or bioenergetics of macrophages isolated from the infarct area. Our results indicate that glutamine metabolism plays a critical role in maintaining LV contractile function following MI, and that glutamine administration improves LV function. Glutamine metabolism may also play a role in regulating macrophage function, but macrophages are not responsive to exogenous pharmacological manipulation of glutamine metabolism.
ABSTRACT
Ciacci & Sviatschi's (2021) 'The Effect of Adult Entertainment Establishments on Sex Crime: Evidence from New York City,' published in The Economic Journal, concluded that opening new adult entertainment businesses reduces sex crimes, with the most compelling finding that '[strip clubs, gentleman's clubs, and escort services] decrease sex crime by 13% per police precinct one week after the opening.' We contend that the study's conclusions speak beyond the data, which cannot support these findings because they do not measure the necessary variables. The study uses the date a business is registered with New York State as a proxy for its opening date, but the actual date of opening comes weeks or months later, after requirements such as inspections, licensure, and community board approval. The study then uses police Stop, Question and Frisk Reports as data about subsequent crimes. As reports created to memorialize forcible police stops based on less than probable cause, 94% of these reports document that the police had an unfounded belief in criminal activity, and the person stopped was innocent of any crime. In effect, what the study has done is measure changes in police encounters with innocent people in the week after an entity has filed the paperwork that will eventually allow it to open as a business. The study lacks construct validity, cannot reject the null hypothesis of its most important finding, and its methods fall short of the rigor necessary to permit replication.
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Although obesity is recognized as a risk factor for cardiorenal and metabolic diseases, the impact of parental obesity on the susceptibility of their offspring to renal injury at adulthood is unknown. We examined the impact of parental obesity on offspring kidney function, morphology, and markers of kidney damage after acute kidney injury (AKI). Offspring from normal (N) diet-fed C57BL/6J parents were fed either N (NN) or a high-fat (H) diet (NH) from weaning until adulthood. Offspring from obese H diet-fed parents were fed N (HN) or H diet (HH) after weaning. All offspring groups were submitted to bilateral AKI by clamping the left and right renal pedicles for 30 min. Compared with male NH and NN offspring from lean parents, male HH and HN offspring from obese parents exhibited higher kidney injury markers such as urinary, renal osteopontin, plasma creatinine, urinary albumin excretion, and neutrophil gelatinase-associated lipocalin (NGAL) levels, and worse histological injury score at 22 wk of age. Only albumin excretion and NGAL were elevated in female HH offspring from obese parents compared with lean and obese offspring from lean parents. We also found an increased mortality rate and worse kidney injury scores after AKI in male offspring from obese parents, regardless of the diet consumed after weaning. Female offspring were protected from major kidney injury after AKI. These results indicate that parental obesity leads to increased kidney injury in their offspring after ischemia-reperfusion in a sex-dependent manner, even when their offspring remain lean.NEW & NOTEWORTHY Offspring from obese parents are more susceptible to kidney injury and worse outcomes following an acute ischemia-reperfusion insult. Male, but not female, offspring from obese parents exhibit increased blood pressure early in life. Female offspring are partially protected against major kidney injury induced by ischemia-reperfusion.
Subject(s)
Acute Kidney Injury , Kidney , Mice, Inbred C57BL , Reperfusion Injury , Animals , Male , Female , Reperfusion Injury/pathology , Reperfusion Injury/metabolism , Acute Kidney Injury/etiology , Acute Kidney Injury/metabolism , Acute Kidney Injury/physiopathology , Acute Kidney Injury/pathology , Kidney/physiopathology , Kidney/pathology , Kidney/metabolism , Sex Factors , Obesity/complications , Obesity/physiopathology , Diet, High-Fat , Pregnancy , Lipocalin-2/metabolism , Obesity, Maternal/metabolism , Obesity, Maternal/complications , Obesity, Maternal/physiopathology , Prenatal Exposure Delayed Effects , Mice , Risk Factors , Disease Models, Animal , Biomarkers/bloodABSTRACT
Signal amplification based on the mechanism of hybridization chain reaction (HCR) provides a unified framework for multiplex, quantitative, high-resolution imaging of RNA and protein targets in highly autofluorescent samples. With conventional bandpass imaging, multiplexing is typically limited to four or five targets owing to the difficulty in separating signals generated by fluorophores with overlapping spectra. Spectral imaging has offered the conceptual promise of higher levels of multiplexing, but it has been challenging to realize this potential in highly autofluorescent samples, including whole-mount vertebrate embryos. Here, we demonstrate robust HCR spectral imaging with linear unmixing, enabling simultaneous imaging of ten RNA and/or protein targets in whole-mount zebrafish embryos and mouse brain sections. Further, we demonstrate that the amplified and unmixed signal in each of the ten channels is quantitative, enabling accurate and precise relative quantitation of RNA and/or protein targets with subcellular resolution, and RNA absolute quantitation with single-molecule resolution, in the anatomical context of highly autofluorescent samples.
Subject(s)
Diagnostic Imaging , Zebrafish , Animals , Mice , Nucleic Acid Hybridization , Embryo, Mammalian , RNAABSTRACT
Diabetes (DM) and hypertension (HTN) are major risk factors for chronic kidney injury, together accounting for >70% of end-stage renal disease. The combination of DM and HTN significantly accelerates development of renal injury; however, the underlying mechanisms of this synergy are still poorly understood. This study assessed whether mitochondria (MT) dysfunction is essential in developing renal injury in a rat model with combined DM and HTN. Type 1 DM was induced in Wistar rats by streptozotocin (STZ). HTN was induced six weeks later by inter-renal aorta constriction between the renal arteries, so that right kidneys were exposed to HTN while left kidneys were exposed to normotension. Kidneys exposed to DM or HTN alone had only mild glomerular injury and urinary albumin excretion (UAE). In contrast, kidneys exposed to DM plus 8 weeks HTN had significantly increased UAE and glomerular structural damage with reduced glomerular filtration rate. Marked increases in MT-derived reactive oxygen species (ROS) were also observed in right kidneys exposed to HTN+DM. We further tested whether treatment with MT-targeted antioxidant (MitoTEMPO) after the onset of HTN attenuates renal injury in rats with DM+HTN. Results show that kidneys in DM+AC+MitoTEMPO rats had lower UAE, less glomerular damage, and preserved MT function compared to untreated DM+AC rats. Our studies indicate that MT-derived ROS play a major role in promoting kidney dysfunction when DM is combined with HTN. Preserving MT function might be a potential therapeutic approach to halt the development of renal injury when DM coexists with HTN.
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The phenological stage of maturity of grasses and supplementation program can impact forage utilization in grazing beef cattle. However, the potential interaction between harvest maturity of Eragrostis tef (teff) hay and energy supplement source was yet to be fully evaluated. Therefore, our objective was to determine the effects of harvest maturity of teff hay and supplemental energy sources on nutrient intake, apparent total-tract nutrient digestion, nitrogen (N) utilization, and ruminal fermentation characteristics in beef heifers. A split-plot design with teff hay harvest maturity as the whole plot and supplemental energy source as the subplot was administered in a three-period (21 d), three × three Latin square design. Six crossbred beef heifers (804 ± 53.6 kg of body weight; BW) were allocated to two harvest maturities (early- (EH]) or late-heading (LH)) and to two supplemental energy sources (no supplement (CON), or rolled corn grain or beet pulp pellet fed at 0.5% of BW). Data were analyzed using SAS. There was no harvest maturity × energy supplement interaction. Although harvest maturity had no impact on total dry matter intake (DMI), crude protein (CP) intake was greater (p < 0.01) for EH than LH heifers. Total intakes of dry (DM) and organic matter (OM) were also greater (p < 0.01) for supplemented than CON heifers, whereas acid detergent fiber (ADF) intake was greater for beet pulp heifers compared to heifers fed the CON diet and supplemental corn grain. Harvest maturity had no impact on ruminal pH. However, mean ruminal pH was lower (p = 0.04), duration pH < 6.2, and molar proportions of butyrate and branched-chain fatty acids were greater (p ≤ 0.049) for heifers fed corn grain compared to CON and beet pulp diets. Heifers fed EH hay had greater (p ≤ 0.02) apparent total-tract DM, OM, CP, NDF, and ADF digestibility than heifers fed LH hay. Although there was no supplemental energy effect on microbial nitrogen (N) flow, it was greater (p < 0.01) for EH than LH heifers. Apparent N retention, which did not differ, was negative across all diets. In summary, delaying the harvest of teff hay from the EH to LH stage of maturity compromised nutrient supply, which was not attenuated by feeding supplemental corn grain and beet pulp at 0.5% of diet DM. Because N retention was negative across harvest maturity, there might be a need to provide both energy and protein supplements to improve growth performance when feeding teff hay to beef cattle.
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PURPOSE OF REVIEW: This review aims to explore the underlying mechanisms that lead to hypertension in glomerular diseases and the advancements in treatment strategies and to provide clinicians with valuable insights into the pathophysiological mechanisms and evidence-based therapeutic approaches for managing hypertension in patients with glomerular diseases. RECENT FINDINGS: In recent years, there have been remarkable advancements in our understanding of the immune and non-immune mechanisms that are involved in the pathogenesis of hypertension in glomerular diseases. Furthermore, this review will encompass the latest data on management strategies, including RAAS inhibition, endothelin receptor blockers, SGLT2 inhibitors, and immune-based therapies. Hypertension (HTN) and cardiovascular diseases are leading causes of mortality in glomerular diseases. The latter are intricately related with hypertension and share common pathophysiological mechanisms. Hypertension in glomerular disease represents a complex and multifaceted interplay between kidney dysfunction, immune-mediated, and non-immune-mediated pathology. Understanding the complex mechanisms involved in this relationship has evolved significantly over the years, shedding light on the pathophysiological processes underlying the development and progression of glomerular disease-associated HTN, and is crucial for developing effective therapeutic strategies and improving patients' outcomes.
Subject(s)
Cardiovascular Diseases , Hypertension , Kidney Diseases , Humans , Antihypertensive Agents/therapeutic use , Kidney Diseases/therapy , Kidney Diseases/etiology , Cardiovascular Diseases/drug therapyABSTRACT
in vitro screening platforms to assess teratogenic potential of compounds are emerging rapidly. ReproTracker is a human induced pluripotent stem cells (hiPSCs)-based biomarker assay that is shown to identify the teratogenicity potential of new pharmaceuticals and chemicals reliably. In its current state, the assay is limited to identifying the potential teratogenic effects and does not immediately quantify a clinical dose relevant to the exposure of chemicals or drugs observable in mothers or fetuses. The goal of this study was to evaluate whether the ReproTracker assay can be extrapolated in vivo and quantitatively predict developmental toxicity exposure levels of two known human teratogens, thalidomide, and carbamazepine. Here, we utilized Physiologically Based Pharmacokinetic (PBPK) modeling to describe the pharmacokinetic behavior of these compounds and conducted an in vitro to in vivo extrapolation (IVIVE) approach to predict human equivalent effect doses (HEDs) that correspond with in vitro concentrations potentially associated with adverse outcomes in ReproTracker. The HEDs derived from the ReproTracker concentration predicted to cause developmental toxicity were close to the reported teratogenic human clinical doses and the HED derived from the rat or rabbit developmental toxicity study. The ReproTracker derived-HED revealed to be sensitive and protective of humans. Overall, this pilot study demonstrated the importance of integrating PBPK model in extrapolating and assessing developmental toxicity in vitro. The combination of these tools demonstrated that they could improve the safety assessment of drugs and chemicals without animal testing.
Subject(s)
Induced Pluripotent Stem Cells , Models, Biological , Humans , Rats , Animals , Rabbits , Pilot Projects , Teratogens/toxicityABSTRACT
Leptin an adipokine with potent effects on energy balance and body weight plays an important role in defining bone architecture in growing mammals. However, major changes in body weight can also influence morphology of trabecular and cortical bone. Therefore, we examined the impact of leptin deficiency on tibia and vertebral body 3D bone architecture independent of changes in body weight. Furthermore, advances in computational 3D image analysis suggest that average morphological values may mask regional specific differences in trabecular bone thickness. The study utilized leptin-deficient Ob/Ob mice (n = 8) weight-paired to C57BL/6 (C57) control mice (n = 8) which were split into either lean or obese groups for 24 ± 2 weeks. Whole tibias and L3 vertebrae were fixed before high resolution microcomputed tomography (µCT) scanning was performed. Leptin deficiency independent of body weight reduced tibia cortical bone volume, trabecular bone volume/tissue volume, number, and mineral density. Mean tibia trabecular thickness showed no significant differences between all groups; however, significant changes in trabecular thickness were found when analyzed by region. This study demonstrates that leptin deficiency significantly impacts tibia and vertebral body trabecular and cortical bone 3D architecture independent of changes in body weight.
Subject(s)
Leptin , Tibia , Animals , Male , Mice , Body Weight , Bone Density , Leptin/deficiency , Mice, Inbred C57BL , Obesity , Spine/diagnostic imaging , Tibia/diagnostic imaging , Vertebral Body , X-Ray MicrotomographyABSTRACT
India has a high burden of Tuberculosis (TB), accounting for a significant portion of global cases. While efforts are being made to engage the formal private sector in the National TB Elimination Program (NTEP) of India, there remains a significant gap in addressing the engagement of Informal Healthcare Providers (IPs), who serve as the first point of contact for healthcare in many communities. Recognizing the increasing evidence of IPs' importance in TB care, it is crucial to enhance their engagement in the NTEP. Therefore, this study explored various factors influencing the engagement of IPs in the program. A qualitative study was conducted in West Bengal, India, involving 23 IPs and 11 Formal Providers (FPs) from different levels of the formal health system. Thematic analysis of the data was conducted following a six-step approach outlined by Braun and Clarke. Three overarching themes were identified in the analysis, encompassing barriers and facilitators to IPs' engagement in the NTEP. The first theme focused on IPs' position and capacity as care providers, highlighting their role as primary care providers and the trust and acceptance extended by the community. The second theme explored policy and system-level drivers and prohibitors, revealing barriers such as role ambiguity, competing tasks, and quality of care issues. Facilitators such as growing recognition of IPs' importance in the health system, an inclusive incentive system, and willingness to collaborate were also identified. The third theme focused on the relationship between the formal and informal systems, highlighting a need to strengthen the relationship between the two. This study sheds light on factors influencing the engagement of IPs in the NTEP of India. It emphasizes the need for role clarity, knowledge enhancement, and improved relationships between formal and informal systems. By addressing these factors, policymakers and stakeholders can strengthen the engagement of IPs in the NTEP.
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Signal amplification based on the mechanism of hybridization chain reaction (HCR) provides a unified framework for multiplex, quantitative, high-resolution imaging of RNA and protein targets in highly autofluorescent samples. With conventional bandpass imaging, multiplexing is typically limited to four or five targets due to the difficulty in separating signals generated by fluorophores with overlapping spectra. Spectral imaging has offered the conceptual promise of higher levels of multiplexing, but it has been challenging to realize this potential in highly autofluorescent samples including whole-mount vertebrate embryos. Here, we demonstrate robust HCR spectral imaging with linear unmixing, enabling simultaneous imaging of 10 RNA and/or protein targets in whole-mount zebrafish embryos and mouse brain sections. Further, we demonstrate that the amplified and unmixed signal in each of 10 channels is quantitative, enabling accurate and precise relative quantitation of RNA and/or protein targets with subcellular resolution, and RNA absolute quantitation with single-molecule resolution, in the anatomical context of highly autofluorescent samples. SUMMARY: Spectral imaging with signal amplification based on the mechanism of hybridization chain reaction enables robust 10-plex, quantitative, high-resolution imaging of RNA and protein targets in whole-mount vertebrate embryos and brain sections.
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Objective Gender bias against female physicians has been frequently demonstrated and associated with negative feelings toward their careers. Gender bias has also been demonstrated in prehospital clinical care. However, potential gender bias during paramedic-physician handoffs has not been studied. This study aimed to identify gender bias during interactions between prehospital personnel and emergency physicians at the time of patient handoff. Methods An observational study was conducted at an urban academic emergency department. Observers were trained to record information from paramedic-physician handoffs but were blind to the nature of the study. The primary outcome was to whom paramedics initially directed the focus of their handoff report based on physician gender, with secondary outcomes of to whom paramedics directed most of their report and whether they asked about further questions based on physician gender. Results There were 784 observed handoffs. There was no significant association between the gender of the physician and which physician received first attention (χ2 {1, N = 782} = 0.9736, p = 0.3238) or majority attention (χ2 {1, N = 780} = 1.9414, p = 0.1635). Paramedics were more likely to ask questions to male attendings than female attendings (χ2 {1, N = 784} = 4.4319, p = 0.0353). Conclusion We identified limited differences in communication based on gender between paramedics and physicians during emergency department patient handoffs.
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We examined potential sex differences in appetite and blood pressure (BP) responses to melanocortin-4 receptor (MC4R) blockade in offspring from lean and obese parents. Offspring from normal (N) diet-fed parents were fed N (NN) or high-fat (H) diets (NH) from weaning until adulthood. Offspring from obese H diet-fed parents were also fed N (HN) or H diets (HH). Adult male and female offspring were implanted with BP telemetry probes and intracerebroventricular cannulas to infuse MC4R antagonist or vehicle. Infusion of the MC4R antagonist SHU-9119 (1 nmol/h) for 7 days caused larger increases in calorie intake and body weight in obese compared with lean offspring. In male offspring, HH and HN groups exhibited higher baseline BP compared with NN and NH, and HH showed a greater reduction in BP during SHU-9119 infusion. In female offspring, HH also showed higher baseline BP and greater reduction in BP during MC4R blockade. SHU-9119 reduced heart rate in all groups, but reductions were more pronounced in offspring from lean parents. Combined α and ß-adrenergic blockade reduced BP more in male HH offspring compared with NN controls. Losartan reduced BP more in male NH, HN, and HH offspring compared with NN controls. Losartan and α- and ß-adrenergic blockade reduced BP similarly in all female groups. These results suggest that endogenous MC4R activity contributes to elevated BP in obese offspring from obese parents. Our findings also indicate important sex differences in the mechanisms of BP control in male and female offspring of obese parents.
Subject(s)
Hypertension , Receptor, Melanocortin, Type 4 , Female , Male , Humans , Adult , Blood Pressure/physiology , Receptor, Melanocortin, Type 4/genetics , Losartan , Sex Characteristics , Obesity , Weight Gain , Adrenergic AgentsABSTRACT
This study examined the washoff of Bacillus globigii (Bg) spores from concrete, asphalt, and grass surfaces by stormwater. Bg is a nonpathogenic surrogate for Bacillus anthracis, which is a biological select agent. Areas (2.74 m × 7.62 m) of concrete, grass, and asphalt were inoculated twice at the field site during the study. Spore concentrations were measured in runoff water after seven rainfall events (1.2-65.4 mm) and complimentary watershed data were collected for soil moisture, depth of water in collection troughs, and rainfall using custom-built telemetry units. An average surface loading of 107.79 Bg spores/m2 resulted in peak spore concentrations in runoff water of 102, 260, and 4.1 CFU/mL from asphalt, concrete, and grass surfaces, respectively. Spore concentrations in the stormwater runoff were greatly reduced by the third rain event after both inoculations, but still detectable in some samples. When initial rainfall events occurred longer after the initial inoculation, the spore concentrations (both peak and average) in the runoff were diminished. The study also compared rainfall data from 4 tipping bucket rain gauges and a laser disdrometer and found they performed similarly for values of total rainfall accumulation while the laser disdrometer provided additional information (total storm kinetic energy) useful in comparing the seven different rain events. The soil moisture probes are recommended for assistance in predicting when to sample sites with intermittent runoff. Sampling trough level readings were critical to understanding the dilution factor of the storm event and the age of the sample collected. Collectively the spore and watershed data are useful for emergency responders faced with remediation decisions after a biological agent incident as the results provide insight into what equipment to deploy and that spores may persist in runoff water at quantifiable levels for months. The spore measurements are also a novel dataset for stormwater model parameterization for biological contamination of urban watersheds.
Subject(s)
Bacillus subtilis , Spores, Bacterial , Rain , Water , Water Movements , Soil , Environmental MonitoringABSTRACT
Limb-girdle muscular dystrophy type R9 (LGMDR9) is a muscle-wasting disease that begins in the hip and shoulder regions of the body. This disease is caused by mutations in fukutin-related protein (FKRP), a glycosyltransferase critical for maintaining muscle cell integrity. Here we investigated potential gene therapies for LGMDR9 containing an FKRP expression construct with untranslated region (UTR) modifications. Initial studies treated an aged dystrophic mouse model (FKRPP448L) with adeno-associated virus vector serotype 6 (AAV6). Grip strength improved in a dose- and time-dependent manner, injected mice exhibited fewer central nuclei and serum creatine kinase levels were 3- and 5-fold lower compared to those in non-injected FKRPP448L mice. Treatment also partially stabilized the respiratory pattern during exercise and improved treadmill running, partially protecting muscle from exercise-induced damage. Western blotting of C2C12 myotubes using a novel rabbit antibody confirmed heightened translation with the UTR modifications. We further explored the question of FKRP toxicity in wild-type mice using high doses of two additional muscle-tropic capsids: AAV9 and AAVMYO1. No toxic effects were detected with either therapeutic agent. These data further support the feasibility of gene therapy to treat LGMDR9.
ABSTRACT
Peripheral administration of tissue inhibitor of metalloproteinases 2 (TIMP2), a protein inhibitor of matrix metalloproteinases (MMPs), has previously been shown to have beneficial effects on cognition and neurons in aged mice. Here, to better understand the potential of recombinant TIMP2 proteins, an IgG4Fc fusion protein (TIMP2-hIgG4) was developed to extend the plasma half-life of TIMP2. Following one month of administration of TIMP2 or TIMP2-hIgG4 via intraperitoneal injections, 23-month-old male C57BL/6J mice showed improved hippocampal-dependent memory in a Y-maze, increased hippocampal cfos gene expression, and increased excitatory synapse density in the CA1 and dentate gyrus (DG) of the hippocampus. Thus, fusion to hIgG4 extended the half-life of TIMP2 while retaining the beneficial cognitive and neuronal effects. Moreover, it retained its ability to cross the blood-brain barrier. To deepen the mechanistic understanding of the beneficial function of TIMP2 on neuronal activity and cognition, a TIMP2 construct lacking MMP inhibitory activity, Ala-TIMP2, was generated, which provides steric hindrance that prevents inhibition of MMPs by the TIMP2 protein while still allowing MMP binding. A comprehensive assessment of the MMP inhibitory and binding capacity of these engineered proteins is outlined. Surprisingly, MMP inhibition by TIMP2 was not essential for its beneficial effects on cognition and neuronal function. These findings both confirm previously published research, expand on the potential mechanism for the beneficial effects of TIMP2, and provide important details for a therapeutic path forward for TIMP2 recombinant proteins in aging-related cognitive decline.