LOX-1 in Cardiovascular Disease: A Comprehensive Molecular and Clinical Review.

LOX-1, ORL-1, or lectin-like oxidized low-density lipoprotein receptor 1 is a transmembrane glycoprotein that binds and internalizes ox-LDL in foam cells. LOX-1 is the main receptor for oxidized low-density lipoproteins (ox-LDL). The LDL comes from food intake and circulates through the bloodstream. LOX-1 belongs to scavenger receptors (SR), which are associated with various cardiovascular diseases. The most important and severe of these is the formation of atherosclerotic plaques in the intimal layer of the endothelium. These plaques can evolve into complicated thrombi with the participation of fibroblasts, activated platelets, apoptotic muscle cells, and macrophages transformed into foam cells. This process causes changes in vascular endothelial homeostasis, leading to partial or total obstruction in the lumen of blood vessels. This obstruction can result in oxygen deprivation to the heart. Recently, LOX-1 has been involved in other pathologies, such as obesity and diabetes mellitus. However, the development of atherosclerosis has been the most relevant due to its relationship with cerebrovascular accidents and heart attacks. In this review, we will summarize findings related to the physiologic and pathophysiological processes of LOX-1 to support the detection, diagnosis, and prevention of those diseases.

Targeting Neutrophil Extracellular Trap Formation: Exploring Promising Pharmacological Strategies for the Treatment of Preeclampsia.

Neutrophils, which constitute the most abundant leukocytes in human blood, emerge as crucial players in the induction of endothelial cell death and the modulation of endothelial cell responses under both physiological and pathological conditions. The hallmark of preeclampsia is endothelial dysfunction induced by systemic inflammation, in which neutrophils, particularly through the formation of neutrophil extracellular traps (NETs), play a pivotal role in the development and perpetuation of endothelial dysfunction and the hypertensive state. Considering the potential of numerous pharmaceutical agents to attenuate NET formation (NETosis) in preeclampsia, a comprehensive assessment of the extensively studied candidates becomes imperative. This review aims to identify mechanisms associated with the induction and negative regulation of NETs in the context of preeclampsia. We discuss potential drugs to modulate NETosis, such as NF-κß inhibitors, vitamin D, and aspirin, and their association with mutagenicity and genotoxicity. Strong evidence supports the notion that molecules involved in the activation of NETs could serve as promising targets for the treatment of preeclampsia.

Tubular mitochondrial pyruvate carrier disruption elicits redox adaptations that protect from acute kidney injury.

OBJECTIVE: Energy-intensive kidney reabsorption processes essential for normal whole-body function are maintained by tubular epithelial cell metabolism. Although tubular metabolism changes markedly following acute kidney injury (AKI), it remains unclear which metabolic alterations are beneficial or detrimental. By analyzing large-scale, publicly available datasets, we observed that AKI consistently leads to downregulation of the mitochondrial pyruvate carrier (MPC). This investigation aimed to understand the contribution of the tubular MPC to kidney function, metabolism, and acute injury severity. METHODS: We generated tubular epithelial cell-specific Mpc1 knockout (MPC TubKO) mice and employed renal function tests, in vivo renal 13C-glucose tracing, mechanistic enzyme activity assays, and tests of injury and survival in an established rhabdomyolysis model of AKI. RESULTS: MPC TubKO mice retained normal kidney function, displayed unchanged markers of kidney injury, but exhibited coordinately increased enzyme activities of the pentose phosphate pathway and the glutathione and thioredoxin oxidant defense systems. Following rhabdomyolysis-induced AKI, compared to WT control mice, MPC TubKO mice showed increased glycolysis, decreased kidney injury and oxidative stress markers, and strikingly increased survival. CONCLUSIONS: Our findings suggest that decreased renal tubular mitochondrial pyruvate uptake hormetically upregulates oxidant defense systems before AKI and is a beneficial adaptive response after rhabdomyolysis-induced AKI. This raises the possibility of therapeutically modulating the MPC to attenuate AKI severity.

Pre-clinical evaluation of biomarkers for the early detection of nephrotoxicity following alpha-particle radioligand therapy.

PURPOSE: Cancer treatment with alpha-emitter-based radioligand therapies (α-RLTs) demonstrates promising tumor responses. Radiolabeled peptides are filtered through glomeruli, followed by potential reabsorption of a fraction by proximal tubules, which may cause acute kidney injury (AKI) and chronic kidney disease (CKD). Because tubular cells are considered the primary site of radiopeptides' renal reabsorption and potential injury, the current use of kidney biomarkers of glomerular functional loss limits the evaluation of possible nephrotoxicity and its early detection. This study aimed to investigate whether urinary secretion of tubular injury biomarkers could be used as an additional non-invasive sensitive diagnostic tool to identify unrecognizable tubular damage and risk of long-term α-RLT nephrotoxicity. METHODS: A bifunctional cyclic peptide, melanocortin 1 ligand (MC1L), labeled with [203Pb]Pb-MC1L, was used for [212Pb]Pb-MC1L biodistribution and absorbed dose measurements in CD-1 Elite mice. Mice were treated with [212Pb]Pb-MC1L in a dose-escalation study up to levels of radioactivity intended to induce kidney injury. The approach enabled prospective kidney functional and injury biomarker evaluation and late kidney histological analysis to validate these biomarkers. RESULTS: Biodistribution analysis identified [212Pb]Pb-MC1L reabsorption in kidneys with a dose deposition of 2.8, 8.9, and 20 Gy for 0.9, 3.0, and 6.7 MBq injected [212Pb]Pb-MC1L doses, respectively. As expected, mice receiving 6.7 MBq had significant weight loss and CKD evidence based on serum creatinine, cystatin C, and kidney histological alterations 28 weeks after treatment. A dose-dependent urinary neutrophil gelatinase-associated lipocalin (NGAL, tubular injury biomarker) urinary excretion the day after [212Pb]Pb-MC1L treatment highly correlated with the severity of late tubulointerstitial injury and histological findings. CONCLUSION: Urine NGAL secretion could be a potential early diagnostic tool to identify unrecognized tubular damage and predict long-term α-RLT-related nephrotoxicity.

Pre-clinical Evaluation of Biomarkers for Early Detection of Nephrotoxicity Following Alpha-particle Radioligand Therapy.

Purpose: Cancer treatment with alpha-emitter-based radioligand therapies (α-RLTs) demonstrates promising tumor responses. Radiolabeled peptides are filtered through glomeruli, followed by potential reabsorption of a fraction by proximal tubules, which may cause acute kidney injury (AKI) and chronic kidney disease (CKD). Because tubular cells are considered the primary site of radiopeptides' renal reabsorption and potential injury, the current use of kidney biomarkers of glomerular functional loss limits the evaluation of possible nephrotoxicity and its early detection. This study aimed to investigate whether urinary secretion of tubular injury biomarkers could be used as additional non-invasive sensitive diagnostic tool to identify unrecognizable tubular damage and risk of long-term α-RLTs nephrotoxicity. Methods: A bifunctional cyclic peptide, melanocortin ligand-1(MC1L), labeled with [ 203 Pb]Pb-MC1L, was used for [ 212 Pb]Pb-MC1L biodistribution and absorbed dose measurements in CD-1 Elite mice. Mice were treated with [ 212 Pb]Pb-MC1L in a dose escalation study up to levels of radioactivity intended to induce kidney injury. The approach enabled prospective kidney functional and injury biomarker evaluation and late kidney histological analysis to validate these biomarkers. Results: Biodistribution analysis identified [ 212 Pb]Pb-MC1L reabsorption in kidneys with a dose deposition of 2.8, 8.9, and 20 Gy for 0.9, 3.0, and 6.7 MBq injected [ 212 Pb]Pb-MC1L doses, respectively. As expected, mice receiving 6.7 MBq had significant weight loss and CKD evidence based on serum creatinine, cystatin C, and kidney histological alterations 28 weeks after treatment. A dose-dependent urinary Neutrophil gelatinase-associated lipocalin (NGAL, tubular injury biomarker) urinary excretion the day after [ 212 Pb]Pb-MC1L treatment highly correlated with the severity of late tubulointerstitial injury and histological findings. Conclusion: urine NGAL secretion could be a potential early diagnostic tool to identify unrecognized tubular damage and predict long-term α-RLT-related nephrotoxicity.

Engineered Extracellular Vesicle-Based Therapies for Valvular Heart Disease.

Introduction: Valvular heart disease represents a significant burden to the healthcare system, with approximately 5 million cases diagnosed annually in the US. Among these cases, calcific aortic stenosis (CAS) stands out as the most prevalent form of valvular heart disease in the aging population.  CAS is characterized by the progressive calcification of the aortic valve leaflets, leading to valve stiffening. While aortic valve replacement is the standard of care for CAS patients, the long-term durability of prosthetic devices is poor, calling for innovative strategies to halt  or reverse disease progression. Here, we explor the potential use of novel extracellular vesicle (EV)-based nanocarriers for delivering molecular payloads to the affected valve tissue. This approach aims to reduce inflammation and potentially promote resorption of the calcified tissue. Methods: Engineered EVs loaded with the reprogramming myeloid transcription factors, CEBPA and Spi1, known to mediate the transdifferentiation of committed endothelial cells into macrophages. We evaluated the ability of these engineered EVs to deliver DNA and transcripts encoding CEBPA and Spil into calcified aortic valve tissue obtained from patients undergoing valve replacement due to aortic stenosis. We also investigated whether these EVs could induce the transdifferentiation of endothelial cells into macrophage-like cells. Results: Engineered EVs loaded with CEBPA + Spi1 were successfully derived from human dermal fibroblasts. Peak EV loading was found to be at 4 h after nanotransfection of donor cells.  These CEBPA + Spi1 loaded EVs effectively transfected aortic valve cells, resulting in the successful induction of transdifferentiation, both in vitro with  endothelial cells and ex vivo with valvular endothelial cells, leading to the development of anti-inflammatory macrophage-like cells. Conclusions: Our findings highlight the potential of engineered EVs as a next generation nanocarrier to target aberrant calcifications on diseased heart valves. This development holds promise as a novel therapy for high-risk patients who may not be suitable candidates for valve replacement surgery. Supplementary Information: The online version contains supplementary material available at 10.1007/s12195-023-00783-x.

Mitochondrial Oxidative Metabolism: An Emerging Therapeutic Target to Improve CKD Outcomes.

Chronic kidney disease (CKD) predisposes one toward end-stage renal disease (ESRD) and its associated morbidity and mortality. Significant metabolic perturbations in conjunction with alterations in redox status during CKD may induce increased production of reactive oxygen species (ROS), including superoxide (O2●-) and hydrogen peroxide (H2O2). Increased O2●- and H2O2 may contribute to the overall progression of renal injury as well as catalyze the onset of comorbidities. In this review, we discuss the role of mitochondrial oxidative metabolism in the pathology of CKD and the recent developments in treating CKD progression specifically targeted to the mitochondria. Recently published results from a Phase 2b clinical trial by our group as well as recently released data from a ROMAN: Phase 3 trial (NCT03689712) suggest avasopasem manganese (AVA) may protect kidneys from cisplatin-induced CKD. Several antioxidants are under investigation to protect normal tissues from cancer-therapy-associated injury. Although many of these antioxidants demonstrate efficacy in pre-clinical models, clinically relevant novel compounds that reduce the severity of AKI and delay the progression to CKD are needed to reduce the burden of kidney disease. In this review, we focus on the various metabolic pathways in the kidney, discuss the role of mitochondrial metabolism in kidney disease, and the general involvement of mitochondrial oxidative metabolism in CKD progression. Furthermore, we present up-to-date literature on utilizing targets of mitochondrial metabolism to delay the pathology of CKD in pre-clinical and clinical models. Finally, we discuss the current clinical trials that target the mitochondria that could potentially be instrumental in advancing the clinical exploration and prevention of CKD.

Mechanisms of Immunothrombosis by SARS-CoV-2.

SARS-CoV-2 contains certain molecules that are related to the presence of immunothrombosis. Here, we review the pathogen and damage-associated molecular patterns. We also study the imbalance of different molecules participating in immunothrombosis, such as tissue factor, factors of the contact system, histones, and the role of cells, such as endothelial cells, platelets, and neutrophil extracellular traps. Regarding the pathogenetic mechanism, we discuss clinical trials, case-control studies, comparative and translational studies, and observational studies of regulatory or inhibitory molecules, more specifically, extracellular DNA and RNA, histones, sensors for RNA and DNA, as well as heparin and heparinoids. Overall, it appears that a network of cells and molecules identified in this axis is simultaneously but differentially affecting patients at different stages of COVID-19, and this is characterized by endothelial damage, microthrombosis, and inflammation.

Immunothrombotic dysregulation in chagas disease and COVID-19: a comparative study of anticoagulation.

Chagas and COVID-19 are diseases caused by Trypanosoma cruzi and SARS-CoV-2, respectively. These diseases present very different etiological agents despite showing similarities such as susceptibility/risk factors, pathogen-associated molecular patterns (PAMPs), recognition of glycosaminoglycans, inflammation, vascular leakage hypercoagulability, microthrombosis, and endotheliopathy; all of which suggest, in part, treatments with similar principles. Here, both diseases are compared, focusing mainly on the characteristics related to dysregulated immunothrombosis. Given the in-depth investigation of molecules and mechanisms related to microthrombosis in COVID-19, it is necessary to reconsider a prompt treatment of Chagas disease with oral anticoagulants.

Multiple Origins of Extracellular DNA Traps.

Extracellular DNA traps (ETs) are evolutionarily conserved antimicrobial mechanisms present in protozoa, plants, and animals. In this review, we compare their similarities in species of different taxa, and put forward the hypothesis that ETs have multiple origins. Our results are consistent with a process of evolutionary convergence in multicellular organisms through the application of a congruency test. Furthermore, we discuss why multicellularity is related to the presence of a mechanism initiating the formation of ETs.

The influence of hydrogen ions on coagulation in traumatic brain injury, explored by molecular dynamics.

Background: Patients in intensive care units with traumatic brain injuries (TBI) frequently present acid-base abnormalities and coagulability disorders, which complicate their condition.Objective: To identify protonation through in silico simulations of molecules involved in the process of coagulation in standard laboratory tests.Materials and methods: Ten patients with TBI were selected from the intensive care unit in addition to ten "healthy control subjects", and another nine patients as "disease control subjects"; the latter being a comparative group, corresponding to subjects with diabetes mellitus 2 (DM2). Fibrinogen, FVII, FVIII, FIX, FX, and D-dimer in the presence of acidification were evaluated in 20 healthy subjects in order to compare clinical results with molecular dynamics (MD), and to explain proton interactions and coagulation molecules.Results: The TBI group presented a slight, non-significant increase in D-dimer; but this was not present in "disease control subjects". Levels of fibrinogen, FVII, FIX, FX, and D-dimer were affected in the presence of acidification. We observed that various specific residues of coagulation factors "trap" ions.Conclusion: Protonation of tissue factor and factor VIIa may favor anticoagulant mechanisms, and protonation does not affect ligand binding sites of GPIIb/IIIa (PAC1) suggesting other causes for the low affinity to PAC1.

Analysis of SARS-CoV-2 mutations in Mexico, Belize, and isolated regions of Guatemala and its implication in the diagnosis.

The genomic sequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide are publicly available and are derived from studies due to the increase in the number of cases. The importance of study of mutations is related to the possible virulence and diagnosis of SARS-CoV-2. To identify circulating mutations present in SARS-CoV-2 genomic sequences in Mexico, Belize, and Guatemala to find out if the same strain spread to the south, and analyze the specificity of the primers used for diagnosis in these samples. Twenty three complete SARS-CoV-2 genomic sequences, available in the GISAID database from May 8 to September 11, 2020 were analyzed and aligned versus the genomic sequence reported in Wuhan, China (NC_045512.2), using Clustal Omega. Open reading frames were translated using the ExPASy Translate Tool and UCSF Chimera (v.1.12) for amino acid substitutions analysis. Finally, the sequences were aligned versus primers used in the diagnosis of COVID-19. One hundred and eighty seven distinct variants were identified, of which 102 are missense, 66 synonymous and 19 noncoding. P4715L and P5828L substitutions in replicase polyprotein were found, as well as D614G in spike protein and L84S in ORF8 in Mexico, Belize, and Guatemala. The primers design by CDC of United States showed a positive E value. The genomic sequences of SARS-CoV-2 in Mexico, Belize, and Guatemala present similar mutations related to a virulent strain of greater infectivity, which could mean a greater capacity for inclusion in the host genome and be related to an increased spread of the virus in these countries, furthermore, its diagnosis would be affected.

Molecules and Prostaglandins Related to Embryo Tolerance.

It is generally understood that the entry of semen into the female reproductive tract provokes molecular and cellular changes facilitating conception and pregnancy. We show a broader picture of the participation of prostaglandins in the fertilization, implantation and maintenance of the embryo. A large number of cells and molecules are related to signaling networks, which regulate tolerance to implantation and maintenance of the embryo and fetus. In this work, many of those cells and molecules are analyzed. We focus on platelets, polymorphonuclear leukocytes, and group 2 innate lymphoid cells involved in embryo tolerance in order to have a wider view of how prostaglandins participate. The combination of platelets and neutrophil extracellular traps (Nets), uterine innate lymphoid cells (uILC), Treg cells, NK cells, and sex hormones have an important function in immunological tolerance. In both animals and humans, the functions of these cells can be regulated by prostaglandins and soluble factors in seminal plasma to achieve an immunological balance, which maintains fetal-maternal tolerance. Prostaglandins, such as PGI2 and PGE2, play an important role in the suppression of the previously mentioned cells. PGI2 inhibits platelet aggregation, in addition to IL-5 and IL-13 expression in ILC2, and PGE2 inhibits some neutrophil functions, such as chemotaxis and migration processes, leukotriene B4 (LTB4) biosynthesis, ROS production, and the formation of extracellular traps, which could help prevent trophoblast injury and fetal loss. The implications are related to fertility in female when seminal fluid is deposited in the vagina or uterus.

Factors related to asymptomatic or severe COVID-19 infection.

The factors that may contribute to a COVID-19 patient remaining in the asymptomatic stage, or to the infection evolving into the more serious stages are examined. In particular, we refer to the TMPRSS2 expression profile, balance of androgen and estrogen, blood group-A and/or B, nonsynonymous mutations in ORF3, and proteins NS7b and NS8 in SARS-CoV-2. Also, we review other factors related to the susceptibility and pathogenicity of SARS-CoV-2.

TSH Levels in Subclinical Hypothyroidism in the 97.5th Percentile of the Population.

The debate regarding the cutoff point in the treatment of patients with subclinical hypothyroidism (Shypo) is ongoing. Generally, two different groups are identified for treatment by levels of 10 and 20 mIU/L. Nevertheless, the question remains, "what cutoff point should be chosen?" We have written a selective nonsystematic review focused on the 97.5 percentile reference value reported in healthy subjects in a number of countries and observed important disparities, which partly show the challenge of identifying a single cutoff point for those patients needing medication. We identified studies of TSH on the natural history of subclinical hypothyroidism from population-based prospective cohort studies, which follow up patients for several years. The evolution of TSH levels in these patients is variable. Some cases of TSH may return to lower levels at different stages over the years, but others may not, possibly even developing into overt thyroid failure, also variable. We analyzed factors that may explain the normalization of serum TSH levels. In addition, we found that thorough population-based prospective cohort studies following up on TSH levels, thyroid antibodies, and ultrasonography are important in decisions made in the treatment of patients. However, the 97.5 percentile reference value varies in different countries; therefore, an international cutoff point for subclinical hypothyroidism cannot be recommended.

Aggregation and Molecular Properties of ß-Glucosidase Isoform II in Chayote (Sechium edule).

The presence of isoforms of ß-glucosidase has been reported in some grasses such as sorghum, rice and maize. This work aims to extract and characterize isoform II in ß-glucosidase from S. edule. A crude extract was prepared without buffer solution and adjusted to pH 4.6. Contaminating proteins were precipitated at 4 °C for 24 h. The supernatant was purified by chromatography on carboxymethyl cellulose (CMC) column, molecular exclusion on Sephacryl S-200HR, and exchange anionic on QFF column. Electrophoretic analyzes revealed a purified enzyme with aggregating molecular complex on SDS-PAGE, Native-PAGE, and AU-PAGE. Twelve peptides fragments were identified by nano liquid chromatography-tandem mass spectrometry (nano LC-ESI-MS/MS), which presented as 61% identical to Cucurbita moschata ß-glucosidase and 55.74% identical to ß-glucosidase from Cucumis sativus, another Cucurbitaceous member. The relative masses which contained 39% hydrophobic amino acids ranged from 982.49 to 2,781.26. The enzyme showed a specificity to ß-d-glucose with a Km of 4.59 mM, a Vmax value of 104.3 µM∙min-1 and a kcat of 10,087 µM∙min-1 using p-nitrophenyl-ß-D-glucopyranoside. The presence of molecular aggregates can be attributed to non-polar amino acids. This property is not mediated by a ß-glucosidase aggregating factor (BGAF) as in grasses (maize and sorghum). The role of these aggregates is discussed.