Human neutrophil elastase inhibitors: Classification, biological-synthetic sources and their relevance in related diseases.

BACKGROUND: Human neutrophil elastase is a multifunctional protease enzyme whose function is to break the bonds of proteins and degrade them to polypeptides or amino acids. In addition, it plays an essential role in the immune mechanism against bacterial infections and represents a key mediator in tissue remodeling and inflammation. However, when the extracellular release of this enzyme is dysregulated in response to low levels of its physiological inhibitors, it ultimately leads to the degradation of proteins, in particular elastin, as well as other components of the extracellular matrix, producing injury to epithelial cells, which can promote sustained inflammation and affect the innate immune system, and, therefore, be the basis for the development of severe inflammatory diseases, especially those associated with the cardiopulmonary system. OBJECTIVE: This review aims to provide an update on the elastase inhibitory properties of several molecules, either synthetic or biological sources, as well as their classification and relevance in related pathologies since a clear understanding of the function of these molecules with the inhibitory capacity of this protease can provide valuable information for the development of pharmacological therapies that manage to modify the prognosis and survival of various inflammatory diseases. METHODS: Collected data from scientific databases, including PubMed, Google Scholar, Science Direct, Nature, Wiley, Scopus, and Scielo. Articles published in any country and language were included. RESULTS: We reviewed and included 132 articles conceptualizing neutrophil elastase activity and known inhibitors. CONCLUSION: Understanding the mechanism of action of elastase inhibitors based on particular aspects such as their kinetic behavior, structure-function relationship, chemical properties, origin, pharmacodynamics, and experimental progress has allowed for a broad classification of HNE inhibitors.

Molecular Bases of Protein Antigenicity and Determinants of Immunogenicity, Anergy, and Mitogenicity.

BACKGROUND: The immune system is able to recognize substances that originate from inside or outside the body and are potentially harmful. Foreign substances that bind to immune system components exhibit antigenicity and are defined as antigens. The antigens exhibiting immunogenicity can induce innate or adaptive immune responses and give rise to humoral or cell-mediated immunity. The antigens exhibiting mitogenicity can cross-link cell membrane receptors on B and T lymphocytes leading to cell proliferation. All antigens vary greatly in physicochemical features such as biochemical nature, structural complexity, molecular size, foreignness, solubility, and so on. OBJECTIVE: Thus, this review aims to describe the molecular bases of protein-antigenicity and those molecular bases that lead to an immune response, lymphocyte proliferation, or unresponsiveness. CONCLUSION: The epitopes of an antigen are located in surface areas; they are about 880-3,300 Da in size. They are protein, carbohydrate, or lipid in nature. Soluble antigens are smaller than 1 nm and are endocytosed less efficiently than particulate antigens. The more the structural complexity of an antigen increases, the more the antigenicity increases due to the number and variety of epitopes. The smallest immunogens are about 4,000-10,000 Da in size. The more phylogenetically distant immunogens are from the immunogen-recipient, the more immunogenicity increases. Antigens that are immunogens can trigger an innate or adaptive immune response. The innate response is induced by antigens that are pathogen-associated molecular patterns. Exogenous antigens, T Dependent or T Independent, induce humoral immunogenicity. TD protein-antigens require two epitopes, one sequential and one conformational to induce antibodies, whereas, TI non-protein-antigens require only one conformational epitope to induce low-affinity antibodies. Endogenous protein antigens require only one sequential epitope to induce cell-mediated immunogenicity.

Immunomodulatory Activity of Diterpenes over Innate Immunity and Cytokine Production in a Human Alveolar Epithelial Cell Line Infected with Mycobacterium tuberculosis.

BACKGROUND: Mexico has the largest number of the genus salvia plant species, whose main chemical compounds of this genus are diterpenes, these chemical compounds have shown important biological activities such as: antimicrobial, anti-inflammatory and immunomodulatory. OBJECTIVE: This study aimed to evaluate the immunomodulatory activity of three diterpenes: 1) icetexone, 2) anastomosine and 3) 7,20-dihydroanastomosine, isolated from Salvia ballotiflora, over innate immunity and cytokine production in a human alveolar epithelial cell line infected with Mycobacterium tuberculosis. METHODS: The immunomodulatory activity of diterpenes over innate immunity included reactive oxygen and nitrogen species (ROS and RNS) induction in response to infection; cytokine production included TNF-α and TGF-ß induction in response to infection. RESULTS: The diterpenes anastomosine and 7,20-dihydroanastomosine showed a statically significant (p < 0.01) increase of RNS after 36 h of infection and treatment of 2.0 µg/mL. Then, the ROS induction in response to infection showed a consistent statically significant (p < 0.01) increase after 12 h of diterpenes treatments. The cell cultures showed an anti-inflammatory effect, in the case of TGF-ß induction, in response to infection when treated with the diterpenes. On the other hand, there was not any significant effect on TNF-α release. CONCLUSION: The diterpenes anastomosine and 7,20-dihydroanastomosine increased the production of RNS after 36 h of infection and treatment. Besides, the three diterpenes increased the production of ROS after 12 h. This RNS and ROS modulation can be considered as an in vitro correlation of innate immunity in response to Mycobacterium tuberculosis infection; and an indicator of the damage of epithelial lung tissue. This study also showed an anti-inflammatory immune response by means of TGF-ß modulation when compared with control group.

Tannic Acid, as a Structural Moiety Coupled to a Protein Antigen, Exhibiting a Molecular-structure Adjuvant Activity for Antibody Specificity Enhancement.

BACKGROUND: An antigen is a small foreign substance, such as a microorganism structural protein, that may trigger an immune response once inside the body. Antigens are preferentially used rather than completely attenuated microorganisms to develop safe vaccines. Unfortunately, not all antigens are able to induce an immune response. Thus, new adjuvants to enhance the antigen's ability to stimulate immunity must be developed. OBJECTIVES: Therefore, this work aimed to evaluate the molecular-structure adjuvant activity of tannic acid (TA) coupled to a protein antigen in Balb/c mice. METHODS: Bovine serum albumin (BSA) was used as an antigen. The coupling of BSA and TA was mediated by carbodiimide crosslinking, and verified by SDS-PAGE. Forty-two Balb/c mice were divided into seven groups, including two controls without antigen, an antigen control, an adjuvant control, and two treatment groups. An additional group was used for macrophages isolation. A 30-day scheme was used to immunize the mice. The analysis of humoral immunity included immunoglobulin quantification, isotyping and antigen-antibody precipitation. The analysis of cell-mediated immunity included the quantification of nitric oxide from peritoneal macrophages and splenocytes' proliferation assay after treatment stimulation. RESULTS: No differences were found in the antibodies' concentration or isotypes induced with the conjugate or the pure BSA. However, an immunogenicity improvement (p < 0.05) was observed through the specific anti-BSA antibody titers in mice immunized with the conjugate. Besides, macrophage activation (p < 0.05) was detected when stimulated with the treatments containing TA. CONCLUSION: Tannic acid exhibited macrophages' activation properties. Moreover, when TA was incorporated into the structure of a protein antigen, such as BSA, an antibody specificity enhancement was observed. This was a consequence of antigen processing by activated antigen-presenting cells. These results showed the use of tannic acid as a novel candidate for vaccine molecular-structure adjuvant.

Role of ß-Klotho and Malondialdehyde in Metabolic Disorders, HIV Infection, and Antiretroviral Therapy.

Metabolic alterations, resulting from factors such as obesity or infections (HIV), generate inflammation in the body, affecting the immune system and causing oxidative stress. Prolonged exposure to antiretroviral therapy (ART) conditions the appearance of alterations considered risk factors for metabolic syndrome (MetS), affecting the quality of life in people living with HIV/AIDS (PLWHA). ß-klotho is a protein that can counteract levels of oxidative stress. The aim was to determine the relation of ß-klotho and oxidative stress with metabolic alterations in PLWHA. We hypothesized that levels of ß-klotho and malondialdehyde (MDA) are related in PLWHA on ART with overweight/obesity. As a result of comparing cases versus controls, significant differences were obtained in levels of ß-klotho (p = 0.011), MDA (p < 0.0001), body mass index (p = 0.001), and weight (p < 0.0001). The presence of MetS in PLWHA was 21.2% and 10.6% according to the World Health Organization and ATP III (National Cholesterol Education Program Adult Treatment Panel III) criteria, respectively. The founded correlations were of ß-klotho (r = 0.019) and MDA (r = 0.0001), both with CD4+ cells in PLWHA. In controls, ß-klotho was correlated with very low-density lipoprotein (r = 0.035) and atherogenic index (AI; r = 0.037), MDA with AI (r = 0.039), cholesterol, and low-density lipoprotein (r = 0.002). The increase of inflammation in the organism, owing to HIV infection and/or the presence of obesity, conditions metabolic disruption or depletion of elements needed for homeostasis in the human body.

Tannic Acid Exhibits Adjuvant Activity by Enhancing Humoral and Cell-Mediated Immunity Against BSA as a Protein Antigen.

BACKGROUND: Immunization or vaccination is the process of inducing artificial immunity against an antigen taking advantage of the mechanisms of immunological memory. Current vaccines include substances known as adjuvants, which tend to improve the immunogenicity of the antigen, reduce the antigen quantity employed, and boost the immune response in weak responders. Unfortunately, only a few vaccine adjuvants are approved for human use. OBJECTIVE: Thus, the objective of this study was to investigate the effect of Tannic acid on humoral and cell-mediated immunity against bovine serum albumin (BSA) as a protein antigen in Wistar rats. METHODS: In order to establish the Tannic acid concentration to test it as an adjuvant, the lethal dose 50 and maximum non-toxic dose were calculated through cytotoxicity and hemolytic assays with J774 A.1 cell line and rat erythrocytes by resazurin reduction method and UV/vis spectrophotometry. Thirty Wistar rats were divided into 5 groups that included two controls without antigen and three treatment groups of adjuvants plus BSA as a protein antigen. The rats were immunized in a 30-day scheme. Blood samples were collected for humoral immunity analysis by means of immunoglobulin quantification, isotyping and antigen-antibody precipitation inhibition analysis. Rat peritoneal macrophages and splenocytes were isolated for cell-mediated immunity analysis by means of nitric oxide quantification from adjuvant stimulated peritoneal macrophages and lymphocytes proliferation assay. RESULTS: Tannic acid was capable of increasing the immunogenicity of the antigen; besides, it was able to stimulate cell-mediated immunity by means of increased lymphocyte proliferation. Moreover, Tannic acid improved the humoral response by means of increased specific antibodies titers. These activities may be attributed to pattern recognition receptors stimulation. CONCLUSION: Tannic acid was considered biocompatible when tested in vivo because the concentration tested did not show cytotoxicity or hemolytic effect, and there was no detrimental effect observed on the animals' health. These results show Tannic acid as a promising candidate for vaccine adjuvant.

Leptin G-2548A and Leptin Receptor Q223R Gene Polymorphisms are Differently Associated with Oxidative Process in Mexican Mestizo and Indigenous with Obesity.

Leptin levels and oxidative stress are implicated in obesity risk. Reports of association of leptin gene (LEP) and leptin receptor gene (LEPR) polymorphisms with leptin elevation are contradictory in a diverse population. Only a few studies report the linkage of obesity with biochemical markers and genetic factors. OBJECTIVE: The aim of this study was to examine whether plasma lipid peroxidation, antioxidant capability, leptin levels are associate selected LEP -2548 A/G and LEPR Q223R polymorphisms in mestizo and indigenous obesity Mexican population. METHODS: We identified and characterized 50 overweight or obese subjects and 50 healthy, normal- weight volunteers with indigenous Tepehuana or Mexican mestizo ethnicity from Durango, Mexico. LEP -2548 A/G and LEPR Q223R polymorphisms were determined by genotyping. Concentrations of leptin, antioxidant capacity (CA) and lipoperoxidation (LIPX) were determined in fast conditions on plasma with Enzyme-Linked ImmunoSorbent Assay (ELISA) in all participants. RESULTS: The highest genotype frequency was the heterozygous LEPR, which was associated with lipid peroxidation levels in normal-weight Tepehuan populations. A positive correlation was observed (r = 0.5; p <0.01) between LEP polymorphism and lipoperoxidation in normal weight Tepehuan subjects. On the other hand, the LEPR polymorphism was associated with the level of lipoperoxidation (r = 0.13; P <0.05) in mestizo populations of normal weight. CONCLUSION: It is probable that there is a synergistic effect for obesity, where the presence of oxidative stress and single nucleotide polymorphisms (SNP) of leptin and its receptor contributes to the generation of pathological subcutaneous fat of obesity, together with the environmental conditions of the populations.

Insights from Pharmaceutical Biotechnology into Phenolic Biopharmaceuticals against COVID-19.

BACKGROUND: The COVID-19 pandemic had infected more than 3.5M people around the world and more than 250K people died in 187 countries by May 2020. The causal agent of this disease is a coronavirus whose onset of symptoms to death range from 6 to 41 days with a median of 14 days. This period is dependent on several factors such as the presence of comorbidities, age and the efficiency of the innate or adaptive immune responses. METHODS: The effector mechanisms of both types of immune responses depend on the pathogen involved. In the case of a viral infection, the innate immune response may approach the harmful virus through pattern recognition receptors inducing an antiviral state. RESULTS: On the other hand, the adaptive immune response activates antibody production to neutralize or eliminate the virus. Phenolics are plant secondary metabolites with many biological activities for plants and humans against infection. Chemical modification of proteins may enhance their biological properties; thus, a protein of medical interest, for instance, a viral protein can be used as a scaffold to build a biopharmaceutical conjugated or complexated with phenolics exhibiting structural complexity or biological activities to achieve effective phenolic-protein-based therapeutics like vaccine adjuvant complexes, immunogen conjugates, and antiviral conjugates. CONCLUSION: Pharmaceutical biotechnology applies the principles of biotechnology to develop biopharmaceuticals for protein-based therapeutics; such as adjuvants, recombinant proteins, monoclonal antibodies, and antivirals. As neither a vaccine nor a treatment for COVID-19 is currently available, this manuscript focuses on insights from pharmaceutical biotechnology into phenolic biopharmaceuticals against COVID-19.

Klotho-HIV and Oxidative Stress: The Role of Klotho in Cardiovascular Disease Under HIV Infection-A Review.

Combined antiretroviral therapy has improved quality and life expectancy of people living with human immunodeficiency virus (HIV). However, this therapy increases oxidative stress (OS), which in turn causes alterations in lipid and carbon metabolism, kidney disease, liver cirrhosis, and increased risk of cardiovascular disease. The Klotho gene has been implicated in cardiovascular risk increase. Klotho protein expression at X level decreases the risk of heart disease. HIV-positive people usually present low plasma levels of Klotho; thus, contributing to some extent to an increase in cardiovascular risk for these types of patients, mostly by favoring atherosclerosis. Therefore, our aim is to provide an overview of the effect of OS on Klotho protein and its consequent cardiometabolic alterations in HIV-positive patients on antiretroviral therapy.

All-trans retinoic acid improves pancreatic cell proliferation on induced type 1 diabetic rats.

All-trans retinoic acid (ATRA) has been extensively studied as an integrating component of endocrine functions in the pancreas. The aim of this study was to evaluate the effects of ATRA on physiopathological biomarkers in an experimental model of rat with type 1 diabetes induced by alloxan (T1D). Twenty Wistar rats were divided equally into five groups, each receiving a different treatment: a control group (CG), a diabetic group without T1D treatment, a diabetic group treated with ATRA, a diabetic group supplemented with vitamin E (VIT E), and a group that was given olive oil (V). The administration of ATRA for 17 days produced a significant reduction in weight and glucose levels, compared to the T1D and VIT E groups. The evaluation of total antioxidant capacity (TAC) and lipoperoxidation showed no relevant difference among the groups. The results of the histological analysis showed similarities both in the size and in the number of islets of Langerhans in the pancreatic tissue obtained from the ATRA group and the CG. ATRA displayed a significant reduction of glycemic values in diabetic rats. Ultrastructurally, ß-cells, acinar, and ductal cells restored their normal appearance. ATRA can contribute to the recovery of pancreatic damage due to alloxan induction. It seems that the antioxidant effect of ATRA is not responsible for the differences observed.

Implicación del factor de necrosis tumoral alfa en el síndrome de ovario poliquístico / Involvement of TNF-alpha in the polycystic ovary syndrome

Resumen: ANTECEDENTES: De 6 a 14% de las mujeres padecen síndrome de ovario poliquístico. En la práctica clínica este síndrome se subdianostica, circunstancia que deriva en complicaciones propias del padecimiento que incluyen: obesidad, resistencia a la insulina, alteraciones metabólicas e infertilidad. La fisiopatología no se ha definido por completo y en la actualidad se plantea la asociación de un proceso metabólico e inflamatorio crónico, donde las citocinas inflamatorias pueden tener alteraciones en su efecto y en su señalización. OBJETIVO: Comunicar lo encontrado en una revisión sistemática actualizada de la implicación del factor de necrosis tumoral alfa en pacientes con síndrome de ovario poliquístico. METODOLOGÍA: Revisión narrativa de artículos científicos indexados en Pub Med-NCBI, Web of Science, Google Scholar y Scopus, publicados en inglés o español entre 2014 y 2018 que en el título y resumen incluyeron los conceptos y asociación del síndrome de ovario poliquístico y del factor de necrosis tumoral alfa. RESULTADOS: Se identificaron 43 artículos; luego de eliminar los duplicados quedaron 29 y, al final, la síntesis se efectuó con 11 artículos. Las publicaciones provinieron de distintos países: 54% de los estudios se efectuaron en Chile, Estados Unidos e Irán, proporcionalmente; el resto de los estudios se llevaron a cabo en Rusia, China, Korea, Egipto y Pakistán. CONCLUSIONES: El factor de necrosis tumoral alfa es una citocina asociada con diferentes sistemas que tiene participación en el síndrome de ovario poliquístico.

Abstract: BACKGROUND: Polycystic ovary syndrome (PCOS) is a pathology present in 6 to 14% of women. However, in clinical practice it is underdiagnosed, which implies a presence of complications of the pathology that includes obesity, insulin resistance, metabolic alterations and infertility. The pathophysiology is not well defined, and the association of a chronic metabolic and inflammatory process is currently being considered, where inflammatory cytokines can present alterations both in their effect and in their signaling. OBJETIVE: To present the results of an updated systematic review of the involvement of TNF-alpha in polycystic ovary syndrome. METHODOLOGY: Narrative revision of articles indexed in Pub Med-NCBI, Web of Science, Google Scholar and Scopus, published in English or Spanish between 2014 and 2018 that included the concepts and association of polycystic ovary syndrome and tumor necrosis factor alpha in the title and abstract. RESULTS: 43 articles were identified; after eliminating the duplicates, 29 remained and, in the end, the synthesis was carried out with 11 articles. The publications came from different countries: 54% of the studies were carried out in Chile, the United States and Iran, proportionally; the rest of the studies were carried out in Russia, China, Korea, Egypt and Pakistan. CONCLUSIONS: TNF-alpha is a cytokine associated with different systems that is involved in polycystic ovary syndrome.

[Relation of leptin in plasma with oxidative damage in indigenous tepehuán and mestizo populations from Durango]. / Relación de la leptina en plasma con el daño oxidativo en poblaciones indígena tepehuana y mestiza de Durango.

BACKGROUND: Obesity is a multifactorial metabolic disorder that involves lipid peroxidation (LPX), activating the antioxidant systems to counteract cellular damage. Objective: To evaluate the correlation between the antioxidant capacity and LPX levels of /eptin, in indigenous Tepehuan and Mestizo populations of the State of Durango. METHODS: We conducted a nutritional clinical study and lipid profile to confirm the state of health of a group of 60 indigenous Tepehuan of Mezquital and 68 mestizos subjects of Durango city, aged between 18 to 59 years. We determined the concentrations of leptin, antioxidant capacity and LPX in fasting conditions on plasma of participants, comparing averages, minimum, maximum, and standard deviation through ANOVA and Kruskai-Wal/is. For the correlation of variables, Pearson test was applied, getting the r value. RESULTS: Leptin levels were lower in indigenous Tepehuan than mestizos independent of body mass index. Mestizo subjects and Tepehuan with overweight and obesity (OW/0) or both ethnic groups show a greater degree of LPX (3.39 ± 0.31, 2.72 ± 0.54 MDA J.lmol/1, respectively; p < 0.05); however, OW/0 mestizos show more activation of its (0.37±0. 03 meqltrolox) than Tepehuan normal weight (NW) and OW/0 (0.32 ±0. 01 meq/trolox). The correlation between antioxidant capacity and LPX in mixed OW/0 was positive (r = 0.9; p < 0. 001). There is a correlation between levels of leptin and the antioxidant capacity of Tepehuan subjects both NW and OW/0 (r = 0.40; p < 0.05 and r = -0.66; p < 0.0001, respectively). CONCLUSION: Tepehuan groups with OW/0 have less oxidative damage, while antioxidant mechanisms have a smaller activation than the top crosses of the same nutritional condition. The results suggest that antioxidant capacity has an implication on the regulation of leptin levels in Tepehuan subjects.