Synergistic effect of β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli in vitro / 生物工程学报

The widespread of tigecycline resistance gene tet(X4) has a serious impact on the clinical efficacy of tigecycline. The development of effective antibiotic adjuvants to combat the looming tigecycline resistance is needed. The synergistic activity between the natural compound β-thujaplicin and tigecycline in vitro was determined by the checkerboard broth microdilution assay and time-dependent killing curve. The mechanism underlining the synergistic effect between β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli was investigated by determining cell membrane permeability, bacterial intracellular reactive oxygen species (ROS) content, iron content, and tigecycline content. β-thujaplicin exhibited potentiation effect on tigecycline against tet(X4)-positive E. coli in vitro, and presented no significant hemolysis and cytotoxicity within the range of antibacterial concentrations. Mechanistic studies demonstrated that β-thujaplicin significantly increased the permeability of bacterial cell membranes, chelated bacterial intracellular iron, disrupted the iron homeostasis and significantly increased intracellular ROS level. The synergistic effect of β-thujaplicin and tigecycline was identified to be related to interfere with bacterial iron metabolism and facilitate bacterial cell membrane permeability. Our studies provided theoretical and practical data for the application of combined β-thujaplicin with tigecycline in the treatment of tet(X4)-positive E. coli infection.

Role of Ferroptosis in Cardiovascular Diseases and Chinese Medicine Treatment Based on Iron Homeostasis： A Review / 中国实验方剂学杂志

Cardiovascular diseases are a class of circulatory system diseases involving the heart and vessels， including arrhythmia， hypertension， coronary heart disease， myocardial infarction， heart failure and so on. Due to the complicated pathogenesis， diverse disease types， and difficult treatment， cardiovascular diseases pose serious threatens to the human health. Therefore， it is urgent to develop effective therapies. Ferroptosis， a new type of cell death different from autophagy and apoptosis， is iron-dependent and accompanied by lipid peroxide accumulation. The mechanism of ferroptosis is complex. Recent studies have shown that iron homeostasis plays a role in the occurrence of ferroptosis， which may be induced by iron intake， utilization， and output and iron-related protein synthesis. In addition， iron homeostasis and ferroptosis have been confirmed to be involved in the pathological process of cardiovascular diseases， so regulating iron homeostasis and ferroptosis in cardiomyocytes may be a focus of the future research on cardiovascular diseases. Traditional Chinese medicine （TCM） provides a unique treatment method， and the unique syndrome differentiation system and treatment methods have been widely used in the clinical diagnosis， prevention， and treatment of cardiovascular diseases. Studies have demonstrated that TCM compound prescriptions and the active components in Chinese medicinal materials can regulate iron homeostasis and ferroptosis to protect cardiomyocytes. This paper introduces the mechanism of iron homeostasis in regulating ferroptosis and summarizes the effects of iron homeostasis-mediated ferroptosis on cardiovascular diseases. Furthermore， the research progress of TCM in regulating iron homeostasis-mediated ferroptosis in cardiovascular diseases is reviewed to provide new ideas for TCM prevention and treatment of cardiovascular diseases.

Research progress and therapeutic perspective of iron transport balance based on "iron-inflammation" homeostatic coupling theory / 药学学报

The iron and inflammation homeostasis are closely coupled, forming an integrated functional unit under physiological conditions. "Iron transport balance" has become the key mechanism to maintain iron homeostasis through bidirectional regulation of iron uptake and release and dynamic management of transmembrane concentration. It is also the physiological basis for the inflammatory balance between promotion and resolution. Under pathological conditions, represented by inflammatory bowel disease (IBD), disturbed iron transportation was highly involved in almost every step of inflammatory diseases. Therefore, the iron transporting rebalancing provides the mechanistic basis and effective approach for the normalization of inflammatory microenvironment. Macrophage is the key regulator of inflammation homeostasis and determinant for iron transport balance. Unfortunately, the current clinical transformation based on iron transport balance theory has still been insufficient. Sometimes, this strategy even showed high complexity and contradiction, severely restricting its clinical application. By summarizing the theoretical research progress of iron transport balance, especially its relevance to macrophage phenotypic polarization, this review aims to explore the therapeutic value in inflammation intervention by targeting iron transporting balance. This review will provide the necessary knowledge and hints for the research and development of candidate drugs in treating inflammatory diseases.

Research progress of iron metabolism and iron homeostasis imbalance / 公共卫生与预防医学

Iron is an important trace element in human body. It is involved in heme synthesis, myelin sheath formation, mitochondrial respiratory chain electron transfer, DNA replication, repair，epigenetic control and so on. In order to maintain iron homeostasis, the body maintains iron balance by regulating the absorption of dietary iron by intestinal cells, recovery of iron by macrophages and storage of iron in liver cells. These iron metabolism regulation processes involve sophisticated cellular and molecular regulatory systems. When iron homeostasis is broken, both iron deficiency and iron overload will result in damage to the body. In this review, we review the research progress on the absorption, distribution and recovery of iron, the cellular and molecular regulatory mechanisms of iron metabolism and the consequences of iron homeostasis imbalance.

Neuroprotective effects of kukoamine A on 6-OHDA-induced Parkinson's model through apoptosis and iron accumulation inhibition / 中草药·英文版

Objective: Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in substantia nigra (SN). Our previous study demonstrated kukoamine A (KuA) to exhibit strong neuroprotective effects through antioxidative stress, and autophagy in MPTP/MPP

Association between weather seasonality and blood parameters in riverine populations of the Brazilian Amazon / Relação da sazonalidade climática com parâmetros sanguíneos de ribeirinhos residentes na Amazônia brasileira

Abstract Objective: To analyze the seasonality of blood parameters related to iron homeostasis, inflammation, and allergy in two riverine populations from the Brazilian Amazon. Methods: This was a cross-sectional study of 120 children and adolescents of school age, living in riverine communities of Porto Velho, Rondonia, Brazil, describing the hematocrit, hemoglobin, ferritin, serum iron, total white blood cell count, lymphocytes, eosinophils, C-reactive protein, and immunoglobulin E levels in the dry and rainy seasons. The chi-squared test and the prevalence ratio were used for the comparison of proportions and mean analysis using paired Student's t-test. Results: Hemoglobin (13.3 g/dL) and hematocrit (40.9%) showed higher average values in the dry season. Anemia prevalence was approximately 4% and 12% in the dry and rainy seasons, respectively. Serum iron was lower in the dry season, with a mean of 68.7 mcg/dL. The prevalence of iron deficiency was 25.8% in the dry season and 9.2% in the rainy season. Serum ferritin did not show abnormal values in both seasons; however, the mean values were higher in the dry season (48.5 ng/mL). The parameters of eosinophils, lymphocytes, global leukocyte count, C-reactive protein and immunoglobulin E showed no seasonal differences. C-reactive protein and immunoglobulin E showed abnormal values in approximately 7% and 60% of the examinations, respectively. Conclusion: Hematological parameters of the red cell series and blood iron homeostasis had seasonal variation, which coincided with the dry season in the region, in which an increase in atmospheric pollutants derived from fires is observed.

Resumo Objetivo: Analisar a sazonalidade climática de parâmetros sanguíneos relacionados à homeostase do ferro, inflamação e alergia em duas populações ribeirinhas da Amazônia brasileira. Método: Fez-se um estudo transversal em 120 crianças e adolescentes em idade escolar, residentes em comunidades ribeirinhas de Porto Velho, Rondônia. Foram analisados hematócrito, hemoglobina, ferritina, ferro sérico, leucometria global, linfócitos, eosinófilos, proteína C-reativa e imunoglobulina E nas estações seca e chuvosa. Usaram-se o teste do qui-quadrado e a razão de prevalência para a comparação das proporções, além do teste t de Student pareado para a análise de médias. Resultados: Hemoglobina (13,3 g/dL) e hematócrito (40,9%) apresentaram maiores valores médios no período de seca. A prevalência de anemia foi de 4% e 12% na seca e na chuva, respectivamente. O ferro sérico foi menor no período de seca com média de 68,7 mcg/dL. A prevalência de deficiência de ferro foi em média 25,8% na seca e 9,2% na chuva. A concentração sérica de ferritina não apresentou valores alterados em ambos os períodos, no entanto os valores médios apresentaram-se mais elevados na seca (48,5 ng/mL). Os parâmetros dos eosinófilos, linfócitos, leucometria global, proteína C-reativa e imunoglobulina E não apresentaram diferenças sazonais. A proteína C-reativa e a imunoglobulina E apresentaram valores alterados em 7% e 60% dos exames feitos, respectivamente. Conclusão: Os parâmetros hematológicos da série vermelha e a homeostasia ferro sanguíneo apresentaram variação sazonal, que coincide com o período de seca na região, no qual se observa aumento dos poluentes atmosféricos derivados das queimadas.

Prohepcidina y estado del hierro e inflamación en escolares sanos o H. pylori positivos asintomáticos / Prohepcidine iron status and inflammation in healthy and asymptomatic H. pylori school children / Pró-hepcidina estado de ferro e inflamação em estudantes saudáveis ou H. pylori positivos assintomáticos

El eje hepcidina-ferroportina es determinante en la homeostasis del hierro. Niveles elevados de hepcidina reducen la capacidad de absorción intestinal del hierro, así como su movilización entre tejidos. Una condición que produce valores séricos elevados de hepcidina es la infección. Como la infección con Helicobacter pylori (Hp) predispone a una deficiencia de hierro, en este estudio se evaluaron los niveles séricos de Pro-Hepcidina (PH), un precursor de la hepcidina, en un grupo de escolares asintomáticos, infectados con Hp (80 niños) y se los comparó con un grupo similar de niños sanos (59 niños). Los resultados mostraron que los niños infectados en los que se detectó la presencia de Hp (test de aire espirado) tenían valores de proteína C reactiva (PCR) significativamente más altos que los niños sanos. Ambos grupos presentaron valores similares de: adecuación de la ingesta de hierro, ferritina sérica (Fs), hemoglobina, hematocrito, receptores solubles de transferrina. La prevalencia de anemia y deficiencia subclínica de hierro en el grupo total (infectados + no infectados) fue de 10 y 60%, respectivamente sin diferencias entre los grupos. Sin embargo, en el grupo de niños sanos la PH sérica correlacionó significativamente (r=0,730/p<0,001) con los niveles de Fs, mientras que en los niños infectados, los niveles de PH no correlacionaron con la Fs, pero correlacionaron con la severidad de la infección (r=0,52/p<0,001). Esta tendencia de la PH a aumentar con la severidad de la infección podría explicar la mayor prevalencia de deficiencia de hierro en pacientes infectados con Hp.

The hepcidin-ferroportin axis is crucial in iron homeostasis. High serum hepcidine reduces iron intestinal absorption and tissue iron mobilization. Infection and inflammation increase serum hepcidin, predisposing to iron deficiency. Since Helicobacter pylori (Hp) infection has been associated to iron deficiency, the serum levels of prohepcidin PH (a precursor of hepcidin) were evaluated in 80 school children infected with Hp but without gastric symptoms. This was compared with PH levels in a group of 59 non Hp infected children. The results showed that infected children (exhaled air method) had higher levels of protein C reactive protein (CRP) than the non-infected group. Both groups had similar levels of iron consumption, serum ferritin (Fs), hemoglobin, hematocrit, soluble transferrin receptors and PH. The prevalence of anemia and of subclinical iron deficiency in the whole group (infected + non-infected) reached 10 and 60% respectively with no differences between groups. However, in the group of non-infected children, serum PH correlated (r=0.730/ p<0.001) with Fs levels whereas in the infected children, PH did not correlate with Fs but it correlated with the severity of the infection (r = 0.52/p<0.001). The tendency of PH to increase with the severity of infection could explain the higher prevalence of iron deficiency seen in Hp infection.

O eixo hepcidina-ferroportina é determinante na homeostase do ferro. Níveis elevados de hepcidina reduzem a capacidade de absorção intestinal do ferro, bem como sua mobilização entre tecidos. Uma condição que produz valores séricos elevados de hepcidina é a infecção. Como a infecção pelo Helicobacter pylori (Hp) predispõe a uma deficiência de ferro, neste estudo foram avaliados os níveis séricos de Pro-hepcidina (PH), um precursor da hepcidina em um grupo de estudantes assintomáticos infectados com Hp (80 crianças) e foram comparados com um grupo similar de crianças saudáveis (59 crianças). Os resultados mostraram que as crianças infectadas em que se detectou a presença de Hp (método de ar exalado) tinham valores de proteína C-reativa (PCR) significativamente mais elevada do que as crianças saudáveis. Ambos os grupos tiveram valores semelhantes de adequação da ingestão de ferro, ferritina sérica (Fs), hemoglobina, hematócrito, receptores solúveis de transferrina. A prevalência de anemia e deficiência subclínica de ferro no grupo total (infectados + não infectados) foi de 10 e 60%, respectivamente, sem diferenças entre os grupos. No entanto, no grupo de crianças saudáveis a PH sérica correlacionou significativamente (r=0,730/p<0,001) com os níveis de Fs, ao passo que em crianças infectadas, os níveis de PH não correlacionaram com a Fs, mas correlacionaram com a gravidade da infecção (r=0,52/p<0,001). Esta tendência da PH a aumentar com a gravidade da infecção poderia explicar a elevada prevalência de deficiência de ferro em pacientes infectados com Hp.

Disruption of iron homeostasis and relevant pharmacotherapies in Alzheimer's disease / 药学学报

Iron is the most abundant metal element to support the body's physiological activities and play crucial roles in the central nervous system. Iron homeostasis is under strict control in normal circumstances, and some diseases will occur once the homeostasis was disrupted. Numerous researches suggest that iron homeostasis disruptes in Alzheimer's disease (AD) and the homeostasis disruption interacts with AD's hallmarks. Dispute still exists on how iron plays a role in AD despite of the great number of researches. This article will focus on iron metabolism, normal function in the brain and recent therapies of AD based on iron chelation.

Regulación de la hepcidina y homeostasis del hierro: avances y perspectivas / Regulation of hepcidin and iron homeostasis: progress and prospects

El estudio de los desórdenes genéticos del metabolismo del hierro, la identificación de sus transportadores y el descubrimiento de la hepcidina, hormona reguladora de la homeostasia del hierro, han contribuido grandemente a aumentar los conocimientos sobre este metabolismo y han cambiado sustancialmente la visión sobre las enfermedades relacionadas con alteraciones del metabolismo férrico. En la última década, no solo se han esclarecido elementos de la patogénesis de estas enfermedades, sino que ya se vislumbran aplicaciones terapéuticas de estos avances. Así, ya se habla de una nueva era basada en el tratamiento de los desórdenes de la homeostasia del hierro a través de la modulación de la hepcidina

The study of genetic disorders of iron metabolism, identification of transporters and the discovery of hepcidin- a hormone regulating iron homeostasis- have contributed greatly to increase awareness of this metabolism. Substantially, the vision on diseases related to disorders of iron metabolism has been changed. In the last decade, elements of the pathogenesis of these diseases have not only been clarified, but therapeutic applications of these advances are looming. Thus, there are expectations of a new era based on the treatment of iron homeostasis disorders through hepcidin modulation

Hemocromatosis hereditaria: presentación de 2 casos y revisión de la literatura / Hereditary hemochromatosis: presentation of 2 cases and literature review

La Hemocromatosis incluye una variedad de síndromes crónicos de origen genético que cursan con sobrecarga de hierro, y puede ser clasificada de acuerdo a las mutaciones genéticas en cuatro grupos, del tipo 1 al tipo 4. De éstos, el tipo más frecuente es la hemocromatosis hereditaria tipo 1, que corresponde al 90% de los casos. La hemocromatosis hereditaria es un desorden recesivo en el que la mutación dominante del gen HFE genera una absorción incrementada de hierro que causa severa sobrecarga férrica tisular. En una población de origen caucásico, 4 a 5 personas de cada 1000 son homocigóticas para la mutación C282Y del gen HFE. En poblaciones de origen hispánico la prevalencia es menor, 4 a 5 de cada 10000. El gen HFE está localizado en el cromosoma 6 y puede tener tres tipos de mutaciones, siendo la más común la denominada C282Y.

Hemochromatosis includes a variety of chronic syndromes of genetic origin with iron overload, which can be classified according to genetic mutations in four groups, from type 1 to type 4. Of these, the most frequent type is type 1 hereditary hemochromatosis, which corresponds to over 90% of cases. Hereditary hemochromatosis is a recessive disorder in which a dominant mutation of the hemochromatosis gene (HFE) generates an increased absorption and severe iron overload. The American study showed that a multi-ethnic population of every 227 white people is homozygous for the C282Y HFE gene mutation, implicated in hemochromatosis type 1. The HFE, is located on chromosome 6, and may have three types of mutations of this gene, however the most common mutation is C282Y.

Fisiologia e metabolismo do ferro: [revisão] / Iron physiology and metabolism: [review]

O conhecimento sobre a fisiologia e metabolismo do ferro foi bastante incrementado nos últimos anos. A identificação de alguns genes e as repercussões quando de suas mutações, principalmente as relacionadas ao acúmulo de ferro, auxiliaram no entendimento dos mecanismos regulatórios responsáveis pela manutenção da homeostase desse nutriente essencial para numerosos processos bioquímicos. A função de diversas moléculas já está bem estabelecida, como da transferrina e seu receptor e, nas últimas décadas, novas moléculas têm sido identificadas, como a ferroportina, o transportador de metal divalente e hemojuvelina. Um elegante mecanismo de controle mantém o equilíbrio entre os processos de absorção do ferro, reciclagem, mobilização, utilização e estoque. Alterações no sincronismo desses processos podem causar tanto a deficiência como a sobrecarga de ferro, ambos com importantes repercussões clínicas para o paciente. Nessa minirrevisão serão abordados aspectos relacionados ao metabolismo do ferro e à participação de várias proteínas e mediadores envolvidos. Serão também apresentados os mecanismos regulatórios celular e sistêmico responsáveis pela disponibilidade do ferro em concentrações ideais para a manutenção de sua homeostase.

Knowledge of the iron physiology and metabolism has increased greatly over the last few years. The identification of genes and the consequences of mutations, especially those related to the accumulation of iron, have improved the understanding of the regulatory mechanisms responsible for maintaining homeostasis of this essential nutrient in many biochemical processes. The function of several molecules is well established, as in the case of transferrin and its receptor and, in recent decades, new molecules have been identified such as ferroportin, divalent metal transporter, hemojuvelin and hepcidin. An elegant control mechanism maintains the balance between the processes of iron absorption, recycling, mobilization, utilization and storage. Disturbances in the synchronism among those processes may lead either to iron deficiency or to iron overload, both of which have important clinical consequences. This mini-review attempts to describe aspects related to iron metabolism and the participation of several proteins and mediators involved in these mechanisms. Moreover, intracellular and systemic regulation mechanisms responsible for providing the most suitable iron concentration for iron homeostasis maintenance will be presented.

Matriptasa 2:: nuevo eslabón en el metabolismo del hierro / Matriptase 2:: a new link in iron metabolism

El mantenimiento de la homeostasia del hierro es esencial para el funcionamiento fisiológico normal de los seres vivos. Recientemente se descubrió que la matriptasa 2, una serin proteasa transmembrana tipo II, también conocida por las siglas en inglés TMPRSS6, tiene una función esencial en la homeostasis de este mineral. Este hallazgo derivó inicialmente de la observación de que ratones con deficiencia de esta proteína presentaban anemia como consecuencia de la elevación de los niveles de hepcidina y la interrupción de la absorción intestinal de hierro. Los análisis posteriores in vitro demostraron que la matriptasa 2 suprime la vía de estimulación de la transcripción de la hepcidina que implica a la hemojuvelina como co-receptor. En concordancia con el patrón de anemia de los ratones mutantes, se encontró que el patrón de individuos con anemia por deficiencia de hierro resistente al hierro (en inglés IRIDA), era ocasionado por mutaciones del gen Tmprss6 que implican anulación de la actividad proteolítica de la enzima. En este trabajo se presentan aspectos relacionados con la identificación y caracterización de la matriptasa 2, así como su participación en el metabolismo del hierro.

The maintenance of iron homeostasis is essential for the normal physiological functioning of the living beings. Recently, it was discovered the Matriptase 2, a type II trans-membrane serine protease, also known by English acronyms TMPRSS6, having an essential function in homeostasis of this mineral. This finding initially derived from the observation that mice deficient of this protein had anemia as consequence of rise of hepcidine levels and the interruption of iron intestinal absorption. The in vitro later analyses showed that 2 Matriptase suppress the stimulation way of hepcidine transcription involving to hemojuvelin as a co-receptor. In agreement with the anemia pattern of mutant mice, we founded that pattern from subjects presenting with iron-deficiency anemia and iron-resistant (IRIDA) was created by Tmprsst gen mutations involving the elimination of enzymatic proteolytic activity. In present paper are showed the features related to identification and characterization of the 2 Matriptase, as well as, its involvement in iron metabolism.