Hypoxic mast cells accelerate the proliferation, collagen accumulation and phenotypic alteration of human lung fibroblasts

The Application of Drugs and Nano-Therapies Targeting Immune Cells in Hypoxic Inflammation

Immune cells are pivotal in the dynamic interplay between hypoxia and inflammation. During hypoxic conditions, HIF-1α, a crucial transcription factor, facilitates the adaptation of immune cells to the hypoxic micro-environment. This adaptation includes regulating immune cell metabolism, significantly impacting inflammation development. Strategies for anti-inflammatory and hypoxic relief have been proposed, aiming to disrupt the hypoxia-inflammation nexus. Research extensively focuses on anti-inflammatory agents and materials that target immune cells. These primarily mitigate hypoxic inflammation by encouraging M2-macrophage polarization, restraining neutrophil proliferation and infiltration, and maintaining Treg/TH17 balance. Additionally, oxygen-releasing nano-materials play a significant role. By alleviating hypoxia and clearing reactive oxygen species (ROS), these nano-materials indirectly influence immune cell functions. This paper delves into the response of immune cells under hypoxic conditions and the resultant effects on inflammation. It provides a comprehensive overview of various therapies targeting specific immune cells for anti-inflammatory purposes and explores nano-materials that either carry or generate oxygen to alleviate anoxic micro-environments.

Inflammation and immunity in the pathogenesis of hypoxic pulmonary hypertension

Hypoxic pulmonary hypertension (HPH) is a complicated vascular disorder characterized by diverse mechanisms that lead to elevated blood pressure in pulmonary circulation. Recent evidence indicates that HPH is not simply a pathological syndrome but is instead a complex lesion of cellular metabolism, inflammation, and proliferation driven by the reprogramming of gene expression patterns. One of the key mechanisms underlying HPH is hypoxia, which drives immune/inflammation to mediate complex vascular homeostasis that collaboratively controls vascular remodeling in the lungs. This is caused by the prolonged infiltration of immune cells and an increase in several pro-inflammatory factors, which ultimately leads to immune dysregulation. Hypoxia has been associated with metabolic reprogramming, immunological dysregulation, and adverse pulmonary vascular remodeling in preclinical studies. Many animal models have been developed to mimic HPH; however, many of them do not accurately represent the human disease state and may not be suitable for testing new therapeutic strategies. The scientific understanding of HPH is rapidly evolving, and recent efforts have focused on understanding the complex interplay among hypoxia, inflammation, and cellular metabolism in the development of this disease. Through continued research and the development of more sophisticated animal models, it is hoped that we will be able to gain a deeper understanding of the underlying mechanisms of HPH and implement more effective therapies for this debilitating disease.

Nutritional activities of luteolin in obesity and associated metabolic diseases: an eye on adipose tissues

Obesity is characterized by excessive body fat accumulation and is a high-risk factor for metabolic comorbidities, including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular disease. In lean individuals, adipose tissue (AT) is not only an important regulatory organ for energy storage and metabolism, but also an indispensable immune and endocrine organ. The sustained energy imbalance induces adipocyte hypotrophy and hyperplasia as well as AT remodeling, accompanied by chronic low-grade inflammation and adipocytes dysfunction in AT, ultimately leading to systemic insulin resistance and ectopic lipid deposition. Luteolin is a natural flavonoid widely distributed in fruits and vegetables and possesses multifold biological activities, such as antioxidant, anticancer, and anti-inflammatory activities. Diet supplementation of this flavonoid has been reported to inhibit AT lipogenesis and inflammation as well as the ectopic lipid deposition, increase AT thermogenesis and systemic energy expenditure, and finally improve obesity and associated metabolic diseases. The purpose of this review is to reveal the nutritional activities of luteolin in obesity and its complications with emphasis on its action on AT energy metabolism, immunoregulation, and endocrine intervention.

Investigation of a Hypoxia-Immune-Related Microenvironment Gene Signature and Prediction Model for Idiopathic Pulmonary Fibrosis

Background

There is growing evidence found that the role of hypoxia and immune status in idiopathic pulmonary fibrosis (IPF). However, there are few studies about the role of hypoxia and immune status in the lung milieu in the prognosis of IPF. This study aimed to develop a hypoxia-immune-related prediction model for the prognosis of IPF.

Methods

Hypoxia and immune status were estimated with microarray data of a discovery cohort from the GEO database using UMAP and ESTIMATE algorithms respectively. The Cox regression model with the LASSO method was used for identifying prognostic genes and developing hypoxia-immune-related genes. Cibersort was used to evaluate the difference of 22 kinds of immune cell infiltration. Three independent validation cohorts from GEO database were used for external validation. Peripheral blood mononuclear cell (PBMC) and bronchoalveolar lavage fluid (BALF) were collected to be tested by Quantitative reverse transcriptase-PCR (qRT-PCR) and flow cytometry from 22 clinical samples, including 13 healthy controls, six patients with non-fibrotic pneumonia and three patients with pulmonary fibrosis.

Results

Hypoxia and immune status were significantly associated with the prognosis of IPF patients. High hypoxia and high immune status were identified as risk factors for overall survival. CD8+ T cell, activated CD4+ memory T cell, NK cell, activated mast cell, M1 and M0 macrophages were identified as key immune cells in hypoxia-immune-related microenvironment. A prediction model for IPF prognosis was established based on the hypoxia-immune-related one protective and nine risk DEGs. In the independent validation cohorts, the prognostic prediction model performed the significant applicability in peripheral whole blood, peripheral blood mononuclear cell, and lung tissue of IPF patients. The preliminary clinical specimen validation suggested the reliability of most conclusions.

Conclusions

The hypoxia-immune-based prediction model for the prognosis of IPF provides a new idea for prognosis and treatment.

Pretreatment with melatonin improves ovarian tissue cryopreservation for transplantation

BACKGROUD

Melatonin has anti-inflammatory and antioxidative actions at the mitochondrial level. This indole-containing molecule may protect ovarian grafts during the process of cryopreservation. Therefore, we aimed to determine whether melatonin pretreatment improves rat ovarian graft quality.

METHODS

Twenty-six female rats were allocated to two study groups of thirteen animals each: 1) control group: ovaries cryopreserved using the standard protocol; and 2) melatonin group: ovaries cryopreserved in a medium with melatonin. Ten rats of each group were submitted to 24-h freezing, and whole ovaries autologous and avascular transplantation with retroperitoneal placement. After postoperative (PO) day 15, daily vaginal smears were obtained for estrous cycle characterization. Between PO days 30 and 35, the animals were euthanized and ovarian grafts were recovered for histological and immunohistochemical (Ki-67, cleaved caspase-3, TUNEL, von Willebrand factor, estrogen, and progesterone receptors) analyses. The ovaries of the three remaining rats from each group were studied immediately after thawing to assess the effects of cryopreservation. ANOVA and Tukey's tests were used and the rejection level of the null hypothesis was set at 0.05 or 5% (p < 0.05).

RESULTS

Melatonin promoted faster restart of the estrous cycle and increased the expression of mature follicles, collagen type I, von Willebrand factor, Ki-67, and cleaved caspase-3 on corpora lutea and estrogen receptors in the ovaries as compared to control. There was a reduction in apoptosis by TUNEL on follicles, corpora lutea, and collagen type III.

CONCLUSION

Based on the evaluated parameters, melatonin may promote the quality of ovarian grafts. Reproductive function enhancement should be further studied.