A High-Salt Diet Disturbs the Development and Function of Natural Killer Cells in Mice

Effects of dietary intervention on human diseases: molecular mechanisms and therapeutic potential

Diet, serving as a vital source of nutrients, exerts a profound influence on human health and disease progression. Recently, dietary interventions have emerged as promising adjunctive treatment strategies not only for cancer but also for neurodegenerative diseases, autoimmune diseases, cardiovascular diseases, and metabolic disorders. These interventions have demonstrated substantial potential in modulating metabolism, disease trajectory, and therapeutic responses. Metabolic reprogramming is a hallmark of malignant progression, and a deeper understanding of this phenomenon in tumors and its effects on immune regulation is a significant challenge that impedes cancer eradication. Dietary intake, as a key environmental factor, can influence tumor metabolism. Emerging evidence indicates that dietary interventions might affect the nutrient availability in tumors, thereby increasing the efficacy of cancer treatments. However, the intricate interplay between dietary interventions and the pathogenesis of cancer and other diseases is complex. Despite encouraging results, the mechanisms underlying diet-based therapeutic strategies remain largely unexplored, often resulting in underutilization in disease management. In this review, we aim to illuminate the potential effects of various dietary interventions, including calorie restriction, fasting-mimicking diet, ketogenic diet, protein restriction diet, high-salt diet, high-fat diet, and high-fiber diet, on cancer and the aforementioned diseases. We explore the multifaceted impacts of these dietary interventions, encompassing their immunomodulatory effects, other biological impacts, and underlying molecular mechanisms. This review offers valuable insights into the potential application of these dietary interventions as adjunctive therapies in disease management.

High salt diet does not impact the development of acute myeloid leukemia in mice

The gut microbiota has not only been implicated in the development of some cancers but has also been shown to modulate the efficacy of cancer therapeutics. Although the microbiota is an attractive target in cancer therapy, there is limited data available regarding the relevance of microbiota and dietary interventions in the various types of tumors. Recently, a high salt diet (HSD) has attracted attention in cancer development owing to its profound effects on modulating microbiota and immune responses. Here, we investigated the impact of HSD on microbiota, immune responses, and the development of acute myeloid leukemia using two syngeneic transplantation models. HSD significantly changes the microbiota composition, TH17 responses, and NK cells. However, we found no influence of HSD on tumor development. The kinetics and characteristics of tumor development were similar despite varying the number of injected tumor cells. Our data show that the effects of the microbiome and dietary interventions can be tumor-specific and may not apply to all types of cancers.

The modulatory effect of high salt on immune cells and related diseases

BACKGROUND

The adverse effect of excessive salt intake has been recognized in decades. Researchers have mainly focused on the association between salt intake and hypertension. However, studies in recent years have proposed the existence of extra-renal sodium storage and provided insight into the immunomodulatory function of sodium.

OBJECTIVES

In this review, we discuss the modulatory effects of high salt on various innate and adaptive immune cells and immune-regulated diseases.

METHODS

We identified papers through electronic searches of PubMed database from inception to March 2022.

RESULTS

An increasing body of evidence has demonstrated that high salt can modulate the differentiation, activation and function of multiple immune cells. Furthermore, a high-salt diet can increase tissue sodium concentrations and influence the immune responses in microenvironments, thereby affecting the development of immune-regulated diseases, including hypertension, multiple sclerosis, cancer and infections. These findings provide a novel mechanism for the pathology of certain diseases and indicate that salt might serve as a target or potential therapeutic agent in different disease contexts.

CONCLUSION

High salt has a profound impact on the differentiation, activation and function of multiple immune cells. Additionally, an HSD can modulate the development of various immune-regulated diseases.

Calcitriol ameliorates damage in high-salt diet-induced hypertension: Evidence of communication with the gut-kidney axis

Several studies have established a link between high-salt diet, inflammation, and hypertension. Vitamin D supplementation has shown anti-inflammatory effects in many diseases; gut microbiota is also associated with a wide variety of cardiovascular diseases, but potential role of vitamin D and gut microbiota in high-salt diet-induced hypertension remains unclear. Therefore, we used rats with hypertension induced by a high-salt diet as the research object and analyzed the transcriptome of their tissues (kidney and colon) and gut microbiome to conduct an overall analysis of the gut-kidney axis. We aimed to confirm the effects of high salt and calcitriol on the gut-kidney immune system and the composition of the intestinal flora. We demonstrate that consumption of a high-salt diet results in hypertension and inflammation in the colon and kidney and alteration of gut microbiota composition and function. High-salt diet-induced hypertension was found to be associated with seven microbial taxa and mainly associated with reduced production of the protective short-chain fatty acid butyrate. Calcitriol can reduce colon and kidney inflammation, and there are gene expression changes consistent with restored intestinal barrier function. The protective effect of calcitriol may be mediated indirectly by immunological properties. Additionally, the molecular pathways of the gut microbiota-mediated blood pressure regulation may be related to circadian rhythm signals, which needs to be further investigated. An innovative association analysis of the microbiota may be a key strategy to understanding the association between gene patterns and host.

Clinical observation of the efficacy of PD-1/PD-L1 inhibitors in the treatment of patients with advanced solid tumors

INTRODUCTION

Programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors are proved to be promising and are applied for the treatment of a variety of solid tumors. This retrospective study evaluated the efficacy of PD-1/PD-L1 inhibitors in patients with advanced solid tumors and explore the effect of clinical characteristics on it.

MATERIALS AND METHODS

From October 2017 to April 2020, a total of 90 patients from Capital Medical University Affiliated Beijing Friendship Hospital were enrolled.

RESULTS

At a median follow-up of 10.55 months, objective response was observed in 23 patients and the objective response rate was 25.6%. The median progression-free survival (PFS) was 5.5 months (95% confidence interval [CI], 3.69-7.37). The 6m-PFS was 45.8% and 12m-PFS was 25.1%. The median overall survival (OS) was 16.9 months (95% CI, not reached [NR]-NR). The 12m-OS was 58.1% and 18m-OS was 48.1%.

CONCLUSION

The efficacy of PD-1/PD-L1 inhibitors in the treatment of advanced solid tumors was comparable to previous studies. ECOG performance status, smoking status, liver metastasis, neutrophil-to-lymphocyte ratio were independently correlated with PFS while liver metastasis and lactate dehydrogenase level were independently correlated with OS.

Impact of maternal nutrition in viral infections during pregnancy

Other than being a physiological process, pregnancy is a condition characterized by major adaptations of maternal endocrine and metabolic homeostasis that are necessary to accommodate the fetoplacental unit. Unfortunately, all these systemic, cellular, and molecular changes in maternal physiology also make the mother and the fetus more prone to adverse outcomes, including numerous alterations arising from viral infections. Common infections during pregnancy that have long been recognized as congenitally and perinatally transmissible to newborns include toxoplasmosis, rubella, cytomegalovirus, and herpes simplex viruses (originally coined as ToRCH infections). In addition, enterovirus, parvovirus B19, hepatitis virus, varicella-zoster virus, human immunodeficiency virus, Zika and Dengue virus, and, more recently, coronavirus infections including Middle Eastern respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS) infections (especially the novel SARS-CoV-2 responsible for the ongoing COVID-19 pandemic), constitute relevant targets for current research on maternal-fetal interactions in viral infections during pregnancy. Appropriate maternal education from preconception to the early postnatal period is crucial to promote healthy pregnancies in general and to prevent and/or reduce the impact of viral infections in particular. Specifically, an adequate lifestyle based on proper nutrition plans and feeding interventions, whenever possible, might be crucial to reduce the risk of virus-related gestational diseases and accompanying complications in later life. Here we aim to provide an overview of the emerging literature addressing the impact of nutrition in the context of potentially harmful viral infections during pregnancy.