Effects of boron on the proliferation, apoptosis and immune function of splenic lymphocytes through ERα and ERβ

Boric Acid Improved Cryopreserved Mouse Embryo Development

Boric acid (BA) is an essential trace element that is required to support the metabolic pathways in plants, humans, and animals. The present study investigates the in vitro development and quality of single-cell mouse embryos in a BA-added culture medium after cryopreservation using the solid-surface vitrification method. For this purpose, the pronuclear-stage embryos derived from superovulated C57Bl/6j mouse strains and the one-cell embryos were then cryopreserved using the solid-surface vitrification (SSV) method. After thawing, the embryos were cultured in a BA-added medium at 37 °C in a 5% CO2 environment until the blastocyst stage. The resulting in vitro development rates of the embryos in the control group, SSV group, and SSV + 1.62 × 10-4 μM BA group were 68.11% (36/59), 40.16% (16/48), and 64.92% (28/48) respectively, indicating that the BA supported the in vitro development of the embryos cryopreserved using the SSV method. Our results suggest that the addition of boric acid to the culture media increased the development rate of the embryos that were vitrified using the SSV method.

MAPK Signaling Pathway Plays Different Regulatory Roles in the Effects of Boric Acid on Proliferation, Apoptosis, and Immune Function of Splenic Lymphocytes in Rats

Boron is one of the essential trace elements in animals. Although boron supplementation can enhance immune function and promote cell proliferation, high-dose boron supplementation can negatively affect immune function and inhibit cell proliferation. Furthermore, its action pathway is unknown. In this study, ERK1/2, JNK, and p38MAPK signaling pathways were blocked using specific blockers to investigate the impact of low-dose and high-dose boron on proliferation, apoptosis, and immune function of lymphocytes, and the expression of genes related to cell proliferation and apoptosis in rats. The addition of 0.4 mmol/L boron did not affect the ratio of CD4+/CD8+ T cells (P>0.05), IgG and IFN-γ contents (P>0.05), the proliferation rate of lymphocytes (P>0.05), and mRNA and protein expressions of PCNA (P>0.05) in the spleen after ERK1/2 signal pathway was selectively inhibited. Moreover, the addition of 40 mmol/L boron did not affect the proportion of CD4+ T cells, contents of IgG and cytokines (IL-2 and IL-4), proliferation and apoptosis rates of lymphocytes, and expression of proliferation- and apoptosis-related genes in the spleen. Meanwhile, the addition of 0.4 mmol/l boron increased the ratio of CD4+/CD8+ T cells (P<0.05 or P<0.01), IFN-γ or IgG contents (P<0.05), and the proliferation rate of lymphocytes (P<0.05) in spleen after selective inhibition of JNK or p38MAPK signaling pathways, while the protein expression of Caspase-3 decreased (P<0.05 or P<0.01). Furthermore, 40 mmol/L boron decreased the proportion of lymphocyte subsets, cytokine contents, proliferation rate of lymphocytes, and mRNA and protein expressions of PCNA. In contrast, the mRNA and protein expressions of Caspase-3 and protein expression of Bax were increased. These results indicate that ERK1/2 signaling pathway mainly regulates the effects of low-dose and high-dose boron on proliferation, apoptosis, and immune function of splenic lymphocytes.

Boron enhances adaptive responses and biological performance via hormetic mechanisms

Boron is shown in the present review to induce hormetic dose responses in a broad range of biological models, organ systems and endpoints. Of particular importance is that numerous hormetic findings have been reported with whole animal studies, with extensive dose response evaluations with the optimal dosing being similar across multiple organ systems. These findings appear to be underappreciated and suggest that boron may have clinically significant systemic effects beyond that of its putative and more subtle essentiality functions. The re-exploration of boron's bioactivity as seen through hormetic mechanisms may also underscore the value of this approach to the assessment of micronutrient effects in human health and disease.

Effects of Boron-Containing Compounds on Liposoluble Hormone Functions

Boron-containing compounds (BCC), particularly boronic acids and derivatives, are being increasingly tested as diagnostic and therapeutic agents. Some effects of BCC involve phenomena linked to the action of steroid or thyroid hormones; among these, are the effects on muscle mass or basal metabolism. Additionally, some toxicology reports on mammals, including humans, sound an alert concerning damage to several systems, among which are the negative effects on the induction of male infertility. Systemic and local mechanisms to explain changes in metabolism and impaired fertility were collected and presented. Then, we presented the putative pharmacodynamic and pharmacokinetic mechanisms involved and demonstrated in these events. In addition, it is proposed that there are adducts of some oxygenated BCC with cis-diols in fructose, an essential source of energy for sperm–cell motility, an uncoupling of sex hormone-binding globulin (SHBG) and its ligands, and the modulation of the DNA synthetic rate. These effects share the reactivity of boron-containing compounds on the cis-diols of key molecules. Moreover, data reporting no DNA damage after BCC administration are included. Further studies are required to support the clear role of BCC through these events to disrupt metabolism or fertility in mammals. If such phenomena are confirmed and elucidated, an advance could be useful to design strategies for avoiding BCC toxicity after BCC administration, and possibly for designing metabolism regulators and contraceptive drugs, among other purposes. Boronic derivatives and carboranes have been proposed and studied in this field.

Transcriptome Profiling of Duodenum Reveals the Importance of Boron Supplementation in Modulating Immune Activities in Rats

As an essential trace element, appropriate boron supplementation can promote immune function of animals. To illustrate the effects of boron in a rat model, RNA-Seq was conducted for the RNA from duodenum after treatment with different concentration of boron in which boron was given in the form of boric acid. More than 47 million reads were obtained in 0, 10, and 320 mg/L boron (0, 57.21, and 1830.66 mg/L boric acid) treatment groups that produced 58 965 402, 48 607 328, and 46 760 660 clean reads, respectively. More than 95% of the clean reads were successfully matched to the rat reference genome and assembled to generate 32 662 transcripts. A total of 624 and 391 differentially expressed candidate genes (DEGs) were found between 0 vs.10 and 0 vs. 320 mg/L boron comparison groups. We also identified transcription start site, transcription terminal site, and skipped exons as the main alternative splicing events. GO annotations revealed most of DEGs were involved in the regulation of immune activity. The DEGs were enriched in influenza A, herpes simplex infection, cytosolic DNA-sensing pathway, and antigen processing and presentation signaling pathways. The expression levels of genes enriched in these signaling pathways indicate that lower doses of boron could achieve better effects on promoting immune response in the duodenum. These effects on the immune system appear to be mediated via altering the expression patterns of genes involved in the related signaling pathways in a dose-dependent pattern. These data provide more insights into the molecular mechanisms of immune regulation in rats in response to dietary boron treatment.

2D Materials and Primary Human Dendritic Cells: A Comparative Cytotoxicity Study

Human health can be affected by materials indirectly through exposure to the environment or directly through close contact and uptake. With the ever-growing use of 2D materials in many applications such as electronics, medical therapeutics, molecular sensing, and energy storage, it has become more pertinent to investigate their impact on the immune system. Dendritic cells (DCs) are highly important, considering their role as the main link between the innate and the adaptive immune system. By using primary human DCs, it is shown that hexagonal boron nitride (hBN), graphene oxide (GO) and molybdenum disulphide have minimal effects on viability. In particular, it is evidenced that hBN and GO increase DC maturation, while GO leads to the release of reactive oxygen species and pro-inflammatory cytokines. hBN and MoS₂ increase T cell proliferation with and without the presence of DCs. hBN in particular does not show any sign of downstream T cell polarization. The study allows ranking of the three materials in terms of inherent toxicity, providing the following trend: GO > hBN ≈ MoS₂ , with GO the most cytotoxic.

Diversity of effects induced by boron-containing compounds on immune response cells and on antibodies in basal state

BACKGROUND

It has been reported that boron induces changes in the immune response, including in inflammatory processes. Recently, the effect of boric acid has been documented on the differentiation of lymphocyte clusters in mice and rats. However, the differences among boron-containing compounds (BCC) have been poorly explored.

METHODS

In this study, we analyzed the effects after oral administration of boric acid (BOR), methylboronic (MET), 3-thyenylboronic (3TB), 4-hydroxymethyl-phenylboronic (4MP) and 4-methanesulfonyl-phenylboronic (4SP) acids on the populations of lymphocytes from spleen and Peyer's patch (PP) as well as on antibodies. Groups of six male BALB/c were orally treated with 4.6 mg/kg of body weight with BOR, MET, 3TB, 4MP, and 4SP/daily for 10 days or vehicle (VEH) as a control group. After euthanasia, the spleen and small intestine were dissected. We conducted flow cytometry assays to assess B, CD3⁺ T, CD4⁺ T, and CD8⁺ T cells. Levels of IgG and IgM in serum, and IgA in intestinal fluid samples were analyzed by enzyme immunoassay.

RESULTS

In particular, we observed the effects of the administration of boronic acids on the number of lymphocytes; these changes were more notable in spleen than in PP. We found different profiles for each boron-containing compound, that is BOR induced an increase in the percentage of CD8⁺ T and CD19⁺/IgA⁺ cells in spleen, but a decrease in CD8⁺ T and B220⁺/CD19⁺ cells in PP. Meanwhile MET induced a decrease of CD4⁺ T in spleen, but induced an increase of CD4⁺ T cells and a decrease in the number of CD8⁺ T cells in PP. Boronic acids with an aromatic ring moiety induced changes in serum immunoglobulins levels, while 3TB acid induced a notable increase in S-IgA.

CONCLUSIONS

Effects in lymphocyte populations and antibodies are different for each tested compound. These results highlight the establishment of the necessary structure-activity relationship for BCC as immunomodulatory drugs. This is relevant in the biomedical field due to their attractiveness for selecting compounds to develop therapeutic tools.

GPR30 mediated effects of boron on rat spleen lymphocyte proliferation, apoptosis, and immune function

Supplementing different quantities of boron can significantly affect immune function in rat spleen, but the mechanism of action behind this effect remains unclear. Our purpose was to study the involvement of the estrogen membrane receptor GPR30 in the effect of boron on the proliferation, apoptosis, and immune function of rat spleen lymphocytes. Results showed that the addition of 0.4 mmol/L boron had a beneficial effect on the immune function and proliferation of spleen lymphocytes, but the addition of 40 mmol/L boron had opposite effect. After using G-15 to selectively inhibit GPR30, the proportions of CD4⁺ and CD8⁺ T cells, the content of IL-2 and IFN-γ, and the expression of PCNA protein were significantly decreased, while lymphocyte apoptosis rate increased significantly (p < 0.05 or p < 0.01). After G-15 treatment, the addition of 0.4 mmol/L boron had no effects on T cell subsets, lymphocyte proliferation, PCNA protein expression, and IgG and cytokine content (P > 0.05), while the addition of 40 mmol/L boron did not change the effects on lymphocyte subsets, proliferation and apoptosis. The results suggested that GPR30 mediates the effects of 0.4 mmol/L boron boron on the proliferation, apoptosis and immune function of spleen lymphocytes.