Editorial: Steroids and Secosteroids in the Modulation of Inflammation and Immunity

Corticosteroids in posterior reversible encephalopathy syndrome: Friend or foe? A systematic review

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a complex neurological disorder characterized by symptoms such as headaches, seizures, confusion, and visual disturbances. The pathophysiology of PRES involves endothelial dysfunction, disrupted cerebral autoregulation, and resulting vasogenic edema. Hypertension and other factors that alter cerebral autoregulation are critical in its development. Corticosteroids, widely used for their anti-inflammatory and immunosuppressive properties, play a controversial role in PRES.

AIM

To elucidate the dual role of corticosteroids in the context of PRES by critically evaluating the existing literature. Specifically, it seeks to assess the results of PRES induced by corticosteroid therapy and the efficacy and safety of corticosteroids in the treatment of PRES. By synthesizing case reports and series, this review aims to provide a comprehensive understanding of the mechanisms, clinical presentations, and management strategies associated with corticosteroid-related PRES.

METHODS

The review was carried out according to the PRISMA guidelines. The databases searched included Science Direct, PubMed, and Hinari. The search strategy encompassed terms related to corticosteroids and PRES. Studies were included if they were peer-reviewed articles examining corticosteroids in PRES, excluding non-English publications, reviews, and editorials. Data on patient demographics, clinical characteristics, imaging findings, corticosteroid regimens, and outcomes were extracted. The risk of bias was evaluated using the Joanna Briggs Institute tool for case reports.

RESULTS

A total of 56 cases of PRES (66.1% women, 33.9% men) potentially induced by corticosteroids and 14 cases in which corticosteroids were used to treat PRES were identified. Cases of PRES reportedly caused by corticosteroids showed a mean age of approximately 25.2 years, with seizures, headaches, hypertension, and visual disturbances being common clinical sequelae. Magnetic resonance findings typically revealed vasogenic edema in the bilateral parieto-occipital lobes. High-dose or prolonged corticosteroid therapy was a significant risk factor. On the contrary, in the treatment cases, corticosteroids were associated with positive outcomes, including resolution of vasogenic edema and stabilization of symptoms, particularly in patients with underlying inflammatory or autoimmune diseases.

CONCLUSION

Corticosteroids have a dual role in PRES, capable of both inducing and treating the condition. The current body of literature suggests that corticosteroids may play a greater role as a precipitating agent of PRES rather than treating. Corticosteroids may induce PRES through hypertension and subsequent increased cerebral blood flow and loss of autoregulation. Corticosteroids may aid in the management of PRES: (1) Enhancing endothelial stability; (2) Anti-inflammatory properties; and (3) Improving blood-brain barrier integrity. Mechanisms which may reduce or mitigate vasogenic edema formation.

Potent Anti-Cancer Activity of 1-Dehydrodiosgenone from the Product of Microbial Transformation of Steroid Saponins

Steroids are extensively used in the pharmaceutical industry as industrial raw materials for the production of anti-inflammatory and anti-tumor drugs. Microbial transformation, an environmentally friendly method, displays the potential for preparing steroids on an industrial scale. In this study, four steroids, including Diosgenin, Smilagenone, Yamogenin, and 1-Dehydrodiosgenone, were isolated and identified from the solid-state fermentation (SSF) product of a novel Fusarium oxysporum strain, and their anti-tumor activities were investigated. The cytotoxicity assay showed that 1-Dehydrodiosgenone had significant inhibitory effects on three tumor cell lines, Hala, A549, and Mad-MB468 cells, with IC50s of 6.59 μM, 5.43 μM, and 4.81 μM, respectively. 1-Dehydrodiosgenone significantly induced apoptosis and necrosis of Hala, A549, and Mad-MB468 cells by upregulating the expressions of cleaved caspase-3, cleaved PARP, Bax, and Bad. Moreover, no significant organ damage was observed in mice based on safety tests. Therefore, 1-Dehydrodiosgenone is expected to be developed as a safe and broad-spectrum anti-cancer agent.

Research on Bone Cells in Health and Disease

Bone-forming osteoblasts, osteocytes, and bone-resorbing osteoclasts are responsible for life-long skeletal remodeling [...].

Efficacy of epidural steroid injection in the treatment of sciatica secondary to lumbar disc herniation: a systematic review and meta-analysis

Epidural steroid injection for the treatment of sciatica caused by disc herniation is increasingly used worldwide, but its effectiveness remains controversial. The review aiming to analyze the efficacy of epidural steroid injection on sciatica caused by lumbar disc herniation. Randomized controlled trials (RCTs) investigating the use of epidural steroid injections in the management of sciatica induced by lumbar disc herniation were collected from PubMed and other databases from January, 2008 to December, 2023, with epidural steroid injection in the test group and epidural local anesthetic and/or placebo in the control group. Pain relief rate, assessed by numerical rating scale (NRS) and visual analogue scale (VAS) scores, and function recovery, evaluated by Roland Morris Disability Questionnaire (RMDQ) and Oswestry Disability Index (ODI) scores, were recorded and compared. Meta-analysis was performed by Review Manager. In comparison to the control group, epidural steroid injections have been shown to be effective for providing short- (within 3 months) [MD = 0.44, 95%CI (0.20, 0.68), p = 0.0003] and medium-term (within 6 months) [MD = 0.66, 95%CI (0.09,1.22), p = 0.02] pain relief for sciatica caused by lumbar disc herniation, while its long-term pain-relief effect were limited. However, the administration of epidural steroid injections did not lead to a significant improvement on sciatic nerve function in short- [MD = 0.79, 95%CI = (0.39, 1.98), p = 0.19] and long-term [MD = 0.47, 95% CI = (-0.86, 1.80), p = 0.49] assessed by IOD. Furthermore, the analysis revealed that administering epidural steroid injections resulted in a reduction in opioid usage among patients with lumbar disc herniation [MD = -14.45, 95% CI = (-24.61, -4.29), p = 0.005]. The incidence of epidural steroid injection was low. Epidural steroid injection has demonstrated notable efficacy in relieving sciatica caused by lumbar disc herniation in short to medium-term. Therefore, it is recommended as a viable treatment option for individuals suffering from sciatica.

De novo steroidogenesis in tumor cells drives bone metastasis and osteoclastogenesis

Osteoclasts play a central role in cancer-cell-induced osteolysis, but the molecular mechanisms of osteoclast activation during bone metastasis formation are incompletely understood. By performing RNA sequencing on a mouse breast carcinoma cell line with higher bone-metastatic potential, here we identify the enzyme CYP11A1 strongly upregulated in osteotropic tumor cells. Genetic deletion of Cyp11a1 in tumor cells leads to a decreased number of bone metastases but does not alter primary tumor growth and lung metastasis formation in mice. The product of CYP11A1 activity, pregnenolone, increases the number and function of mouse and human osteoclasts in vitro but does not alter osteoclast-specific gene expression. Instead, tumor-derived pregnenolone strongly enhances the fusion of pre-osteoclasts via prolyl 4-hydroxylase subunit beta (P4HB), identified as a potential interaction partner of pregnenolone. Taken together, our results demonstrate that Cyp11a1-expressing tumor cells produce pregnenolone, which is capable of promoting bone metastasis formation and osteoclast development via P4HB.

Local Effects of Steroid Hormones within the Bone Microenvironment

Steroid hormone production via the adrenal cortex, gonads, and placenta (so-called glandular steroidogenesis) is responsible for the endocrine control of the body's homeostasis and is organized by a feedback regulatory mechanism based on the hypothalamus-pituitary-steroidogenic gland axis. On the other hand, recently discovered extraglandular steroidogenesis occurring locally in different tissues is instead linked to paracrine or autocrine signaling, and it is independent of the control by the hypothalamus and pituitary glands. Bone cells, such as bone-forming osteoblasts, osteoblast-derived osteocytes, and bone-resorbing osteoclasts, respond to steroid hormones produced by both glandular and extraglandular steroidogenesis. Recently, new techniques to identify steroid hormones, as well as synthetic steroids and steroidogenesis inhibitors, have been introduced, which greatly empowered steroid hormone research. Based on recent literature and new advances in the field, here we review the local role of steroid hormones in regulating bone homeostasis and skeletal lesion formation. The novel idea of extraglandular steroidogenesis occurring within the skeletal system raises the possibility of the development of new therapies for the treatment of bone diseases.

Insight into the Interaction Mechanism of Vitamin D against Metabolic Syndrome: A Meta-Analysis and In Silico Study

As a dietary supplement or functional food additive, vitamin D (VD) deficiency may impact extra-skeletal functions associated with metabolic syndrome (MetS) risk factors. However, the precise effects and mechanisms of VD supplementation on dyslipidemia and insulin resistance in MetS subjects remain controversial. Here, we investigate potential therapeutic targets, pathways and mechanisms of VD against MetS through a comprehensive strategy including meta-analysis, network pharmacology analysis, molecular docking, dynamics simulations, and quantum chemical calculations. Our results reveal that VD supplementation significantly reduces triglyceride levels, fasting glucose, and insulin concentrations in subjects, thereby improving insulin homeostasis to some extent. We theoretically identify 14 core MetS-associated targets. Notably, VD exhibits substantial interactions with three targets (PPARγ, FABP4, and HMGCR) in the PPAR signaling pathway, indicating that VD can modulate this pathway. Van der Waals forces predominantly stabilize the complexes formed between VD and the three targets. Nonetheless, to provide valuable insights for personalized MetS management, further research is necessary to confirm our findings, emphasizing the importance of exploring genetic variability in VD response. In conclusion, our study contributes insights into the mechanisms of VD in preventing and treating MetS through dietary supplementation, promoting the development of VD-based functional foods or nutritious diets.

Tumors produce glucocorticoids by metabolite recycling, not synthesis, and activate Tregs to promote growth

Glucocorticoids are steroid hormones with potent immunosuppressive properties. Their primary source is the adrenals, where they are generated via de novo synthesis from cholesterol. In addition, many tissues have a recycling pathway in which glucocorticoids are regenerated from inactive metabolites by the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1, encoded by Hsd11b1). Here, we find that multiple tumor types express Hsd11b1 and produce active glucocorticoids. Genetic ablation of Hsd11b1 in such cells had no effect on in vitro growth, but reduced in vivo tumor progression, which corresponded with increased frequencies of CD8+ tumor-infiltrating lymphocytes (TILs) expressing activation markers and producing effector cytokines. Tumor-derived glucocorticoids were found to promote signatures of Treg activation and suppress signatures of conventional T cell activation in tumor-infiltrating Tregs. Indeed, CD8+ T cell activation was restored and tumor growth reduced in mice with Treg-specific glucocorticoid receptor deficiency. Importantly, pharmacologic inhibition of 11β-HSD1 reduced tumor growth to the same degree as gene knockout and rendered immunotherapy-resistant tumors susceptible to PD-1 blockade. Given that HSD11B1 expression is upregulated in many human tumors and that inhibition of 11β-HSD1 is well tolerated in clinical studies, these data suggest that targeting 11β-HSD1 may be a beneficial adjunct in cancer therapy.

Structural analysis of melanosomes in living mammalian cells using scanning electron-assisted dielectric microscopy with deep neural network

Melanins are the main pigments found in mammals. Their synthesis and transfer to keratinocytes have been widely investigated for many years. However, analysis has been mainly carried out using fixed rather than live cells. In this study, we have analysed the melanosomes in living mammalian cells using newly developed scanning electron-assisted dielectric microscopy (SE-ADM). The melanosomes in human melanoma MNT-1 cells were observed as clear black particles in SE-ADM. The main structure of melanosomes was toroidal while that of normal melanocytes was ellipsoidal. In tyrosinase knockout MNT-1 cells, not only the black particles in the SE-ADM images but also the Raman shift of melanin peaks completely disappeared suggesting that the black particles were really melanosomes. We developed a deep neural network (DNN) system to automatically detect melanosomes in cells and analysed their diameter and roundness. In terms of melanosome morphology, the diameter of melanosomes in melanoma cells did not change while that in normal melanocytes increased during culture. The established DNN analysis system with SE-ADM can be used for other particles, e.g. exosomes, lysosomes, and other biological particles.

The Use of Metabolomics as a Tool to Compare the Regulatory Mechanisms in the Cecum, Ileum, and Jejunum in Healthy Rabbits and with Diarrhea

Simple Summary

The problems caused by antibiotic abuse have swept the world, and the Chinese government has responded to calls for a comprehensive ban on antibiotics. However, not using antibiotics also challenges China’s existing livestock industry. Based on this, we carried out a nontargeted metabolomics analysis of the jejunum, ileum, and cecum of diarrhea rabbits and normal rabbits fed with antibiotic-free diets, respectively, to find out the mechanism of action of each intestinal segment group and between different intestinal segments. The screened differential metabolites were mostly related to intestinal barrier, intestinal inflammation, and autophagy after a KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. In this paper, we analyzed the metabolic pathways that were significantly different between different intestinal segments and illustrated the mechanism and potential connections of the screened differential metabolites in different intestinal segments in the form of charts.

Abstract

For many years, antibiotics in feed have been an effective and economical means to promote growth and disease resistance in livestock production. However, the rampant abuse of antibiotics has also brought very serious harm to human health and the environment. Therefore, the Chinese government promulgated laws and regulations on 1 July 2020, to prohibit the use of antibiotics in feed. To improve the effect of antibiotic-free feeding on China’s existing rabbit industry, we used the nontargeted metabolomics method to detect the differences between diarrhea rabbits (Dia) and normal rabbits (Con) on an antibiotic-free diet. A total of 1902 different metabolites were identified. A KEGG analysis showed that in the cecum, metabolites were mainly concentrated in bile secretion, antifolate resistance, aldosterone synthesis, and secretion pathways. The ileal metabolites were mainly concentrated in tyrosine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, steroid hormone biosynthesis, alanine, aspartate, and glutamate metabolism. The metabolites in the jejunum were mainly rich in panquinone and other terpenoid compound quinone biosynthesis, AMPK (adenosine 5′-monophosphate (AMP)-activated protein kinase) signal, inositol phosphate metabolism, and pentose phosphate pathway. After a deep excavation of the discovered differential metabolites and metabolic pathways with large differences between groups, it was found that these metabolic pathways mainly involved intestinal inflammation, intestinal barrier, and autophagy. The results showed that panquinone and other terpenoids could increase AMPK activity to promote cell metabolism and autophagy, thus trying to prevent inflammation and alleviate intestinal disease symptoms. In addition, we discussed the possible reasons for the changes in the levels of seven intestinal endogenous metabolites in rabbits in the diarrhea group. The possibility of improving diarrhea by adding amino acids to feed was discussed. In addition, the intermediate products produced by the pentose phosphate pathway and coenzyme Q had a positive effect on steroid hormone biosynthesis to combat intestinal inflammation.