Vitamin D inhibits captopril-induced cell detachment and apoptosis in keratinocytes

Vitamin D status in patients with autoimmune bullous dermatoses: a meta-analysis

BACKGROUND

The association between autoimmune bullous dermatoses (AIBD) and serum vitamin D levels has been revealed by some studies, however, inconsistent.

OBJECTIVES

We aimed to evaluate the difference in vitamin D status between AIBD patients and controls.

METHODS

We searched the studies about the vitamin D status of AIBD patients in electronic databases published before January 2020. Mean difference (MD) and 95% confidence intervals (CI) of eligible studies were calculated in meta-analyses of 25(OH)D levels. Pooled odds ratio (OR) and 95%CI were used in analyses of the prevalence of hypovitaminosis D. Different subgroup analyses, sensitivity analyses and publication bias assessment were conducted.

RESULTS

We included nine case-control studies in the meta-analysis. Vitamin D level was significantly lower in both pemphigus (MD: -7.02, 95%CI: -10.30 to -3.74) and bullous pemphigoid (BP) (MD: -6.37, 95%CI: -12.15 to -0.58) patients than that in controls. Active pemphigus patients were at higher risk of presenting hypovitaminosis D (OR: 6.95, 95%CI: 1.37-35.25).

CONCLUSIONS

Abnormal vitamin D status are more common in AIBD patients than that in general population. Therefore, regular monitoring of vitamin D levels and vitamin D supplementation should be considered as part of the management strategy for AIBD.

Mechanism-based therapeutic targets of pemphigus vulgaris: A scoping review of pathogenic molecular pathways

Pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterised by cell-cell detachment or acantholysis. The mechanisms which follow antibody (Ab) binding and culminate in acantholytic changes and skin/mucosal blistering have not been fully clarified. Current treatment strategies are not specific to PV pathophysiology and although life-saving, harbour considerable side effects. We aimed to systematically assess the molecules amenable to targeted treatments that follow Ab binding and are associated with PV acantholysis. The resulting scoping review was conducted under PRISMA-ScR guidelines with clear inclusion and exclusion criteria and focused specifically on kinases, caspases, proteases, hydrolytic enzymes and other molecules of interest postulated to take part in the pathophysiology of PV. The review process resulted in the identification of 882 articles, of which 56 were eligible for qualitative synthesis. From the included articles, the majority (n = 42) used PV-IgG as the pathogenic agent, mainly via in vitro (n = 16) and in vivo (n = 10) models. Twenty-five molecules were found to play a pathogenic role in PV, including uPA, ADAM10, EGFR, Src, PKC, cdk2, ERK, PLC, calmodulin, NOS, p38MAPK and caspase-3. Selective inhibition of these molecules resulted in varying degrees of reduction in acantholysis and blistering. The pathogenic molecules identified in this review represent potential candidates for clinical translation.

Effects of vitamin D on drugs: Response and disposal

Vitamin D supplementation and vitamin D deficiency are common in clinical experience and in daily life. Vitamin D not only promotes calcium absorption and immune regulation, but also changes drug effects (pharmacodynamics and adverse reactions) and drug disposal in vivo when combined with various commonly used clinical drugs. The extensive physiological effects of vitamin D may cause synergism effects or alleviation of adverse reactions, and vitamin D's affect on drugs in vivo disposal through drug transporters or metabolic enzymes may also lead to changes in drug effects. Herein, the effects of vitamin D combined with commonly used drugs were reviewed from the perspective of drug efficacy and adverse reactions. The effects of vitamin D on drug transport and metabolism were summarized and analyzed. Hopefully, more attention will be paid to vitamin D supplementation and deficiency in clinical treatment and drug research and development.

Vitamin D Receptor Is Necessary for Mitochondrial Function and Cell Health

Vitamin D receptor (VDR) mediates many genomic and non-genomic effects of vitamin D. Recently, the mitochondrial effects of vitamin D have been characterized in many cell types. In this article, we investigated the importance of VDR not only in mitochondrial activity and integrity but also in cell health. The silencing of the receptor in different healthy, non-transformed, and cancer cells initially decreased cell growth and modulated the cell cycle. We demonstrated that, in silenced cells, the increased respiratory activity was associated with elevated reactive oxygen species (ROS) production. In the long run, the absence of the receptor caused impairment of mitochondrial integrity and, finally, cell death. Our data reveal that VDR plays a central role in protecting cells from excessive respiration and production of ROS that leads to cell damage. Because we confirmed our observations in different models of both normal and cancer cells, we conclude that VDR is essential for the health of human tissues.

Calcitriol exerts anti-inflammatory effects in keratinocytes treated with autoantibodies from a patient with bullous pemphigoid

BACKGROUND

The hormonally active vitamin D metabolite calcitriol and its analogues exert potent effects on cellular differentiation and regulation of immune responses. Although topical vitamin D analogues are widely used for treatment of psoriasis and vitamin D has been increasingly implicated in prevention and protection from several autoimmune diseases, experimental and clinical data in autoimmune bullous diseases are generally lacking.

OBJECTIVE

Here, we investigated the effects of calcitriol on keratinocytes treated by bullous pemphigoid (BP) autoantibodies.

METHODS

Human keratinocyte (HaCaT) cells were treated with purified human BP or normal IgG from one BP patient and healthy subject, respectively, in the absence or presence of calcitriol and effects on (i) cell viability, (ii) IL-6 and IL-8 secretion, (iii) STAT3 and NFκB activation, (iv) heat shock protein 70 (Hsp70) level, and (v) vitamin D receptor (VDR) expression were studied.

RESULTS

We found that BP IgG-induced IL-6 and IL-8 release from HaCaT cells was reduced in the presence of non-toxic doses of calcitriol. Additionally, calcitriol blunted BP IgG-mediated STAT3 phosphorylation and NFκB activity, whereas Hsp70 and VDR expression were not affected.

CONCLUSION

Although the results of this study are based on autoantibodies prepared from a single patient, they show that calcitriol protects from BP IgG-induced inflammatory processes in vitro, thus favouring its potential inclusion into the therapeutic repertoire of BP.

Menadione : sodium orthovanadate combination eliminates and inhibits migration of detached cancer cells

Exposure of cancer cells to anticancer agents in cultures induces detachment of cells that are usually considered dead. These drug-induced detached cells (D-IDCs) may represent a clinical problem for chemotherapy since they may survive anoikis, enter the circulation, invade other tissues and resume proliferation, creating a metastasis, especially in tissues where the bioavailability of anticancer agents is not enough to eliminate all cancer cells. In this study we evaluated the antiproliferative effect of menadione : sodium orthovanadate (M : SO) combination on A549 lung cancer cells as well as the ability of M : SO to induce cell detachment. In addition, we followed the fate and chemosensitivity of M : SO-induced detached cells. Using transwell chambers, we found that a fraction of the M : SO-induced detached cells were viable and, furthermore, were able to migrate, re-attach, and resume proliferation when re-incubated in drug-free media. The total elimination of A549 detachment-resistant cells and M : SO-induced detached cells were successfully eliminated by equivalent M : SO concentration (17.5 μM : 17.5 μM). Thus, M : SO prevented cell migration. Similar results were obtained on DBTRG.05MG human glioma cells. Our data guarantee further studies to evaluate the in vivo occurrence of D-IDCs, their implications for invasiveness and metastasis and their sensitivity to anticancer drugs.