Association between Parvovirus B19 and thyroid/celiac autoantibodies among T1DM pediatric patients

OBJECTIVE

In recent years, an overwhelming association between Pediatric Type 1 Diabetes Mellitus (T1DM) and autoimmune diseases has been largely reported. The current study was designed to determine a possible association between autoimmune thyroiditis (AIT), celiac disease (CD) - associated autoantibodies, and Parvovirus B19 infection among pediatric T1DM cases in the southwestern region of Saudi Arabia.

PATIENTS AND METHODS

Blood samples from age groups 1-18 years attending the Diabetic Clinic were collected over a period of 12 months. Serum anti-thyroid peroxidase (TPO), anti-thyroglobulin (TG), anti-tissue transglutaminase immunoglobulin A (TG-IgA), endomysial IgA (EMA-IgA), Parvovirus B19-IgG and IgM antibodies were detected by standard methods.

RESULTS

The results showed the prevalence of autoantibodies against thyroid and CD among pediatric T1DM patients to be 44 (25%) and 25 (14.4%), respectively. The prevalence of antibodies against B19 was 70 (40%). Further determination of the prevalence of Parvovirus B19-IgG antibodies and thyroid antibodies among T1DM pediatric patients revealed that there was a significant association between them with a p<0.0491.

CONCLUSIONS

The prevalence of autoantibodies against the thyroid was higher among the seropositive Parvovirus B19 children with T1DM. A positive association between the prevalence of autoantibodies against thyroid disease and the increase in the duration of diabetes was also noted. Hence, periodic screening of T1DM patients for B19 antibodies and autoantibodies for thyroid is crucial.

Immunomodulatory and anti-cancer potential of cloves (Syzygium aromaticum) bud extract and its phytogenic silver nanoparticles

Clove plant (Syzygium aromaticum) is one of the Myrtaceae family. It's a common flavor in food and the traditional medicine. The study's objective was to ascertain whether the clove bud aqueous extract (CAE) and CAE + nanosilver have any biological effects on immune cells and HT-29 colon cancer cell line. Nanosilver was produced through green synthesis approach using CAE. Produced nanosilver was characterized via electron microscope (scanning, SEM) and ultraviolet-visible spectroscopy. CAE and CAE + nanosilver were examined for their active biomolecules using FTIR analysis, p53 contents using real-time PCR, apoptosis and cell cycle arrest power on HT-29 cancer cell line via flow cytometerty and immunomodulatory potential utilizing MTT assay. Results cleared that a spherical nanosilver with a diameter range of 53 nm was formed by CAE. There were several active biomolecules in CAE and CAE + nanosilver. CAE and CAE + nanosilver increased the p53 protein expression and apoptotic cell number in HT-29 colon cancer cells. CAE and CAE + nanosilver could arrest HT-29 cells at the phase G2/M. CAE and CAE + nanosilver stimulated quiescent and PHA-pre-treated splenic cells at higher concentrations, and CAE suppressed quiescent splenic cell when diluted. In conclusion, the safe edible Syzygium aromaticum plant can be utilized to make anti-tumor agent, essentially for colon tumor. As Syzygium aromaticum plant could stimulate immune cells, it can be used as immune-stimulatory agent that can help fight tumor and tumor development.

Synergistic antibacterial and mosquitocidal effect of Passiflora foetida synthesized silver nanoparticles

Silver nanoparticles are opted to have various applications in different fields ranging from traditional medicines to culinary items. It is toxic and most effective against bacteria, fungi viruses, parasites, parasite carrying vectors such as mosquitoes and their larvae and other eukaryotic microorganisms at low concentration without any side effects and toxicity to humans. In view of these data, the present research has been investigated by synthesizing silver nanoparticles using 1mM silver nitrate and aqueous extract of Passiflora foetida. The variation of nanoparticles in size and shape concerning the concentration of extract prepared were analysed. The formation of silver nanoparticles was confirmed by colour changing from yellowish green to reddish-brown implicating the surface plasmon resonance. Further, it was concluded by obtaining an absorbance peak at 420 nm using UV-Visible spectrophotometer analysis. FTIR analysis was used to identify the capping ligands, which included alkanes, aromatic groups and nitro compounds. The average grain size of ~12 nm to 14 nm with crystalline phase was revealed by X-ray Diffraction studies. The SEM images depicted the surface morphology with agglomeration; TEM studies showed the shape of nanoparticles as spherical and hexagonal with sizes ranging from 40 nm to 100 nm and EDAX analysis confirmed the presence of elemental silver as the principal constituent. The characterized silver nanoparticles were then tested for synergistic antibacterial effects with tetracycline, and the results show that they are more active against E. coli and S. aureus, but moderately effective against B. cereus and K. pneumoniae . It also had a strong larval and pupal toxic effects on the dengue vector, Aedes aegypti with the highest mortality. As a result, silver nanoparticles could be a viable alternative for a variety of applications.

Appraising the therapeutical potentials of Alchornea laxiflora (Benth.) Pax & K. Hoffm., an underexplored medicinal herb: A systematic review

Ethnopharmacological relevance: Alchornea laxiflora (Benth.) Pax & K. Hoffm. (Euphorbiaceae) is an important traditional medicinal plant grown in tropical Africa. The stem, leaves, and root have been widely used in the folk medicine systems in Nigeria, Cameroon, South Africa, and Ghana to treat various ailments, including inflammatory, infectious, and central nervous system disorders, such as anxiety and epilepsy. Material and methods: The scientific name of the plant was validated using the "The Plant List," "Kew Royal Botanic Gardens," and Tropicos Nomenclatural databases. The literature search on A. laxiflora was performed using electronic search engines and databases such as Google scholar, ScienceDirect, PubMed, AJOL, Scopus, and Mendeley. Results: To the best of our knowledge, no specific and detailed review has been reported on A. laxiflora. Consequently, this review provides an up-to-date systematic presentation on ethnobotany, phytoconstituents, pharmacological activities, and toxicity profiles of A. laxiflora. Phytochemical investigations disclosed the presence of important compounds, such as alkaloids, flavonoids, phenolics, terpenoids, and fatty acids. Furthermore, various pharmacological activities and traditional uses reported for this botanical drug were discussed comprehensively. Conclusion: This systemic review presents the current status and perspectives of A. laxiflora as a potential therapeutic modality that would assist future researchers in exploring this African botanical drug as a source of novel drug candidates for varied diseases.

Haematological Traits in Symptomatic and Asymptomatic COVID-19 Positive Patients for Predicting Severity and Hospitalization

Objective

Materials and Methods

Results

Conclusion

Chronic metabolic and induced stress impacts mesenchymal stromal cell differentiation and modulation of dental origin in-vitro

The impact of induced (smoking) and metabolic stress (diabetes) on dental stem cells with respect to pre-impact consideration on differentiation and bone formation were investigated. The progenitor stem cells isolated from dental pulp, follicle and gingival tissues were phenotyped and subjected to nicotine and high glucose stress mimicking the smoking and diabetic condition in-vitro. The results showed that the cellular viability post treatment with 100 µM nicotine and 10uM glucose was about 86% to 89% respectively in all the three cell types while about 73% in combined nicotine and glucose treatment. No variation in the expression of pro-inflammatory TNF-α, IL-1β and IL-12 in all the three cell types were noticed. The observed viability in nicotine treated cells were due to elevated IL-6, IL-10 while in glucose was due to brain derived neurotropic factor (BDNF). Higher expression of IL-4, IL-6, IL-10, TGF-β and heme oxygenase −1 (HO-1) were found high in both stressors treated cells. Differentiation and mineralization markers Alkaline phosphatase (ALP), Collagenase I (COL1), Osteocalcin, Runt related transcription factor 2 (RUNX2), Osteopontin and Bone sialoprotein were expressed in the dental pulp stem cells (DPSCs) and gingival mesenchymal stem cells (GMSCs) at varying levels post nicotine or glucose treatment while not significantly observed in dental follicular stem cells (DFSCs). Therefore, it is evident that the stem cells of varied dental origin responded to the stress are more or less uniform with physiological delay in differentiation into osteoblast. It is evident from the study that, the metabolic or induced stress subverts the process of regenerative healing by mesenchymal stromal cells with their anatomical niche.

Glucose and oleic acid mediate cellular alterations in GLP-1-induced insulin-positive differentiating UCBMSCs

Coordinated effects of glucose and oleic acid on glucagon-like peptide-1 (GLP-1) mediated differentiation of insulin-positive differentiating umbilical cord mesenchymal stromal cells (dUCBMSCs) was studied using a co-culture of NCI-H716 (GLP-1+) and UCBMSCs (insulin+). The addition of 2.5 mM glucose increased the proliferation of NCI-H716 cells by 30% and induced transformation of UCBMSCs into insulin-secreting cells in 18 days as compared to 22 days in control cells. Oleic acid (25 μM) showed decrease in cell proliferation, autophagy, and apoptosis in NCI-H716 cells while no effect was observed in dUCBMSCs. Prolonged glucose and oleic acid resulted in apoptosis and cell cycle changes in dUCBMSCs after day 18 while higher concentrations resulted in cell death. Additionally, the expression of FAS and ACC mRNA was observed in NCI-H716 and dUCBMSCs post 24-hr addition of glucose and/or oleic acid. Absorption of oleic acid was high in NCI-H716 compared to dUCBMSCs. Taken together, optimal concentrations of glucose and oleic acid could be a key factor in stimulating intrinsic GLP-1, which in turn stimulates differentiating MSCs in a glucose-dependent manner. PRACTICAL APPLICATIONS: The aim of this article was to study whether differentiating or differentiated MSCs after mobilization or post-transplant would require optimal glucose and oleic acid to naturally stimulate intrinsic GLP-1, or otherwise, the high or long-term overload of glucose or oleic acid could result in inhibition of differentiated cells resulting in failure of insulin secretion.

Mapping Research on miRNAs in Cancer: A Global DataAnalysis and Bibliometric Profiling Analysis

miRNAs biomarkers are emerging as an essential part of clinical oncology. Their oncogenic and tumour suppressor properties playing a role in malignancy has generated interest in their potential for use in disease prognosis. While several studies on miRNA have been carried out across the globe, evaluating the clinical implications of miRNAs in cancer diagnosis and prognosis research has currently not been attempted. A study delineating the area of miRNA research, including the topics presently being focused on, the seminal papers in this field, and the direction of research interest, does not exist. This study aims to conduct a large-scale, global data analysis and bibliometric profiling analysis of studies to evaluate the research output of clinical implications of miRNAs in cancer diagnosis and prognosis listed in the SCOPUS database. A systematic search strategy was followed to identify and extract all relevant studies, subsequently analysed to generate a bibliometric map. SPSS software (version 27) was used to calculate bibliometric indicators or parameters for analysis, such as year and country of affiliation with leading authors, journals, and institutions. It is also used to analyse annual research outputs, including total citations and the number of times it has been cited with productive nations and H-index. The number of global research articles retrieved for miRNA-Cancer research over the study period 2003 to 2019 was 18,636. Between 2012 and 2019, the growth rate of global publications is six times (n = 15,959; 90.71 percent articles) that of 2003 to 2011. (2704; 9.29 per cent articles). China published the most publications in the field of miRNA in cancer (n = 7782; 41%), while the United States had the most citations (n = 327,538; 48%) during the time span. Of these journals, Oncotarget has the highest percentage of article publications. The journal Cancer Research had the most citations (n = 41,876), with 6.20 per cent (n = 41,876). This study revealed a wide variety of journals in which miRNA-Cancer research are published; these bibliometric parameters exhibit crucial clinical information on performance assessment of research productivity and quality of research output. Therefore, this study provides a helpful reference for clinical oncologists, cancer scientists, policy decision-makers and clinical data researchers.

Clinical Theragnostic Relationship between Chemotherapeutic Resistance, and Sensitivity and miRNA Expressions in Head and Neck Cancers: A Systematic Review and Meta-Analysis Protocol

Background: The microRNAs (miRNAs) are small noncoding single-stranded RNAs typically 19-25 nucleotides long and regulated by cellular and epigenetic factors. These miRNAs plays important part in several pathways necessary for cancer development, an altered miRNA expression can be oncogenic or tumor-suppressive. Recent experimental results on miRNA have illuminated a different perspective of the molecular pathogenesis of head and neck cancers. Regulation of miRNA can have a detrimental effect on the efficacy of chemotherapeutic drugs in both neoadjuvant and adjuvant settings. This miRNA-induced chemoresistance can influence the prognosis and survival rate. The focus of the study is on how regulations of various miRNA levels contribute to chemoresistance in head and neck cancer (HNC). Recent findings suggest that up or down-regulation of miRNAs may lead to resistance towards various chemotherapeutic drugs, which may influence the prognosis. Methods: Studies on miRNA-specific chemoresistance in HNC were collected through literary (bibliographic) databases, including SCOPUS, PubMed, Nature, Elsevier, etc., and were systematically reviewed following PRISMA-P guidelines (Preferred Reporting Items for Systematic Review and Meta-analysis Protocol). We evaluated various miRNAs, their up and downregulation, the effect of altered regulation on the patient's prognosis, resistant cell lines, etc. The data evaluated will be represented in the form of a review and meta-analysis. Discussion: This meta-analysis aims to explore the miRNA-induced chemoresistance in HNC and thus to aid further researches on this topic. PROSPERO registration: CRD42018104657.

Cassia auriculata leaf extract ameliorates diabetic nephropathy by attenuating autophagic necroptosis via RIP-1/RIP-3-p-p38MAPK signaling

Diabetic nephropathy (DN) is the most common manifestation of high glucose induced diabetes mellitus. In this study, we report the effects of Cassia auriculata ethanol leaf extract (CALE) on DN-associated cell toxicity and complications. The effects of CALE were screened in vitro using RGE cells. Cell viability was assessed using MTT and flow cytometry. Male Sprague-Dawley rats were divided into control, DN and treatment groups (n = 8). The DN and treatment groups received 60 mg/kg/bw of streptozotocin in citrate buffer, while the treatment group was administered 150 mg/kg/bw of CALE for 10 weeks. Biochemical analysis was conducted using spectrophotometry. Kidney tissues were analyzed using hematoxylin and eosin staining and transmission electron microscopy. CD365-KIM-1 expression was assessed using flow cytometry and signalling proteins were detected using western blotting. Treatment with 30-mM glucose reduced the viability of RGE cells in a time-dependent manner and increased the population of dead RGE cells. Cotreatment with CALE reduced cell death and glucose induced protein expression of LC3-II, RIP-1 and RIP-3 in a dose-dependent manner. In addition, CALE improved the biochemical complications, renal dysfunction and pathophysiology of rats with DN and partially or fully restored the expression of key DN-associated signalling proteins, such as KIM-1 LC3-II, RIP-1, RIP-3 and p-p38MAPK in kidney cells. CALE showed protective effects, and improved DN-associated complications in RGE cells under high glucose stress conditions, potentially by inhibiting autophagic-necroptosis signals. Additionally, CALE improved the biochemical and pathological features of kidney injury while reducing autophagic-necroptosis in rat renal cells via the LC3-II-RIP-p38MAPK pathway. PRACTICAL APPLICATIONS: Results from the current investigation will add information to the literature on glucose induced renal toxicity and the protective effects of CALE over the complications of diabetic nephropathy (DN). The mechanistic investigations of the study will add light on the autophagic/necroptosis signals in DN and open new routes of investigations to study the efficacy of CALE in diabetes-related complications.

FCX, an arylidene derivative, induces apoptosis in androgen receptor-selective prostate cancer cells

Context

Rational screening of arylidene derivatives for biological activities has resulted in many lead molecules with anticancer properties with effective therapeutic window.

Aims

In the current study, FCX, an arylidene derivative, was screened for anticolon and prostate cancer activity.

Settings and Design

Prostate and colon cancer cell lines were used to check the FCX effect on proliferation, apoptosis, and mechanism of drug action.

Subjects and Methods

LNCaP, PC-3, HCT-8, and HT-29 cells were treated with various concentrations of the FCX. MTT assay was performed to check proliferation, propidium iodide and Hoechst dual staining for DNA fragmentation, and Annexin V binding assay for apoptosis, and cell cycle assay was done using flow cytometry. Functional androgen-mutated receptor cells were used mechanistic pathway elucidation.

Statistical Analysis Used

A minimum of three individual replicates at different time periods were taken as mean value. The data were expressed in mean ± standard deviation. Student's t-test and one-way ANOVA were used to assess the statistical difference between the groups.

Results

FCX inhibited proliferation of prostate cancer cell lines in a dose-dependent manner with more selectivity toward LNCaP cells. Nuclear fragmentation and dose-dependent increase in Annexin V-positive LNCaP cells revealed apoptosis. Cell cycle G2/M phase arrest along with sub-G0/G1 population augmented the antiproliferative observations. Addition of FCX in the presence of estradiol, testosterone, and dehydroepiandrosterone, LNCaP cells markedly caused a dose-dependent increase in cell proliferation indicating the compound activity to be facilitated through androgen receptor pathway.

Conclusions

Together with the results, it is evident that FCX has a wide therapeutic window in the in vitro inhibition of the prostate cancer cells mediated by hormone-dependent effects.

Prevalence of toxoplasmosis, rubella, cytomegalovirus, and herpes (TORCH) infections among women attending the antenatal care clinic, maternity hospital in Abha, Southwestern Saudi Arabia

Objectives:

To investigate the presence of toxoplasmosis, rubella, cytomegalovirus, and herpes (TORCH) infections in women attending at the antenatal care clinic in Abha, Kingdom of Saudi Arabia (KSA).

Methods:

A total of 190 blood samples were collected from Abha maternity hospital in Aseer region, KSA, from February 2018 to May 2019 and screened with the TORCH panel (toxoplasmagondii [IgG/IgM], cytomegalovirus [CMV] [IgG/IgM], rubella [IgG/IgM], and herpes simplex type 1 and 2 [IgG/IgM]).

Results:

The mean age was 31.42±6.514 years and gestational age was 32.48±6.168 weeks. Serum IgG was positive for Toxoplasma gondii (T. gondii) (27.4%), herpes simplex type 1 (HSV-1) (94.7%), herpes simplex type 2 (HSV-2) (0.5%), CMV (100%), and rubella (88.9%). Serum IgM was positive only for CMV (9.5%). Though, there was an association between abortions from previous pregnancies (26.5%), intrauterine death (5.8%), premature labor (3.2%), microcephaly (1.6%), other congenital diseases (1.6%) and low birth weight (0.5%) with current IgG positivity for TORCH infections, the results were not statistically significant.

Conclusion:

Seropositivity for IgG antibodies correlate with TORCH-associated pregnancy complications in Abha, KSA; however, IgM positive CMV pregnant cases warrant further systematic investigation to understand the implications of CMV on outcomes during pregnancy.

Proteomic profiling of various human dental stem cells - a systematic review

BACKGROUND

The proteomic signature or profile best describes the functional component of a cell during its routine metabolic and survival activities. Additional complexity in differentiation and maturation is observed in stem/progenitor cells. The role of functional proteins at the cellular level has long been attributed to anatomical niches, and stem cells do not deflect from this attribution. Human dental stem cells (hDSCs), on the whole, are a combination of mesenchymal and epithelial coordinates observed throughout craniofacial bones to pulp.

AIM

To specify the proteomic profile and compare each type of hDSC with other mesenchymal stem cells (MSCs) of various niches. Furthermore, we analyzed the characteristics of the microenvironment and preconditioning changes associated with the proteomic profile of hDSCs and their influence on committed lineage differentiation.

METHODS

Literature searches were performed in PubMed, EMBASE, Scopus, and Web of Science databases, from January 1990 to December 2018. An extra inquiry of the grey literature was completed on Google Scholar, ProQuest, and OpenGrey. Relevant MeSH terms (PubMed) and keywords related to dental stem cells were used independently and in combination.

RESULTS

The initial search resulted in 134 articles. Of the 134 full-texts assessed, 96 articles were excluded and 38 articles that met the eligibility criteria were reviewed. The overall assessment of hDSCs and other MSCs suggests that differences in the proteomic profile can be due to stem cellular complexity acquired from varied tissue sources during embryonic development. However, our comparison of the proteomic profile suffered inconsistencies due to the heterogeneity of various hDSCs. We believe that the existence of a heterogeneous population of stem cells at a given niche determines the modalities of regeneration or tissue repair. Added prominences to the differences present between various hDSCs have been reasoned out.

CONCLUSION

Systematic review on proteomic studies of various hDSCs are promising as an eye-opener for revisiting the proteomic profile and in-depth analysis to elucidate more refined mechanisms of hDSC functionalities.

High altitude as a possible factor for dysbiosis of salivary microbiome in orthodontic patients

BACKGROUND

External stressors such as high altitude and low oxygen are known to affect the human microbiome, and in light of the increased occurrence of dental caries and periodontitis in orthodontic patients, the effect of high altitude and the altered oral environment in orthodontic patients on the oral salivary microbiome was researched.

MATERIALS & METHODS

31 orthodontic patients from high altitude, Aseer region and 25 orthodontic patients, residing at sea level, as controls were included. DNA isolation was done from the saliva collected from the study participants. V3 area of 16s RNA was targeted by universal primers through PCR to decipher the salivary microbiome in both the groups.

RESULTS

A total of 11 genera belonging to 4 phyla of bacteria were identified in both groups. The most abundant microbiome at the phylum level was: Firmicutes, Bacteroidetes Proteobacteria, and Cyanobacteria. The salivary microbiome was more diverse in sea level controls compared to that of the orthodontic patients at high altitude wherein the presence of only two main phyla: Firmicutes and Proteobacteria were seen. The controls revealed Firmicutes, Proteobacteria, Bacteroidetes and Cyanobacteria.

CONCLUSIONS

The findings of the study suggest that the biodiversity of the salivary microbiome is severely perturbed under the cumulative influences of high altitude and presence of fixed orthodontic appliance. Under these circumstances, a strict and meticulous oral hygiene regimen should be recommended and followed to avoid harmful effects on the periodontal tissues.

Healthcare workers' perspectives on healthcare-associated infections and infection control practices: a video-reflexive ethnography study in the Asir region of Saudi Arabia

Background

Healthcare-associated infections (HAIs) are a global public health problem. For the fulfillment of Saudi Arabia’s Vision 2030, the promotion of preventive care medicine through HAI management is a crucial issue. This study explores the perspectives of Saudi tertiary healthcare workers (HCWs) on HAIs and infection control measures.

Methods

Quantitative data were assessed to determine HCWs’ knowledge of HAI and their attitudes towards and practice of infection control measures. Semi-structured interviews were used to collect qualitative data from 40 doctors and nurses. The interviews were audio-recorded and transcribed verbatim. Further, routine sterile procedures in the wards and intensive care units were video recorded, and the footage was discussed by the infection control team and the personnel involved in the videos. This discussion was videographed and transcribed. Both interview data and reflective discussion of the video were analysed using thematic analysis. The quantitative data were analysed using the Kruskal–Wallis test and logistic regression analysis.

Results

Kruskal–Wallis test revealed no difference in mean knowledge, attitude, or practice scores between nurses/ doctors or the genders. There was a significant difference in knowledge score and practice scores between the Intensive care unit & the Paediatric ward /infection control department with the maximum scores in knowledge and practice among participants from the intensive care unit. Logistic regression analysis for dependent variables (knowledge and attitude) and independent variables like age, gender, designation, and departments was not significant. The qualitative data yielded four themes: knowledge of HAI and infection control, infection control measures in practice, a shortfall in infection control measures and HAI, and required implementation. Video-reflexive ethnography (VRE) revealed lapses in handwashing practice and proper usage of personal protective equipment (PPE), especially surgical masks.

Conclusion

Early introduction of training programmes in medical and nursing schools and video demonstrations of appropriate infection control practices during sterile procedures would be highly beneficial to HCWs. A possible reason for the outbreak of Middle East Respiratory Syndrome coronavirus in this part of Saudi Arabia could be a lapse in PPE usage. Intensive training programs for all the HCWs, strict vigilant protocols, and a willingness to change behaviour and practice, will significantly benefit the spread of outbreaks.

Cytokine physiognomies of MSCs from varied sources confirm the regenerative commitment post-coculture with activated neutrophils

The interaction of mesenchymal stromal cells (MSCs) with paracrine signals and immunological cells, and their responses and regenerative commitment thereafter, is understudied. In the current investigation, we compared MSCs from the umbilical cord blood (UCB), dental pulp (DP), and liposuction material (LS) on their ability to respond to activated neutrophils. Cytokine profiling (interleukin-1α [IL-1α], IL-2, IL-4, IL-6, IL-8, tumor necrosis factor-α [TNF-α], interferon-γ [IFN-γ], transforming growth factor-β [TGF-β]), cellular proliferation and osteogenic differentiation patterns were assessed. The results showed largely comparable cytokine profiles with higher TNF-α and IFN-γ levels in LSMSCs owing to their mature cellular phenotype. The viability and proliferation between LS/DP/UCB MSCs were comparable in the coculture group, while direct activation of MSCs with lipopolysaccharide (LPS) showed comparable proliferation with significant cell death in UCB MSCs and slightly higher cell death in the other two types of MSC. Furthermore, when MSCs post-neutrophil exposure were induced for osteogenic differentiation, though all the MSCs devoid of the sources differentiated, we observed rapid and significant turnover of DPMSCs positive of osteogenic markers rather than LS and UCB MSCs. We further observed a significant turnover of IL-1α and TGF-β at mRNA and cytokine levels, indicating the commitment of MSCs to differentiate through interacting with immunological cells or bacterial products like neutrophils or LPS, respectively. Taken together, these results suggest that MSCs have more or less similar cytokine responses devoid of their anatomical niche. They readily switch over from the cytokine responsive cell phenotype at the immunological microenvironment to differentiate and regenerate tissue in response to cellular signals.

(2E)-2-Benzylidene-4,7-dimethyl-2,3-dihydro-1H-inden-1-one (MLT-401), a novel arylidene indanone derivative, scavenges free radicals and exhibits antiproliferative activity of Jurkat cells

Background

The arylidene indanone scaffold has contributed many lead molecules in chemotherapeutic anticancer agent research.

Objectives

To determine the oxidant-scavenging activities and antiproliferative activity of (2E)-2-benzylidene-4,7-dimethyl-2,3-dihydro-1H-inden-1-one (MLT-401), an arylidene indanone derivative.

Methods

Jurkat cells, primary lymphocytes, and Vero cells were treated with MLT-401. Antioxidant properties of MLT-401 were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH)-based, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS)-based, and ferric-reducing antioxidant potential (FRAP) assays. Inhibition of cell proliferation was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-based assay. Nuclear status was determined using a DNA fragmentation assay, and cell cycle stage was analyzed by flow cytometry. Mitochondrial membrane enzyme activities were measured using colorimetric methods.

Results

The antioxidant assays gave MLT-401 half maximal inhibitory concentration (IC50) values of 1611 nM (DPPH-based assay), 2115 nM (ABTS-based assay), and 1586 nM (FRAP assay). MLT-401 inhibited proliferation of Jurkat cells with a concentration for 50% of maximal inhibition of cell proliferation (GI50) of 341.5 nM, being 12- and 9-fold less than GI50 concentrations for normal lymphocytes and Vero cells, respectively. MLT-401 caused nuclear fragmentation and DNA laddering as seen by electrophoresis. Jurkat cells showed a time-dependent accumulation of sub G0/G1 cells after MLT-401 treatment. Mitochondrial membrane-bound Na+/K+ ATPase, Ca2+ ATPase, and Mg2+ ATPase activities were inhibited by MLT-401 in a dose-dependent manner.

Conclusion

MLT-401 possesses significant antiproliferative activity and scavenges free radicals released through mitochondrial membrane damage in a Jurkat cell line model of cancer cells. Further investigation of MLT-401 as a chemotherapeutic anticancer agent and development of other arylidene indanone analogues are warranted. A detailed elucidation of mechanistic pathways is required for further development.

Thymoquinone attenuates IgE-mediated allergic response via pi3k-Akt-NFκB pathway and upregulation of the Nrf2-HO1 axis

IgE-dependent reactions mediate the majority of allergic diseases. This study explores the effects of thymoquinone (Tq) on IgE-mediated allergic response in activated mast cells, basophils, and neutrophils. Tq treatment resulted in a dose-dependent decrease in levels of TNF-α and IL-4 in activated RBL-2H3 cells. Tq inhibited the degranulation of these cells with an IC₅₀ value of 56.37 µM. Moreover, the compound suppressed basophil activation induced through FcεRI receptors with an IC₅₀ value of 45.76 µM in heparinized human whole blood. Likewise, neutrophil migration and elastase activity were dose-dependently reduced. While Tq decreased the phosphorylation of Akt and NFκB in activated RBL-2H3 cells, it increased nuclear Nrf2 and HO-1 antioxidant proteins. Our results indicate that Tq possesses demonstrable activity in cellular models of IgE-mediated allergic reactions. PRACTICAL APPLICATIONS: The current study sheds light on the mechanistic pathways of Tq on IgE-based response in activated mast cells, basophils, and neutrophils. The output of this preclinical in vitro study may be translated into better chemotherapeutic applications of Tq and its analogs in the treatment of allergic inflammation. However, a detailed investigation of in vivo models is recommended.

Thymoquinone attenuates oxidative stress of kidney mitochondria and exerts nephroprotective effects in oxonic acid-induced hyperuricemia rats

BACKGROUND

Recent studies indicate hyperuricemia as an aggravating factor for kidney diseases progression. Basic research for novel agents to reduce hyperuricemia and kidney abnormalities will be highly rewarding. Herein, we report Thymoquinone (Tq) as an active constituent of Nigella sativa to have renal protective effective against oxonic acid (OA)-induced hyperuricemia, hypertension, and renal oxidative stress in rat models.

METHODS

OA 750 mg/kg BW for 12 weeks was used to induce uricemia in Sprague dawley rats. Tq at 10 and 20 mg/kg BW were administered along with OA for treatment groups. Plasma uric acid concentration and systolic blood pressure were measured. Oxidative stress markers, total ATP content, and membrane bound ATPases were measured in renal mitochondria. Anti-oxidant enzymes were analyzed in the renal tissues. Apoptosis in renal tissue was detected. Key signaling proteins for apoptosis, oxidative stress, and lipid oxidation pathways were determined.

RESULTS

OA induced both circulating uric acid levels and hypertension in the control group which was brought down on Tq treatments. Tq effectively prevented accumulation of uric acid and oxidative stress in the renal tissues. Tq also proved to increase the total ATP content of the renal mitochondria and prevented the apoptosis induced by OA. Tq increased the expressions of phosphorylated Akt, Nrf2, and HO-1 proteins while decreasing the levels of cleaved caspase-3 in renal cells.

CONCLUSION

In summary, Tq exhibited protective effects on hyperuricemia-mediated renal oxidative stress and mitochondrial abnormalities which could be mediated by Nrf2/HO-1, Akt signaling pathways.

FCX-146, a potent allosteric inhibitor of Akt kinase in cancer cells: Lead optimization of the second-generation arylidene indanone scaffold

Akt, a serine-threonine protein kinase, is regulated by class-I PI3K signaling. Akt regulates a wide variety of cell processes including cell proliferation, survival, and angiogenesis through serine/threonine phosphorylation of downstream targets including mTOR and glycogen-synthase-kinase-3-beta (GSK3β). Targeting cancer-specific overexpression of Akt protein could be an efficient way to control cancer-cell proliferation. However, the ATP-competitive inhibitors are challenged by the highly conserved ATP binding site, and by competition with high cellular concentrations of ATP. We previously developed an allosteric inhibitor, 2-arylidene-4, 7-dimethyl indan-1-one (FXY-1) that showed promising activity against several lung cancer models. In this work, we designed a congeneric series of molecules based on FXY-1 and optimized lead based on computational, in vitro assays. Computational screening followed by enzyme-inhibition and cell-proliferation assays identified a derivative (FCX-146) as a new lead molecule with threefold greater potency than the parent compound. FCX-146 increased apoptosis in HL-60 cells, mediated in part through decreased expression of antiapoptotic Bcl-2 protein and increased levels of Bax-2 and Caspase-3. Molecular-dynamic simulations showed stable binding of FCX-146 to an allosteric (i.e., noncatalytic) pocket in Akt. Together, we propose FCX-146 as a potent second-generation arylidene indanone compound that binds to the allosteric pocket of Akt and potently inhibits its activation.

Sero-prevalence and risk factors of brucellosis among suspected febrile patients attending a referral hospital in southern Saudi Arabia (2014-2018)

BACKGROUND

Human brucellosis is an infectious zoonotic disease caused by Brucella spp. It is one of the most public health problems that remains largely neglected in developing counties, including Saudi Arabia. Brucellosis is particularly prevalent among rural people who have constant contact with livestock.

METHODS

A cross-sectional sero-epidemiological study conducted in Aseer Central Hospital, South Saudi Arabia, between 2014 and 2018 among 7567 patients. Serum samples were analyzed for Brucella antibodies using slide agglutination test. Serology results and patient's demographic data were analyzed by GraphPad Prism. Results were presented as mean ± SEM and differences between two groups were assessed by t-test and p < 0.05 was considered significant.

RESULTS

The prevalence of brucellosis among the admitted suspected 7567 cases was 12.8% (10.4-15.7%; CI 95%). The highest prevalence rate was detected during 2015, the rate decreased to the lowest level during the last three years (p < 0.05). Higher rate of brucellosis was observed among males than females (p < 0.05) and most cases were reported during summer season (p < 0.05). The highest prevalence rate was observed in age group 21-40 year old (40.5%) followed by 41-60 years (27.7%). The lowest prevalence rate was noticed in old and young children (15 and 3%, respectively). Cross-transmission of brucellosis was seen within family (1%) and high titers (> 1280) was noticed in 22% of the hospitalized patients. The major symptoms were fatigue, hyperhidrosis, fever and joint pain.

CONCLUSION

Our findings showed a high prevalence of human brucellosis among suspected patients in Aseer region. This indicates that clinical suspicion is a valid criterion and the endemic nature of the disease. The disease status requires early laboratory detection and confirmation to start prompt treatment to decrease patients suffering.

Rational combinations of indirubin and arylidene derivatives exhibit synergism in human non-small cell lung carcinoma cells

Rational combination of natural and synthetic derivatives to treat lung cancer has advantages of both efficacy and safety. Herein, the combination of indirubin-3-monoxime (I3M), a chemical derived from Chinese herbal medicine and FXY-1, a synthetic arylidene derivative, was tested for combined activity in lung cancer cells. A dose-dependent synergistic reduction in cell viability was recorded with the combinations in A549 and NCI-H460 cells. Combination treatments of I3M and FXY-1 showed antimetastatic effects in both cells. Cell cycle analysis revealed G₁ growth phase reduction with subsequent accumulation of sub G₀ contents. Annexin V assay revealed higher apoptotic cells with combinations compared to individual treatments. I3M + FXY-1 combination significantly decreased the antiapoptotic Bcl-2 protein and increased pro-apoptotic Bax protein levels. These results demonstrate efficacy of I3M + FXY-1 in lung cancer cells and suggest further preclinical research in animal models to develop it into a new form combination chemotherapeutic against lung cancer. PRACTICAL APPLICATIONS: Current investigation will open new options in rational combinations of natural and synthetic compounds to treat cancer. The observed efficacy and safety of the combinations will add to the advantage of higher therapeutic window in formulating treatment regimens. The antimetastatic effects by the combinations provides promising efficacy in controlling the lung cancer progression. A detailed in vivo investigation is recommended to transform the combinations to novel chemotherapeutic options against lung cancer.

Human metapneumovirus in Pediatric Patients with Acute Respiratory Tract Infections in the Aseer Region of Saudi Arabia

Background:

Human metapneumovirus (hMPV) is a Paramyxovirus known to cause acute respiratory tract infections in children and young adults. To date, there is no study from the Aseer region of Saudi Arabia determining the proportion and severity of hMPV infection among pediatric hospitalized patients with respiratory infections.

Objectives:

The objective of this study is to determine the presence of hMPV antigens in the nasopharyngeal secretions of pediatric patients hospitalized with respiratory tract infections in the Aseer region of Saudi Arabia.

Materials and Methods:

This prospective, serological hospital-based study included all pediatric patients who were admitted to Aseer Central Hospital, Abha, Saudi Arabia, from July 2016 to November 2017 with upper and/or lower respiratory tract infections. Basic demographics of patients and their clinical data on and after admission were recorded. Direct fluorescent antibody assay was used to detect the presence of hMPV antigens in the obtained nasopharyngeal secretion specimens.

Results:

During the study, 91 pediatric patients were hospitalized due to upper and/or lower respiratory tract infections, of which 9.9% were positive for hMPV. These patients were aged 9 months to 16 years, were from Abha city or its surrounding localities and were mostly (77.8%) hospitalized during autumn or winter. The most common diagnosis on admission was bronchopneumonia (55.5%) and aspiration pneumonia (22.2%), and some patients also had underlying chronic conditions such as chronic heart disease (22.2%) and bronchial asthma (11.1%).

Conclusions:

The results obtained indicated that hMPV is a potential etiologic factor for the commonly occurring acute respiratory infections in hospitalized children from the Aseer region of Saudi Arabia. hMPV infection was also found to be associated with complicated respiratory conditions such as bronchopneumonia, chronic heart disease and bronchial asthma.

Mesenchymal Stem Cells (MSCs) Coculture Protects [Ca2+]i Orchestrated Oxidant Mediated Damage in Differentiated Neurons In Vitro

Cell-therapy modalities using mesenchymal stem (MSCs) in experimental strokes are being investigated due to the role of MSCs in neuroprotection and regeneration. It is necessary to know the sequence of events that occur during stress and how MSCs complement the rescue of neuronal cell death mediated by [Ca²⁺]_i and reactive oxygen species (ROS). In the current study, SH-SY5Y-differentiated neuronal cells were subjected to in vitro cerebral ischemia-like stress and were experimentally rescued from cell death using an MSCs/neuronal cell coculture model. Neuronal cell death was characterized by the induction of proinflammatory tumor necrosis factor (TNF)-α, interleukin (IL)-1β and -12, up to 35-fold with corresponding downregulation of anti-inflammatory cytokine transforming growth factor (TGF)-β, IL-6 and -10 by approximately 1 to 7 fold. Increased intracellular calcium [Ca²⁺]_i and ROS clearly reaffirmed oxidative stress-mediated apoptosis, while upregulation of nuclear factor NF-κB and cyclo-oxygenase (COX)-2 expressions, along with ~41% accumulation of early and late phase apoptotic cells, confirmed ischemic stress-mediated cell death. Stressed neuronal cells were rescued from death when cocultured with MSCs via increased expression of anti-inflammatory cytokines (TGF-β, 17%; IL-6, 4%; and IL-10, 13%), significantly downregulated NF-κB and proinflammatory COX-2 expression. Further accumulation of early and late apoptotic cells was diminished to 23%, while corresponding cell death decreased from 40% to 17%. Low superoxide dismutase 1 (SOD1) expression at the mRNA level was rescued by MSCs coculture, while no significant changes were observed with catalase (CAT) and glutathione peroxidase (GPx). Interestingly, increased serotonin release into the culture supernatant was proportionate to the elevated [Ca²⁺]_i and corresponding ROS, which were later rescued by the MSCs coculture to near normalcy. Taken together, all of these results primarily support MSCs-mediated modulation of stressed neuronal cell survival in vitro.

Feasibility of cord blood bank in high altitude Abha: preclinical impacts

We explored the possibility of the cryo-storage of cord blood hematopoietic stem cells (CBHPSC) with respect to the quantity, quality and biologic efficacy of high altitude (HA) region Abha against sea level (SL) region. The results of the post-processed total nucleated cell count was 8.03 ± 0.31 × 10⁷ and 8.44 ± 0.23 × 10⁷ cells in the HA and SL regions respectively. The mean post processing viability of the nucleated cells was about 87.03 ± 1.39 (HA) and 88.33 ± 1.55% (SL) while post thaw cells were 85.61 ± 1.44 (HA) and 86.58 ± 1.61% (SL) after transient cryo-storage. The proliferation of CBHSCs after thawing were comparable between the HA and SL regions. The results of the colony forming unit (CFU) assays of CFU-E, CFU-GEMM, CFU-GM and BFU-E were comparable between HA and SL in both fresh and post thaw, while a declining trend with viability was significant. The differentiation capability of post thaw samples into adipocytes and osteocytes were comparable between HA and SL regions. Overall from the results, it can be evidenced that HA cord blood collection, processing or storage does not hinder the quality or biological efficacy of the CBHPSC.

MSCs ameliorates DPN induced cellular pathology via [Ca2+ ]i homeostasis and scavenging the pro-inflammatory cytokines

The MSCs of various origins are known to ameliorate or modulate cell survival strategies. We investigated, whether UCB MSCs could improve the survival of the human neuronal cells and/or fibroblast assaulted with DPN sera. The results showed, the co-culture of UCB MSCs with human neuronal cells and/or fibroblasts could effectively scavenge the pro-inflammatory cytokines TNF-α, IL-1β, IFN-ɤ and IL - 12 and control the pro-apoptotic expression of p53/Bax. Further co-culture of UCB MSCs have shown to induce anti-inflammatory cytokines like IL-4, IL-10 and TGF-β and anti-apoptotic Bclxl/Bcl2 expression in the DPN sera stressed cells. Amelioration of elevated [Ca²⁺ ]_i and cROS, the portent behind the NFκB/Caspase-3 mediated inflammation in DPN rescued the cells from apoptosis. The results of systemic administration of BM MSCs improved DPN pathology in rat as extrapolated from human cell model. The BM MSCs ameliorated prolonged distal motor latency (control: 0.70 ± 0.06, DPN: 1.29 ± 0.13 m/s DPN + BM MSCs: 0.89 ± 0.02 m/s, p < 0.05) and lowered high amplitude of compound muscle action potentials (CMAPs) (control: 12.36 ± 0.41, DPN: 7.52 ± 0.61 mV, DPN + MSCs: 8.79 ± 0.53 mV, p < 0.05), while slowly restoring the plasma glucose levels. Together, all these results showed that administration of BM or UCB MSCs improved the DPN via ameliorating pro-inflammatory cytokine signaling and [Ca²⁺ ]_i homeostasis.

Elevated basal cytosolic calcium of endothelial cells influences the post-surgical outcome in diabetic CTS

Background Type 2 diabetes mellitus (T2DM)-induced neuropathy and ischemia-reperfusion post-surgery prolong carpal tunnel syndrome (CTS) pathology, but the effect of T2DM on the prognostic outcome of carpal tunnel (CT) release surgery needs to be investigated. Materials and methods A total of 64 individuals with CTS underwent CT release surgery. HbA1c levels identified their diabetic status. The individual prognostic outcomes were measured by nerve conduction velocity (NCV), amplitude, and latency. Measurement of [Ca²⁺]_c and reactive oxygen species (ROS) from isolated endothelial cells (ECs) revealed the oxidative burden of the normal and diabetic CTS phenotypes. Results CTS individuals with HbA1c > 7 showed decreased NCV (≈22 m/s) and amplitude (≈4.2 mV) with increased latency (≈6 ms), compared to groups with HbA1c ≤ 7. Further to CT release surgery, the reversal of the nerve conduction to normalcy was greatly influenced by the diabetic profile of the individuals. Our results showed elevated basal [Ca²⁺]_c and corresponding high cytosolic ROS in the ECs isolated from individuals with HbA1c > 7 compared to the diabetic and healthy control groups. Conclusion The individuals with diabetic index showed suboptimal neuronal performance pre- and post-CT release surgery. Oxidative stress mediated by high [Ca²⁺]_c and ROS of ECs dissipates to adjoining cells worsening the pathology of the untreated CTS.

Antioxidants and NOS inhibitors selectively targets manganese-induced cell volume via Na-K-Cl cotransporter-1 in astrocytes

Manganese has shown to be involved in astrocyte swelling. Several factors such as transporters, exchangers and ion channels are attributed to astrocyte swelling as a result in the deregulation of cell volume. Products of oxidation and nitration have been implied to be involved in the pathophysiology of swelling; however, the direct link and mechanism of manganese induced astrocyte swelling has not been fully elucidated. In the current study, we used rat primary astrocyte cultures to investigate the activation of Na-K-Cl cotransporter-1 (NKCC1) a downstream mechanism for free radical induced astrocyte swelling as a result of manganese toxicity. Our results showed manganese, oxidants and NO donors as potent inducer of oxidation and nitration of NKCC1. Our results further confirmed that manganese (50 μM) increased the total protein, phosphorylation and activity of NKCC1 as well as cell volume (p < 0.05 vs. control). NKCC1 inhibitor (bumetanide), NKCC1-siRNA, antioxidants; DMTU, MnTBAP, tempol, catalase and Vit-E, NOS inhibitor; L-NAME, peroxinitrite scavenger; uric acid all significantly reversed the effects of NKCC1 activation (p < 0.05). From the current investigation we infer that manganese or oxidants and NO induced activation, oxidation/nitration of NKCC1 play an important role in the astrocyte swelling.

LETM1-dependent mitochondrial Ca2+ flux modulates cellular bioenergetics and proliferation

Dysregulation of mitochondrial Ca(2+)-dependent bioenergetics has been implicated in various pathophysiological settings, including neurodegeneration and myocardial infarction. Although mitochondrial Ca(2+) transport has been characterized, and several molecules, including LETM1, have been identified, the functional role of LETM1-mediated Ca(2+) transport remains unresolved. This study examines LETM1-mediated mitochondrial Ca(2+) transport and bioenergetics in multiple cell types, including fibroblasts derived from patients with Wolf-Hirschhorn syndrome (WHS). The results show that both mitochondrial Ca(2+) influx and efflux rates are impaired in LETM1 knockdown, and similar phenotypes were observed in ΔEF hand, (D676A D688K)LETM1 mutant-overexpressed cells, and in cells derived from patients with WHS. Although LETM1 levels were lower in WHS-derived fibroblasts, the mitochondrial Ca(2+) uniporter components MCU, MCUR1, and MICU1 remain unaltered. In addition, the MCU mitoplast patch-clamp current (IMCU) was largely unaffected in LETM1-knockdown cells. Silencing of LETM1 also impaired basal mitochondrial oxygen consumption, possibly via complex IV inactivation and ATP production. Remarkably, LETM1 knockdown also resulted in increased reactive oxygen species production. Further, LETM1 silencing promoted AMPK activation, autophagy, and cell cycle arrest. Reconstitution of LETM1 or antioxidant overexpression rescued mitochondrial Ca(2+) transport and bioenergetics. These findings reveal the role of LETM1-dependent mitochondrial Ca(2+) flux in shaping cellular bioenergetics.

SLC25A23 augments mitochondrial Ca²⁺ uptake, interacts with MCU, and induces oxidative stress-mediated cell death

Emerging findings suggest that two lineages of mitochondrial Ca(2+) uptake participate during active and resting states: 1) the major eukaryotic membrane potential-dependent mitochondrial Ca(2+) uniporter and 2) the evolutionarily conserved exchangers and solute carriers, which are also involved in ion transport. Although the influx of Ca(2+) across the inner mitochondrial membrane maintains metabolic functions and cell death signal transduction, the mechanisms that regulate mitochondrial Ca(2+) accumulation are unclear. Solute carriers--solute carrier 25A23 (SLC25A23), SLC25A24, and SLC25A25--represent a family of EF-hand-containing mitochondrial proteins that transport Mg-ATP/Pi across the inner membrane. RNA interference-mediated knockdown of SLC25A23 but not SLC25A24 and SLC25A25 decreases mitochondrial Ca(2+) uptake and reduces cytosolic Ca(2+) clearance after histamine stimulation. Ectopic expression of SLC25A23 EF-hand-domain mutants exhibits a dominant-negative phenotype of reduced mitochondrial Ca(2+) uptake. In addition, SLC25A23 interacts with mitochondrial Ca(2+) uniporter (MCU; CCDC109A) and MICU1 (CBARA1) while also increasing IMCU. In addition, SLC25A23 knockdown lowers basal mROS accumulation, attenuates oxidant-induced ATP decline, and reduces cell death. Further, reconstitution with short hairpin RNA-insensitive SLC25A23 cDNA restores mitochondrial Ca(2+) uptake and superoxide production. These findings indicate that SLC25A23 plays an important role in mitochondrial matrix Ca(2+) influx.

MICU1 motifs define mitochondrial calcium uniporter binding and activity

Resting mitochondrial matrix Ca(2+) is maintained through a mitochondrial calcium uptake 1 (MICU1)-established threshold inhibition of mitochondrial calcium uniporter (MCU) activity. It is not known how MICU1 interacts with MCU to establish this Ca(2+) threshold for mitochondrial Ca(2+) uptake and MCU activity. Here, we show that MICU1 localizes to the mitochondrial matrix side of the inner mitochondrial membrane and MICU1/MCU binding is determined by a MICU1 N-terminal polybasic domain and two interacting coiled-coil domains of MCU. Further investigation reveals that MICU1 forms homo-oligomers, and this oligomerization is independent of the polybasic region. However, the polybasic region confers MICU1 oligomeric binding to MCU and controls mitochondrial Ca(2+) current (IMCU). Moreover, MICU1 EF hands regulate MCU channel activity, but do not determine MCU binding. Loss of MICU1 promotes MCU activation leading to oxidative burden and a halt to cell migration. These studies establish a molecular mechanism for MICU1 control of MCU-mediated mitochondrial Ca(2+) accumulation, and dysregulation of this mechanism probably enhances vascular dysfunction.

Blockade of NOX2 and STIM1 signaling limits lipopolysaccharide-induced vascular inflammation

During sepsis, acute lung injury (ALI) results from activation of innate immune cells and endothelial cells by endotoxins, leading to systemic inflammation through proinflammatory cytokine overproduction, oxidative stress, and intracellular Ca2+ overload. Despite considerable investigation, the underlying molecular mechanism(s) leading to LPS-induced ALI remain elusive. To determine whether stromal interaction molecule 1-dependent (STIM1-dependent) signaling drives endothelial dysfunction in response to LPS, we investigated oxidative and STIM1 signaling of EC-specific Stim1-knockout mice. Here we report that LPS-mediated Ca2+ oscillations are ablated in ECs deficient in Nox2, Stim1, and type II inositol triphosphate receptor (Itpr2). LPS-induced nuclear factor of activated T cells (NFAT) nuclear accumulation was abrogated by either antioxidant supplementation or Ca2+ chelation. Moreover, ECs lacking either Nox2 or Stim1 failed to trigger store-operated Ca2+ entry (SOCe) and NFAT nuclear accumulation. LPS-induced vascular permeability changes were reduced in EC-specific Stim1-/- mice, despite elevation of systemic cytokine levels. Additionally, inhibition of STIM1 signaling prevented receptor-interacting protein 3-dependent (RIP3-dependent) EC death. Remarkably, BTP2, a small-molecule calcium release-activated calcium (CRAC) channel blocker administered after insult, halted LPS-induced vascular leakage and pulmonary edema. These results indicate that ROS-driven Ca2+ signaling promotes vascular barrier dysfunction and that the SOCe machinery may provide crucial therapeutic targets to limit sepsis-induced ALI.

MICU1 is an essential gatekeeper for MCU-mediated mitochondrial Ca(2+) uptake that regulates cell survival

Mitochondrial Ca(2+) (Ca(2+)(m)) uptake is mediated by an inner membrane Ca(2+) channel called the uniporter. Ca(2+) uptake is driven by the considerable voltage present across the inner membrane (ΔΨ(m)) generated by proton pumping by the respiratory chain. Mitochondrial matrix Ca(2+) concentration is maintained five to six orders of magnitude lower than its equilibrium level, but the molecular mechanisms for how this is achieved are not clear. Here, we demonstrate that the mitochondrial protein MICU1 is required to preserve normal [Ca(2+)](m) under basal conditions. In its absence, mitochondria become constitutively loaded with Ca(2+), triggering excessive reactive oxygen species generation and sensitivity to apoptotic stress. MICU1 interacts with the uniporter pore-forming subunit MCU and sets a Ca(2+) threshold for Ca(2+)(m) uptake without affecting the kinetic properties of MCU-mediated Ca(2+) uptake. Thus, MICU1 is a gatekeeper of MCU-mediated Ca(2+)(m) uptake that is essential to prevent [Ca(2+)](m) overload and associated stress.

MCUR1 is an essential component of mitochondrial Ca2+ uptake that regulates cellular metabolism

Ca(2+) flux across the mitochondrial inner membrane regulates bioenergetics, cytoplasmic Ca(2+) signals and activation of cell death pathways. Mitochondrial Ca(2+) uptake occurs at regions of close apposition with intracellular Ca(2+) release sites, driven by the inner membrane voltage generated by oxidative phosphorylation and mediated by a Ca(2+) selective ion channel (MiCa; ref. ) called the uniporter whose complete molecular identity remains unknown. Mitochondrial calcium uniporter (MCU) was recently identified as the likely ion-conducting pore. In addition, MICU1 was identified as a mitochondrial regulator of uniporter-mediated Ca(2+) uptake in HeLa cells. Here we identified CCDC90A, hereafter referred to as MCUR1 (mitochondrial calcium uniporter regulator 1), an integral membrane protein required for MCU-dependent mitochondrial Ca(2+) uptake. MCUR1 binds to MCU and regulates ruthenium-red-sensitive MCU-dependent Ca(2+) uptake. MCUR1 knockdown does not alter MCU localization, but abrogates Ca(2+) uptake by energized mitochondria in intact and permeabilized cells. Ablation of MCUR1 disrupts oxidative phosphorylation, lowers cellular ATP and activates AMP kinase-dependent pro-survival autophagy. Thus, MCUR1 is a critical component of a mitochondrial uniporter channel complex required for mitochondrial Ca(2+) uptake and maintenance of normal cellular bioenergetics.