Abnormal Calcium Research Articles

Updated Perspectives on Keratinocytes and Psoriasis: Keratinocytes are More Than Innocent Bystanders.

Psoriasis is a complex disease triggered by genetic, immunologic, and environmental stimuli. Many genes have been linked to psoriasis, like the psoriasis susceptibility genes, some of which are critical in keratinocyte biology and epidermal barrier function. Still, the exact pathogenesis of psoriasis is unknown. In the disease, the balance between the proliferative and differentiative processes of keratinocytes becomes altered. Multiple studies have highlighted the role of dysregulated immune cells in provoking the inflammatory responses seen in psoriasis. In addition to immune cells, accumulating evidence shows that keratinocytes are involved in psoriasis pathogenesis, as discussed in this review. Although certain immune cell-derived factors stimulate keratinocyte hyperproliferation, activated keratinocytes can also produce anti-microbial peptides, cytokines, and chemokines that can promote their proliferation, as well as recruit immune cells to help initiate and reinforce inflammatory feedback loops. Psoriatic keratinocytes also show intrinsic differences from normal keratinocytes even after removal from the in vivo inflammatory environment; thus, psoriatic keratinocytes have been found to exhibit abnormal calcium metabolism and possible epigenetic changes that contribute to psoriasis. The Koebner phenomenon, in which injury promotes the development of psoriatic lesions, also provides evidence for keratinocytes’ contributions to disease pathogenesis. Furthermore, transgenic mouse studies have confirmed the importance of keratinocytes in the etiology of psoriasis. Finally, in addition to immune cells and keratinocytes, data in the literature support roles for other cell types, tissues, and systems in psoriasis development. These other contributors are all potential targets for therapies, suggesting the importance of a holistic approach when treating psoriasis.

GENÇ DAİMİ DİŞLERDE PARSİYEL PULPOTOMİ TEDAVİSİ

ABSTRACT Partial pulpotomy is a treatment method used to reach healthy pulp tissue by removal of the inflamed pulp tissue in 1-3 mm depth from the caries exposed teeth. Pulpal bleeding should be controlled using bactericidal agents, such as sodium hypochlorite or chlorhexidine, and then the pulp tissue should be covered with a biocompatible material, such as MTA. MTA should be placed on the exposed area and the surrounding dentate with a thickness of at least 1.5 mm and resin modified glass ionomer cement should be applied on it. The tooth must be restored permanently. The remaining pulp tissue after partial pulpotomy should be vital and no adverse signs or symptoms, such as swelling, pain, or tenderness, should be observed after treatment. Radiographically, internal or external root resorption, periapical radiolucency, abnormal calcification, or other pathological changes should not be observed, root development in immature teeth should continue, and the apex should be closed.

New sarcoidosis guidelines: Are we near to perfection?

New sarcoidosis guidelines: Are we near to perfection?

Rewiring of 3D Chromatin Topology Orchestrates Transcriptional Reprogramming and the Development of Human Dilated Cardiomyopathy.

Transcriptional reconfiguration is central to heart failure, the most common cause of which is dilated cardiomyopathy (DCM). The effect of 3-dimensional chromatin topology on transcriptional dysregulation and pathogenesis in human DCM remains elusive. We generated a compendium of 3-dimensional epigenome and transcriptome maps from 101 biobanked human DCM and nonfailing heart tissues through highly integrative chromatin immunoprecipitation (H3K27ac [acetylation of lysine 27 on histone H3]), in situ high-throughput chromosome conformation capture, chromatin immunoprecipitation sequencing, assay for transposase-accessible chromatin using sequencing, and RNA sequencing. We used human induced pluripotent stem cell-derived cardiomyocytes and mouse models to interrogate the key transcription factor implicated in 3-dimensional chromatin organization and transcriptional regulation in DCM pathogenesis. We discovered that the active regulatory elements (H3K27ac peaks) and their connectome (H3K27ac loops) were extensively reprogrammed in DCM hearts and contributed to transcriptional dysregulation implicated in DCM development. For example, we identified that nontranscribing NPPA-AS1 (natriuretic peptide A antisense RNA 1) promoter functions as an enhancer and physically interacts with the NPPA (natriuretic peptide A) and NPPB (natriuretic peptide B) promoters, leading to the cotranscription of NPPA and NPPB in DCM hearts. We revealed that DCM-enriched H3K27ac loops largely resided in conserved high-order chromatin architectures (compartments, topologically associating domains) and their anchors unexpectedly had equivalent chromatin accessibility. We discovered that the DCM-enriched H3K27ac loop anchors exhibited a strong enrichment for HAND1 (heart and neural crest derivatives expressed 1), a key transcription factor involved in early cardiogenesis. In line with this, its protein expression was upregulated in human DCM and mouse failing hearts. To further validate whether HAND1 is a causal driver for the reprogramming of enhancer-promoter connectome in DCM hearts, we performed comprehensive 3-dimensional epigenome mappings in human induced pluripotent stem cell-derived cardiomyocytes. We found that forced overexpression of HAND1 in human induced pluripotent stem cell-derived cardiomyocytes induced a distinct gain of enhancer-promoter connectivity and correspondingly increased the expression of their connected genes implicated in DCM pathogenesis, thus recapitulating the transcriptional signature in human DCM hearts. Electrophysiology analysis demonstrated that forced overexpression of HAND1 in human induced pluripotent stem cell-derived cardiomyocytes induced abnormal calcium handling. Furthermore, cardiomyocyte-specific overexpression of Hand1 in the mouse hearts resulted in dilated cardiac remodeling with impaired contractility/Ca2+ handling in cardiomyocytes, increased ratio of heart weight/body weight, and compromised cardiac function, which were ascribed to recapitulation of transcriptional reprogramming in DCM. This study provided novel chromatin topology insights into DCM pathogenesis and illustrated a model whereby a single transcription factor (HAND1) reprograms the genome-wide enhancer-promoter connectome to drive DCM pathogenesis.

The role of neutrophil elastase in aortic valve calcification

BackgroundCalcific aortic valve disease (CAVD) is the most commonly valvular disease in the western countries initiated by inflammation and abnormal calcium deposition. Currently, there is no clinical drug for CAVD. Neutrophil elastase (NE) plays a causal role in inflammation and participates actively in cardiovascular diseases. However, the effect of NE on valve calcification remains unclear. So we next explore whether it is involved in valve calcification and the molecular mechanisms involved.MethodsNE expression and activity in calcific aortic valve stenosis (CAVD) patients (n = 58) and healthy patients (n = 30) were measured by enzyme-linked immunosorbent assay (ELISA), western blot and immunohistochemistry (IHC). Porcine aortic valve interstitial cells (pVICs) were isolated and used in vitro expriments. The effects of NE on pVICs inflammation, apoptosis and calcification were detected by TUNEL assay, MTT assay, reverse transcription polymerase chain reaction (RT-PCR) and western blot. The effects of NE knockdown and NE activity inhibitor Alvelestat on pVICs inflammation, apoptosis and calcification under osteogenic medium induction were also detected by RT-PCR, western blot, alkaline phosphatase staining and alizarin red staining. Changes of Intracellular signaling pathways after NE treatment were measured by western blot. Apolipoprotein E−/− (APOE−/−) mice were employed in this study to establish the important role of Alvelestat in valve calcification. HE was used to detected the thickness of valve. IHC was used to detected the NE and α-SMA expression in APOE−/− mice. Echocardiography was employed to assess the heat function of APOE−/− mice.ResultsThe level and activity of NE were evaluated in patients with CAVD and calcified valve tissues. NE promoted inflammation, apoptosis and phenotype transition in pVICs in the presence or absence of osteogenic medium. Under osteogenic medium induction, NE silencing or NE inhibitor Alvelestat both suppressed the osteogenic differentiation of pVICs. Mechanically, NE played its role in promoting osteogenic differentiation of pVICs by activating the NF-κB and AKT signaling pathway. Alvelestat alleviated valve thickening and decreased the expression of NE and α-SMA in western diet-induced APOE−/− mice. Alvelestat also reduced NE activity and partially improved the heart function of APOE−/−mice.ConclusionsCollectively, NE is highly involved in the pathogenesis of valve calcification. Targeting NE such as Alvelestat may be a potential treatment for CAVD.

Comparison of calcium levels in patients with benign paroxysmal positional vertigo and the other type of vertigo

Introduction: Benign paroxysmal positional vertigo (BPPV) is commonly found in older women; caused by the presence of otoconia in semicircular canals, which will stimulate the ampulla. Degeneration of otoconia and abnormal calcium metabolism could contribute to BPPV. This study aims to find a difference in serum calcium levels between idiopathic BPPV and non-BPPV vertigo patients. Methods: Cross-sectional study was held in Wahidin Sudirohusodo hospital in Makassar from August to October 2019. Subjects who fulfilled the criteria were divided into two groups (BPPV and non-BPPV). Venous blood was taken to obtain serum calcium levels. Statistical analysis was performed with SPSS software version 21. Chi-square and Mann-Whitney tests were used to determine the relationship between variables. Result: As many as 45 subjects were grouped into BPPV (n=30) and non-BPPV (n=15). Majority of subjects were female (n=30). Mean serum calcium level was significantly lower in BPPV group (8.51±0.67 vs 8.9±0.63; p=0.023). Area under curve of serum calcium level according to vertigo type was 22.4% (p<0.05). Optimal cut-off point for serum calcium level was 8.55 (p=0.024). Discussion: Majority of subjects in this study were females between 40-60 years old. Patients with BPPV tend to have lower serum calcium levels. Possible underlying me-chanisms include estrogen deficiency, otoconial degeneration, vitamin D deficiency, lack of sunlight, and abnormal calcium me-tabolism. Examination of serum calcium level and calcium supplementation could be considered for these patients. Some factors that affect serum calcium level were not considered in this study. It was concluded that examination of serum calcium level and calcium supplementation could be considered for patients with BPPV.

Disorders of Blood Gases, Electrolytes, Magnesium, Albumin and Calcium Metabolism in SARS-CoV-2-infected Patients

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-infection is characterized by several malfunctions, including severe pulmonary disorders. Other metabolic consequences of SARS-CoV-2-infection have not been clearly defined. The present study assessed the status of blood gases, calcium metabolism, and electrolytes in SARS-CoV-2-infected individuals. One hundred and thirty-four newly diagnosed SARS-CoV-2-infected patients (age ranged 65-82years) attending Mullingar Regional Hospital, Republic of Ireland, participated in this study. They all had pulmonary disorders, pyrexia, body pains, etc. SARS-CoV-2 was confirmed in all patients using the RT-PCR molecular test method. The data of another 121 plasma samples of apparently normal, non-SARS-CoV-2-infected individuals taken before the emergence of Covid-19 served as controls. Levels of partial pressure of oxygen (pO2), saturated oxygen (SatO2), partial pressure of carbon dioxide (pCO2), and ionized calcium (Ca2+) were determined in all participants using the potentiometric method in RAPIDPOINT 500 Blood Gases System. Plasma vitamin-D was determined by immune enzymatically technique using DXi 800 Access Immunoassay System. Total calcium, phosphate, albumin, magnesium, and electrolytes were determined by the photometric method using Beckman Au680- Chemistry Analyzer. The results showed significantly (p<0.05) higher levels of pCO2 and HCO3- in COVID-19-patients compared to controls. Significantly(p<0.05) lower levels of pO2, SatO2, pH, K+, albumin, total-calcium, Ca2+, magnesium, and vitamin-D were observed in COVID-19 patients compared to controls. Corrected calcium, PO4-, Na+, and Cl- levels did not show significant (p>0.05) changes in the COVID-19-patients compared to controls. Abnormal blood gases, acidosis, hypomagnesaemia, hypoalbuminemia, hypovitaminosis D and calcium metabolic disorders could be features of COVID-19-disease.

Chronic exposure to tralopyril induced abnormal growth and calcium regulation of turbot (Scophthalmus maximus)

Tralopyril is an emerging marine antifouling agent with limited data on its effects on fish growth and calcium regulation. To determine the changes induced by long-term exposure to tralopyril, multi-levels (such as molecular, biochemical, and individual levels) responses were measured in turbot at different concentrations (1 μg/L, 20 μg/L). The results showed that 1 μg/L mainly affected the immune response, while 20 μg/L affected the synthesis and metabolism of steroids and fat. However, different concentrations of tralopyril affected the synthesis, secretion and action of parathyroid hormone and growth hormone. The expression of GH/IGF axis gene and the level of growth hormone increased significantly, leading to abnormal growth. The energy tradeoff between immunity and growth at 1 μg/L tralopyril pressure may inhibit growth. The change of Ca2+ level was accompanied by the disturbance of PTH-related gene expression. The results of molecular docking showed that the disturbance of Ca2+ regulation might be attributed to the inhibition of vitamin D receptor by tralopyril, which affected the vitamin D signaling pathway. This study provides scientific data for the in-depth understanding and risk assessment of the toxicological effects of tralopyril and reveals the potential threat of tralopyril to environmental health.

Impact of High-Flux Hemodialysis on Chronic Inflammation, Antioxidant Capacity, Body Temperature, and Immune Function in Patients with Chronic Renal Failure.

In order to probe into the impact of high-flux dialysis and hemodiafiltration on patients with chronic rental failure, this paper selects in total 92 cases with chronic renal failure receiving hemodialysis from November 2018 to July 2021, allocating them into two groups based on the random table, each with 46 cases. The control group received hemodiafiltration, the observation group is given high-flux hemodialysis, and we compared serum inflammatory factor level and antioxidant factor level before and after treatment, as well as cellular immune factor level (CD3+, CD4+) and humoral immune factor level (IgE) before and after treatment in the two groups; the renal function, serum total calcium ion level, and serum phosphorus ion level in the two groups were compared before and after treatment, as well as the proportion of metabolic abnormalities in calcium and phosphorus ion levels during treatment; the trend of changes in axillary temperature during treatment in the two groups is analyzed. After treatment, serum inflammatory factor level (hs-CRP & TNF-α) is lower than that in the control group (P < 0.05), antioxidant factor level (MDA) is lower than that in the control group (P < 0.05), and SOD level is higher than that in the control group (P < 05). After treatment CD3+ and CD4+ levels in the observation group are higher than those in the control group (P < 0.05). For patients with chronic renal failure, high-flux hemodialysis is available to better reduce inflammatory response, improve antioxidant and immune capacity in the body, and help maintain calcium and phosphorus metabolic balance.

Micro-CT study on isolated teeth with hereditary dentin defects.

To construct the three-dimensional structure of the isolated teeth of patients with dentinogenesis imperfecta type Ⅱ (DGI-Ⅱ) and dentin dysplasia type Ⅰ (DD-Ⅰ) by using Micro-CT and explore internal structure and hard tissue mineralization density. The three-dimensional structures of the third molars collected from patients with DGI-Ⅱ and DD-Ⅰ and healthy individuals of the same age were reconstructed by using Micro-CT (Mimics 17.0). The internal structures of the affected teeth along the sagittal and transverse planes were observed. The grayscale values of the enamel, crown dentin, and root dentin were calculated. Then, the mineralization densities of the different parts of the teeth of the three groups were analyzed. The detailed three-dimensional models of the mandibular third molars with hereditary dentin defects were successfully constructed. The models contained the models of the enamel cap, dentin core, and pulp cavity. Sagittal and transverse section scans revealed that in patients with DGI-Ⅱ, the pulp cavity was incompletely calcified and the root canal was narrow, whereas in those with DD-Ⅰ, the pulp cavity and root canal were obliterated and the root of the tooth was absent. The analysis of the grayscale values showed that compared with those in the healthy group, the grayscale values of the enamel, crown dentin, and root dentin were lower in the DGI-Ⅱ and DD-Ⅰ groups (P<0.01). No significant differences in the grayscale values of the enamel and crown dentin were found between the DGI-Ⅱ and DD-Ⅰ groups (P>0.05), whereas the grayscale value of the root dentin showed statistically significant differences between the two groups (P<0.01). The application of Micro-CT provided a simple and accurate method for the three-dimensional structure reconstruction and quantitative analysis of the mineralization density of isolated teeth with hereditary dentin defects. Although the dentin mineralization density of DGI-Ⅱ and DD-Ⅰ teeth decreased, the decrement shown by DD-Ⅰ teeth was more significant than that shown by DGI-Ⅱ teeth. The pulp cavity had abnormal calcifications, and the root canal was narrow or even occluded.

Malfunction of airway basal stem cells plays a crucial role in pathophysiology of tracheobronchopathia osteoplastica

Understanding disease-associated stem cell abnormality has major clinical implications for prevention and treatment of human disorders, as well as for regenerative medicine. Here we report a multifaceted study on airway epithelial stem cells in Tracheobronchopathia Osteochondroplastica (TO), an under-detected tracheobronchial disorder of unknown etiology and lack of specific treatment. Epithelial squamous metaplasia and heterotopic bone formation with abnormal cartilage proliferation and calcium deposits are key pathological hallmarks of this disorder, but it is unknown whether they are coincident or share certain pathogenic mechanisms in common. By functional evaluation and genome-wide profiling at both transcriptional and epigenetic levels, we reveal a role of airway basal cells in TO progression by acting as a repository of inflammatory and TGFβ-BMP signals, which contributes to both epithelial metaplasia and mesenchymal osteo-chondrogenesis via extracellular signaling and matrix remodeling. Restoration of microenvironment by cell correction or local pathway intervention may provide therapeutic benefits.

Caveolin-3 and Arrhythmias: Insights into the Molecular Mechanisms.

Caveolin-3 is a muscle-specific protein on the membrane of myocytes correlated with a variety of cardiovascular diseases. It is now clear that the caveolin-3 plays a critical role in the cardiovascular system and a significant role in cardiac protective signaling. Mutations in the gene encoding caveolin-3 cause a broad spectrum of clinical phenotypes, ranging from persistent elevations in the serum levels of creatine kinase in asymptomatic humans to cardiomyopathy. The influence of Caveolin-3(CAV-3) mutations on current density parallels the effect on channel trafficking. For example, mutations in the CAV-3 gene promote ventricular arrhythmogenesis in long QT syndrome 9 by a combined decrease in the loss of the inward rectifier current (IK1) and gain of the late sodium current (INa-L). The functional significance of the caveolin-3 has proved that caveolin-3 overexpression or knockdown contributes to the occurrence and development of arrhythmias. Caveolin-3 overexpression could lead to reduced diastolic spontaneous Ca2+ waves, thus leading to the abnormal L-Type calcium channel current-induced ventricular arrhythmias. Moreover, CAV-3 knockdown resulted in a shift to more negative values in the hyperpolarization-activated cyclic nucleotide channel 4 current (IHCN4) activation curve and a significant decrease in IHCN4 whole-cell current density. Recent evidence indicates that caveolin-3 plays a significant role in adipose tissue and is related to obesity development. The role of caveolin-3 in glucose homeostasis has attracted increasing attention. This review highlights the underlining mechanisms of caveolin-3 in arrhythmia. Progress in this field may contribute to novel therapeutic approaches for patients prone to developing arrhythmia.

Low Turnover Renal Osteodystrophy With Abnormal Bone Quality and Vascular Calcification in Patients With Mild-to-Moderate CKD

IntroductionLimited information is available on renal osteodystrophy (ROD) and vascular calcification (VC) during early chronic kidney disease (CKD). This study was designed to evaluate ROD and VC in 32 patients with CKD stages II to IV.MethodsPatients underwent dual-energy X-ray absorptiometry (DXA) for assessment of bone mineral density (BMD) and trabecular bone score (TBS), thoracic computed tomography for VC scoring using the Agatston method, and anterior iliac crest bone biopsy for mineralized bone histology, histomorphometry, and Fourier transform infrared spectroscopy (FTIR). Classical and novel bone markers were determined in the blood.ResultsMean estimated glomerular filtration rate (eGFR) was 44 ± 16 ml/min per 1.73 m2. Of the patients, 84% had low bone turnover. In Whites, eGFR correlated negatively with the turnover parameter activation frequency (Ac.f) (r −0.48, P = 0.019) and with parameters of bone formation. Most patients had VC (>80%) which correlated positively with levels of phosphorus, c-terminal fibroblast growth factor-23, and activin. Aortic calcifications (ACs) correlated negatively with bone formation rate (BFR) and Ac.f (rho −0.62, −0.61, P < 0.001). TBS correlated negatively with coronary calcification (rho −0.42, P = 0.019) and AC (rho −0.57, P = 0.001). These relationships remained after adjustment of age. The mineral-to-matrix ratio, an FTIR metric reflecting bone quality, was negatively related to Ac.f and positively related to AC.ConclusionLow bone turnover and VC are predominant in early stages of CKD. This is the first study demonstrating mineral abnormalities indicating reduced bone quality in these stages of CKD.

Evaluation of a calcium, magnesium and phosphate clinical ordering tool in the emergency department.

We developed a clinical tool comprising patient risk factors for having an abnormal calcium (Ca), magnesium (Mg) or phosphate (PO4) level. We hypothesized that patients without a risk factor do not require testing. This study examined the tool's potential utility for rationalizing Ca, Mg and PO4 ordering in the emergency department (ED). We undertook a retrospective observational study in a single metropolitan ED. Patients aged 18years or more who presented between July and December 2019 were included if they had a Ca, Mg or PO4 test during their ED stay. Demographic and clinical data, including the presence of risk factors, were extracted from the medical record. The primary outcome was a clinically significant abnormal Ca, Mg or PO4 level (>0.2mmol/l above or below the laboratory reference range). Calcium, Mg and PO4 levels were measured on 1426, 1296 and 1099 patients, respectively. The positive and negative predictive values and likelihood ratios of the tool identifying a patient with a Ca level>0.2mmol/l outside the range were 0.05, 0.99, 1.59 and 0.41, respectively. The values for Mg were 0.02, 1.00, 1.44 and 0.35 and those for PO4 were 0.15, 0.93, 1.38 and 0.57, respectively. The majority of patients not identified as having an abnormal level did not receive electrolyte correction treatment. Application of the tool would have resulted in a 35.8% cost reduction. The tool failed to predict a very small proportion of patients (approximately 1%) with an abnormal Ca or Mg level and for whom it would have been desirable to have these levels measured. It may help rationalize Ca and Mg ordering and reduce laboratory costs.

Common synaptic phenotypes arising from diverse mutations in the human NMDA receptor subunit GluN2A

Dominant mutations in the human gene GRIN2A, encoding NMDA receptor (NMDAR) subunit GluN2A, make a significant and growing contribution to the catalogue of published single-gene epilepsies. Understanding the disease mechanism in these epilepsy patients is complicated by the surprising diversity of effects that the mutations have on NMDARs. Here we have examined the cell-autonomous effect of five GluN2A mutations, 3 loss-of-function and 2 gain-of-function, on evoked NMDAR-mediated synaptic currents (NMDA-EPSCs) in CA1 pyramidal neurons in cultured hippocampal slices. Despite the mutants differing in their functional incorporation at synapses, prolonged NMDA-EPSC current decays (with only marginal changes in charge transfer) were a common effect for both gain- and loss-of-function mutants. Modelling NMDA-EPSCs with mutant properties in a CA1 neuron revealed that the effect of GRIN2A mutations can lead to abnormal temporal integration and spine calcium dynamics during trains of concerted synaptic activity. Investigations beyond establishing the molecular defects of GluN2A mutants are much needed to understand their impact on synaptic transmission.

Various facets of excitotoxicity

Aim: Excitotoxicity results from unusually increased activation of excitatory amino acid receptors leading to neuronal death. Since glutamate is the main excitatory neurotransmitter in the central nervous system, it is also the most common excitotoxicity trigger. This uncontrolled neuronal response participates in various neurodegenerative diseases, such as ischemia, hypoglycemia, Huntington’s, Parkinson’s and Alzheimer’s disease. Thus, the investigation in the field expanded a lot in the past decade, leading to in vitro modelling adaptations. However, much performed work on glutamate-induced excitotoxicity is methodologically inconsistent in the literature. The field lacks reproducibility, which is one of the main fundaments of empirical science. In this regard, the literature was summarized and the main methodological features were critically evaluated, aiming to guide the researchers that are starting in the field. Methods: Published data since 1985 from PUBMED were collected and analyzed to observe which in vitro experimental conditions of excitotoxicity were reproducible. The suggested methods were based on the characteristics of excitotoxicity, such as abnormal intracellular calcium mediated signaling, mitochondria impairment, reactive oxygen species accumulation and cell death. Various conditions and comparative controls were used to design the standard investigation of excitotoxicity, such as culture medium content (presence of glutamate and aspartate), time interval of induction and the concentration of the inductor, based on the most reproducible published ones. Results: Our results and critical analysis point to some experimental conditions to consider, such as primary cultured neurons are more sensitive to glutamate and the response obtained is more robust than in other models; excitotoxicity mediated effects are better observed one hour following the stimulus; the culture medium should contain low levels of glutamate or aspartate or glycine. Online available phosphoproteomic data on excitotoxicity using the primary cortical neurons in vitro model supported the same conditions proposed by us. Conclusions: This manuscript will facilitate the design of any research for excitotoxic or neuroprotective compounds in physiological and pathophysiological conditions by standardizing and improving experimental conditions.

Delayed intrinsicoid deflection: Electrocardiographic harbinger of heart disease.

Delayed intrinsicoid deflection (DID) is an emerging electrocardiogram (ECG) marker of major clinical significance that is increasingly getting attention. Intrinsicoid deflection measures ventricular depolarization in the initial portion of the QRS complex, and DID is defined as an R wave peak time of ≥50 ms in leads V5 and V6. Prior studies have identified an independent association between DID and cardiovascular conditions such as left ventricular hypertrophy, heart failure, and sudden cardiac death. The exact mechanism that results in DID remains unknown. Animal models indicate that DID may result from abnormal calcium and potassium conductance as well as extracellular matrix remodeling. DID remains an ECG marker of interest given its potential predictive value of underlying cardiovascular pathology and adverse events. This review provides an update on the proposed mechanisms and associations, as well as the clinical and research implications of DID.

Interaction of Mitochondrial Calcium and ROS in Neurodegeneration.

Neurodegenerative disorders are currently incurable devastating diseases which are characterized by the slow and progressive loss of neurons in specific brain regions. Progress in the investigation of the mechanisms of these disorders helped to identify a number of genes associated with familial forms of these diseases and a number of toxins and risk factors which trigger sporadic and toxic forms of these diseases. Recently, some similarities in the mechanisms of neurodegenerative diseases were identified, including the involvement of mitochondria, oxidative stress, and the abnormality of Ca2+ signaling in neurons and astrocytes. Thus, mitochondria produce reactive oxygen species during metabolism which play a further role in redox signaling, but this may also act as an additional trigger for abnormal mitochondrial calcium handling, resulting in mitochondrial calcium overload. Combinations of these factors can be the trigger of neuronal cell death in some pathologies. Here, we review the latest literature on the crosstalk of reactive oxygen species and Ca2+ in brain mitochondria in physiology and beyond, considering how changes in mitochondrial metabolism or redox signaling can convert this interaction into a pathological event.

Chondrocyte-derived exosomes promote cartilage calcification in temporomandibular joint osteoarthritis

BackgroundsAbnormal cartilage calcification is one of the pathological changes of temporomandibular joint (TMJ) osteoarthritis (OA). Recent studies have reported that exosomes can regulate the formation of abnormal calcified nodules in diseases including atherosclerosis and chronic kidney disease. However, the influences of chondrocyte-derived exosomes on abnormal cartilage calcification in TMJ OA are still unclear.MethodsTMJ OA was induced by unilateral anterior crossbite (UAC) for 4, 8, or 12 weeks in rats to observe abnormal calcification in TMJ condylar cartilage and exosome formation. Concomitantly, GW4869, the inhibitor of exosome formation, was locally injected to the TMJ of rats under stimulation of UAC, while the exosomes extracted from primary condylar chondrocytes stimulated with fluid flow shear stress (FFSS) were locally injected to rats TMJ.ResultsAbnormal calcification was enhanced in the degenerative cartilage of TMJ OA in UAC rats, and a large number of exosome-like structures with diameters of 50-150 nm were found in the calcified cartilage together with decreased expression of matrix Gla protein (MGP) and increased expression of CD63, tissue-nonspecific alkaline phosphatase (TNAP) and nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1). After FFSS stimulation, the number of exosomes secreted by chondrocytes and the numbers of calcified nodules were increased in cultured cells, and the protein levels of MGP, TNAP, and NPP1 in exosomes were changed. Inhibition of exosome formation, TNAP, and NPP1 or supplementation with exogenous MGP effectively alleviated FFSS-induced chondrocyte calcification. Local injection of GW4869, the exosome inhibitor, alleviated TMJ OA-related cartilage degeneration and calcification in UAC rats. Local injection of exosomes obtained from chondrocytes stimulated by FFSS to the TMJs of normal rats induced cartilage degeneration and calcification similar to that in TMJ OA.ConclusionsAbnormal biomechanical loading leads to enhanced formation of chondrocyte-derived exosomes, in which promoters of calcification increased and inhibitors decreased, resulting in accelerating abnormal cartilage calcification in TMJ OA. The inhibition of degenerative chondrocyte-derived exosomes is expected to be a new way to prevent and treat TMJ OA.

Histopathology of Duchenne muscular dystrophy in correlation with changes in proteomic biomarkers.

Duchenne muscular dystrophy is an inherited disorder of early childhood that affects multiple systems in the body. Besides late-onset cardio-respiratory syndrome and various body-wide pathophysiological changes, X-linked muscular dystrophy is primarily classified as a disorder of the skeletal musculature. This is reflected by severe histopathological alterations in voluntary contractile tissues, including progressive fibre degeneration, fat substitution, reactive myofibrosis and chronic inflammation. The underlying cause for dystrophinopathy are genetic abnormalities in the DMD gene, which can result in the almost complete loss of the membrane cytoskeletal protein dystrophin, which triggers the collapse of the dystrophin-associated glycoprotein complex and disintegration of sarcolemmal integrity. This in turn results in an increased frequency of membrane micro-rupturing and abnormal calcium ion fluxes through the impaired plasmalemma, which renders muscle fibres more susceptible to enhanced proteolytic degradation and necrosis. This review focuses on the complexity of skeletal muscle changes in X-linked muscular dystrophy and outlines cell biological and histological alterations in correlation to proteome-wide variations as judged by mass spectrometric analyses. This includes a general outline of sample handling, subcellular fraction protocols and modern proteomic approaches using gel electrophoretic and liquid chromatographic methods for efficient protein separation prior to mass spectrometry. The proteomic profiling of the dystrophic and highly fibrotic diaphragm muscle is described as an example to swiftly identify novel proteomic markers of complex histopathological changes during skeletal muscle degeneration. The potential usefulness of new protein markers is examined in relation to key histopathological hallmarks for establishing improved diagnostic, prognostic and therapy-monitoring approaches in the field of dystrophinopathy.