Carbon monoxide-induced autophagy enhances human mesenchymal stromal cell function via paracrine actions in murine polymicrobial sepsis

Sepsis is a life-threatening process due to organ dysfunction resulting from severe infections. Mesenchymal stromal cells (MSCs) are being investigated as therapy for sepsis, along with conditioning regimens to improve their function. Carbon monoxide (CO) gas, which is cytoprotective at low doses, induces autophagy and is a mediator of inflammation. We evaluated CO-induced autophagy in human MSCs (hMSCs), and its impact on cell function in murine cecal ligation and puncture. Conditioning of hMSCs with CO ex vivo resulted in enhanced survival and bacterial clearance in vivo, and neutrophil phagocytosis of bacteria in vitro. Decreased neutrophil infiltration and less parenchymal cell death in organs were associated with increased macrophage efferocytosis of apoptotic neutrophils, promoting resolution of inflammation. These CO effects were lost when the cells were exposed to autophagy inhibition prior to gas exposure. When assessing paracrine actions of CO-induced autophagy, extracellular vesicles (EVs) were predominantly responsible. CO had no effect on EV production, but altered their miRNA cargo. Increased expression of miR-145-3p and miR-193a-3p by CO was blunted with disruption of autophagy, and inhibitors of these miRNAs led to a loss of neutrophil phagocytosis and macrophage efferocytosis. Collectively, CO-induced autophagy enhanced hMSC function during sepsis via paracrine actions of MSC-derived EVs.

Epigallocatechin-3-gallate restores mitochondrial homeostasis impairment by inhibiting HDAC1-mediated NRF1 histone deacetylation in cardiac hypertrophy

Decompensated cardiac hypertrophy is accompanied by impaired mitochondrial homeostasis, whether histone acetylation is involved in this process is yet to be determined. The role of HDAC1-mediated NRF1 histone deacetylation was investigated in transverse aortic constriction (TAC)-induced hypertrophy in rats and phenylephrine (PE)-induced hypertrophic cardiomyocytes. Administration of epigallocatechin-3-gallate (EGCG), an inhibitor of HDAC1, restored cardiac function, decreased heart/body weight and fibrosis, increased the ratio of mtDNA/nDNA and the percentage of LysoTracker+ CMs in TAC, compared with TAC without receiving EGCG. In PE-treated hypertrophic H9C2 cells, EGCG attenuated cell hypertrophy and increased LC3B II+MitoTracker+ puncta, as well as the ratio of mtDNA/nDNA. Interestingly, NRF1 but not PGC-1α expression was decreased in TAC- or PE-induced hypertrophic hearts or cells, respectively, while EGCG upregulated both NRF1 and PGC-1α in vitro. EGCG treatment also increased the interaction between PGC-1α and NRF1. In addition to inhibiting HDAC1 expression, EGCG decreased the binding of HDAC1 and increased the binding of acH3K9 or acH3K14 in the promotor regions of PGC-1α and NRF1. In neonatal rat cardiomyocytes, restored NRF1, TFAM and FUNDC1 were abolished by the overexpression of HDAC1. Collectively, data suggest that NRF1 reduction was averted by EGCG via inhibiting HDAC1-mediated histone deacetylation. Acetylation of NRF1 histone may play a key role in maintaining mitochondrial homeostasis associated with cardiac hypertrophy.

Clinical feature, GALC variant spectrum, and genotype-phenotype correlation in Korean Krabbe disease patients: Multicenter experience over 13 years

Krabbe disease (KD) is an autosomal recessive neurodegenerative disorder caused by deficiency of the galactocerebrosidase (GALC) due to variants in the GALC gene. Here, we provide the first and the largest comprehensive analysis of clinical and genetic characteristics, and genotype-phenotype correlations of KD in Korean in comparison with other ethnic groups. From June 2010 to June 2023, 10 patients were diagnosed with KD through sequencing of GALC. Clinical features, and results of GALC sequencing, biochemical test, neuroimaging, and neurophysiologic test were obtained from medical records. An additional nine previously reported Korean KD patients were included for review. In Korean KD patients, the median age of onset was 2 years (3 months-34 years) and the most common phenotype was adult-onset (33%, 6/18) KD, followed by infantile KD (28%, 5/18). The most frequent variants were c.683_694delinsCTC (23%) and c.1901T>C (23%), while the 30-kb deletion was absent. Having two heterozygous pathogenic missense variants was associated with later-onset phenotype. Clinical features were similar to those of other ethnic groups. In Korean KD patients, the most common phenotype was the adult-onset type and the GALC variant spectrum was different from that of the Caucasian population. This study would further our understanding of KD.

Discovery of N-benzylbenzamide-based allosteric inhibitors of Aurora kinase A

Aurora kinases (AurkA/B/C) regulate the assembly of bipolar mitotic spindles and the fidelity of chromosome segregation during mitosis, and are attractive therapeutic targets for cancers. Numerous ATP-competitive AurkA inhibitors have been developed as potential anti-cancer agents. Recently, a few allosteric inhibitors have been reported that bind to the allosteric Y-pocket within AurkA kinase domain and disrupt the interaction between AurkA and its activator TPX2. Herein we report a novel allosteric AurkA inhibitor (6h) of N-benzylbenzamide backbone. Compound 6h suppressed the both catalytic activity and non-catalytic functions of AurkA. The inhibitory activity of 6h against AurkA (IC50 = 6.50 μM) was comparable to that of the most potent allosteric AurkA inhibitor AurkinA. Docking analysis against the Y-pocket revealed important pharmacophores and interactions that were coherent with structure-activity relationship. In addition, 6h suppressed DNA replication in G1-S phase, which is a feature of allosteric inhibition of AurA. Our current study may provide a useful insight in designing potent allosteric AurkA inhibitors.

Striated preferentially expressed gene deficiency leads to mitochondrial dysfunction in developing cardiomyocytes

A deficiency of striated preferentially expressed gene (Speg), a member of the myosin light chain kinase family, results in abnormal myofibril structure and function of immature cardiomyocytes (CMs), corresponding with a dilated cardiomyopathy, heart failure and perinatal death. Mitochondrial development plays a role in cardiomyocyte maturation. Therefore, this study investigated whether Speg deficiency ( - / - ) in CMs would result in mitochondrial abnormalities. Speg wild-type and Speg-/- C57BL/6 littermate mice were utilized for assessment of mitochondrial structure by transmission electron and confocal microscopies. Speg was expressed in the first and second heart fields at embryonic (E) day 7.5, prior to the expression of mitochondrial Na+/Ca2+/Li+ exchanger (NCLX) at E8.5. Decreases in NCLX expression (E11.5) and the mitochondrial-to-nuclear DNA ratio (E13.5) were observed in Speg-/- hearts. Imaging of E18.5 Speg-/- hearts revealed abnormal mitochondrial cristae, corresponding with decreased ATP production in cells fed glucose or palmitate, increased levels of mitochondrial superoxide and depolarization of mitochondrial membrane potential. Interestingly, phosphorylated (p) PGC-1α, a key mediator of mitochondrial development, was significantly reduced in Speg-/- hearts during screening for targeted genes. Besides Z-line expression, Speg partially co-localized with PGC-1α in the sarcomeric region and was found in the same complex by co-immunoprecipitation. Overexpression of a Speg internal serine/threonine kinase domain in Speg-/- CMs promoted translocation of pPGC-1α into the nucleus, and restored ATP production that was abolished by siRNA-mediated silencing of PGC-1α. Our results demonstrate a critical role of Speg in mitochondrial development and energy metabolism in CMs, mediated in part by phosphorylation of PGC-1α.

Autophagy mediates an amplification loop during ferroptosis

Ferroptosis, a programmed cell death, has been identified and associated with cancer and various other diseases. Ferroptosis is defined as a reactive oxygen species (ROS)-dependent cell death related to iron accumulation and lipid peroxidation, which is different from apoptosis, necrosis, autophagy, and other forms of cell death. However, accumulating evidence has revealed a link between autophagy and ferroptosis at the molecular level and has suggested that autophagy is involved in regulating the accumulation of iron-dependent lipid peroxidation and ROS during ferroptosis. Understanding the roles and pathophysiological processes of autophagy during ferroptosis may provide effective strategies for the treatment of ferroptosis-related diseases. In this review, we summarize the current knowledge regarding the regulatory mechanisms underlying ferroptosis, including iron and lipid metabolism, and its association with the autophagy pathway. In addition, we discuss the contribution of autophagy to ferroptosis and elucidate the role of autophagy as a ferroptosis enhancer during ROS-dependent ferroptosis.

Comprehensive Evaluation of the NeoBase 2 Non-derivatized MSMS Assay and Exploration of Analytes With Significantly Different Concentrations Between Term and Preterm Neonates

Background

Despite the popularity of the NeoBase 2 Non-derivatized MSMS assay (PerkinElmer, Turku, Finland), there are no reports of its comprehensive evaluation, including the ability to distinguish transient tyrosinemia of the newborn (TTN) from tyrosinemia type 1 (TYR 1) using succinylacetone (SUAC). No newborn screening (NBS) cutoffs for preterm neonates in the Korean population have been suggested. We evaluated the NeoBase 2 assay and identified analytes requiring different cutoffs in preterm neonates.

Methods

Residual NBS dried blood spot samples and proficiency testing (PT) materials of the Newborn Screening Quality Assurance Program and the Korean Association of External Quality Assessment Service were used. Precision, accuracy, limit of detection (LOD), lower limit of quantification (LLOQ), linearity, recovery, carryover, and performance of SUAC were evaluated. Cutoffs were determined, and analytes requiring different cutoffs in preterm neonates were investigated.

Results

Mean CVs for within-run and between-day precision were within 15%. Accuracy analysis indicated high agreement with in-house derivatized assay results and results of other PT participants. All analytes demonstrated acceptable LOD, LLOQ, and linearity. Recoveries were acceptable, except for SUAC. Carryover was negligible. Cutoffs were established for all analytes; Tyr, adenosine, and C20:0-lysophosphatidylcholine required different cutoffs in preterm neonates. Differential diagnosis of TYR 1 and TTN was successful with simultaneous Tyr and SUAC measurement.

Conclusions

The NeoBase 2 assay demonstrated satisfactory performance. The additional analytes provide a wider diagnostic coverage, and the simultaneous measurement of Tyr and SUAC is efficient in excluding TYR 1. The new cutoffs for preterm neonates may decrease false-positive rates, without compromising diagnostic sensitivity.

Diagnostic Performance of Interferon Gamma Release Assay (IGRA) for Cell-Mediated Immune Responses to SARS-CoV-2

BACKGROUND

As SARS-CoV-2 infection became a pandemic, much effort has been made to measure both antibody production and T cell response to SARS-CoV-2 to diagnose COVID-19 patients or find out their immune status. Authors tried to determine the optimal cutoff value and evaluate clinical performance of one interferon-γ release assay (IGRA) kit and compared their results with serological antibody assay in COVID-19 patients.

METHODS

Study subjects included 100 patients confirmed as COVID-19 with RT-PCR method and 88 healthy volunteers who were PCR negative. IGRA tests were performed using STANDARDTM E Covi-FERON ELISA. Presence of SARS-CoV-2 antibodies was detected using STANDARD Q COVID-19 IgM/IgG Plus Test. Cutoff value was assessed using receiver operating characteristic (ROC) curve.

RESULTS

The cutoff value was 0.24 IU/mL and the area under the curve (AUC) of the ROC curve was 0.973 with 95% confidence interval (CI) of 0.940 - 1.005. At this cutoff value, sensitivity and specificity were 91.7% and 100%, respectively. In addition, when compared with antibody test, concordance rate was 95%.

CONCLUSIONS

STANDARDTM E Covi-FERON ELISA showed high sensitivity and specificity, when the cutoff value was 0.24 IU/mL. It was also consistent with the antibody test. IGRA test was a good indicator of cellular immune response in COVID-19 patients.

Evaluation of two SARS-CoV-2 IgG/IgM Rapid Tests in Capillary Blood Samples

BACKGROUND

As COVID-19 has spread rapidly around the world, it has become essential to detect the virus quickly and accurately for disease prevention and control. Therefore, in response to the COVID-19 pandemic, the need for rapid serological point-of-care test has increased. Recently, many antibody tests have been developed to detect IgM and/or IgG to SARS-CoV-2 in human blood. The authors conducted a prospective study to evaluate the performance of a rapid chromatographic immunoassay and a fluorescent immunoassay for the qualitative detection of specific antibodies, IgM and IgG to SARS-CoV-2 in capillary blood samples, compared to the real-time RT-PCR.

METHODS

The subjects included 70 patients who were confirmed positive by real-time RT-PCR and 70 people who were negative. STANDARD Q COVID-19 IgM/IgG Plus Test (chromatographic immunoassay) and Fluorescent immunoassay for IgM and IgG to SARS-CoV-2 (fluorescent immunoassay) were performed using capillary blood samples. Based on the results of real-time RT-PCR assay, clinical sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of two rapid tests were investigated. And the agreement rate between two rapid tests was also presented.

RESULTS

Sensitivity, specificity, PPV and NPV of the chromatographic immunoassay were 82.9%, 98.6%, 98.3%, and 85.2%, respectively. At more than 7 days after the onset of symptoms, sensitivity increased to 87.3%. Sensitivity, specificity, PPV, and NPV were 81.4%, 100.0%, 100.0%, and 84.3%, respectively, for the fluorescent immunoassay. At more than 7 days after the onset of symptoms, sensitivity increased to 85.7%. The agreement rate of the two tests was 97.1%.

CONCLUSIONS

STANDARD Q COVID-19 IgM/IgG Plus Test and STANDARD F COVID-19 IgM/IgG Combo FIA turned out very specific and sensitive enough to detect individuals infected to SARS-CoV-2. Also, these tests were simple, fast, visually interpretable, and required a small amount of capillary whole blood.

Severe congenital neutropenia mimicking chronic idiopathic neutropenia: a case report

Severe chronic neutropenia is classified as severe congenital, cyclic, autoimmune, or idiopathic. However, there is a lot of uncertainty regarding the diagnosis of severe congenital neutropenia (SCN) and chronic idiopathic neutropenia, and this uncertainty affects further evaluations and treatments. A 20-year-old man presented with fever and knee abrasions after a bicycle accident. On admission, his initial absolute neutrophil count (ANC) was 30/µL. He had no medical history of persistent severe neutropenia with periodic oscillation of ANC. Although his fever resolved after appropriate antibiotic therapy, ANC remained at 80/µL. Bone marrow (BM) aspiration and biopsy were performed, and a BM smear showed myeloid maturation arrest. Moreover, genetic mutation test results showed a heterozygous missense variant in exon 4 of the neutrophil elastase ELANE: c597+1G>C (pV190-F199del). The patient was diagnosed with SCN. After discharge, we routinely checked his ANC level and monitored any signs of infection with minimum use of granulocyte colony-stimulating factor (G-CSF), considering its potential risk of leukemic transformation. Considering that SCN can be fatal, timely diagnosis and appropriate management with G-CSF are essential. We report the case of a patient with SCN caused by ELANE mutation who had atypical clinical manifestations. For a more accurate diagnosis and treatment of severe chronic neutropenia, further studies are needed to elucidate the various clinical features of ELANE.

Changes in the Distribution of Respiratory Microorganisms before and during the COVID-19 Pandemic, Daegu, Korea

BACKGROUND

Acute respiratory infection (ARI) is the most common infectious disease in all ages and genders worldwide. Respiratory microorganisms such as respiratory viruses, are commonly responsible for causing ARI. COVID-19 is still prevalent in Korea. The implementation of lockdown and strict control measures, the mandatory wearing of masks, and social distancing are critical steps for controlling the risk of COVID-19 spread. This study was conducted to find out how these changes in daily lives impacted the distribution of respiratory microorganisms.

METHODS

A retrospective study was conducted to identify the incidence and distribution patterns of ARI-causing respiratory microorganisms before (Period Ⅰ) and during the COVID-19 pandemic (Period Ⅱ) in terms of detection method, age, month, and season. In particular, data in Periods Ⅰ and Ⅱ were compared for eight major kinds of respiratory microorganisms: adenovirus (AdV), human metapneumovirus (HMPV), human rhinovirus/enterovirus (Rhino/Entero), influenza virus (Flu) A, Flu B, human parainfluenza virus (HPIV) 3, respiratory syncytial virus, and Mycoplasma pneumoniae.

RESULTS

A total of 27,191 respiratory specimens were tested, of which 5,513 were obtained from children and adolescents (age groups 1 ⁓ 5) and 21,678 from adults (age group 6). The overall positive rates for at least one respiratory microorganism in Periods Ⅰ and Ⅱ were 23.1% (1,199/5,193) and 4.9% (1,070/21,998), respectively (p < 0.001). The overall positive rates in male and female patients were significantly different (8.7% vs. 7.9%; p = 0.016). On the FilmArray™ RP assay, positive rates in all age groups decreased significantly in Period Ⅱ compared with Period Ⅰ. AdV, Rhino/Entero, and Flu A were detected in all four seasons, but HMPV and HPIV3 were not detected. The overall positive rates on FilmArray and the Flu antigen test in Period Ⅱ were significantly decreased. In the COVID-19 test, the positive rates were high in March and April 2020, and decreased thereafter, but these increased again in the winter of 2020/2021.

CONCLUSIONS

Life changes due to COVID-19 pandemic have had a significant impact on the distribution of respiratory microorganisms; our study results might provide useful information on respiratory virus epidemiology.

Patients presenting high fever with lymphadenopathy after COVID-19 vaccination were diagnosed with hemophagocytic lymphohistiocytosis

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still continuing worldwide. Currently, two mRNA-based vaccines and two DNA vaccines using an adenovirus vector are representative vaccines. Since the SARS-CoV-2 vaccines began to be administered, a significant decrease in new infections and COVID-19-associated death has been reported. However, various adverse events from mild symptoms to death have also been described after vaccination.

CASE DESCRIPTION

Patients with high fever and lymphadenopathy who are diagnosed with hemophagocytic lymphohistiocytosis (HLH) after COVID-19 vaccination are very rare, and there is no standard management guideline for these patients thus far. Herein, we described two cases of HLH after the administration of an mRNA-based vaccine and adenovirus vector vaccine.

DISCUSSION

HLH is a life-threatening hyperinflammatory syndrome that occurs due to persistent stimulation of lymphocytes and histiocytes in various underlying conditions at all ages. Although the exact mechanisms and risk factors of COVID-19 vaccination-related HLH are still unknown, vigorous immune stimulation may trigger a huge cytokine storm, rarely resulting in HLH. It is important to note that early suspicion by clinicians can lower the mortality rate.

Prenatal diagnosis of combined methylmalonic acidemia and homocystinuria cobalamin C type using clinical exome sequencing and targeted gene analysis

Background

Combined methylmalonic acidemia and homocystinuria is a rare inherited disorder of intracellular cobalamin metabolism caused by biallelic variants in one of the following genes: MMACHC (cblC), MMADHC (cblD), LMBRD1 (cblF), ABCD4 (cblJ), THAP11 (cblX‐like), and ZNF143 (cblX‐like), or a hemizygous variant in HCFC1 (cblX). Prenatal diagnosis of combined methylmalonic acidemia with homocystinuria is crucial for high‐risk couples since the disorder can be life‐threatening for offspring. We would like to describe two infant deaths both of which are likely attributable to cblC despite not having a genetic confirmation, and subsequent pregnancy and prenatal genetic testing.

Methods

Parental clinical exome sequencing and targeted Sanger sequencing of MMACHC gene in amniotic fluid was performed to check the carrier status of the fetus.

Results

Parental clinical exome sequencing revealed a heterozygous pathogenic variant [NM_015506.2:c.217C>T (p.Arg73*)] in the MMACHC gene of the mother and [NM_015506.2:c.609G>A (p.Trp203*)] in the MMACHC gene of the father. Targeted Sanger sequencing of MMACHC gene in amniotic fluid revealed that the fetus carried only one nonsense variant [NM_015506.2:c.609G>A (p.Trp203*)], which was inherited from the father. The mother delivered a healthy baby and the neonate did not show any symptoms or signs of combined methylmalonic acidemia and homocystinuria after birth.

Conclusion

We present a case of prenatal diagnosis with parental exome sequencing, which successfully diagnosed the carrier status of the fetus and parents in a combined methylmalonic acidemia and homocystinuria family.

Mesenchymal stromal cell-derived syndecan-2 regulates the immune response during sepsis to foster bacterial clearance and resolution of inflammation

Sepsis is a life-threatening process related to a dysregulated host response to an underlying infection, which results in organ dysfunction and poor outcomes. Therapeutic strategies using mesenchymal stromal cells (MSCs) are under investigation for sepsis, with efforts to improve cellular utility. Syndecan (SDC) proteins are transmembrane proteoglycans involved with cellular signaling events including tissue repair and modulating inflammation. Bone marrow-derived human MSCs express syndecan-2 (SDC2) at a level higher than other SDC family members; thus, we explored SDC2 in MSC function. Administration of human MSCs silenced for SDC2 in experimental sepsis resulted in decreased bacterial clearance, and increased tissue injury and mortality compared with wild-type MSCs. These findings were associated with a loss of resolution of inflammation in the peritoneal cavity, and higher levels of proinflammatory mediators in organs. MSCs silenced for SDC2 had a decreased ability to promote phagocytosis of apoptotic neutrophils by macrophages in the peritoneum, and also a diminished capability to convert macrophages from a proinflammatory to a proresolution phenotype via cellular or paracrine actions. Extracellular vesicles are a paracrine effector of MSCs that may contribute to resolution of inflammation, and their production was dramatically reduced in SDC2-silenced human MSCs. Collectively, these data demonstrate the importance of SDC2 for cellular and paracrine function of human MSCs during sepsis.

Sulfasalazine attenuates tamoxifen-induced toxicity in human retinal pigment epithelial cells

Tamoxifen, a nonsteroidal estrogen receptor (ER) antagonist, is used routinely as a chemotherapeutic agent for ER-positive breast cancer. However, it is also causes side effects, including retinotoxicity. The retinal pigment epithelium (RPE) has been recognized as the primary target of tamoxifen-induced retinotoxicity. The RPE plays an essential physiological role in the normal functioning of the retina. Nonetheless, potential therapeutic agents to prevent tamoxifen-induced retinotoxicity in breast cancer patients have not been investigated. Here, we evaluated the action mechanisms of sulfasalazine against tamoxifen- induced RPE cell death. Tamoxifen induced reactive oxygen species (ROS)-mediated autophagic cell death and caspase-1-mediated pyroptosis in RPE cells. However, sulfasalazine reduced tamoxifen-induced total ROS and ROS-mediated autophagic RPE cell death. Also, mRNA levels of tamoxifen-induced pyroptosis-related genes, IL-1β, NLRP3, and procaspase-1, also decreased in the presence of sulfasalazine in RPE cells. Additionally, the mRNA levels of tamoxifen-induced AMD-related genes, such as complement factor I (CFI), complement factor H (CFH), apolipoprotein E (APOE), apolipoprotein J (APOJ), toll-like receptor 2 (TLR2) and toll-like receptor 4 (TLR4), were downregulated in RPE cells. Together, these data provide novel insight into the therapeutic effects of sulfasalazine against tamoxifen-induced RPE cell death. [BMB Reports 2020; 53(5): 284-289].

Nucleotide-binding oligomerization domain protein 2 attenuates ER stress-induced cell death in vascular smooth muscle cells

Nucleotide-binding oligomerization domain protein 2 (NOD2), an intracellular pattern recognition receptor, plays important roles in inflammation and cell death. Previously, we have shown that NOD2 is expressed in vascular smooth muscle cells (VSMCs) and that NOD2 deficiency promotes VSMC proliferation, migration, and neointimal formation after vascular injury. However, its role in endoplasmic reticulum (ER) stress-induced cell death in VSMCs remains unclear. Thus, the objective of this study was to evaluate ER stress-induced viability of mouse primary VSMCs. NOD2 deficiency increased ER stress-induced cell death and expression levels of apoptosis mediators (cleaved caspase-3, Bax, and Bak) in VSMCs in the presence of tunicamycin (TM), an ER stress inducer. In contrast, ER stress-induced cell death and expression levels of apoptosis mediators (cleaved caspase-3, Bax, and Bak) were decreased in NOD2-overexpressed VSMCs. We found that the IRE-1α-XBP1 pathway, one of unfolded protein response branches, was decreased in NOD2-deficient VSMCs and reversed in NOD2-overexpressed VSMCs in the presence of TM. Furthermore, NOD2 deficiency reduced the expression of XBP1 target genes such as GRP78, PDI-1, and Herpud1, thus improving cell survival. Taken together, these data suggest that the induction of ER stress through NOD2 expression can protect against TM-induced cell death in VSMCs. These results may contribute to a new paradigm in vascular homeostasis. [BMB Reports 2019; 52(11): 665-670].

Nucleotide-binding oligomerization domain protein 2 deficiency enhances CHOP expression and plaque necrosis in advanced atherosclerotic lesions

Endoplasmic reticulum (ER) stress-induced cell death of vascular smooth muscle cells (VSMCs) is extensively involved in atherosclerotic plaque stabilization. We previously reported that nucleotide-binding oligomerization domain protein 2 (NOD2) participated in vascular homeostasis and tissue injury. However, the role and underlying mechanisms of NOD2 remain unknown in ER stress-induced cell death of VSMC during vascular diseases, including advanced atherosclerosis. Here, we report that NOD2 specifically interacted with ER stress sensor activating transcription factor 6 (ATF6) and suppressed the expression of proapoptotic transcription factor CHOP (C/EBP homologous protein) during ER stress. CHOP-positive cells were increased in neointimal lesions after femoral artery injury in NOD2-deficient mice. In particular, a NOD2 ligand, MDP, and overexpression of NOD2 decreased CHOP expression in wild-type VSMCs. NOD2 interacted with an ER stress sensor molecule, ATF6, and acted as a negative regulator for ATF6 activation and its downstream target molecule, CHOP, that regulates ER stress-induced apoptosis. Moreover, NOD2 deficiency promoted disruption of advanced atherosclerotic lesions and CHOP expression in NOD2^-/- ApoE^-/- mice. Our findings indicate an unsuspected critical role for NOD2 in ER stress-induced cell death.

Myeloperoxidase Deficiency Manifesting as Pseudoneutropenia with Low Mean Peroxidase Index and High Monocyte Count in 4 Adult Patients

Myeloperoxidase (MPO) deficiency, one of the most common inherited phagocyte defects, and may exist as a transient phenomenon in combination with some clinical condition. Hematological analyzer ADVIA 2120i is used to identify the different types of leukocytes based on their size and staining properties, and by mean peroxidase index (MPXI). When MPO deficiency is present, neutrophils may be incorrectly counted as monocytes with lower MPXI values. We encountered a few cases of MPO deficiency with abnormally high monocytes counts resulting in pseudoneutropenia. These abnormal reports could lead to a mistaken diagnosis of severe neutropenia, which could result in unnecessary therapy. Manual differential count exhibited the normal differential count in every case. Every case yielded a markedly low MPXI value below -20. In conclusion, we suggest that MPO deficiency must be considered in patients especially when abnormally high monocyte counts combined with low MPXI values are observed.

Oxidative Stress-Induced Pentraxin 3 Expression Human Retinal Pigment Epithelial Cells is Involved in the Pathogenesis of Age-Related Macular Degeneration

(1) Background: Age-related macular degeneration (AMD) is closely related with retinal pigment epithelial (RPE) cell dysfunction. Although the exact pathogenesis of AMD remains largely unknown, oxidative stress-induced RPE damage is believed to be one of the primary causes. We investigated the molecular mechanisms of pentraxin 3 (PTX3) expression and its biological functions during oxidative injury. (2) Methods: Using enzyme-linked immunosorbent assays and real-time reverse transcription-polymerase chain reaction, we analyzed mRNA and protein levels of PTX3 in the presence or absence of oxidative stress inducer, sodium iodate (NaIO₃), in primary human H-RPE and ARPE-19 cells. Furthermore, we assessed cell death, antioxidant enzyme expression, and AMD-associated gene expression to determine the biological functions of PTX3 under oxidative stress. (3) Results: NaIO₃ increased PTX3 expression, in a dose- and time-dependent manner, in H-RPE and ARPE-19 cells. We found phosphorylated Akt, a downstream target of the PI3 kinase pathway, phosphor- mitogen-activated protein kinase kinase 1/2 (ERK), and intracellular reactive oxygen species (ROS) were predominantly induced by NaIO₃. NaIO₃-induced PTX3 expression was decreased in the presence of phosphoinositide 3 (PI3) kinase inhibitors, ERK inhibitors, and ROS scavengers. Furthermore, NaIO₃ enhanced mRNA expression of antioxidant enzymes such as glucose-6-phosphate dehydrogenase (G6PDH), catalase (CAT), and glutathione S-reductase (GSR) in the control shRNA expressing RPE cells, but not in hPTX3 shRNA expressing RPE cells. Interestingly, NaIO₃ did not induce mRNA expression of AMD marker genes, such as complement factor I (CFI), complement factor H (CFH), apolipoprotein E (APOE), and toll-like receptor 4 (TLR4) in hPTX3 shRNA expressing RPE cells. 4) Conclusions: These results suggest that PTX3 accelerates RPE cell death and might be involved in AMD development in the presence of oxidative stress.

Recombinant factor VIII Fc fusion protein for immune tolerance induction in patients with severe haemophilia A with inhibitors-A retrospective analysis

INTRODUCTION

Immune tolerance induction (ITI) is the gold standard for eradication of factor VIII inhibitors in severe haemophilia A; however, it usually requires treatment for extended periods with associated high burden on patients and healthcare resources.

AIM

Review outcomes of ITI with recombinant factor VIII Fc fusion protein (rFVIIIFc) in patients with severe haemophilia A and high-titre inhibitors.

METHODS

Multicentre retrospective chart review of severe haemophilia A patients treated with rFVIIIFc for ITI.

RESULTS

Of 19 patients, 7 were first-time ITI and 12 were rescue ITI. Of 7 first-time patients, 6 had at least 1 high-risk feature for ITI failure. Four of 7 first-time patients were tolerized in a median of 7.8 months. The remaining 3 patients continue on rFVIIIFc ITI. Of 12 rescue patients, 7 initially achieved a negative Bethesda titre (≤0.6) in a median of 3.3 months, 1 had a decrease in Bethesda titre and continues on rFVIIIFc ITI and 4 have not demonstrated a decrease in Bethesda titre. Of these 4, 3 continue on rFVIIIFc ITI and 1 switched to bypass therapy alone. Two initially responsive patients transitioned to other factors due to recurrence. Overall, 16 of 19 patients remain on rFVIIIFc (prophylaxis or ITI). For those still undergoing ITI, longer follow-up is needed to determine final outcomes. No adverse events reported.

CONCLUSIONS

Recombinant factor VIII Fc fusion protein demonstrated rapid time to tolerization in high-risk first-time ITI patients. For rescue ITI, rFVIIIFc showed therapeutic benefit in some patients who previously failed ITI with other products. These findings highlight the need to further evaluate the use of rFVIIIFc for ITI.

NOD2 deficiency exacerbates hypoxia-induced pulmonary hypertension and enhances pulmonary vascular smooth muscle cell proliferation

Expression of nucleotide-binding oligomerization domain protein 2 (NOD2) is upregulated in pulmonary artery smooth muscle cells (PASMCs) during hypoxia. To investigate the involvement of NOD2 in the pulmonary vascular response to hypoxia, we subjected wild-type and NOD2-deficient mice to chronic normobaric hypoxic conditions. Compared to wild-type mice, NOD2-deficient mice developed severe pulmonary hypertension with exaggerated elevation of right ventricular systolic pressure, profound right ventricular hypertrophy and striking vascular remodeling after exposure to hypoxia. Pulmonary vascular remodeling in NOD2-deficient mice was characterized by increased PASMC proliferation. Furthermore, hypoxia-inducible factor-1α expression and Akt phosphorylation were upregulated in PASMCs from NOD2-deficient mice exposed to hypoxia. Our findings revealed that the absence of NOD2 exacerbated hypoxia-induced PASMC proliferation, pulmonary hypertension and vascular remodeling, but had no effect on PASMC migration or contractility.

Tunicamycin-induced Endoplasmic Reticulum Stress Upregulates the Expression of Pentraxin 3 in Human Retinal Pigment Epithelial Cells

PURPOSE

To investigate the production of long pentraxin 3 (PTX3) in response to tunicamycin-induced endoplasmic reticulum (ER) stress and its role in ER stress-associated cell death, PTX3 expression was evaluated in the human retinal pigment epithelial cell line, ARPE-19.

METHODS

PTX3 production in ARPE-19 cells was analyzed in the absence or presence of tunicamycin treatment by enzyme-linked immunosorbent assay. PTX3 protein and mRNA levels were estimated using western blot analysis and real-time reverse transcription-polymerase chain reaction, respectively. Protein and mRNA levels of CCAAT-enhancer-binding protein homologous protein (CHOP) and ARPE-19 cell viability were measured in the presence of tunicamycin-induced ER stress in control or PTX3 small hairpin RNA (shRNA)-transfected ARPE-19 cells.

RESULTS

The protein and mRNA levels of PTX3 were found to be significantly increased by tunicamycin treatment. PTX3 production was significantly decreased in inositol-requiring enzyme 1α shRNA-transfected ARPE-19 cells compared to control shRNA-transfected cells. Furthermore, pretreatment with the NF-κB inhibitor abolished tunicamycin-induced PTX3 production. Decreased cell viability and prolonged protein and mRNA expression of CHOP were observed under tunicamycin-induced ER stress in PTX3 shRNA transfected ARPE-19 cells.

CONCLUSIONS

These results suggest that PTX3 production increased in the presence of tunicamycin-induced ER stress. Therefore, PTX3 could be an important protector of ER stress-induced cell death in human retinal pigment epithelial cells. Inositol-requiring enzyme 1α and the NF-κB signaling pathway may serve as potential targets for regulation of PTX3 expression in the retina. Therefore, their role in PTX3 expression needs to be further investigated.

One-year mortality in patients with bone and soft tissue sarcomas as an indicator of delay in presentation

INTRODUCTION

For many cancers, one-year mortality following diagnosis is a reflection of either advanced stage at diagnosis, multiple co-morbidities and/or complications of treatment. One-year mortality has not been reported for soft tissue or bone sarcomas. This study reports 1-year sarcoma mortality data over a 25-year period, investigates prognostic factors and considers whether a delay in presentation affects 1-year mortality.

METHODS

A total of 4,945 newly diagnosed bone sarcoma and soft tissue sarcoma patients were identified from a prospectively maintained, single institution oncology database. Of these, 595 (12%) died within 1 year of diagnosis. Both patient factors and tumour characteristics available at diagnosis were analysed for effect.

RESULTS

There was significant variation in one-year mortality between different histological subtypes. There has been no significant change in mortality rate during the last 25 years (mean: 11.7%, standard deviation: 2.8 percentage points). Soft tissue sarcoma patients who survived over one year reported a longer duration of symptoms preceding diagnosis than those who died (median: 26 vs 20 weeks, p<0.001). Prognostic factors identified in both bone and soft tissue sarcomas mirrored those for mid to long-term survival, with high tumour stage, large tumour size, metastases at diagnosis and increasing age having the greatest predictive effect.

CONCLUSIONS

One-year mortality in bone and soft tissue sarcoma patients is easy to measure, and could be a proxy for late presentation and therefore a potential performance indicator, similar to other cancers. It is possible to predict the risk of one-year mortality using factors available at diagnosis. Death within one year does not correlate with a long history but is associated with advanced disease at diagnosis.

Massive endoprosthetic replacement for bone metastases resulting from renal cell carcinoma: factors influencing patient survival

BACKGROUND

Surgery remains the main treatment of bone metastases due to renal cell carcinoma (RCC). We reviewed 135 patients treated with resection and endoprosthetic replacement (EPR) and examined clinico-pathological factors predicting survival.

METHODS

Surgical and oncological outcomes were examined using a prospectively maintained database between 1976 and 2012. Survival rates were calculated by Kaplan-Meier method. Multivariate analyses were performed to investigate factors predictive of increased survival.

RESULTS

At diagnosis, 81 patients had synchronous RCC and bone metastases and the remaining developed metachronous metastases after primary treatment for RCC. The majority were solitary tumours (75%) and 77% had ≥ one concurrent visceral metastases. The median age at surgery was 61 years old (IQR 53-69). The median follow-up was 20 months (IQR 10-43) and the overall survival was 72% at one-year. This declined to 45% and 28% at three and five-years, respectively. After adjustments for prognostic factors, there was an increased risk of death in patients with multiple skeletal metastases (HR = 2), ≥one visceral metastases (HR = 3) and local recurrence (HR = 3) (all p ≤ 0.01). Ten patients required revision (7%) and the risk of revision was 4% at one-year and remained low at 8% from two years postoperatively.

CONCLUSION

Patients with solitary bone lesions and no visceral metastases should be considered for bone resection and EPR. As survival beyond one-year can be expected in a majority of patients and the risk of further surgery after EPR is low, patients with multiple skeletal metastases and visceral metastases should also be considered.

Human retinal pigment epithelial cells express the long pentraxin PTX3

PURPOSE

To determine whether the long pentraxin 3 (PTX3) is expressed in human retinal pigment epithelial cells and is induced by inflammatory cytokines, interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ), expression of PTX3 was investigated in the human retinal pigment epithelial cell line, ARPE-19 cells.

METHODS

In ARPE-19 cells, we first analyzed PTX3 production in the presence or absence of inflammatory cytokines, IL-1β, TNF-α, and IFN-γ, dose- and time-dependently using enzyme-linked immunosorbent assay. Protein and mRNA expression of PTX3 was measured with western blotting analysis and real-time reverse transcription-polymerase chain reaction. Specific inhibitors were used to determine the signaling pathways of inflammatory cytokine-induced PTX3 expression.

RESULTS

In this study, production of PTX3 was induced by IL-1β and TNF-α dose- and time-dependently, but not by IFN-γ in ARPE-19 cells. Protein and mRNA expression of PTX3 was significantly upregulated in the presence of IL-1β and TNF-α. Furthermore, pretreatment with extracellular signal-regulated kinase1/2 and nuclear factor kappa-light-chain-enhancer of activated B cells specific inhibitor abolished IL-1β and TNF-α-induced PTX3 production, but the other inhibitors had no effect.

CONCLUSIONS

These results suggested that human retinal pigment epithelial cells may be a major source of PTX3 production in the presence of proinflammatory cytokines, IL-1β and TNF-α, and could be an important mediator for host defense and inflammatory response in the retina. The importance of the mitogen-activated protein kinase/extracellular signal-regulated kinase1/2 and nuclear factor kappa-light-chain-enhancer of activated B cells pathways for regulated PTX3 expression may be a potential target for PTX3 regulation in the retina.

Early results of a non-invasive extendible prosthesis for limb-salvage surgery in children with bone tumours

We reviewed our initial seven-year experience with a non-invasive extendible prosthesis in 34 children with primary bone tumours. The distal femur was replaced in 25 cases, total femur in five, proximal femur in one and proximal tibia in three. The mean follow-up was 44 months (15 to 86) and 27 patients (79%) remain alive. The prostheses were lengthened by an electromagnetic induction mechanism in an outpatient setting and a mean extension of 32 mm (4 to 80) was achieved without anaesthesia. There were lengthening complications in two children: failed lengthening in one and the formation of scar tissue in the other. Deep infection developed in six patients (18%) and local recurrence in three. A total of 11 patients required further surgery to the leg. Amputation was necessary in five patients (20%) and a two-stage revision in another. There were no cases of loosening, but two patients had implant breakage and required revision. The mean Musculoskeletal Tumor Society functional score was 85% (60% to 100%) at last known follow-up. These early results demonstrate that the non-invasive extendible prosthesis allows successful lengthening without surgical intervention, but the high incidence of infection is a cause for concern.

Strategy for comprehensive identification of post-translational modifications in cellular proteins, including low abundant modifications: application to glyceraldehyde-3-phosphate dehydrogenase

Post-translational modifications (PTMs) play key roles in the regulation of biological functions of proteins. Although some progress has been made in identifying several PTMs using existing approaches involving a combination of affinity-based enrichment and mass spectrometric analysis, comprehensive identification of PTMs remains a challenging problem in proteomics because of the dynamic complexities of PTMs in vivo and their low abundance. We describe here a strategy for rapid, efficient, and comprehensive identification of PTMs occurring in biological processes in vivo. It involves a selectively excluded mass screening analysis (SEMSA) of unmodified peptides during liquid chromatography-electrospray ionization-quadrupole-time-of-flight tandem mass spectrometry (LC-ESI-q-TOF MS/MS) through replicated runs of a purified protein on two-dimensional gel. A precursor ion list of unmodified peptides with high mass intensities was obtained during the initial run followed by exclusion of these unmodified peptides in subsequent runs. The exclusion list can grow as long as replicate runs are iteratively performed. This enables the identifications of modified peptides with precursor ions of low intensities by MS/MS sequencing. Application of this approach in combination with the PTM search algorithm MODi to GAPDH protein in vivo modified by oxidative stress provides information on multiple protein modifications (19 types of modification on 42 sites) with >92% peptide coverage and the additional potential for finding novel modifications, such as transformation of Cys to Ser. On the basis of the information of precursor ion m/z, quantitative analysis of PTM was performed for identifying molecular changes in heterogeneous protein populations. Our results show that PTMs in mammalian systems in vivo are more complicated and heterogeneous than previously reported. We believe that this strategy has significant potential because it permits systematic characterization of multiple PTMs in functional proteomics.

Glucosamine modulates chondrocyte proliferation, matrix synthesis, and gene expression

OBJECTIVE

To investigate the effects of glucosamine (GlcN) on chondrocyte proliferation, matrix production, and gene expression for providing insights into the biochemical basis of its reported beneficial effects in osteoarthritis (OA).

METHODS

Dose-dependent effect of GlcN on cell morphology, proliferation, cartilage matrix production and gene expression was examined by incubating primary bovine chondrocytes with various amounts of GlcN in monolayers (2D) and in cell-laden hydrogels (3D constructs). Histology, immunofluorescent staining and biochemical analyses were used to determine the effect of GlcN on cartilage matrix production in 3D constructs. The impact of GlcN on gene expression was evaluated with real-time polymerase chain reaction (PCR).

RESULTS

GlcN concentration and culture conditions significantly affected the cell behavior. Quantitative detection of matrix production in cell-laden hydrogels indicated a relatively narrow window of GlcN concentration that promotes matrix production (while limiting cellular proliferation, but not cell viability). Notably, GlcN enhanced cartilage specific matrix components, aggrecan and collagen type II, in a dose-dependent manner up to 2 mM but the effect was lost by 15 mM. Additionally, GlcN treatment up-regulated transforming growth factor-beta1 (TGF-beta1) mRNA levels.

CONCLUSION

Results indicate that culture conditions play a significant role in determining the effect of GlcN on chondrocytes, explaining both the previously reported beneficial and deleterious effects of this sugar. The ability of GlcN to alter TGF-beta1 signaling provides a biochemical mechanism for GlcN activity on chondrocytes that up to now has remained elusive. The observed anabolic effect of optimal GlcN concentrations on chondrocytes may be useful in formulating effective cartilage repair strategies.