CDH18 is a fetal epicardial biomarker regulating differentiation towards vascular smooth muscle cells.

The epicardium is a mesothelial layer covering the myocardium serving as a progenitor source during cardiac development. The epicardium reactivates upon cardiac injury supporting cardiac repair and regeneration. Fine-tuned balanced signaling regulates cell plasticity and cell-fate decisions of epicardial-derived cells (EPCDs) via epicardial-to-mesenchymal transition (EMT). However, powerful tools to investigate epicardial function, including markers with pivotal roles in developmental signaling, are still lacking. Here, we recapitulated epicardiogenesis using human induced pluripotent stem cells (hiPSCs) and identified type II classical cadherin CDH18 as a biomarker defining lineage specification in human active epicardium. The loss of CDH18 led to the onset of EMT and specific differentiation towards cardiac smooth muscle cells. Furthermore, GATA4 regulated epicardial CDH18 expression. These results highlight the importance of tracing CDH18 expression in hiPSC-derived epicardial cells, providing a model for investigating epicardial function in human development and disease and enabling new possibilities for regenerative medicine.

MCM10 compensates for Myc-induced DNA replication stress in breast cancer stem-like cells.

Cancer stem-like cells (CSCs) induce drug resistance and recurrence of tumors when they experience DNA replication stress. However, the mechanisms underlying DNA replication stress in CSCs and its compensation remain unclear. Here, we demonstrate that upregulated c-Myc expression induces stronger DNA replication stress in patient-derived breast CSCs than in differentiated cancer cells. Our results suggest critical roles for mini-chromosome maintenance protein 10 (MCM10), a firing (activating) factor of DNA replication origins, to compensate for DNA replication stress in CSCs. MCM10 expression is upregulated in CSCs and is maintained by c-Myc. c-Myc-dependent collisions between RNA transcription and DNA replication machinery may occur in nuclei, thereby causing DNA replication stress. MCM10 may activate dormant replication origins close to these collisions to ensure the progression of replication. Moreover, patient-derived breast CSCs were found to be dependent on MCM10 for their maintenance, even after enrichment for CSCs that were resistant to paclitaxel, the standard chemotherapeutic agent. Further, MCM10 depletion decreased the growth of cancer cells, but not of normal cells. Therefore, MCM10 may robustly compensate for DNA replication stress and facilitate genome duplication in cancer cells in the S-phase, which is more pronounced in CSCs. Overall, we provide a preclinical rationale to target the c-Myc-MCM10 axis for preventing drug resistance and recurrence of tumors.

Dialysis-related amyloidosis associated with a novel ß2-microglobulin variant.

Till date, there had been no reported case of dialysis-related amyloidosis (DRA) associated with a ß2-microglobulin variant. We report here a 41-year-old haemodialysis patient with systemic amyloidosis, exhibiting macroglossia and swelling salivary glands, uncommon clinical manifestations for DRA. Molecular analysis showed that the patient had a new variant of ß2-microglobulin (V27M). Extracted amyloid protein was predominantly composed of variant ß2-microglobulin. In vitro analysis revealed that this variant ß2-microglobulin had a strong amyloidogenic propensity, probably owing to the decreased stability caused by a bulky methionine residue. Our data clearly show that V27M variant is amyloidogenic and this mutation results in unusual clinical manifestations. To date, only one amyloidogenic ß2-microglobulin variant (D76N) has been reported in non-dialysis patients. It is noteworthy that the V27M and D76N variants show substantial differences in both clinical phenotypes and pathomechanical features. This is the first case of DRA associated with a naturally occurring ß2-microglobulin variant.

Tocilizumab-induced immunocomplex glomerulonephritis: a report of two cases.

We report here two cases of membranoproliferative glomerulonephritis that developed during treatment of rheumatoid arthritis with tocilizumab. In both cases, the initial findings were proteinuria and haematuria, followed by development of bilateral lower leg oedema. One of the patients was weakly positive for anti-nuclear antibody; both had hypocomplementaemia. The patients' renal impairment gradually resolved with discontinuation of tocilizumab followed by treatment with moderate doses of oral prednisolone. Pathological examination of renal biopsies resulted in diagnoses of immunocomplex glomerulonephritis and immunofluorescence staining revealed depositions of IgG, IgA, and IgM, accompanied by C3. Tocilizumab rarely induces autoimmune disorders; therefore, the underlying mechanism is unknown. One patient with immunocomplex glomerulonephritis that may have been associated with tocilizumab therapy for rheumatoid arthritis has been reported previously; that patient and our two are similar in their clinical courses and pathological findings. We conclude that such glomerulonephritis can occur during tocilizumab treatment, but this is rare. Clinicians should be aware of the possibility of paradoxical development of autoimmune diseases during tocilizumab therapy.

Tolvaptan in Japanese patients with later-stage autosomal dominant polycystic kidney disease.

BACKGROUND: A recent study demonstrated that tolvaptan slowed estimated glomerular filtration rate (eGFR) decline in later-stage autosomal dominant polycystic kidney disease (ADPKD) patients. However, Japanese patients were not included in that trial, therefore tolvaptan's efficacy in Japanese patients with advanced chronic kidney disease (CKD) has remained unknown. METHODS: In this prospective cohort study, 54 patients with ADPKD who had eGFR ≥ 15 ml/min/1.73 m2 and total kidney volume (TKV) ≥ 750 ml were treated with tolvaptan. The primary endpoint was the change in height-adjusted total kidney volume (htTKV) and eGFR after 1-year treatment with tolvaptan. Then, we compared the primary endpoint between later CKD stage (baseline eGFR < 45 ml/min/1.73 m2) and earlier CKD stage (baseline eGFR ≥ 45 ml/min/1.73 m2). RESULTS: The rate of kidney growth during the 1-year treatment did not differ significantly between earlier and later CKD stages. The median and interquartile range of relative change in htTKV in later CKD stage was 8.2%/year [4.4, 26.6], as compared with 5.7%/year [1.6, 16.4] in earlier CKD stage (p = 0.17). Nor did the rate of eGFR decline between earlier and later CKD stages. The relative annual change in eGFR in later CKD stage was - 9.7%/year [- 15.9, - 2.1], as compared with - 6.8%/year [- 11.1, 0.1] in earlier CKD stage (p = 0.18). CONCLUSION: This analysis indicates that the efficacy of tolvaptan for Japanese patients with later stage ADPKD was not significantly different from that of Japanese patients with earlier stage ADPKD.

Our Approaches to Selective Plasma Exchange.

Plasma exchange (PE) therapy is the most commonly used treatment in Japan today. The issue with PE is that it removes coagulation factors and other essential molecules during the treatment process. Fresh frozen plasma (FFP) is used to replace the essential molecules which are lost. However, FFP can be a source of various complications. We have been researching an alternative method, selective PE, consisting of a membrane with smaller pores, which prevents large and essential molecules from being removed while removing waste from the patient's blood.

Anti-RNA polymerase III antibody-associated scleroderma renal crisis in a patient with limited cutaneous systemic sclerosis: A case report.

A 69-year-old Japanese man was presented with hypertensive crisis. Renal histology revealed malignant nephrosclerosis, including an onion skin pattern with fibrinoid necrosis of the small arteries from arterioles up to interlobular arteries. Immunological investigation clarified positive anti-RNA polymerase (RNAP) III antibody, and limited cutaneous systemic sclerosis (Lc SSc) was diagnosed by skin biopsy as the underlying disease causing scleroderma renal crisis (SRC). Angiotensin covering enzyme (ACE) inhibitor therapy and calcium antagonist were effective for his renal condition. Although an association between SRC and anti-RNAP III antibody has already been reported in patients with diffuse cutaneous SSc (Dc SSc), this case indicates that SRC with hypetensive emergency with malignant nephrosclerosis can also be diagnosed on patients with Lc SSc patients by the examination of anti-RNAP III antibody.

Renal histology and MRI in a 25-year-old Japanese man with nephronophthisis 4
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We investigated a 25-year-old Japanese man who had polycystic kidneys and end-stage renal failure without a positive family history. Ultrasonography revealed enlarged kidneys with increased echogenicity and multiple cystic lesions. MRI showed replacement of both kidneys by cystic lesions without definite walls. Renal biopsy demonstrated interstitial fibrosis, especially at the corticomedullary junction. The residual tubular system showed starfish-like disruption. Tubules with cystic dilation were mainly the distal loop of Henle and the distal tubules since immunohistochemical staining was positive for cytokeratin 7 (the distal loop of Henle and the distal tubule) and Tamm-Horsfall protein (the distal loop of Henle), while being negative for aquaporin 3 (the collecting duct) and CD10 (proximal tubule). Comprehensive genetic analysis identified compound heterozygous missense mutations of NPHP4 with autosomal recessive inheritance since his asymptomatic parents each had a single heterozygous missense mutation of NPHP4. In conclusion, MRI and immunohistochemical analysis of renal biopsy specimens may be useful for evaluation of this disease.
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Evaluation of the functions of the temporary catheter with various tip types.

INTRODUCTION: A temporary catheter (TC) is used short-term and for emergencies. There are some cases when we cannot withdraw blood immediately after inserting the catheter in our patients. The reason is said to be the tips of the TC sticking to the vascular walls. OBJECTIVE: We evaluated examined 3 catheters with different tip shapes in a simulation circuit to assess the effect on the blood flow. METHODS: Water was circulated in the simulation circuit at 1 L/minute. Next, we inserted each TC into the model, and the TCs were connected to the dialysis circuit at 200 mL/minute. We put gold powder into the simulation circuit. We visually observed the movement of the gold power at the head of the catheter and measured the recirculation rate. RESULT: The uplift type TC was able to perform blood removal and reinfusion with the least difficulties. All recirculation rates were less than 1%. The hindrance caused by hitting a vascular wall is believed to have been reduced. CONCLUSION: With the manipulation of the catheter tip shapes, blood was able to circulate smoothly. We expect less blood clots and a decrease in sticking to the vascular wall. We plan to study these 3 catheters at clinical tests in the future.

Renal histology and MRI findings in a 37-year-old Japanese patient with autosomal recessive polycystic kidney disease
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A 37-year-old Japanese man with a serum creatinine level of 2.5 mg/dL and hepatomegaly was admitted to our hospital for investigation of renal failure. Magnetic resonance imaging (MRI) showed hepatomegaly with small cystic lesions that had high signal intensity on T2-weighted images. There was no splenomegaly, and the kidneys were nearly normal in size with a few small cystic lesions. Renal biopsy revealed that interstitial fibrosis and tubular atrophy affected 60% of the cortex. There was cystic tubular dilation, mainly affecting the distal loop of Henle and distal tubules, since immunohistochemical staining of the dilated tubules was positive for cytokeratin 7 and Tamm-Horsfall protein but was negative for aquaporin 3 and CD10. Immunofluorescence microscopy and electron microscopy did not demonstrate any immune deposits. Genetic analysis identified two different heterozygous missense variants of PKHD1, while the patient's asymptomatic parents were each heterozygous for a single PKHD1 mutation. Accordingly, autosomal recessive polycystic kidney disease (-ARPKD) due to compound heterozygous PKHD1 mutation was diagnosed. The renal biopsy findings of this patient may be nonspecific, but they were different from the typical renal histology of infantile ARPKD. In conclusion, the renal features of adult-onset ARPKD may differ from those of infantile disease.
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Negative regulation of DSS-induced experimental colitis by PILRα.

Inflammatory bowel disease is thought to be a complex multifactorial disease, in which an increased inflammatory response plays an important role. Paired immunoglobulin-like type 2 receptor α (PILRα), well conserved in almost all mammals, is an inhibitory receptor containing immunoreceptor tyrosine-based inhibitory motifs in the cytoplasmic domain. PILRα is mainly expressed on myeloid cells and plays an important role in the regulation of inflammation. In the present study, we investigated the function of PILRα in inflammatory bowel disease using PILRα-deficient mice. When mice were orally administered dextran sulfate sodium (DSS), colonic mucosal injury and inflammation were significantly exacerbated in DSS-treated PILRα-deficient mice compared with wild-type (WT) mice. Flow cytometric analysis revealed that neutrophil and macrophage cell numbers were higher in the colons of DSS-treated PILRα-deficient mice than in those of WT mice. Blockade of CXCR2 expressed on neutrophils using a CXCR2 inhibitor decreased the severity of colitis observed in PILRα-deficient mice. These results suggest that PILRα negatively regulates inflammatory colitis by regulating the infiltration of inflammatory cells such as neutrophils and macrophages.

The enzyme Cyp26b1 mediates inhibition of mast cell activation by fibroblasts to maintain skin-barrier homeostasis.

Mast cells (MCs) mature locally, thus possessing tissue-dependent phenotypes for their critical roles in both protective immunity against pathogens and the development of allergy or inflammation. We previously reported that MCs highly express P2X7, a receptor for extracellular ATP, in the colon but not in the skin. The ATP-P2X7 pathway induces MC activation and consequently exacerbates the inflammation. Here, we identified the mechanisms by which P2X7 expression on MCs is reduced by fibroblasts in the skin, but not in the other tissues. The retinoic-acid-degrading enzyme Cyp26b1 is highly expressed in skin fibroblasts, and its inhibition resulted in the upregulation of P2X7 on MCs. We also noted the increased expression of P2X7 on skin MCs and consequent P2X7- and MC-dependent dermatitis (so-called retinoid dermatitis) in the presence of excessive amounts of retinoic acid. These results demonstrate a unique skin-barrier homeostatic network operating through Cyp26b1-mediated inhibition of ATP-dependent MC activation by fibroblasts.

Quantification of trace elements in natural samples by electrospray ionization mass spectrometry with a size-exclusion column based on the formation of metal-aminopolycarboxylate complexes.

Metal ions were determined by ESI-MS in the negative ion mode as monovalent negative ions of their aminopolycarboxylic acid (APC) complexes, e.g., [Al(cydta)](-), [Pb(Hcydta)](-), where excess amounts of the APC agents were added to sample solutions. Among several APCs studied, we chose trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) as the best chelating agent because of higher stabilities and higher sensitivities of the complexes. The ionization efficiency of these metal complexes was strongly affected by the presence of matrix salts, e.g., NaCl, KNO(3), and etc. Thus, a size exclusion column (Sephadex G-10) was used for the online separation of the metal-APC complexes from other matrix salts. This method was successfully applied to the quantitative analyses for total amounts of Al, Ni, Cu, Zn, and Pb in the biological certified reference materials, olive leaves (BCR-062) and plankton (BCR-414). The detection limits of the present methods for these elements were several to several ten nanomolar levels. Moreover, this approach was extended to determine ultratraces of fluoride based on the formation of the ternary complex of aluminum, fluoride and nitrilotriacetic acid (NTA), i.e., [AlF(nta)](-). Its detection limit was 10 nM and was 2 orders of magnitude better than that of a fluoride ion selective electrode method. This method was applied to determine fluoride in tap water, river water, and green tea samples.