Cytosolic nucleic acid sensing and mitochondrial transcriptomic changes as early triggers of metabolic disease in db/db mice

Animal models of diabetes, such as db/db mice, are a useful tool for deciphering the genetic background of molecular changes at the initial stages of disease development. Our goal was to find early transcriptomic changes in three tissues involved in metabolism regulation in db/db mice: adipose tissue, muscle tissue and liver tissue. Nine animals (three per time point) were studied. Tissues were collected at 8, 12 and 16 weeks of age. Transcriptome-wide analysis was performed using mRNA-seq. Libraries were sequenced on NextSeq (Illumina). Differential expression (DE) analysis was performed with edgeR. The analysis of the gene expression profile shared by all three tissues revealed eight upregulated genes (Irf7, Sp100, Neb, Stat2, Oas2, Rtp4, H2-T24 and Oasl2) as early as between 8 and 12 weeks of age. The most pronounced differences were found in liver tissue: nine DE genes between 8 and 12 weeks of age (Irf7, Ly6a, Ly6g6d, H2-Dma, Pld4, Ly86, Fcer1g, Ly6e and Idi1) and five between 12 and 16 weeks of age (Irf7, Plac8, Ifi44, Xaf1 and Ly6a) (adj. p-value < 0.05). The mitochondrial transcriptomic profile also changed with time: we found two downregulated genes in mice between 8 and 12 weeks old (Ckmt2 and Cox6a2) and five DE genes between 12 and 16 weeks of age (Mavs, Tomm40L, Mtfp1, Ckmt2 and Cox6a2). The KEGG pathway analysis showed significant enrichment in pathways related to the autoimmune response and cytosolic DNA sensing. Our results suggest an important involvement of the immunological response, mainly cytosolic nucleic acid sensing, and mitochondrial signalling in the early stages of diabetes and obesity.

First genetic characteristics of Polish patients with idiopathic pulmonary arterial hypertension

Introduction

Pulmonary arterial hypertension (PAH) is a rare, severe disorder of multifactorial origin. Genetic alterations in BMP/SMAD pathways were previously associated with disease development, however the exact role of other genetic factors from BMP/SMAD signalling is still unclear.

Purpose

We aimed to search for known PAH-associated mutations and potential novel variants responsible for disease onset in Polish PAH patients.

Methods

We prospectively recruited 93 consecutive idiopathic PAH patients from a single pulmonary hypertension reference centre between years 2009 and 2020. Eligible patients had pre-capillary pulmonary hypertension with pulmonary vascular resistance &gt;3 Wood units in the absence of other causes of pre-capillary pulmonary hypertension. The presence of large gene rearrangements was analyzed by the Multiplex Ligation-dependent Probe Amplification (MLPA) reactions in the ENG, ACVRL1 and BMPR2 genes (SALSA MLPA Kit, MRC-Holland). We have further sequenced a panel of selected 48 genes from BMP/SMAD and related pathways using next-generation sequencing (SureSelect XT library preparation Kit, Agilent; NextSeq 500 sequencer, Illumina) and assessed causative potential of rare variants (minor allele frequency in non-finish Europeans below 1%) with Mutation Taster web-based tool.

Results

We identified at least one likely-causative variant of investigated genes in 51 (54.8%) subjects. Large genomic rearrangements were found by MLPA in 2 patients in ENG and ACVRL1 (ALK1) genes. We have found mutations in BMPR2 gene in 12 patients (12.5%) from our cohort with most variants present in one sample and 3 variants present in 2 samples. Mutations were located mostly in protein kinase domain (6 variants) and Activin type I and II receptor domain (2 variants). We have found 5 likely pathogenic variants in 6 patients in genes previously associated with PAH other than BMPR2 (SMAD9, KCNA5, KCNK3, EIF2AK4). In total, potentially disease causing mutations in literature-known genes, were present in 18 patients, which accounted for 18.75% of tested cohort. Medium impact variants were also present in KCNA5, TGFBR2, AQP7, BMP6, EIF2AK4, FBP1, NOTCH1, NOTCH3, SMAD7, TBX4, TGFB2, TOPBP1, GDF5, IL6, PPARA, RXRA, KCNK3, KLF4, BMPR1B, ILK, TGFBR1, SMAD9, PPARD and TGFB3 genes. Additionally, in one patient with clinical diagnosis of pulmonary venoocclusive disease we identified an unknown homozygous frameshift variant (p.Phe1523fs/c.4567_4570delTTTG) in exon 35 of EIF2AK4 gene.

Conclusions

We found potentially disease causing mutations in 18,75% Polish patients diagnosed with IPAH most of them were present in BMPR2 gene which is in line with data from other European cohorts. Additionally we found an unknown mutation in the EIF2AK4 gene.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Narodowe Centrum Nauki - National Science Centre

Urocortin 2 in patients with hypertension treated with angiotensin converting enzyme inhibitors or angiotensin receptor blockers

Urocortin 2 (Ucn2) - corticotropin-releasing hormone receptor 2 signalling has favourable effects in the cardiovascular system, including vasodilation, lowering of blood pressure and systemic peripheral resistance, increase in cardiac output and cardiac contractility, as well as cardioprotection against ischemia-reperfusion injury. Vasodilation and lowering of blood pressure seem to be very interesting and important effects, but their mechanism and interaction with the antihypertensive drugs have not been evaluated. The aim of the present study was to assess the relationship between Ucn2 concentration and antihypertensive therapy in patients with primary hypertension. We examined a group of 65 patients with primary hypertension receiving at least 3 antihypertensive drugs. In all of them plasma level of Ucn2, anthropometric measurements, biochemical tests, ambulatory blood pressure monitoring (ABPM), and echocardiography were performed. There were no differences in Ucn2 level related to beta-blockers, calcium channel blockers or diuretics, but we observed that in patients treated with angiotensin converting enzyme inhibitors (ACEI) (n = 52) serum Ucn2 levels were significantly higher than in patients treated with angiotensin-receptor blockers (ARBs) (n = 13) (10.93 versus 5.56 ng/mL; P < 0.05). Moreover, we did not observe any differences in terms of blood pressure on ABPM, biochemical measurements, left ventricular mass index, or presence of diabetes. In addition, in a small subgroup receiving alpha-blockers we also found a lower level of Ucn2, with coexisting higher systolic blood pressure at night, higher left ventricle mass index (LVMI) and more frequent occurrences of diabetes compared to non-alpha-blockers. Our findings suggest that the hypotensive action of renin-angiotensin-aldosterone system blockade may be related to the urocortin system. Ucn2 may be an important element in the mosaic of blood pressure-lowering factors in patients treated for essential hypertension.

Abstract P467: Urocortin 2 Levels and Metabolic Profile in Patients With Primary Hypertension

Objective: Urocortin 2 (UCN 2) has powerful hemodynamic and neurohormonal actions. Some recent studies suggest that ucn2 may also decrease the steroid production. The aim of this study was to assess the relationship between the serum concentration of UCN 2 and metabolic parameters in patients with primary hypertension.

Methods: We examined 65 participants with essential hypertension treated with at least 3 antihypertensive medications. The evaluation included anthropometric measurements (BMI, WHR) and ambulatory blood pressure monitoring (ABPM). Moreover we evaluated metabolic parameters in blood serum: glucose, total cholesterol , low-density cholesterol (LDL-C), high density cholesterol (HDL-C), triglycerides (TG), HbA1c, insulin, cortisol, hsCRP. For the analysis of UCN 2 serum level we used ELISA Kit.

We divided the surveyed subjects into two groups according to the urocortin’s median value. The comparative analyses between the groups were based on the student’s T-test, U Mann-Whitney and Chi 2 . To examine the relationships between selected parameters we used Pearson and Spearman correlations.

Conclusion: Subjects with higher level of UCN 2 have lower concentration of total cholesterol and LDL-C, however changes in UCN 2 concentration were not associated with others metabolic parameters.

Ucn2 may play a protective role in cardiovascular morbidity through reduction of cholesterol synthesis and development of visceral obesity in patients with arterial hypertension.

[Primary synovial chondromatosis of the shoulder]

AIM

To demonstrate the various patterns of primary synovial chondromatosis (PSC) around the shoulder and to discuss a therapeutic algorithm.

METHOD

In this retrospective study, 6 patients with histologically proven PSC were operated on. The diagnosis was based on clinical examination, plain X-rays, ultrasonography and MRI in 5/6 patients. Also, a histological examination was done in all cases. According to the localisation of the disease, surgery was done by endoscopy alone, endoscopy together with open surgery or direct open surgery.

RESULTS

In one case each, we saw an isolated disease of the subacromial bursa or the gleno-humeral joint. In two cases, we found an intraarticular affection together with the biceps tendon sheath. The other two patients showed a massive periarticular deposition of loose bodies together with a defect of the rotator cuff. All patients with intraarticular disease (5/6) showed different stages of chondromalacia. In 5 of 6 patients all bodies could be removed at surgery. At follow-up after 36 months the patients subjectively rated the result as satisfactory to excellent. In the patients with total removal of the bodies, no recurrences were seen on plain X-ray or ultrasonography.

CONCLUSION

PSC around the shoulder appears with a variable pattern. According to the possible late complications described in the literature (i. e., secondary osteoarthritis, involvement of the rotator cuff and secondary malignant transformation), we find operative treatment justified. Surgery addressing removal of loose bodies and partial synovectomy allows good results. The operative approach (endoscopy or open surgery) is related to the localisation and severity of the condition.

External reference markers for the correction of head rotation in brain single-photon emission tomography

Accurate reorientation of brain single-photon emission tomography (SPET) is required for quantitative procedures and for correlation with other imaging modalities. Traditionally, brain SPET has utilized reoriented slices parallel to the orbitomeatal line (OML). Reorientation using internal landmarks would be more convenient but has not been systematically compared with the use of external landmarks. We compared the interobserver reproducibility for defining the sagittal and coronal angular deviations using internal landmarks, a visual method based upon external reference markers, and an automated method based upon external reference markers. Internal landmarks were inaccurate for defining the OML whether this was based upon the frontal-occipital or frontal-cerebellar plane. External reference markers resulted in significantly lower interobserver differences for both sagittal and coronal reorientation. An operator-independent implementation proved to be feasible and provided an objective measure of marker coplanarity. In summary, external reference markers should be used when reproducible reorientation and ROI placement are required.

Regulation of transcription of katE and katF in Escherichia coli

Fusion plasmids with lacZ under the control of the katE (encoding catalase or hydroperoxidase HPII) and katF (encoding a sigma factor-like protein required for katE expression) promoters were constructed. Expression from both katE and katF promoters was low in rich medium but elevated in poor medium during log-phase growth. Furthermore, the slowdown in growth as cells entered the stationary phase in rich medium, a result of carbon source depletion, was associated with an increase in katE and katF expression. A simple reduction in the carbon source level as the cells entered the stationary phase was not responsible for the increase in expression, because transferring the culture to a medium with no glucose did not induce expression from either promoter. Spent rich medium from stationary-phase cells was capable of inducing expression, as were simple aromatic acids such as benzoate, o-hydroxybenzoate, and p-aminobenzoate added to new medium. Anaerobiosis did not cause an increase in expression, nor did it significantly change the pattern of expression. Regardless of the medium, katF expression was always turned on before or coincidently with katE expression; in the presence of benzoate katF was fully induced, whereas katE was only partially induced, suggesting that a factor in addition to KatF protein was involved in katE expression. During prolonged aerobic incubation, cells lacking katF died off more rapidly than did cells lacking either katE or katG.

Absence of genotoxic activity of refined smoke flavor (RSF) in two bacterial short-term tests

The genotoxic activities of refined smoke flavor (RSF) produced in Poland and used in food processing were investigated in 2 bacterial short-term tests. Its mutagenic activity was examined in the Salmonella/histidine plate assay and its SOS-inducing capacity in the SOS Chromotest both without and with 'activation' by a rat liver homogenate. No genotoxic activity was detected using these 2 bacterial tests.