Mitochondrial calcium uniporter promotes mitophagy by regulating the PINK1/Parkin pathway in caerulein­treated pancreatic ductal epithelial cells in vitro.

The mitochondrial calcium uniporter (MCU) is a major protein for the uptake of mitochondrial calcium to regulate intracellular energy metabolism, including processes such as mitophagy. The present study investigated the effect of the MCU on mitophagy in pancreatic ductal epithelial cells (PDECs) in acute pancreatitis (AP) in vitro. The normal human PDECs (HPDE6-C7) were treated with caerulein (CAE) to induce AP-like changes, with or without ruthenium red to inhibit the MCU. The mitochondrial membrane potentials (MMPs) and mitochondrial Ca2+ levels were analyzed by fluorescence. The expression levels of MCU, LC3, p62, and translocase of the outer mitochondrial membrane complex subunit 20 (TOMM20), putative kinase 1 (PINK1), and Parkin were measured by western blotting and immunofluorescence. Mitophagy was observed by confocal fluorescence microscopy and transmission electron microscopy. The results showed that CAE increased the MCU protein expression, mitochondrial Ca2+ levels, MMP depolarization and the protein expression of mitophagy markers including the LC3II/I ratio, PINK1, and Parkin. CAE decreased the protein expression of p62 and TOMM20, and promoted the formation of mitophagosomes in HPDE6-C7 cells. Notably, changes in these markers were reversed by inhibiting the MCU. In conclusion, an activated MCU may promote mitophagy by regulating the PINK1/Parkin pathway in PDECs in AP.

Research Note: A recombinant duck-derived H6N2 subtype avian influenza virus can replicate and shed in young chickens and cause disease.

The H6N2 subtype avian influenza virus (AIV) is commonly detected in the migratory waterfowl reservoirs. Previously, H6N2 AIV was believed to be nonpathogenic to young chickens and could not infect or shed in their respiratory tract under experimental conditions. However, in present study, a highly recombinant strain of duck-derived H6N2 AIV was discovered and isolated for pathogenicity tests. The results revealed that H6N2 could induce seroconversion in chickens and high morbidity of over 86.7%, along with evident upper respiratory tract hemorrhage. Moreover, 5 substitutions were detected in the upper respiratory tract shedding reisolated virus, with a high viral load in the target organs of infected chickens. In contrast, ducks failed to exhibit any symptoms, pathological lesions, or viral shedding, while demonstrated seroconversion and high viral load in the livers. These findings indicate that H6N2 AIV could also show pathogenicity to chickens under experimental conditions, thereby effectively replicating and shedding in chickens. Therefore, the study provides further elucidations on the pathogenicity of H6N2 AIV.

The conserved L1089 in the S2 subunit of avian infectious bronchitis virus determines viral kidney tropism by disrupting virus-cell fusion.

The virulence of avian gamma-coronavirus infectious bronchitis viruses (IBV) for the kidney has led to high mortality in dominant-genotype isolations, but the key sites of viral protein that determine kidney tropism are still not fully clear. In this study, the amino acid sequences of the S2 subunit of IBVs with opposing adaptivity to chicken embryonic kidney cells (CEKs) were aligned to identify putative sites associated with differences in viral adaptability. The S2 gene and the putative sites of the non-adapted CN strain were introduced into the CEKs-adapted SczyC30 strain to rescue seven mutants. Analysis of growth characteristics showed that the replacement of the entire S2 subunit and the L1089I substitution in the S2 subunit entirely abolished the proliferation of recombinant IBV in CEKs as well as in primary chicken oviduct epithelial cells. Pathogenicity assays also support the decisive role of this L1089 for viral nephrotropism, and this non-nephrotropic L1089I substitution significantly attenuates pathogenicity. Analysis of the putative cause of proliferation inhibition in CEKs suggests that the L1089I substitution affects neither virus attachment nor endocytosis, but instead fails to form double-membrane vesicles to initiate the viral replication and translation. Position 1089 of the IBV S2 subunit is conservative and predicted to lie in heptad repeat 2 domains. It is therefore reasonable to conclude that the L1089I substitution alters the nephrotropism of parent strain by affecting virus-cell fusion. These findings provide crucial insights into the adaptive mechanisms of IBV and have applications in the development of vaccines and drugs against IB.

Downregulated miR-23b-3p expression acts as a predictor of hepatocellular carcinoma progression: A study based on public data and RT-qPCR verification.

Mounting evidence has shown that miR-23b-3p, which is associated with cell proliferation, invasion, and apoptosis, acts as a biomarker for diagnosis and outcomes in numerous cancers. However, the clinicopathological implication of miR-23b-3p in hepatocellular carcinoma (HCC) remains unclear. Our study evaluated the role of miR-23b-3p in HCC and investigated its potential application as a marker for preliminary diagnosis and therapy in HCC. High-throughput data from the NCBI Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were collected and analyzed. One hundred and one tissue sections of HCC were paired with adjacent non-cancerous HCC as further supplements. miR-23b-3p expression was detected using quantitative real-time PCR. Additionally, the relationship between miR-23b-3p expression and HCC progression and Time-to-recurrence (months) was explored. Ten algorithms were applied to predict the prospective target genes of miR-23b-3p. Next, we conducted bioinformatics analysis for further study. miR-23b-3p expression was pronouncedly decreased in HCC tissues in contrast with their paired adjacent non-cancerous HCC (P<0.001) with RT-qPCR. In total, 405 targets, acquired with consistent prediction from at least five databases, were used for the bioinformatics analysis. According to the Gene Ontology (GO) analysis, all targets were classified into biological processes, cellular components and molecular functions. In the pathway analysis, targets of miR-23b-3p were primarily enriched in the signaling pathways of renal cell carcinoma, hepatitis B and pancreatic cancer (corrected P-value <0.05). In the protein-protein interaction (PPI) network for miR-23b-3p, a total of 8 targets, including SRC, AKT1, EGFR, CTNNB1, BCL2, SMAD3, PTEN and KDM6A, were located in the key nodes with high degree (>35). In conclusion, this study provides impressive illumination of the potential role of miR-23b-3p in HCC tumorigenesis and progression. Furthermore, miR-23b-3p may act as a predictor of HCC and could be a new treatment target.

Health-related quality of life in gastroesophageal reflux patients with noncardiac chest pain: Emphasis on the role of psychological distress.

AIM: To investigate the effects of depression and anxiety on health-related quality of life (QoL) in gastroesophageal reflux disease (GERD) patients and those suffering from cardiac (CCP) and noncardiac (NCCP) chest pain in Wuhan, China. METHODS: In this cross-sectional study, a total of 358 consecutive patients with GERD were enrolled in Wuhan, China, of which 176 subjects had complaints of chest pain. Those with chest pain underwent coronary angiography and were divided into a CCP group (52 cases) and NCCP group (124 cases). Validated GERD questionnaires were completed, and the 36-item Short-Form Health Survey and Hospital Anxiety/Depression Scale were used for evaluation of QoL and psychological symptoms, respectively. RESULTS: There were similar ratios and levels of depression and anxiety in GERD with NCCP and CCP. However, the QoL was obviously lower in GERD with CCP than NCCP (48.34 ± 17.68 vs 60.21 ± 20.27, P < 0.01). In the GERD-NCCP group, rather than the GERD-CCP group, the physical and mental QoL were much poorer in subjects with depression and/or anxiety than those without anxiety or depression. Anxiety and depression had strong negative correlations with both physical and mental health in GERD-NCCP (all P < 0.01), but only a weak relationship with mental components of QoL in GERD-CCP. CONCLUSION: High levels of anxiety and depression may be more related to the poorer QoL in GERD patients with NCCP than those with CCP. This highlights the importance of evaluation and management of psychological impact for improving QoL in GERD-NCCP patients.

The effect of position on esophageal structure and function determined with solid-state high-resolution manometry.

OBJECTIVE: To investigate the influence of posture on the anatomy and function of esophageal sphincters using solid-state high-resolution manometry. METHODS: Fifty individuals underwent esophageal manometry with a 36-channel solid-state catheter in the supine and upright positions. The length and pressure of the esophageal sphincters, as well as the esophageal and intra-abdominal lengths of lower esophageal sphincter (LES), were recorded. The residual pressure of the upper esophageal sphincter (UES) and the 4-s integrated relaxation pressure were also measured when the participants swallowed 10 consecutive servings of water (5 mL each). The Bland-Altman plot was used to assess agreement between these parameters in the supine and upright positions. RESULTS: The LES resting pressure was significantly decreased in the upright position compared with the supine position (13.85 ± 5.90 mmHg vs 18.09 ± 7.80 mmHg, P = 0.000). Weaker integrated relaxation pressures were observed when the participants were in the upright position (5.66 ± 3.33 mmHg vs 7.80 ± 3.25 mmHg, P = 0.000). Compared with the supine position, the upright esophageal length was longer (P = 0.004) and the upper border of the LES was lower (P = 0.050) when the individuals were in the upright position. The agreement between the two positions was acceptable for the esophageal length, LES upper border location and LES pressure measurements. CONCLUSIONS: Body position exerts a greater influence on the LES than on the UES. Thus, it is necessary to establish normal values for the LES basal pressure and residual pressure in different positions.

Changes of neuronal activities after gut electrical stimulation with different parameters and locations in lateral hypothalamus area of obese rats.

This study tested the effects of the gastrointestinal pulse train electrical stimulation with different parameters and at different locations on the neuronal activities of the lateral hypothalamus area (LHA) in obese rats in order to find the optimal stimulation parameter and location. Eight gastric electrical stimulations (GES) with different parameters were performed and the neuronal activities of gastric-distension responsive (GD-R) neurons in LHA were observed. The effects of stimulations with 8 parameters were compared to find the optimal parameter. Then the optimal parameter was used to perform electrical stimulation at duodenum and ileum, and the effects of the duodenal and ileac stimulation on the GD-R neurons in LHA were compared with the gastric stimulation of optimal parameter. The results showed that GES with the lowest energy parameter (0.3 ms, 3 mA, 20 Hz, 2 s on, 3 s off) activated the least neurons. The effects of GES with other parameters whose pulse width was 0.3 ms were not significantly different from those of the lowest energy parameter. Most gastric stimulations whose pulse width was 3 ms activated more LHA neurons than the smallest energy parameter stimulation, and the effects of those 3 ms gastric stimulations were similar. Accordingly, the lowest energy parameter was recognized as the optimal parameter. The effects of stimulations with the optimal parameter at stomach, duodenum and ileum on the LHA neuronal activities were not different. Collectively, gastrointestinal electrical stimulation (GIES) with relatively large pulse width might have stronger effects to the neuronal activities of GD-R neurons in LHA of obese rats. The effects of the GIES at different locations (stomach, duodenum and ileum) on those neurons are similar, and GES is preferential because of its easy clinical performance and safety.