Distinct Transcriptional and Functional Differences of Lung Resident and Monocyte-Derived Alveolar Macrophages During the Recovery Period of Acute Lung Injury

In acute lung injury, two subsets of lung macrophages exist in the alveoli: tissue-resident alveolar macrophages (AMs) and monocyte-derived alveolar macrophages (MDMs).However, it is unclear whether these 2 subsets of macrophages have different functions and characteristics during the recovery phase. RNA-sequencing of AMs and MDMs from the recovery period of LPS-induced lung injury mice revealed their differences in proliferation, cell death, phagocytosis, inflammation and tissue repair. Using flow cytometry, we found that AMs showed a higher ability to proliferate, whereas MDMs expressed a larger amount of cell death. We also compared the ability of phagocytosing apoptotic cells and activating adaptive immunity and found that AMs have a stronger ability to phagocytose, while MDMs are the cells that activate lymphocytes during the resolving phase. By testing surface markers, we found that MDMs were more prone to the M1 phenotype, but expressed a higher level of pro-repairing genes. Finally, analysis of a publicly available set of single-cell RNA-sequencing data on bronchoalveolar lavage cells from patients with SARS-CoV-2 infection validated the double-sided role of MDMs. Blockade of inflammatory MDM recruitment using CCR2 −/− mice effectively attenuates lung injury. Therefore, AMs and MDMs exhibited large differences during recovery. AMs are long-lived M2-like tissue-resident macrophages that have a strong ability to proliferate and phagocytose. MDMs are a paradoxical group of macrophages that promote the repair of tissue damage despite being strongly pro-inflammatory early in infection, and they may undergo cell death as inflammation fades. Preventing the massive recruitment of inflammatory MDMs or promoting their transition to pro-repairing phenotype may be a new direction for the treatment of acute lung injury.

Therapeutic inhibition of SGK1 suppresses colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of death worldwide. Thus, the development of new therapeutic targets for CRC treatment is urgently needed. SGK1 is involved in various cellular activities, and its dysregulation can result in multiple cancers. However, little is known about its roles and associated molecular mechanisms in CRC. In present study, we found that SGK1 was highly expressed in tumor tissues compared with peri-tumor samples from CRC patients. In vitro experiments revealed that SGK1 overexpression promoted colonic tumor cell proliferation and migration and inhibited cell apoptosis induced by 5-fluorouracil (5-FU), while SGK1 shRNA and inhibitors showed the inverse effects. Using CRC xenograft mice models, we demonstrated that knockdown or therapeutic inhibition of SGK1 repressed tumor cell proliferation and tumor growth. Moreover, SGK1 inhibitors increased p27 expression and promoted p27 nuclear accumulation in colorectal cancer cells, and p27 siRNAs could attenuate the repression of CRC cell proliferation induced by SGK1 inhibitors. Collectively, SGK1 promotes colorectal cancer development via regulation of CRC cell proliferation, migration and survival. Inhibition of SGK1 represents a novel strategy for the treatment of CRC.

miR-31a-5p promotes postnatal cardiomyocyte proliferation by targeting RhoBTB1

A limited number of microRNAs (miRNAs, miRs) have been reported to control postnatal cardiomyocyte proliferation, but their strong regulatory effects suggest a possible therapeutic approach to stimulate regenerative capacity in the diseased myocardium. This study aimed to investigate the miRNAs responsible for postnatal cardiomyocyte proliferation and their downstream targets. Here, we compared miRNA profiles in cardiomyocytes between postnatal day 0 (P0) and day 10 (P10) using miRNA arrays, and found that 21 miRNAs were upregulated at P10, whereas 11 were downregulated. Among them, miR-31a-5p was identified as being able to promote cardiomyocyte proliferation as determined by proliferating cell nuclear antigen (PCNA) expression, double immunofluorescent labeling for α-actinin and 5-ethynyl-2-deoxyuridine (EdU) or Ki-67, and cell number counting, whereas miR-31a-5p inhibition could reduce their levels. RhoBTB1 was identified as a target gene of miR-31a-5p, mediating the regulatory effect of miR-31a-5p in cardiomyocyte proliferation. Importantly, neonatal rats injected with a miR-31a-5p antagomir at day 0 for three consecutive days exhibited reduced expression of markers of cardiomyocyte proliferation including PCNA expression and double immunofluorescent labeling for α-actinin and EdU, Ki-67 or phospho-histone-H3. In conclusion, miR-31a-5p controls postnatal cardiomyocyte proliferation by targeting RhoBTB1, and increasing miR-31a-5p level might be a novel therapeutic strategy for enhancing cardiac reparative processes.

In vitro observation of haemolymph melanization and melanin-related biosynthesis enzyme genes in silkworm, Bombyx mori / 生物工程学报

The observation statistics suggested that the haemolymph melanization speed of larvae became fast and the growth inhibition of Escherichia coli was strong as the quantities of feeding on mulberry leaves increased. The RT-PCR result showed that the mRNA expressions of melanin biosynthesis enzyme BmTan, BmPo-1, BmYellow-f and BmDdc were high in the haemolyph of 5 L 3 d larvae. The qPCR analysis showed Bmtan, Bmddc, Bmyellow, Bmebony and Bmblack, especially Bmddc expression were significantly higher in black disease larvae than in normal larvae. Compared with control, Ddc inhibitors drastically inhibited the lipopolysaccharide-induced haemolymph melanization. In addition, the content of Dopa and Dopamine markedly rose after E. coli injection. These indicated that haemolymph melanization was linked to immune defenses and Bmddc may play a role in melanization response of haemolymph immune in silkworm.

A single hospital study on portal vein thrombosis in cirrhotic patients - clinical characteristics & risk factors

Background & objectives: Discrepancies exist in the reported prevalence of portal vein thrombosis (PVT), and its clinical characteristics and sites of occurrence need to be elucidated. The risk factors for PVT are also poorly understood. This single centre study was undertaken to determine the clinical characteristics, sites of occurrence, and risk factors associated with PVT in patients with liver cirrhosis. Methods: Hospitalized cirrhotic patients (N = 162) were segregated into the PVT and non-PVT groups. Indices possibly associated with PVT were measured and PVT was detected by both Doppler ultrasonography and computed tomography portal angiography. The portal vein diameter and flow velocity and splenic thickness were measured by ultrasonography. Results: PVT was found in 40 patients (24.7%); in 34 PVT patients (85%), the liver cirrhosis resulted from hepatitis B virus infections. Most (90%) patients were Child-Pugh classes B and C, with similar distribution between the groups. PVT was seen in 20 patients in the portal and superior mesenteric veins; ascites, abdominal pain, gastrointestinal bleeding, and jaundice were common findings in PVT patients. Haemoglobin levels and blood platelet counts (BPCs) were significantly lower and splenic thickness was greater in PVT than in non-PVT patients (P<0.01). There was a significant positive correlation between BPCs and platelet aggregation rates (R = 0.533, P<0.01). Interpretation & conclusions: The occurrence of PVT was 24.7 per cent, primarily in post-hepatitis B liver cirrhosis patients. PVT occurred mainly in the portal vein trunk and superior mesenteric vein. Different PVT sites may account for the differing clinical presentations. The lower levels of haemoglobin and BPCs as well as splenic thickening were associated with PVT. Splenic thickening may be a risk factor for PVT.

Pathophysiological mechanisms of cognitive impairment caused by chronic cerebral hypoperfusion / 国际脑血管病杂志

Chronic cerebral hypoperfusion is a common pathological state. Cognitive impairment is its main manifestation in early stage, and it will eventually result in persistent or progressive cognitive impairment and neurological deficits. Chronic cerebral hypoperfusion caused neuronal damage, synapse abnormity, energy impairment and the function defects of central cholinergic system and monoaminergic system are its pathophysiological mechanisms resulting in cognitive impairment.