OBJECTIVETo investigate the effects of D-galactose (D-gal) on aging of rat marrow mesenchymal stem cells (MSCs) and its mechanism.

METHODSMSCs isolated from young (7 d) SD rats were randomly divided into four groups:control group, 1g/L, 10g/L and 50g/L D-gal treatment groups. In control group MSCs were cultured in DMEM containing 10% FBS for 48 h. In the D-gal treatment groups, MSCs were cultured in DMEM containing 10% FBS with 1g/L, 10g/L or 50g/L D-gal for 48 h. The senescence-associated changes were examined with SA-β-galactosidase (SA-β-gal) staining, the expressions of p53, p21 and p16 were detected by Western blot. The living and apoptotic cells were determined by AO/EB staining. Cell proliferation was detected by MTT assay. SOD activity was measured by xanthine oxidase method, and the MDA content was estimated with thiobarbituric acid (TBA) method.

RESULTSCompared to control group, the number of SA-β-gal positive cells and the expression of p53, p21 and p16 were significantly increased in the 10g/L and 50g/L D-gal treatment groups. The apoptosis rate in 50g/L D-gal group was significantly higher than that in control group (P<0.01). The proliferation of MSCs was decreased in the 10g/L and 50g/L D-gal groups compared to control group (P<0.05). After 10g/L and 50g/L D-gal treatment, SOD activity was significantly decreased (P<0.01), and MDA level was increased (P<0.01).

CONCLUSIONThe aging of MSCs can be induced by 10g/L and 50g/L D-gal, which may be associated with the elevated levels of oxidative stress.

Animals ; Apoptosis ; drug effects ; Cells, Cultured ; Cellular Senescence ; drug effects ; Galactose ; pharmacology ; Male ; Mesenchymal Stromal Cells ; drug effects ; physiology ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the changes of cholinergic nerves in doxorubicin (DOX)-induced rat failing heart and tumor necrosis factor-α (TNF-α) in the heart tissue and serum.

METHODSAdult Sprague-Dawley rats were randomized into control (n=10) and DOX-induced chronic heart failure (CHF) groups (n=15), and in the latter group, the rats were given intraperitoneal injections of 2.5 mg/kg DOX once a week for 6 weeks, with a total cumulative dose of 15 mg/kg. The control rats were injected with normal saline (1 ml/week). Karnovsky-Roots histochemical staining combined with point counting was used to demonstrate the distribution of cholinergic nerves in the heart. The expression levels of TNF-α in the heart tissue and serum were determined with ELISA.

RESULTSPositively stained cholinergic nerves were found in all the rat hearts in the two groups, but in CHF group, the point counts of cholinergic nerves were significantly lower than that of the control group (P<0.01). Compared with the control rats, those with DOX-induced CHF showed elevated levels of TNF-α both in the heart tissue and in the serum (P<0.01).

CONCLUSIONIn rats with DOX-induced CHF, the parasympathetic nervous system is down-regulated in the failing heart, and the diminished cholinergic anti-inflammatory pathway may play an important role in the progression of CHF.

Animals ; Cholinergic Agents ; pharmacology ; Cholinergic Fibers ; drug effects ; Doxorubicin ; pharmacology ; Heart ; drug effects ; innervation ; Heart Failure ; chemically induced ; metabolism ; Male ; Myocardium ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism

Objective To evaluate the protective effect and underlying mechanism of ulinastatin on hepatic ischemia-reperfusion injury. Methods Twenty-four male SD rats were divided into three groups: sham operation group (Sham group), hepatic ischemia-reperfusion injury group (HIRI group) and hepatic ischemia-reperfusion injury + ulinastatin pretreatment group (HIRI+UTI group), with 8 rats in each group. The HIRI rat models were established by occluding hepatic portal vein and hepatic artery for 1 h. In the HIRI+UTI group, the rats were intraperitoneally injected with ulinastatin at 30 min before model establishment, and an equivalent amount of normal saline was given in the Sham and HIRI groups. The rats were sacrificed at 6 h after model establishment. Serum samples were collected to detect alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Pathological changes of liver tissues were observed by hematoxylin-eosin (HE) staining. Ultrastructural changes of mitochondria in liver tissues were observed by transmission electron microscopy. The expression of glutathione peroxidase 4 (GPX4) was determined by immunofluorescent staining. The contents of malondialdehyde (MDA), glutathione (GSH), Fe, reactive oxygen species (ROS) and GPX4 were detected. The expression levels of GPX4 and acyl-CoA synthetase long-chain family 4 (ACSL4) messenger RNA (mRNA) and proteins in liver tissue were measured. Results Compared with the Sham group, serum ALT and AST levels were up-regulated, pathological changes such as congestion, hepatocyte necrosis and abnormal hepatic lobule structure were observed, pathological score was increased, the mitochondria shrank, the membrane density was increased, the mitochondrial crest was damaged or even absent, the contents of ROS, MDA and Fe were elevated, the GSH content was decreased, the fluorescent intensity of GPX4 was weakened, the relative expression levels of ACSL4 mRNA and protein were up-regulated, and the relative expression levels of GPX4 mRNA and protein were down-regulated in the HIRI group (all P<0.05). Compared with the HIRI group, serum ALT and AST levels were down-regulated, liver tissue injury was alleviated, pathological score was decreased, mitochondrial shrinkage and crest breakage were mitigated, the contents of ROS, MDA and Fe were down-regulated, the GSH content was up-regulated, the fluorescent intensity of GPX4 was enhanced, the relative expression levels of ACSL4 mRNA and protein were down-regulated, and the relative expression levels of GPX4 mRNA and protein were up-regulated in the HIRI+UTI group (all P<0.05). Conclusions Ulinastatin may alleviate hepatic ischemia-reperfusion injury in rats probably through inhibiting ferroptosis.

The Omicron family of SARS-CoV-2 variants are currently driving the COVID-19 pandemic. Here we analyzed the clinical laboratory test results of 9911 Omicron BA.2.2 sublineages-infected symptomatic patients without earlier infection histories during a SARS-CoV-2 outbreak in Shanghai in spring 2022. Compared to an earlier patient cohort infected by SARS-CoV-2 prototype strains in 2020, BA.2.2 infection led to distinct fluctuations of pathophysiological markers in the peripheral blood. In particular, severe/critical cases of COVID-19 post BA.2.2 infection were associated with less pro-inflammatory macrophage activation and stronger interferon alpha response in the bronchoalveolar microenvironment. Importantly, the abnormal biomarkers were significantly subdued in individuals who had been immunized by 2 or 3 doses of SARS-CoV-2 prototype-inactivated vaccines, supporting the estimation of an overall 96.02% of protection rate against severe/critical disease in the 4854 cases in our BA.2.2 patient cohort with traceable vaccination records. Furthermore, even though age was a critical risk factor of the severity of COVID-19 post BA.2.2 infection, vaccination-elicited protection against severe/critical COVID-19 reached 90.15% in patients aged ≽ 60 years old. Together, our study delineates the pathophysiological features of Omicron BA.2.2 sublineages and demonstrates significant protection conferred by prior prototype-based inactivated vaccines.
Humans ; Aged ; Middle Aged ; COVID-19/prevention & control* ; SARS-CoV-2 ; Pandemics/prevention & control* ; China/epidemiology* ; Disease Outbreaks/prevention & control* ; Vaccination