Autophagic Cell Death and Apoptosis Jointly Mediate Cisatracurium Besylate-Induced Cell Injury

Necroptosis in Pneumonia: Therapeutic Strategies and Future Perspectives

Pneumonia remains a major global health challenge, necessitating the development of effective therapeutic approaches. Recently, necroptosis, a regulated form of cell death, has garnered attention in the fields of pharmacology and immunology for its role in the pathogenesis of pneumonia. Characterized by cell death and inflammatory responses, necroptosis is a key mechanism contributing to tissue damage and immune dysregulation in various diseases, including pneumonia. This review comprehensively analyzes the role of necroptosis in pneumonia and explores potential pharmacological interventions targeting this cell death pathway. Moreover, we highlight the intricate interplay between necroptosis and immune responses in pneumonia, revealing a bidirectional relationship between necrotic cell death and inflammatory signaling. Importantly, we assess current therapeutic strategies modulating necroptosis, encompassing synthetic inhibitors, natural products, and other drugs targeting key components of the programmed necrosis pathway. The article also discusses challenges and future directions in targeting programmed necrosis for pneumonia treatment, proposing novel therapeutic strategies that combine antibiotics with necroptosis inhibitors. This review underscores the importance of understanding necroptosis in pneumonia and highlights the potential of pharmacological interventions to mitigate tissue damage and restore immune homeostasis in this devastating respiratory infection.

[Effect of Cisatracurium to Intensify Diaphragmatic Atrophy in Mechanically Ventilated Rats]

OBJECTIVE

To investigate the role of cisatracurium in diaphragm atrophy in mechanically ventilated (MV) rats and its possible mechanism.

METHODS

30 adult male Sprague-Dawley (SD) rats were randomly assigned to 5 groups: Rats in the control (CON) group ( n=6) were fasted for 30 h without any other intervention; rats in the MV group ( n=6) were fasted for 6 h, and then mechanically ventilated for 24 h while receiving continuous infusion of sodium pentobarbital and 0.9% NaCl; rats in the MV+cisatracurium (MVC) group ( n=6) were fasted for 6 h, and then mechanically ventilated for 24 h while receiving continuous infusion of sodium pentobarbital and cisatracurium; rats in the MV+chloroquine (QMV) group ( n=6) and rats in the MV+cisatracurium+chloroquine (QMVC) group ( n=6) received intraperitoneal injection of chloroquine (30 mg/kg), an autophagy inhibitor, at 24 h and 30 min prior to MV in addition to the treatments given to the MV group and the MVC group, respectively. The rats in each group were sacrificed 30 hours later, and costal diaphragm muscle specimens were collected. The cross-sectional area (CSA) of the diaphragm fibers was observed through HE staining, and the colocalizations of TOM20 and LC3 were assessed by immunofluorescence staining. The expression levels of PINK1, Parkin, P62 and LC3, the mitophagy-related proteins, and the expression levels of MAFbx and MURF-1, muscular-atrophy-related proteins, were evaluated by Western blot.

RESULTS

Respective comparisons of the MV group with the CON group and the MVC group with the MV group showed that the CSA decreased ( P<0.05), the expression of MURF-1, MAFbx, PINK1, Parkin and LC3Ⅱ/Ⅰproteins increased ( P<0.05), the number of co-expressed mitochondria of TOM20 and LC3 and the expression of LC3 increased and the expression of P62 protein decreased ( P<0.05) in the MV and MVC groups. Respective comparisons of the QMV group with the MV group and the QMVC group with the MVC group showed that the CSA increased ( P<0.05), the expression of MURF-1, MAFbx, PINK1, Parkin and LC3Ⅱ/Ⅰ proteins increased ( P<0.05), the number of co-expressed mitochondria of TOM20 and LC3 and the expression of LC3 decreased and the expression of P62 protein decreased ( P<0.05) in the QMV and QMVC group.

CONCLUSION

Mechanical ventilation for 24 h caused diaphragm atrophy in SD rats. Cisatracurium may aggravate diaphragm atrophy in mechanically ventilated rats through the autophagy-lysosome (AL) pathway, a process that may be related to the PINK1/Parkin-mediated mitophagy, and chloroquine may reduce diaphragmatic atrophy induced by cisatracurium by blocking the AL pathway.

Selective autophagy of intracellular organelles: recent research advances

Macroautophagy (hereafter called autophagy) is a highly conserved physiological process that degrades over-abundant or damaged organelles, large protein aggregates and invading pathogens via the lysosomal system (the vacuole in plants and yeast). Autophagy is generally induced by stress, such as oxygen-, energy- or amino acid-deprivation, irradiation, drugs, etc. In addition to non-selective bulk degradation, autophagy also occurs in a selective manner, recycling specific organelles, such as mitochondria, peroxisomes, ribosomes, endoplasmic reticulum (ER), lysosomes, nuclei, proteasomes and lipid droplets (LDs). This capability makes selective autophagy a major process in maintaining cellular homeostasis. The dysfunction of selective autophagy is implicated in neurodegenerative diseases (NDDs), tumorigenesis, metabolic disorders, heart failure, etc. Considering the importance of selective autophagy in cell biology, we systemically review the recent advances in our understanding of this process and its regulatory mechanisms. We emphasize the 'cargo-ligand-receptor' model in selective autophagy for specific organelles or cellular components in yeast and mammals, with a focus on mitophagy and ER-phagy, which are finely described as types of selective autophagy. Additionally, we highlight unanswered questions in the field, helping readers focus on the research blind spots that need to be broken.

Autophagy Promotes Porcine Parvovirus Replication and Induces Non-Apoptotic Cell Death in Porcine Placental Trophoblasts

Autophagy plays important roles in the infection and pathogenesis of many viruses, yet the regulatory roles of autophagy in the process of porcine parvovirus (PPV) infection remain unclear. Herein, we show that PPV infection induces autophagy in porcine placental trophoblasts (PTCs). Induction of autophagy by rapamycin (RAPA) inhibited the occurrence of apoptotic cell death, yet promoted viral replication in PPV-infected cells; inhibition of autophagy by 3-MA or ATG5 knockdown increased cellular apoptosis and reduced PPV replication. Interestingly, we found that in the presence of caspase-inhibitor zVAD-fmk, PPV induces non-apoptotic cell death that was characterized by lysosomal damage and associated with autophagy. Induction of complete autophagy flux by RAPA markedly promoted PPV replication compared with incomplete autophagy induced by RAPA plus bafilomycin (RAPA/BAF) in the early phase of PPV infection (24 h.p.i.). Meanwhile, induction of complete autophagy with RAPA increased lysosomal damage and non-apoptotic cell death in the later phase of PPV infection. Therefore, our data suggest that autophagy can enhance PPV replication and promote the occurrence of lysosomal-damage-associated non-apoptotic cell death in PPV-infected porcine placental trophoblasts.