Qian Li

Bio: Qian Li is an academic researcher from University of Gothenburg. The author has contributed to research in topics: Physics & Neurogenesis. The author has an hindex of 6, co-authored 6 publications receiving 609 citations. Previous affiliations of Qian Li include Zhengzhou University.

Isoflurane anesthesia induced persistent, progressive memory impairment, caused a loss of neural stem cells, and reduced neurogenesis in young, but not adult, rodents.

Abstract: Isoflurane and related anesthetics are widely used to anesthetize children, ranging from premature babies to adolescents. Concerns have been raised about the safety of these anesthetics in pediatric patients, particularly regarding possible negative effects on cognition. The purpose of this study was to investigate the effects of repeated isoflurane exposure of juvenile and mature animals on cognition and neurogenesis. Postnatal day 14 (P14) rats and mice, as well as adult (P60) rats, were anesthetized with isoflurane for 35 mins daily for four successive days. Object recognition, place learning and reversal learning as well as cell death and cytogenesis were evaluated. Object recognition and reversal learning were significantly impaired in isoflurane-treated young rats and mice, whereas adult animals were unaffected, and these deficits became more pronounced as the animals grew older. The memory deficit was paralleled by a decrease in the hippocampal stem cell pool and persistently reduced neurogenesis, subsequently causing a reduction in the number of dentate gyrus granule cell neurons in isoflurane-treated rats. There were no signs of increased cell death of progenitors or neurons in the hippocampus. These findings show a previously unknown mechanism of neurotoxicity, causing cognitive deficits in a clearly age-dependent manner.

Neuroprotection by selective neuronal deletion of Atg7 in neonatal brain injury.

Abstract: Perinatal asphyxia induces neuronal cell death and brain injury, and is often associated with irreversible neurological deficits in children. There is an urgent need to elucidate the neuronal death mechanisms occurring after neonatal hypoxia-ischemia (HI). We here investigated the selective neuronal deletion of the Atg7 (autophagy related 7) gene on neuronal cell death and brain injury in a mouse model of severe neonatal hypoxia-ischemia. Neuronal deletion of Atg7 prevented HI-induced autophagy, resulted in 42% decrease of tissue loss compared to wild-type mice after the insult, and reduced cell death in multiple brain regions, including apoptosis, as shown by decreased caspase-dependent and -independent cell death. Moreover, we investigated the lentiform nucleus of human newborns who died after severe perinatal asphyxia and found increased neuronal autophagy after severe hypoxic-ischemic encephalopathy compared to control uninjured brains, as indicated by the numbers of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3)-, LAMP1 (lysosomal-associated membrane protein 1)-, and CTSD (cathepsin D)-positive cells. These findings reveal that selective neuronal deletion of Atg7 is strongly protective against neuronal death and overall brain injury occurring after HI and suggest that inhibition of HI-enhanced autophagy should be considered as a potential therapeutic target for the treatment of human newborns developing severe hypoxic-ischemic encephalopathy.

Lithium reduces apoptosis and autophagy after neonatal hypoxia-ischemia.

Abstract: Lithium is used in the treatment of bipolar mood disorder. Reportedly, lithium can be neuroprotective in models of adult brain ischemia. The purpose of this study was to evaluate the effects of lithium in a model of neonatal hypoxic–ischemic brain injury. Nine-day-old male rats were subjected to unilateral hypoxia–ischemia (HI) and 2 mmol/kg lithium chloride was injected i.p. immediately after the insult. Additional lithium injections, 1 mmol/kg, were administered at 24-h intervals. Pups were killed 6, 24 or 72 h after HI. Lithium reduced the infarct volume from 24.7±2.9 to 13.8±3.3 mm3 (44.1%) and total tissue loss (degeneration + lack of growth) from 67.4±4.4 to 38.4±5.9 mm3 (43.1%) compared with vehicle at 72 h after HI. Injury was reduced in the cortex, hippocampus, thalamus and striatum. Lithium reduced the ischemia-induced dephosphorylation of glycogen synthase kinase-3β and extracellular signal-regulated kinase, the activation of calpain and caspase-3, the mitochondrial release of cytochrome c and apoptosis-inducing factor, as well as autophagy. We conclude that lithium could mitigate the brain injury after HI by inhibiting neuronal apoptosis. The lithium doses used were in the same range as those used in bipolar patients, suggesting that lithium might be safely used for the avoidance of neonatal brain injury.

Lithium-mediated long-term neuroprotection in neonatal rat hypoxia-ischemia is associated with antiinflammatory effects and enhanced proliferation and survival of neural stem/progenitor cells.

Abstract: The aim of this study was to evaluate the long-term effects of lithium treatment on neonatal hypoxic-ischemic brain injury, inflammation, and neural stem/progenitor cell (NSPC) proliferation and survival. Nine-day-old male rats were subjected to unilateral hypoxia-ischemia (HI) and 2 mmol/kg lithium chloride was injected intraperitoneally immediately after the insult. Additional lithium injections, 1 mmol/kg, were administered at 24-hour intervals for 7 days. Animals were killed 6, 24, 72 hours, or 7 weeks after HI. Lithium reduced total tissue loss by 69%, from 89.4±14.6 mm3 in controls (n=15) to 27.6±6.2 mm3 in lithium-treated animals (n=14) 7 weeks after HI (P<0.001). Microglia activation was inhibited by lithium treatment, as judged by Iba-1 and galectin-3 immunostaining, and reduced interleukin-1β and CCL2 levels. Lithium increased progenitor, rather than stem cell, proliferation in both nonischemic and ischemic brains, as judged by 5-bromo-2-deoxyuridine labeling 24 and 72 hours as well as by phospho-histone H3 and brain lipid-binding protein labeling 7 weeks after HI. Lithium treatment also promoted survival of newborn NSPCs, without altering the relative levels of neuronal and astroglial differentiation. In summary, lithium conferred impressive, morphological long-term protection against neonatal HI, at least partly by inhibiting inflammation and promoting NSPC proliferation and survival.

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Abstract: Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field.

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

Abstract: In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

Molecular definitions of autophagy and related processes

Abstract: Over the past two decades, the molecular machinery that underlies autophagic responses has been characterized with ever increasing precision in multiple model organisms. Moreover, it has become clear that autophagy and autophagy-related processes have profound implications for human pathophysiology. However, considerable confusion persists about the use of appropriate terms to indicate specific types of autophagy and some components of the autophagy machinery, which may have detrimental effects on the expansion of the field. Driven by the overt recognition of such a potential obstacle, a panel of leading experts in the field attempts here to define several autophagy-related terms based on specific biochemical features. The ultimate objective of this collaborative exchange is to formulate recommendations that facilitate the dissemination of knowledge within and outside the field of autophagy research.

Pharmacological modulation of autophagy: therapeutic potential and persisting obstacles.

Abstract: Autophagy is central to the maintenance of organismal homeostasis in both physiological and pathological situations Accordingly, alterations in autophagy have been linked to clinically relevant conditions as diverse as cancer, neurodegeneration and cardiac disorders Throughout the past decade, autophagy has attracted considerable attention as a target for the development of novel therapeutics However, such efforts have not yet generated clinically viable interventions In this Review, we discuss the therapeutic potential of autophagy modulators, analyse the obstacles that have limited their development and propose strategies that may unlock the full therapeutic potential of autophagy modulation in the clinic