High mobility group box-1 release from H2O2-injured hepatocytes due to sirt1 functional inhibition

BACKGROUND High mobility group box-1 (HMGB1), recognized as a representative of damageassociated molecular patterns, is released during cell injury/death, triggering the inflammatory response and ultimately resulting in tissue damage. Dozens of studies have shown that HMGB1 is involved in certain diseases, but the details on how injured hepatocytes release HMGB1 need to be elicited. AIM To reveal HMGB1 release mechanism in hepatocytes undergoing oxidative stress. METHODS C57BL6/J male mice were fed a high-fat diet for 12 wk plus a single binge of ethanol to induce severe steatohepatitis. Hepatocytes treated with H2O2 were used to establish an in vitro model. Serum alanine aminotransferase, liver H2O2 content and catalase activity, lactate dehydrogenase and 8-hydroxy-2- deoxyguanosine content, nicotinamide adenine dinucleotide (NAD+) levels, and Sirtuin 1 (Sirt1) activity were detected by spectrophotometry. HMGB1 release was measured by enzyme linked immunosorbent assay. HMGB1 translocation was observed by immunohistochemistry/immunofluorescence or Western blot. Relative mRNA levels were assayed by qPCR and protein expression was detected by Western blot. Acetylated HMGB1 and poly(ADP-ribose)polymerase 1 (Parp1) were analyzed by Immunoprecipitation. RESULTS When hepatocytes were damaged, HMGB1 translocated from the nucleus to the cytoplasm because of its hyperacetylation and was passively released outside both in vivo and in vitro. After treatment with Sirt1-siRNA or Sirt1 inhibitor (EX527), the hyperacetylated HMGB1 in hepatocytes increased, and Sirt1 activity inhibited by H2O2 could be reversed by Parp1 inhibitor (DIQ). Parp1 and Sirt1 are two NAD+-dependent enzymes which play major roles in the decision of a cell to live or die in the context of stress . We showed that NAD+ depletion attributed to Parp1 activation after DNA damage was caused by oxidative stress in hepatocytes and resulted in Sirt1 activity inhibition. On the contrary, Sirt1 suppressed Parp1 by negatively regulating its gene expression and deacetylation. CONCLUSION The functional inhibition between Parp1 and Sirt1 leads to HMGB1 hyperacetylation, which leads to its translocation from the nucleus to the cytoplasm and finally outside the cell.

Proportions of acetyl-histone-positive hepatocytes indicate the functional status and prognosis of cirrhotic patients

AIM:To investigate whether the proportions of acetylhistone-positive hepatocytes could be used as markers of deteriorating liver function.METHODS:In total,611 cirrhotic cases from 3701 patients who were diagnosed during the past 15 years were screened,and 152 follow-up cases were selected.Paraffin tissue microarray was prepared for immunohistochemistry to examine acetyl-histone expression.The proportions of positive hepatocytes were recorded,and their correlations to clinical and laboratory indicators were analyzed statistically.RESULTS:The proportions of H2AK5ac+,H3K9/K14ac+ and H3K27ac+ hepatocytes gradually increased with deteriorating liver function and with increasing levels of serum markers of liver injury.In the follow-up cases,patients with > 70% H2AK5ac+,H3K9/K14ac+ or H3K27ac+ hepatocytes had statistically lower survival rates(P < 0.05).Furthermore,> 70% H2AK5ac+ or H3K27ac+ hepatocytes were strong independent predictors of overall survival(P < 0.05).CONCLUSION:The proportions of acetyl-histonepositive hepatocytes are closely associated with the liver function and prognosis of cirrhotic patients.

Protective effects of ACLF sera on metabolic functions and proliferation of hepatocytes co-cultured with bone marrow MSCs in vitro

AIM： To investigate whether the function of hepatocytes co-cultured with bone marrow mesenchymal stem cells （MSCs） could be maintained in serum from acute-on- chronic liver failure （ACLF） patients.METHODS： Hepatocyte supportive functions and cy- totoxicity of sera from 18 patients with viral hepatitis B-induced ACLF and 18 healthy volunteers were evalu- ated for porcine hepatocytes co-cultured with MSCs and hepatocyte mono-layered culture, respectively. Chemo- kine profile was also examined for the normal serum and liver failure serum.RESULTS： Hepatocyte growth factor （HGF） and Tumor necrosis factor; tumor necrosis factor （TNF）-a were re- markably elevated in response to ACLF while epidermal growth factor （EGF） and VEGF levels were significantly decreased. Liver failure serum samples induced a higher detachment rate, lower viability and decreased liver sup- port functions in the homo-hepatocyte culture. Hepato-cytes co-cultured with MSCs could tolerate the cytotoxic- ity of the serum from ACLF patients and had similar liver support functions compared with the hepatocytes cul- tured with healthy human serum in vitro. In addition, co- cultured hepatocytes maintained a proliferative capability despite of the insult from liver failure serum.CONCLUSION： ACLF serum does not impair the cell morphology, viability, proliferation and overall metabolic capacities of hepatocyte co-cultured with MSCs in vitro.

Hypidone hydrochloride(YL-0919)ameliorates functional deficits after traumatic brain injury in mice by activating the sigma-1 receptor for antioxidation

Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.

Emerging insights into the function of very long chain fatty acids at cerebellar synapses

Very long chain-saturated and-polyunsaturated fatty acids(VLC-SFA and VLC-PUFA, respectively) are a functionally important class of fatty acids containing 28 carbons or more in their acyl chain. They are synthesized by the elongation of very long fatty acids-4(ELOVL4) enzyme, expressed mainly in the brain, retina, skin, testes, and meibomian gland, where these fatty acids are found(Agbaga et al., 2008). Further, these organs exhibit tissuespecific VLC-PUFA and VLC-SFA biosynthesis and incorporation into complex lipids for specific functions. In the brain, skin, and Meibomian glands, the ELOVL4 mainly makes VLC-SFA, which are incorporated into complex sphingolipids. In the retina, the ELOVL4 makes VLC-PUFA that are incorporated into phosphatidylcholine, that are critical for visual function, while in testes and sperm, the VLC-PUFA are incorporated into sphingolipids that are critical for fertility(Yeboah et al., 2021).

Effects of plasma from patients with acute on chronic liver failure on function of cytochrome P450 in immortalized human hepatocytes

BACKGROUND: The bioartificial liver is anticipated to be a promising alternative choice for patients with liver failure. Toxic substances which accumulate in the patients' plasma exert deleterious effects on hepatocytes in the bioreactor, and potentially reduce the efficacy of bioartificial liver devices. This study was designed to investigate the effects of plasma from patients with acute on chronic liver failure (AoCLF) on immortalized human hepatocytes in terms of cytochrome P450 gene expression, drug metabolism activity and detoxification capability. METHODS: Immortalized human hepatocytes (HepLi-2 cells) were cultured in medium containing fetal calf serum or human plasma from three patients with AoCLF. The cytochrome P450 (CYP3A5, CYP2E1, CYP3A4) expression, drug metabolism activity and detoxification capability of HepLi-2 cells were assessed by RT-PCR, lidocaine clearance and ammonia elimination assay. RESULTS: After incubation in medium containing AoCLF plasma for 24 hours, the cytochrome P450 mRNA expression of HepLi-2 cells was not significantly decreased compared with control culture. Ammonia elimination and lidocaine clearance assay showed that the ability of ammonia removal and drug metabolism remained stable. CONCLUSIONS: Immortalized human hepatocytes can be exposed to AoCLF plasma for at least 24 hours with no significant reduction in the function of cytochrome P450. HepLi-2 cells appear to be effective in metabolism and detoxification and can be potentially used in the development of bioartificial liver. (Hepatobiliary Pancreat Dis Int 2010; 9:611-614)

The complex role of protocadherin-19 in brain function:a focus on the oxytocin system

Mutations in the protocadherin-19(PCDH19)gene(Xq22.1)cause the X-linked syndrome known as developmental and epileptic encephalopathy 9(DEE9,OMIM#300088)(Dibbens et al.,2008).DEE9 is characterized by early-onset clustering epilepsy associated with intellectual disability ranging from mild to profound,autism spectrum disorder,and other neuropsychiatric features including schizophrenia,anxiety,attentiondeficit/hyperactivity,and obsessive or aggressive behaviors.While seizures may become less frequent in adolescence,psychiatric comorbidities persist and often worsen with age(Dibbens et al.,2008;Kolc et al.,2020).

Neuropeptide cholecystokinin:a key neuromodulator for hippocampal functions

Spatial memory is crucial for survival within external surroundings and wild environments.The hippocampus,a critical hub for spatial learning and memory formation,has received extensive investigations on how neuromodulators shape its functions(Teixeira et al.,2018;Zhang et al.,2024).However,the landscape of neuromodulations in the hippocampal system remains poorly understood because most studies focus on classical monoamine neuromodulators,such as acetylcholine,serotonin,dopamine,and noradrenaline.The neuropeptides,comprising the most abundant neuromodulators in the central nervous system,play a pivotal role in neural information processing in the hippocampal system.Cholecystokinin(CCK),one of the most abundant neuropeptides,has been implicated in regulating various physiological and neurobiological statuses(Chen et al.,2019).CCK-A receptor(CCK-AR)and CCK-B receptors(CCK-BR)are two key receptors mediating the biological functions of CCK,both of which belong to class-A sevenfold transmembrane G protein-coupled receptors(Nishimura et al.,2015).CCK-AR preferentially reacts to sulfated CCK,whereas CCK-BR binds both CCK and gastrin with similar affinities(Ding et al.,2022).The expression patterns of CCK-AR and CCK-BR are distinct,implying that CCK has various functions in target regions.For instance,CCK-AR is widely expressed in the GI and brain subregions and is hence implicated in the control of digestive function and satiety regulation.Conversely,CCK-BR is abundantly and widely distributed in the central nervous system,which majorly regulates anxiety,learning,and memory(Ding et al.,2022).However,the roles of endogenous CCK and CCK receptors in regulating hippocampal function at electrophysiological and behavioral levels have received less attention.

Corrigendum: MicroRNA-502-3p regulates GABAergic synapse function in hippocampal neurons

There is an error in the name of the cell line in the abstract of the published paper“MicroRNA-502-3p regulates GABAergic synapse function in hippocampal neurons”published on pages 2698-2707,Issue 12,Volume 19 of Neural Regeneration Research(Sharma et al.,2024),because of oversight during final proof checking.The correct description should be“human-GABA receptor A-α1/β2/γ2L human embryonic kidney(HEK)recombinant cell line.”The authors apologize for any inconvenience this correction may cause for readers and editors of Neural Regeneration Research.

Chondroitinase ABC combined with Schwann cell transplantation enhances restoration of neural connection and functional recovery following acute and chronic spinal cord injury

Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.

Emerging role of A-kinase anchoring protein 5 signaling in reward circuit function

There is a strong evidence supporting the hypothesis of synaptic dysfunction as a major contributor to neural circuit and network disruption underlying emotional and mood dysregulation in psychiatric disorders(Simmons et al.,2024).Diverse sets of distinct molecular signaling pathways converge on the synapse to regulate synaptogenesis,synaptic function,and synaptic plasticity in brain regions and circuits through complex interactions organized by numerous multivalent protein scaffolds,including the family of proteins known as A-kinase anchoring proteins(AKAPs).

Effect of sodium citrate plasma on growth and function of hepatocytes

Objective:To observe the effect of sodium citrate plasma (scP) on the growth and function of hepatocytes. Methods: HepG2, fetus and porcine hepatocytes were cultured. The viability, cell cycle and apoptosis, the leakage of LDH, AFP, total protein, glutathione and the changes on morphology of hepatocytes exposured to scP were investigated. Results: (1)Cultured in 10%, 30%, 50%, 100% scP for 24 h, the viability of HepG2 cells was inhibited (F = 40. 108, P = 0. 001). After 48 h, nearly all cells died except 10% scP group. (2)Exposured to scP for 24 h,the percentage of S phase of the cell cycle was significantly increased and apoptosis was also significantly increased compared to control cultures. (3) The leakages of LDH were increased in the HepG2, fetus and porcine hepatocytes following exposure to scP for 5 h. (4) The synthesis of AFP in fetus and porcine hepatocytes were inhibited in medium containing 10% scP for 3 d(t values were 8. 1902, 5. 1034 separately, P<0. 01). Exposure of HepG2 cells to scP within 24 h resulted in a decrease in the total protein synthesis and a increase in the GSH content. (5)Most of HepG2, fetus and porcine hepatocytes died in all except 10% scP groups after 24 h exposed to scP. Conclusion:scP can damage hepatocytes, which results from citric acid and sodium citrate contained in the fluid of blood maintenance.

Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats

Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network level have not been elucidated.This study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve transfer.Sprague–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper trunk.Resting-state brain functional magnetic resonance imaging was obtained 7 months after surgery.The independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the component.Alterations in intra-network resting-state functional connectivity were compared among the groups.Target muscle reinnervation was assessed by behavioral observation(elbow flexion)and electromyography.The results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural pathway.Nerve repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor representation.The thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve transfer.Brain areas related to cognition and emotion were enhanced after end-to-side nerve transfer.Our study revealed important brain networks related to different nerve reconstructions.These networks may be potential targets for enhancing motor recovery.

Restoration of cell polarity and bile excretion function of hepatocytes in sandwich-culture

Objective： To investigate the nature of the restoration of cell polarity and bile excretion function in Sandwich-cultured hepatocytes. Methods ： Freshly isolated hepatocytes from male Sprague-Dawley rats were cultured in a double layer collagen gel Sandwich configuration. Morphological changes were observed under a inverted microscope. The domain specific membrane associated protein DPP IV was tested by immunofluorescence, and the bile excretion function was determined by using fluorescein diacetate. Hepatocytes cultured on a single layer of collagen gel were taken as control. Results.. Adult rat hepatocytes cultured in a double layer collagen gel sandwich configuration regained its morphological and functional polarity and maintained polygonal morphology for at least 4 weeks. Immunofluorescence studies using antibodies against DPP IV showed polarity restoration as early as 48 h. After cultured in the double layer collagen gel Sandwich configuration for 96 h the hepatocytes began to excrete bile; while hepatocytes cultured on a single layer collagen gel had no bile excretion. Conclusion.. Hepatocytes cultured in a double layer collagen gel Sandwich configuration are able to regain their morphological and functional polarity given certain conditions. Hepaotcyte culture is a useful tool for the study of polarity restoration.

Enhancement of motor functional recovery in thoracic spinal cord injury: voluntary wheel running versus forced treadmill exercise

Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury.

Pharmacological targeting cGAS/STING/NF-κB axis by tryptanthrin induces microglia polarization toward M2 phenotype and promotes functional recovery in a mouse model of spinal cord injury

The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury.Regulation of shifting microglia polarization from M1(neurotoxic and proinflammatory type)to M2(neuroprotective and anti-inflammatory type)after spinal cord injury appears to be crucial.Tryptanthrin possesses an anti-inflammatory biological function.However,its roles and the underlying molecular mechanisms in spinal cord injury remain unknown.In this study,we found that tryptanthrin inhibited microglia-derived inflammation by promoting polarization to the M2 phenotype in vitro.Tryptanthrin promoted M2 polarization through inactivating the cGAS/STING/NF-κB pathway.Additionally,we found that targeting the cGAS/STING/NF-κB pathway with tryptanthrin shifted microglia from the M1 to M2 phenotype after spinal cord injury,inhibited neuronal loss,and promoted tissue repair and functional recovery in a mouse model of spinal cord injury.Finally,using a conditional co-culture system,we found that microglia treated with tryptanthrin suppressed endoplasmic reticulum stress-related neuronal apoptosis.Taken together,these results suggest that by targeting the cGAS/STING/NF-κB axis,tryptanthrin attenuates microglia-derived neuroinflammation and promotes functional recovery after spinal cord injury through shifting microglia polarization to the M2 phenotype.

Activation of adult endogenous neurogenesis by a hyaluronic acid collagen gel containing basic fibroblast growth factor promotes remodeling and functional recovery of the injured cerebral cortex

The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury.However,whether it is possible to stimulate neurogenesis and reconstruct cortical layers II to VI in non-neurogenic regions,such as the cortex,remains unknown.In this study,we implanted a hyaluronic acid collagen gel loaded with basic fibroblast growth factor into the motor cortex immediately following traumatic injury.Our findings reveal that this gel effectively stimulated the proliferation and migration of endogenous neural stem/progenitor cells,as well as their differentiation into mature and functionally integrated neurons.Importantly,these new neurons reconstructed the architecture of cortical layers II to VI,integrated into the existing neural circuitry,and ultimately led to improved brain function.These findings offer novel insight into potential clinical treatments for traumatic cerebral cortex injuries.

Protective Actions of Blumea Flavanones on Primary Cultured Hepatocytes and Liver Subcellular Organelle against Lipid Peroxidation

To search for the protective actions of blumea flavanones (BFs) on hepatocytes and hepatic subcellular organelle against lipid peroxidation, monkey′s hepatocytes were isolated and cultured with or without blumea flavanones, then damaged by FeSO 4 cysteine or CCl 4. The lipid peroxidation (malondialdehyde production) and alteration in hepatocyte membrane (leakage of GPT) were estimated. Hepatic subcellular organelles were also isolated and incubated with or without blumea flavanones, then injured by FeSO 4 ascorbate. The generation of malondialdehyde(MDA) was measured. It was found that BFs 10 and 100 μmol·L 1 inhibited the MDA generation and GPT (glutamic pyruvic transaminase) leakage out of hepatocytes that were induced by CCl 4 or FeSO 4 cysteine. BFs could prevent lipid peroxidation initiated by FeSO 4 ascorbate in subcellular organelle suspension. Among BFs, BF 2 possessed the strongest activity. Conclusion: Blumea flavanones possess antioxidation activities that protect monkey′s hepatocytes and hepatic subcellular organelle against injuries induced by FeSO4 or CCl 4.

Protective effects of polydatin against CCl_4-induced injury to primarily cultured rat hepatocytes

AIM To investigate the protective effects of polydatin (PD) against injury to primarily cultured rat hepatocytes induced by CCl 4. METHODS Rat hepatocytes were separated by methods of liver infusion in vivo and cultured medium (7 5×10 5 cells/mL). Two mL or 0 2mL was added into 24 well or 96 well plates respectively. Twenty four hours after cell preculture, PD at concentrations of 10 -7 mol/L-10 -4 mol/L was added into each plate. At the same time injury to hepatocytes was induced by adding 10mmol/L CCl 4. Then, 0 1mL or 1mL culture solution was removed from the 96 well or 24 well plates at 6h , 12h , 24h and 48h after CCl 14 intoxication respectively for the determination of GPT, GSH and MDA. At 48h , the survivability of rat hepatocytes was assayed by the MTT colormetric method. RESULTS After CCl 4 challenge, the release of GPT and the formation of MDA in rat hepatocytes markedly increased and maintained at a high level in 48h , whereas PD with different concentrations could markedly inhibit this elevation with 10 -5 mol/L PD having the strongest effects and inhibiting rate was over 50%. PD could also improve the decreased content of GSH caused by CCl 4 in accordance with the doses used. CCl 4 evidently decreased the hepatocyte survivability from 91 0%±7 9% to 35 4%±3 8%. On the other hand, PD at 10 -7 mol/L-10 -4 mol/L could reverse this change and improve the cell survival rates to 56 1%±5 2%, 65 8%±5 0%, 88 7%±6 8% and 75 2%±7 3%, respectively. CONCLUSION PD at 10 -7 mol/L-10 -4 mol/L could protect primarily cultured rat hepatocytes against CCl 4 induced injury.

Reversible immortalization of human hepatocytes mediated by retroviral transfer and site-specific recombination

AIM: To establish a method for the reversible immortalization of human hepatocytes, which may offer a good and safe source of hepatocytes for practical applications.