Search

Proper metabolic activities facilitate T cell expansion and antitumor function; however, the mechanisms underlying disruption of the T cell metabolic program and function in the tumor microenvironment (TME) remain elusive. Here, we show a zinc finger protein 91–governed (ZFP91-governed) mechanism that disrupts the metabolic pathway and antitumor activity of tumor-infiltrating T cells. Single-cell RNA-Seq revealed that impairments in T cell proliferation and activation correlated with ZFP91 in tissue samples from patients with colorectal cancer. T cell–specific deletion of Zfp91 in mice led to enhanced T cell proliferation and potentiated T cell antitumor function. Loss of ZFP91 increased mammalian target of rapamycin complex 1 (mTORC1) activity to drive T cell glycolysis. Mechanistically, T cell antigen receptor–dependent (TCR-dependent) ZFP91 cytosolic translocation promoted protein phosphatase 2A (PP2A) complex assembly, thereby restricting mTORC1-mediated metabolic reprogramming. Our results demonstrate that ZFP91 perturbs T cell metabolic and functional states in the TME and suggest that targeting ZFP91 may improve the efficacy of cancer immunotherapy.

Objective: This study aimed to investigate the neuroprotective effect of heme oxygenase-1 (HO-1) on the PI3K/AKT signaling pathway in rats with cerebral hemorrhage. Materials and methods: Adult male Sprague-Dawley rats were randomly divided into: a sham group, a model group and an HO-1 inhibitor group (ZnPP group). Functional defects after surgery were scored according to the Longa5 standard. Hemotoxylin and eosin staining was used to detect whether the model was constructed successfully. Superoxide dismutase (SOD) vitality and malondialdehyde (MDA) content were calculated by the xanthine oxidase method and thiobarbituric acid method, respectively. Blood-brain barrier permeability was measured by Evans Blue. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The expression of Bcl-2 and BAX was evaluated by immunohistochemistry and the expression of PI3K, p-PI3K, AKT and p-AKT was tested by Western blotting. Results: The rat intracerebral hemorrhage model was successfully constructed. Compared with the model group, the bleeding in the ZnPP group was more serious, the cell edema and deformation were aggravated, and the neurological deficit score in the rat was significantly increased. In addition, the content of Evans blue, MDA, the number of apoptotic cells, the water content of brain tissue and the expression of BAX were significantly increased, while the SOD activity and the expressions of Bcl-2, p-PI3K and p-AKT protein were decreased. Conclusion: HO-1 could protect the nerves of rats with cerebral hemorrhage by regulating the PI3K/AKT signaling pathway.

The mechanisms governing autophagy initiation in T reg cells remain unclear. Wang et al. identify a ZFP91-dependent mechanism promoting TCR-initiated autophagosome maturation to restrict hyperglycolysis and maintain T reg cell homeostasis and function., Autophagy programs the metabolic and functional fitness of regulatory T (T reg) cells to establish immune tolerance, yet the mechanisms governing autophagy initiation in T reg cells remain unclear. Here, we show that the E3 ubiquitin ligase ZFP91 facilitates autophagy activation to sustain T reg cell metabolic programming and functional integrity. T reg cell–specific deletion of Zfp91 caused T reg cell dysfunction and exacerbated colonic inflammation and inflammation-driven colon carcinogenesis. TCR-triggered autophagy induction largely relied on T reg cell–derived ZFP91 to restrict hyperglycolysis, which is required for the maintenance of T reg cell homeostasis. Mechanistically, ZFP91 rapidly translocated from the nucleus to the cytoplasm in response to TCR stimulation and then mediated BECN1 ubiquitination to promote BECN1–PIK3C3 complex formation. Therefore, our results highlight a ZFP91-dependent mechanism promoting TCR-initiated autophagosome maturation to maintain T reg cell homeostasis and function., Graphical Abstract

STING-dependent cytosolic DNA sensing in dendritic cells (DCs) initiates antitumor immune responses, but how STING signaling is metabolically regulated in the tumor microenvironment remains unknown. Here, we show that oxidative stress is required for STING-induced DC antitumor function through a process that directs SUMO-specific protease 3 (SENP3) activity. DC-specific deletion of Senp3 drives tumor progression by blunting STING-dependent type-I interferon (IFN) signaling in DCs and dampening antitumor immune responses. DC-derived reactive oxygen species (ROS) trigger SENP3 accumulation and the SENP3-IFI204 interaction, thereby catalyzing IFI204 deSUMOylation and boosting STING signaling activation in mice. Consistently, SENP3 senses ROS to facilitate STING-dependent DC activity in tissue samples from colorectal cancer patients. Our results reveal that oxidative stress as a metabolic regulator promotes STING-mediated DC antitumor immune responses and highlights SENP3 as an overflow valve for STING signaling induction in the metabolically abnormal tumor microenvironment.

Metabolic programs are crucial for T reg cell stability and function. Yu et al. report that TRAF3IP3 acts as a pivotal regulator in controlling metabolic fitness to maintain T reg cell stability and function at the lysosome., Metabolic programs are crucial for regulatory T (T reg) cell stability and function, but the underlying mechanisms that regulate T reg cell metabolism are elusive. Here, we report that lysosomal TRAF3IP3 acts as a pivotal regulator in the maintenance of T reg cell metabolic fitness. T reg–specific deletion of Traf3ip3 impairs T reg cell function, causing the development of inflammatory disorders and stronger antitumor T cell responses in mice. Excessive mechanistic target of rapamycin complex 1 (mTORC1)–mediated hyper-glycolytic metabolism is responsible for the instability of TRAF3IP3-deficient T reg cells. Mechanistically, TRAF3IP3 restricts mTORC1 signaling by recruiting the serine-threonine phosphatase catalytic subunit (PP2Ac) to the lysosome, thereby facilitating the interaction of PP2Ac with the mTORC1 component Raptor. Our results define TRAF3IP3 as a metabolic regulator in T reg cell stability and function and suggest a lysosome-specific mTORC1 signaling mechanism that regulates T reg cell metabolism., Graphical Abstract

Objective To investigate the mechanism of dexmedetomidine (Dex) in improving brain damage induced by cerebral ischemia-reperfusion injury in rats. Methods Rats were randomly divided into a sham operation group, ischemia-reperfusion group, Dex group, piracetam group, and yohimbine + Dex group, with 12 rats per group. 2,3,5-Triphenyltetrazolium chloride staining was used to analyze cerebral infarct size. Hematoxylin-eosin staining and immunohistochemistry were used to observe brain damage caused by ischemia-reperfusion. Cognitive and memory functions was detected by Morris water maze test, and the expression of phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2) and phosphorylated cyclic adenosine monophosphate response element binding protein (CREB) were measured by Western blot. Results Cognitive dysfunction was improved in the Dex group and the piracetam group compared with the ischemia-reperfusion group. Compared with the ischemia-reperfusion group, infarct size and neuronal cell death rates were decreased in the Dex group and the piracetam group. The expression of phosphorylated ERK1/2 and phosphorylated CREB in the Dex group was increased, whereas the expression of phosphorylated ERK1/2 and phosphorylated CREB in the yohimbine + Dex group was lower than in the Dex group (P Conclusions Dex improved ischemic brain damage by promoting signal transduction of the ERK/CREB pathway, which may provide new ways for clinical treatment of cerebral ischemia-reperfusion injury.

Regulatory T (Treg) cells are essential for maintaining immune homeostasis and tolerance, but the mechanisms regulating the stability and function of Treg cells have not been fully elucidated. Here we show SUMO-specific protease 3 (SENP3) is a pivotal regulator of Treg cells that functions by controlling the SUMOylation and nuclear localization of BACH2. Treg cell-specific deletion of Senp3 results in T cell activation, autoimmune symptoms and enhanced antitumor T cell responses. SENP3-mediated BACH2 deSUMOylation prevents the nuclear export of BACH2, thereby repressing the genes associated with CD4+ T effector cell differentiation and stabilizing Treg cell-specific gene signatures. Notably, SENP3 accumulation triggered by reactive oxygen species (ROS) is involved in Treg cell-mediated tumor immunosuppression. Our results not only establish the role of SENP3 in the maintenance of Treg cell stability and function via BACH2 deSUMOylation but also clarify the function of SENP3 in the regulation of ROS-induced immune tolerance., Regulatory T cells are crucial for the establishment and maintenance of peripheral immune tolerance, yet the mechanisms regulating their stability and function remain to be fully elucidated. Here the authors show SENP3 maintains Treg cell stability and function via BACH2 deSUMOylation.

To investigate effect of miR-145 on learning and memory ability in rats with epilepsy.Rats with epilepsy were induced by lithium chloride-pilocarpine. miR-145 antagomir and antagomir-control were injected into epileptic brains by the stereotactic technique, respectively. Then, rats were divided into a normal group (N), epilepsy group (Ep), miR-145 antagomir group (A) and antagomir-control group (C). After 1 and 7 days of treatment, the expression of miR-145 and Caspase-9 were detected, and the apoptosis of hippocampal neurons in CA1 of hippocampus was detected. After 7 days of treatment, the learning and memory abilities of rats was measured by using the Morris water maze test.The rat epilepsy model was successfully constructed. Compared with the N group, the target quadrant time and platform crossing times were reduced and the expression of miR-145 and Caspase-9 was increased in the epilepsy groups (P0.05). Compared with the Ep and C groups, the target quadrant time and platform crossing times were increased and the expression of miR-145 and Caspase-9 was down-regulated in the A group (P0.05). The number of apoptotic hippocampal neurons in the hippocampal CAl area of the Ep group was more than that in the N group and in the A group was less than that in the C group at 1 and 7 days after modeling respectively (P0.05).Down-regulated miR-145 improved the apoptosis of hippocampal neurons by reducing the Caspase-9 expression in hippocampus and further affected learning and memory abilities of rats with epilepsy.

Despite several decades of research into the renin-angiotensin system, new aspects of this endocrine system are elucidated every few years, expanding its role not only in hypertension but also in diabetes, oncology, and cardiology. In this review, we describe newly recognized physiologic actions of the angiotensin-converting enzyme (ACE). These include the role of local versus systemic ACE in maintaining blood pressure, the physiology of bradykinin accumulation during ACE inactivation, and the role of alternate "non-angiotensin" substrates and potential non-enzymatic properties of ACE.

The renin angiotensin system (RAS) is a central player in blood pressure control. Its effector peptide, angiotensin II, regulates blood pressure through coordinated actions in multiple tissues. The RAS is generally considered to be an endocrine system, and angiotensin II to be a circulating hormone. In recent years, however, a role for locally produced angiotensin II has been proposed. The major site for angiotensin II production is endothelium, where angiotensin-converting enzyme (ACE) is abundantly expressed. To elucidate the relative importance of circulating angiotensin II versus locally produced angiotensin II, one approach is to create a mouse model in which ACE is expressed in a tissue-specific manner. In this review, we discuss strategies to create such a model. In a mouse model we generated using a novel promoter-swapping technique, the endothelial ACE is eliminated and replaced by ectopic production of ACE in the liver. This model specifically addresses the question of whether local production of angiotensin II is essential for RAS function.

Multipotent progenitor cells self renew throughout an animal’s lifetime and can differentiate to give rise to different cell types. Before we can fully understand the developmental potential of progenitor cells and control their differentiation both in vivo and in vitro as stem cells, identification and characterization of the genes that control stem cell fate must first be obtained. Foxd3, a member of the forkhead family of transcriptional regulators, is required for the maintenance of embryonic stem cells and trophoblast stem cells of the early mouse embryo. We describe here the expression of this protein in the developing pancreas. Foxd3 is expressed in most beta cells and infrequently in alpha and PP cells but is not expressed in somatostatin cells. The subcellular localization of Foxd3 varies with fat content in the diet; with a high fat diet the protein is found primarily in the cytoplasm while a low fat diet results in nuclear localization. Foxd3 is differentially localized in a rat model of diabetes: it is nuclear in ZDF rats but cytoplasmic in their lean counterparts. Foxd3 is nuclear in LepOb/Ob mice.

The resin angiotensin system (RAS) plays an essential role in blood pressure regulation and electrolyte homeostasis. The effecter peptide of the RAS, angiotensin II, is produced by angiotensin converting enzyme (ACE) in multiple tissues. Genetic deletion of ACE in mice resulted a phenotype of low blood pressure, anemia and kidney defects. However, it is not clear whether the lack of the systemic or the local production of angiotensin II caused these defects. To understand the role of local angiotensin II production, we developed a method to achieve tissue specific ACE expression through homologous recombination. In this review, we discuss mouse models in which endothelial ACE was eliminated and replaced by hepatic ACE. These studies suggest that both circulating angiotensin II and local angiotensin II production play a role in angiotensin II generation; the elimination of local angiotensin II generation up-regulates systemic production and maintains physiologic homeostasis.