Dai J, Yang L, Xu T, Si L, Cui C, Sheng X, Chi Z, Mao L, Lian B, Tang B, Bai X, Zhou L, Li S, Wang X, Yan X, Kong Y, Guo J
PMID: 32226509 | DOI: 10.7150/jca.43010
Purpose: Polymorphisms of genes in the platelet-derived growth factor (PDGF) signaling pathway have been found to predict cutaneous melanoma (CM) survival, but their clinical effects in acral melanoma (AM) patients have not been explored. The aim of this study was to characterize the functional effect of the tag single-nucleotide polymorphism (SNP) rs2228230:C>T and assess its association with clinical outcomes in AM patients. Methods: The effect of rs2228230:C>T on mRNA structures and codon usage values were evaluated using in silico analyses. PDGF receptor alpha (PDGFRA) expression vectors with the rs2228230:C or rs2228230:T allele were constructed to evaluate the expression and signaling activity of PDGFRA. The expression of PDGFRA in AM samples was measured using in situ RNAscope hybridization and immunohistochemical staining. The association of the rs2228230 genotype with survival was analyzed in two independent AM cohorts. Results: In silico analyses indicated that the rs2228230:T allele increases the minimum free energy and reduces synonymous codon usage. The rs2228230:T allele decreased the expression of PDGFRA by reducing the stability of its mRNA and protein as well as the signaling activity of the MAPK and PI3K/AKT pathways. PDGFRA mRNA and protein expression was significantly reduced in AM tissues with the rs2228230:T allele. The progression-free survival and overall survival of AM patients with the rs2228230:T allele were significantly longer than those of patients with the CC genotype. Conclusion: Our study indicated that rs2228230:T can reduce the expression of PDGFRA and downstream signaling activity and is associated with better survival in AM patients.
Pei, J;Cai, L;Wang, F;Xu, C;Pei, S;Guo, H;Sun, X;Chun, J;Cong, X;Zhu, W;Zheng, Z;Chen, X;
PMID: 35920162 | DOI: 10.1161/CIRCRESAHA.122.321036
Myocardial infarction (MI) is one of the most dangerous adverse cardiovascular events. Our previous study found that lysophosphatidic acid (LPA) is increased in human peripheral blood after MI, and LPA has a protective effect on the survival and proliferation of various cell types. However, the role of LPA and its receptors in MI is less understood.To study the unknown role of LPA and its receptors in heart during MI.In this study, we found that mice also had elevated LPA level in peripheral blood, as well as increased cardiac expression of its receptor LPA2 in the early stages after MI. With adult and neonate MI models in global Lpar2 knockout (Lpar2-KO) mice, we found Lpar2 deficiency increased vascular leak leading to disruption of its homeostasis, so as to impaired heart function and increased early mortality. Histological examination revealed larger scar size, increased fibrosis, and reduced vascular density in the heart of Lpar2-KO mice. Furthermore, Lpar2-KO also attenuated blood flow recovery after femoral artery ligation with decreased vascular density in gastrocnemius. Our study revealed that Lpar2 was mainly expressed and altered in cardiac endothelial cells during MI, and use of endothelial-specific Lpar2 knockout mice phenocopied the global knockout mice. Additionally, adenovirus-Lpar2 and pharmacologically activated LPA2 significantly improved heart function, reduced scar size, increased vascular formation, and alleviated early mortality by maintaining vascular homeostasis owing to protecting vessels from leakage. Mechanistic studies demonstrated that LPA-LPA2 signaling could promote endothelial cell proliferation through PI3K-Akt/PLC-Raf1-Erk pathway and enhanced endothelial cell tube formation via PKD1-CD36 signaling.Our results indicate that endothelial LPA-LPA2 signaling promotes angiogenesis and maintains vascular homeostasis, which is vital for restoring blood flow and repairing tissue function in ischemic injuries. Targeting LPA-LPA2 signal might have clinical therapeutic potential to protect the heart from ischemic injury.
Brain, behavior, and immunity
Lehmann, ML;Samuels, JD;Kigar, SL;Poffenberger, CN;Lotstein, ML;Herkenham, M;
PMID: 35063606 | DOI: 10.1016/j.bbi.2022.01.011
Immune surveillance of the brain plays an important role in health and disease. Peripheral leukocytes patrol blood-brain barrier interfaces, and after injury, monocytes cross the cerebrovasculature and follow a pattern of pro- and anti-inflammatory activity leading to tissue repair. We have shown that chronic social defeat (CSD) causes scattered vasculature disruptions. Here, we assessed CCR2+ monocyte trafficking to the vascular injury sites in Ccr2wt/rfp reporter mice both during CSD and one week following CSD cessation. We found that CSD for 14 days induced microhemorrhages where plasma fibrinogen leaked into perivascular spaces, but it did not affect the distribution or density of CCR2rfp+ monocytes in the brain. However, after recovery from CSD, many vascularly adhered CCR2+ cells were detected, and gene expression of the CCR2 chemokine receptor ligands CCL7 and CCL12, but not CCL2, was elevated in endothelial cells. Adhered CCR2+ cells were mostly the non-classical, anti-inflammatory Ly6Clo type, and they phagocytosed fibrinogen in perivascular spaces. In CCR2-deficient Ccr2rfp/rfp mice, fibrinogen levels remained elevated in recovery. Fibrinogen infused intracerebroventricularly induced CCR2+ cells to adhere to the vasculature and phagocytose perivascular fibrinogen in Ccr2wt/rfp but not Ccr2rfp/rfp mice. Depletion of monocytes with clodronate liposomes during CSD recovery prevented fibrinogen clearance and blocked behavioral recovery. We hypothesize that peripheral CCR2+ monocytes are not elevated in the brain on day 14 at the end of CSD and do not contribute to its behavioral effects at that time, but in recovery following cessation of stress, they enter the brain and exert restorative functions mediating vascular repair and normalization of behavior.
Pentraxin 3 is a stromally-derived biomarker for detection of pancreatic ductal adenocarcinoma
Goulart, MR;Watt, J;Siddiqui, I;Lawlor, RT;Imrali, A;Hughes, C;Saad, A;ChinAleong, J;Hurt, C;Cox, C;Salvia, R;Mantovani, A;Crnogorac-Jurcevic, T;Mukherjee, S;Scarpa, A;Allavena, P;Kocher, HM;
PMID: 34188166 | DOI: 10.1038/s41698-021-00192-1
Pancreatic ductal adenocarcinoma (PDAC), characterized by dense desmoplastic stroma laid down by pancreatic stellate cells (PSC), has no reliable diagnostic biomarkers for timely detection. A multi-center cohort of PDAC patients and controls (chronic pancreatitis, intra-ductal papillary neoplasms, gallstones and otherwise healthy) donated serum in an ethically approved manner. Serum PTX3 above 4.34 ng/mL has a higher sensitivity (86%, 95% confidence interval (CI): 65-97%) and specificity (86%, 95% CI: 79-91%), positive predictive value (97%) and likelihood ratio (6.05), and is superior when compared to serum CA19-9 and CEA for detection of PDAC. In vitro and ex vivo analyses of PTX3, in human PDAC samples, PSCs, cell lines and transgenic mouse model for PDAC, suggest that PTX3 originates from stromal cells, mainly PSC. In activated PSC, PTX3 secretion could be downregulated by rendering PSC quiescent using all-trans-retinoic acid (ATRA). PTX3 organizes hyaluronan in conjunction with tumor necrosis factor-stimulated gene 6 (TSG-6) and facilitates stellate and cancer cell invasion. In SCALOP clinical trial (ISRCTN96169987) testing chemo-radiotherapy without stromal targeting, PTX3 had no prognostic or predictive role. However, in STARPAC clinical trial (NCT03307148), stromal modulation by ATRA even at first dose is accompanied with serum PTX3 response in patients who later go on to demonstrate disease control but not those in whom the disease progresses. PTX3 is a putative stromally-derived biomarker for PDAC which warrants further testing in prospective, larger, multi-center cohorts and within clinical trials targeting stroma.
Kazantseva M, Eiholzer RA, Mehta S, Taha A, Bowie S, Roth I, Zhou J, Joruiz SM, Royds JA, Hung NA, Slatter TL, Braithwaite AW.
PMID: 29888503 | DOI: 10.1002/path.5111
As tumour protein 53 (p53) isoforms have tumour promoting, migration and inflammatory properties, this study investigated whether p53 isoforms contributed to glioblastoma progression. The expression levels of full-length TP53α (TAp53α) and six TP53 isoforms were quantitated by RT-qPCR in 89 glioblastomas and correlated with TP53 mutation status, tumour-associated macrophage content and various immune cell markers. Elevated levels of Δ133p53β mRNA characterised glioblastomas with increased CD163-positive macrophages and wild-type TP53. In situ based analyses found Δ133p53β expression localised to malignant cells in areas with increased hypoxia, and in cells with the monocyte chemoattractant protein C-C motif chemokine ligand 2 (CCL2) expressed. Tumours with increased Δ133p53β had increased numbers of cell positive for macrophage colony stimulating factor 1 receptor (CSF1R) and programmed death ligand 1 (PDL1). In addition, cells expressing a murine 'mimic' of Δ133p53 (Δ122p53) were resistant to temozolomide treatment and oxidative stress. Our findings suggest elevated Δ133p53β is an alternative pathway to TP53 mutation in glioblastoma that aids tumour progression by promoting an immunosuppressive and chemoresistant environment. Adding Δ133p53β to a TP53 signature along with TP53 mutation status will better predict treatment resistance in glioblastoma.
De Schepper, S;Ge, JZ;Crowley, G;Ferreira, LSS;Garceau, D;Toomey, CE;Sokolova, D;Rueda-Carrasco, J;Shin, SH;Kim, JS;Childs, T;Lashley, T;Burden, JJ;Sasner, M;Sala Frigerio, C;Jung, S;Hong, S;
PMID: 36747024 | DOI: 10.1038/s41593-023-01257-z
Alzheimer's disease (AD) is characterized by synaptic loss, which can result from dysfunctional microglial phagocytosis and complement activation. However, what signals drive aberrant microglia-mediated engulfment of synapses in AD is unclear. Here we report that secreted phosphoprotein 1 (SPP1/osteopontin) is upregulated predominantly by perivascular macrophages and, to a lesser extent, by perivascular fibroblasts. Perivascular SPP1 is required for microglia to engulf synapses and upregulate phagocytic markers including C1qa, Grn and Ctsb in presence of amyloid-β oligomers. Absence of Spp1 expression in AD mouse models results in prevention of synaptic loss. Furthermore, single-cell RNA sequencing and putative cell-cell interaction analyses reveal that perivascular SPP1 induces microglial phagocytic states in the hippocampus of a mouse model of AD. Altogether, we suggest a functional role for SPP1 in perivascular cells-to-microglia crosstalk, whereby SPP1 modulates microglia-mediated synaptic engulfment in mouse models of AD.
A Chemokine Regulatory Loop Induces Cholesterol Synthesis in Lung-Colonizing Triple-Negative Breast Cancer Cells to Fuel Metastatic Growth
Molecular therapy : the journal of the American Society of Gene Therapy
Han, B;Alonso-Valenteen, F;Wang, Z;Deng, N;Lee, TY;Gao, B;Zhang, Y;Xu, Y;Zhang, X;Billet, S;Fan, X;Shiao, S;Bhowmick, N;Medina-Kauwe, L;Giuliano, A;Cui, X;
PMID: 34274535 | DOI: 10.1016/j.ymthe.2021.07.003
Triple-negative breast cancer (TNBC) has a high propensity for organ-specific metastasis. However, the underlying mechanisms are not well understood. Here, we show that the primary TNBC tumor-derived C-X-C motif chemokines 1/2/8 (CXCL1/2/8) stimulate lung resident fibroblasts to produce C-C motif chemokines 2/7 (CCL2/7), which in turn activate cholesterol synthesis in lung-colonizing TNBC cells and induce angiogenesis at lung metastatic sites. Inhibiting cholesterol synthesis in lung-colonizing breast tumor cells by the pulmonary administration of simvastatin-carrying HER3-targeting nanoparticles reduces the angiogenesis and growth of lung metastases in a syngeneic TNBC mouse model. Our findings reveal a novel, chemokine-regulated mechanism for the cholesterol synthesis pathway and a critical role of metastatic site-specific cholesterol synthesis in the pulmonary tropism of TNBC metastasis. The study has implications for the unresolved epidemiological observation that the use of cholesterol-lowering drugs has no effect on breast cancer incidence but can unexpectedly reduce breast cancer mortality, suggesting interventions of cholesterol synthesis in lung metastases as an effective treatment to improve survival in TNBC patients.
"Boldog E, Bakken TE, Hodge RD, Novotny M, Aevermann BD, Baka J, Bordé S, Close JL, Diez-Fuertes F, Ding SL, Faragó N, Kocsis AK, Kovács B, Maltzer Z, McCorrison JM, Miller JA, Molnár G, Oláh G, Ozsvár A, Rózsa M, Shehata SI, Smith KA, Sunkin SM, Tran D
PMID: 30150662 | DOI: 10.1038/s41593-018-0205-2
We describe convergent evidence from transcriptomics, morphology, and physiology for a specialized GABAergic neuron subtype in human cortex. Using unbiased single-nucleus RNA sequencing, we identify ten GABAergic interneuron subtypes with combinatorial gene signatures in human cortical layer 1 and characterize a group of human interneurons with anatomical features never described in rodents, having large 'rosehip'-like axonal boutons and compact arborization. These rosehip cells show an immunohistochemical profile (GAD1+CCK+, CNR1-SST-CALB2-PVALB-) matching a single transcriptomically defined cell type whose specific molecular marker signature is not seen in mouse cortex. Rosehip cells in layer 1 make homotypic gap junctions, predominantly target apical dendritic shafts of layer 3 pyramidal neurons, and inhibit backpropagating pyramidal action potentials in microdomains of the dendritic tuft. These cells are therefore positioned for potent local control of distal dendritic computation in cortical pyramidal neurons.
Shi, Z;Yu, P;Lin, WJ;Chen, S;Hu, X;Chen, S;Cheng, J;Liu, Q;Yang, Y;Li, S;Zhang, Z;Xie, J;Jiang, J;He, B;Li, Y;Li, H;Xu, Y;Zeng, J;Huang, J;Mei, J;Cai, J;Chen, J;Wu, LJ;Ko, H;Tang, Y;
PMID: 36603584 | DOI: 10.1016/j.neuron.2022.12.009
The crosstalk between the nervous and immune systems has gained increasing attention for its emerging role in neurological diseases. Radiation-induced brain injury (RIBI) remains the most common medical complication of cranial radiotherapy, and its pathological mechanisms have yet to be elucidated. Here, using single-cell RNA and T cell receptor sequencing, we found infiltration and clonal expansion of CD8+ T lymphocytes in the lesioned brain tissues of RIBI patients. Furthermore, by strategies of genetic or pharmacologic interruption, we identified a chemotactic action of microglia-derived CCL2/CCL8 chemokines in mediating the infiltration of CCR2+/CCR5+ CD8+ T cells and tissue damage in RIBI mice. Such a chemotactic axis also participated in the progression of cerebral infarction in the mouse model of ischemic injury. Our findings therefore highlight the critical role of microglia in mediating the dysregulation of adaptive immune responses and reveal a potential therapeutic strategy for non-infectious brain diseases.
Molecular Therapy - Methods & Clinical Development
Aldi S, Matic LP, Hamm G, van Keulen D, Tempel D, Holmstrøm K, Szwajda A, Nielsen BS, Emilsson V, Ait-Belkacem R, Lengquist M, Paulsson-Berne G, Eriksson P, Lindeman JHN, Gool AJ, Stauber J, Hedin U, Hurt-Camejo E.
PMID: - | DOI: 10.1016/j.omtm.2018.05.003
Variants in the PLPP3 gene encoding for lipid phosphate phosphohydrolase 3 have been associated with susceptibility to atherosclerosis independently of classical risk factors. PLPP3 inactivates lysophosphatidic acid (LPA), a pro-inflammatory, pro-thrombotic product of phospholipase activity. Here we performed the first exploratory analysis of PLPP3, LPA, and LPA receptors (LPARs 1–6) in human atherosclerosis. PLPP3 transcript and protein were repressed when comparing plaques versus normal arteries and plaques from symptomatic versus asymptomatic patients, and they were negatively associated with risk of adverse cardiovascular events. PLPP3 localized to macrophages, smooth muscle, and endothelial cells (ECs) in plaques. LPAR 2, 5, and especially 6 showed increased expression in plaques, with LPAR6 localized in ECs and positively correlated to PLPP3. Utilizing in situ mass spectrometry imaging, LPA and its precursors were found in the plaque fibrous cap, co-localizing with PLPP3 and LPAR6. In vitro, PLPP3 silencing in ECs under LPA stimulation resulted in increased expression of adhesion molecules and cytokines. LPAR6 silencing inhibited LPA-induced cell activation, but not when PLPP3 was silenced simultaneously. Our results show that repression of PLPP3 plays a key role in atherosclerosis by promoting EC activation. Altogether, the PLPP3 pathway represents a suitable target for investigations into novel therapeutic approaches to ameliorate atherosclerosis.
Auguste, YSS;Ferro, A;Kahng, JA;Xavier, AM;Dixon, JR;Vrudhula, U;Nichitiu, AS;Rosado, D;Wee, TL;Pedmale, UV;Cheadle, L;
PMID: 36171430 | DOI: 10.1038/s41593-022-01170-x
Oligodendrocyte precursor cells (OPCs) give rise to myelinating oligodendrocytes throughout life, but the functions of OPCs are not limited to oligodendrogenesis. Here we show that OPCs contribute to thalamocortical presynapse elimination in the developing and adult mouse visual cortex. OPC-mediated synapse engulfment increases in response to sensory experience during neural circuit refinement. Our data suggest that OPCs may regulate synaptic connectivity in the brain independently of oligodendrogenesis.
Losurdo M, Davidsson J, Sk�ld MK
PMID: 32290212 | DOI: 10.3390/brainsci10040229
Traumatic brain injury (TBI) commonly results in primary diffuse axonal injury (DAI) and associated secondary injuries that evolve through a cascade of pathological mechanisms. We aim at assessing how myelin and oligodendrocytes react to head angular-acceleration-induced TBI in a previously described model. This model induces axonal injuries visible by amyloid precursor protein (APP) expression, predominantly in the corpus callosum and its borders. Brain tissue from a total of 27 adult rats was collected at 24 h, 72 h and 7 d post-injury. Coronal sections were prepared for immunohistochemistry and RNAscope� to investigate DAI and myelin changes (APP, MBP, Rip), oligodendrocyte lineage cell loss (Olig2), oligodendrocyte progenitor cells (OPCs) (NG2, PDGFRa) and neuronal stress (HSP70, ATF3). Oligodendrocytes and OPCs numbers (expressed as percentage of positive cells out of total number of cells) were measured in areas with high APP expression. Results showed non-statistically significant trends with a decrease in oligodendrocyte lineage cells and an increase in OPCs. Levels of myelination were mostly unaltered, although Rip expression differed significantly between sham and injured animals in the frontal brain. Neuronal stress markers were induced at the dorsal cortex and habenular nuclei. We conclude that rotational injury induces DAI and neuronal stress in specific areas. We noticed indications of oligodendrocyte death and regeneration without statistically significant changes at the timepoints measured, despite indications of axonal injuries and neuronal stress. This might suggest that oligodendrocytes are robust enough to withstand this kind of trauma, knowledge important for the understanding of thresholds for cell injury and post-traumatic recovery potential
