Expression of VEGF and its receptors by myeloma cells

Angiogenesis or new vessel formation is an essential component in the growth and progression of neoplasms and there is growing evidence of its importance in hematological malignancies including multiple myeloma (MM). Vascular endothelial growth factor (VEGF) is believed to play a role in tumor angiogenesis. We studied the expression of VEGF and its receptors (VEGFR1 or Flt-1 and VEGFR2 or Flk-1/KDR) by myeloma cell lines and plasma cells isolated from patients, using different methods. VEGF expression by the plasma cells was demonstrated by immunohistochemistry in 18 of 20 patients with MM. Enzyme-linked immunosorbent assay demonstrated VEGF secretion in all six different myeloma cell lines studied. Five patient marrow samples and seven different myeloma cell lines were then studied for VEGF mRNA expression by reverse-transcriptase polymerase chain reaction (RT-PCR), which was positive in all. We further evaluated the expression of both VEGFR1 and VEGFR2 in different myeloma cell lines and five sorted myeloma bone marrow samples by RT-PCR. All the myeloma cell lines expressed VEGFR1 and three of the cell lines expressed VEGFR2. VEGFR1 expression was detected in all and VEGFR2 in all but one of the sorted marrow samples. Increased expression of VEGF by the myeloma cells taken in the context of the suspected prognostic value of marrow angiogenesis suggests a pathogenetic role for this cytokine and presence of its receptors on myeloma cells points toward an autocrine mechanism. Demonstration of the presence of VEGFR2 in our study provides a potential biological explanation for the preclinical activity observed with VEGFR2 inhibitors.

Comparison of sampling methods for the assessment of indoor microbial exposure

Indoor microbial exposure has been related to allergy and respiratory disorders. However, the lack of standardized sampling methodology is problematic when investigating dose-response relationships between exposure and health effects. In this study, different sampling methods were compared regarding their assessment of microbial exposures, including culturable fungi and bacteria, endotoxin, as well as the total inflammatory potential (TIP) of dust samples from Danish homes. The Gesamtstaubprobenahme (GSP) filter sampler and BioSampler were used for sampling of airborne dust, whereas the dust fall collector (DFC), the electrostatic dust fall collector (EDC), and vacuum cleaner were used for sampling of settled dust. The GSP assessed significantly higher microbial levels than the BioSampler, yet measurements from both samplers correlated significantly. Considerably higher levels of fungi, endotoxin, and TIP were found in the EDC compared with the DFC, and regarding fungi, the EDC correlated more strongly and significantly with vacuumed dust than the DFC. Fungi in EDC and vacuum dust correlated most strongly with airborne dust, and in particular, the measurements from the EDC associated well with those from GSP. Settled dust from the EDC was most representative of airborne dust and may thus be considered as a surrogate for the assessment of indoor airborne microbial exposure.

PRACTICAL IMPLICATIONS

Significant discrepancies between sampling methods regarding indoor microbial exposures have been revealed. This study thus facilitates comparison between methods and may therefore be used as a frame of reference when studying the literature or when conducting further studies on indoor microbial exposure. Results also imply that the relatively simple EDC method for the collection of settled dust may be used as an alternative to otherwise tedious and time-consuming airborne dust sampling.

Sorafenib, a dual Raf kinase/vascular endothelial growth factor receptor inhibitor has significant anti-myeloma activity and synergizes with common anti-myeloma drugs

Multiple myeloma is characterized by increased bone marrow neovascularization driven in part by vascular endothelial growth factor (VEGF). In addition, the Ras/Raf/MEK/ERK pathway is critical for the proliferation of myeloma cells and is often upregulated. Sorafenib (Nexavar) is a novel multi-kinase inhibitor that acts predominantly through inhibition of Raf-kinase and VEGF receptor 2, offering the potential for targeting two important aspects of disease biology. In in vitro studies, sorafenib-induced cytotoxicity in MM cell lines as well as freshly isolated patient myeloma cells. It retained its activity against MM cells in co-culture with stromal cells or with interleukin-6, VEGF or IGF; conditions mimicking tumor microenvironment. Examination of cellular signaling pathways showed downregulation of Mcl1 as well as decreased phosphorylation of the STAT3 and MEK/ERK, as potential mechanisms of its anti-tumor effect. Sorafenib induces reciprocal upregulation of Akt phosphorylation; and simultaneous inhibition of downstream mTOR with rapamycin leads to synergistic effects. Sorafenib also synergizes with drugs such as proteasome inhibitors and steroids. In a human in vitro angiogenesis assay, sorafenib showed potent anti-angiogenic activity. Sorafenib, through multiple mechanisms exerts potent anti-myeloma activity and these results favor further clinical evaluation and development of novel sorafenib combinations.

Oxidation in fish oil enriched mayonnaise: ascorbic acid and low pH increase oxidative deterioration

The effect of ascorbic acid (0-4000 ppm) and pH (3.8-6.2) on oxidation and levels of iron and copper in various fractions of mayonnaise enriched with 16% fish oil was investigated. Ascorbic acid induced release of iron from the assumed oil-water interface into the aqueous phase at all pH levels, but this effect of ascorbic acid was strongest at low pH (pH 3.8-4.2). Ascorbic acid generally promoted formation of volatile oxidation compounds and reduced the peroxide value in mayonnaises. Peroxide values and total volatiles generally increased with decreasing pH values, suggesting that low pH promoted oxidation. It is proposed that iron bridges between the egg yolk proteins low-density lipoproteins, lipovitellin, and phosvitin at the oil-water interface are broken at low pH values, whereby iron ions become accessible as oxidation initiators. In the presence of ascorbic acid, oxidation is further enhanced due to the reduction of Fe(3+) to Fe(2+) that rapidly catalyzes lipid oxidation via lipid hydroperoxide decomposition at the oil-water interface in mayonnaise.

Measurement of apoptosis and proliferation of bone marrow plasma cells in patients with plasma cell proliferative disorders

The proliferative rate of malignant plasma cells, as measured by the plasma cell labelling index (PCLI), is an important prognostic factor in multiple myeloma (MM); however, the PCLI alone is probably Inadequate to describe tumour growth because it ignores the idea that myeloma cells may have a reduced rate of apoptosis. The aims of this study were to develop a flow cytometric method to measure the apoptosis index of fresh marrow plasma cells and develop a plasma cell growth index (PCGI) that related both proliferation and apoptosis to disease activity. Marrow aspirates were obtained from 91 patients with plasma cell disorders and the plasma cells in apoptosis were identified by either 7-amino actinomycin-D (7-AAD) or annexin V-FITC three-colour flow cytometry. The median plasma cell apoptotic index (PCAI) for patients with monoclonal gammopathy of undetermined significance (MGUS), smouldering or indolent myeloma (SMM/IMM), and new multiple myeloma (MM) was 5.2, 3.4 and 2.4, respectively (P=0.03, MGUS v MM). The median PCLI for these same patient groups was 0.0, 0.2 and 0.6, respectively (P<0.001, MGUS v MM). The paired PCLI and PCAI for each sample were used to derive the PCGI=2 + [PCLI-(O.1)(PCAI)]. The median PCGI for patients with inactive disease (MGUS, SMM/IMM or amyloidosis) was 1.8 compared to 2.4 for those with active disease (new or relapsed MM) (P<0.001). These results suggest that a decrease in the PCAI may be a factor in the progression from MGUS to SMM to overt MM.

[Content of trans-fatty acids in food]

The fatty acid composition of the fat in 197 food samples has been analyzed by gas liquid chromatography. The use of a 30 m capillary column coated with CPSil88 permitted the separation of the cis and trans isomers. The trans fatty acid content of milk and milk products ranged from 1.9 to 7.9%. Meat samples from ruminants contained 2.0-10.6% trans fatty acids. In pork fat the amounts were less than 0.5%. Sausages and other meat products contained high levels of pork fat. Therefore these samples contained less than 1% trans fatty acids, with the exception of some pure beef products. The amounts of trans fatty acids in foods which may contain hydrogenated oils ranged from 0 to 34.9%. In food samples with high levels of trans fatty acids lower contents of saturated fatty acids were analyzed.

Distribution of endothelin-1 (ET) receptors (ET(A) and ET(B)) and immunoreactive ET-1 in porcine saphenous vein-carotid artery interposition grafts

Proliferation of vascular smooth muscle cells (VSMC) is a principal event in neointima formation in saphenous vein-coronary artery bypass grafts. Since endothelin-1 (ET-1) promotes VSMC replication and ET-1 receptor antagonists inhibit neointima formation in arterial injury models, it is reasonable to propose that ET-1 may be involved in neointima formation in vein grafts. However, it is not known what alterations of ET-1 and its receptors (if any) occur in vein grafts. The objective of this study, therefore, was to investigate the distribution of ET-1 and ET-1 receptor subtypes (ET(A) and ET(B)) in porcine vein grafts. Unilateral interposition saphenous vein grafting was performed by end to end anastomosis after excision of a segment of carotid artery in Landrace pigs. One month after surgery, vein grafts, ungrafted saphenous veins and carotid arteries were excised, ET-1 immunoreactivity identified by immunocytochemistry and ET(A) and ET(B) receptor subtypes studied using autoradiography. In vein grafts, there was a greater density of ET(A) compared to ET(B) receptors in both the tunica media and neointima. ET(A) binding in the tunica media of ungrafted saphenous vein was greater than that in the carotid artery or vein grafts, but greater in the vein graft compared to the carotid artery. Immunoreactive ET-1 was located in endothelial cells and throughout the neointima of the vein graft. Dense ET-1 binding (to both ET(A) and ET(B) receptors) was also associated with microvessels in the adventitia within the graft. In vein grafts, there was strong ET(B) binding to neutrophils which were present in high numbers at the subendothelium and within the adventitia. It is concluded ET(A) receptors may play a role in vein graft thickening at the medial and neointimal VSMC level, whereas ET(B) receptors may play a role in microangiogenesis. The higher levels of ET(A) receptors in the tunica media of ungrafted saphenous vein relative to the carotid artery and vein graft may also render this conduit susceptible to neointima formation. These data indicate that studies on the effect of ET receptor antagonists on the pathobiology of vein graft disease is warranted.

Prevalence of the fimbrial antigens F18 and K88 and of enterotoxins and verotoxins among Escherichia coli isolated from weaned pigs

Until recently, the fimbrial F18 antigen has been provisionally designated F107, 2134P, or 8813. Using the slide agglutination test, this antigen was shown to be present on 139 of 160 Escherichia coli strains of type O139:K82 and on all of the 146 K88-negative strains of the other pathogenic porcine serotypes. These strains were isolated from weaned pigs which in most cases had died from postweaning colibacillosis. All strains were haemolytic. With only three exceptions, they produced verotoxin and/or enterotoxin. The F18ab variant strongly predominated on the O139:K82 strains and was found on about half of the O138:K81 strains and a few O157 strains, whereas the other strains carried the F18ac variant. In serotypes which can carry either F18 or K88 fimbriae, closer clonal relationships between the strains associated with F18 and those associated with K88 were missing.

Nitric oxide synthase and adenylyl and guanylyl cyclase activity in porcine interposition vein grafts

BACKGROUND

A high proportion of autologous saphenous vein grafts occlude as the result of intimal thickening. Blood vessels synthesize substances that may inhibit such intimal thickening. These include cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are stimulated by prostacyclin and nitric oxide, respectively. The prostacyclin-cAMP and nitric oxide-cGMP axes were therefore investigated in porcine vein grafts.

METHODS

Saphenous vein-carotid artery interposition graft procedures were carried out in pigs. One month after the operation, ungrafted saphenous veins, vein grafts, and carotid arteries were excised, the formation of cAMP and cGMP was assessed by radioimmunoassay, and the nitric oxide synthase content was determined by autoradiography.

RESULTS

The formation of cAMP and nitroprusside-stimulated cGMP was significantly diminished in vein grafts compared with ungrafted saphenous veins and carotid arteries. Calimycin-stimulated cGMP synthesis (nitric oxide release dependent) and the endothelial nitric oxide synthase content (autoradiography) were significantly elevated in vein grafts compared with ungrafted saphenous veins but were significantly less than those in carotid arteries.

CONCLUSIONS

Adenylyl and guanylyl cyclase activity are down-regulated in vein grafts, which may contribute to the development of intimal and medial thickening. Nitric oxide release and endothelial nitric oxide synthase content are up-regulated in vein grafts, which is indicative of an adaptation to the arterial conditions of shear stress and pulsatile pressure.

First observation of self-amplified spontaneous emission in a free-electron laser at 109 nm wavelength

We present the first observation of self-amplified spontaneous emission (SASE) in a free-electron laser (FEL) in the vacuum ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approximately 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width, and intensity fluctuations, are all consistent with the present models for SASE FELs.

Cardiac expression of polysialylated NCAM in the chicken embryo: correlation with the ventricular conduction system

The neural cell adhesion molecule (NCAM) and its polysialic acid moeity (PSA) affect cellular interactions during the development of the nervous system and skeletal muscle. NCAM has also been identified in the embryonic heart of various species including humans. However, knowledge regarding the role of NCAM and its function-modulating PSA in cardiogenesis is limited. The distribution of NCAM and its PSA in the ventricular myocardium of chicken embryos was determined by indirect immunofluorescence staining. The NCAM polypeptide was found throughout the cardiac myocardium. In contrast PSA was located in discrete regions in stage 20 to 44 embryos (during and after septation). Myocardium at the subendocardial regions of the atrioventricular canal and ventricular trabeculae were PSA positive by stage 20. At later stages, transverse sections of the postseptation heart just below the level of the atrioventricular interface revealed a PSA-positive bundle of myocardium in the septum. This bundle was continuous with two branches at a more apical level which in turn were continuous with the PSA-positive subendocardial myocardium lining the left and right ventricles. This pattern of PSA in the myocardium was similar to that of the ventricular conduction system configuration defined in the adult heart. Electron micrographs of the subendocardium of the ventricular septum revealed PSA positivity on myofibril-containing cells with the ultrastructural location of Purkinje fibers. At later stages (35-44) a subset of cells within PSA-positive regions was stained by an antibody against an isoform of the myosin heavy chain found in adult Purkinje fibers. These cells and surrounding tissue lacked PSA in the adult heart. Thus polysialylated NCAM may be modulating cell-cell interactions during the development of the ventricular conduction system.

X-Ray Absorption Spectrum of the N_{2}^{+} Molecular Ion

The x-ray absorption spectrum of N_{2}^{+} in the K-edge region has been measured by irradiation of ions stored in a cryogenic radio frequency ion trap with synchrotron radiation. We interpret the experimental results with the help of restricted active space multiconfiguration theory. Spectroscopic constants of the 1σ_{u}^{-1} ^{2}Σ_{u}^{+} state, and the two 1σ_{u}^{-1}3σ_{g}^{-1}1π_{g} ^{2}Π_{u} states are determined from the measurements. The charge of the ground state together with spin coupling involving several open shells give rise to double excitations and configuration mixing, and a complete breakdown of the orbital picture for higher lying core-excited states.

Synthesis of the rare disaccharide nigerose by structure-based design of a phosphorylase mutant with altered regioselectivity

In the absence of the natural acceptor inorganic phosphate wild-type sucrose phosphorylase from Bifidobacterium adolescentis (BaSP) produces maltose (4-O-α-d-glucopyranosyl-d-glucose) and kojibiose (2-O-α-d-glucopyranosyl-d-glucose) as sole transfer products. A Q345F exchange switches the enzyme's regioselectivity from 2 to 3 exclusively, yielding the rare sugar nigerose (3-O-α-d-glucopyranosyl-d-glucose, sakebiose).

Impact of community-based education on health care evaluation in patients with acute chest pain syndromes: the Wabasha Heart Attack Team (WHAT) project

BACKGROUND

Community education programmes focused on raising public awareness of the symptomatology of acute coronary syndromes have had mixed results.

OBJECTIVES

The Wabasha Heart Attack Team project, a unique multidisciplinary public education effort in Minnesota, sought to educate area citizens about signs and symptoms of acute myocardial infarction (MI).

METHODS

After an intensive 1-month education period, we compared presentations for emergency evaluation of chest pain during the study period with baseline data from the same seasonal period of the preceding year.

RESULTS

Visits to the Emergency Room for symptomatic heart disease increased significantly during the study period (56 patients versus 46 patients during the baseline period), as did the percentage of patients presenting with acute MI (18% versus 12%, P < 0.05). Use of emergency medical services for pre-hospital evaluation was significantly increased (41% versus 27%, P < 0.05).

CONCLUSION

A community education campaign can significantly increase use of pre-hospital emergency medical service resources and may increase the number of patients presenting with acute chest pain symptoms, including MI.

Regional variations in endothelin-1 and its receptor subtypes in human coronary vasculature: pathophysiological implications in coronary disease

Endothelin-1 is a potent vasoconstrictor peptide and mitogen for vascular smooth muscle cells. Increased plasma or tissue levels of endothelin-1 have been described after myocardial infarction and in atherosclerosis, suggesting that this peptide may play a pathophysiological role in various coronary syndromes. Here, we have studied regional variations in ET-1 and its receptors in control and atherosclerotic human coronary vasculature using standard immunohistochemistry and in vitro autoradiography. ET-1 immunoreactivity was associated with luminal endothelial cells and smooth muscle cells at regions of atherosclerosis. ET(A) receptors were present on smooth muscle cells of coronary arteries and on cardiac myocytes. Medial ET(B) receptor binding at the proximal region of coronary arteries was weak, but increased significantly towards distal regions of this vessel (p<0.005 in control and p<0.0005 in ischaemic heart disease). Microvascular endothelial cells in the adventitia of coronary arteries, myocardial microvessels and the endocardial endothelium expressed the ET(B) receptor exclusively. The receptor variations revealed in this study provide supporting evidence that ET-1 is associated with (1) vascular smooth muscle and endothelial cell proliferation, including areas of intimal hyperplasia and regions of neovascularization (2) increased ET-1-induced reactivity of distal portions of the human coronary artery, (3) ET-1-mediated constriction of myocardial microvessels. These results provide new insights into different potential roles for this peptide in healthy and diseased human coronary vasculature.

Access to the Bis-benzene Cobalt(I) Sandwich Cation and its Derivatives: Synthons for a "Naked" Cobalt(I) Source?

The synthesis and structural characterization of the hitherto unknown parent Co(bz)₂⁺ (bz=benzene) complex and several of its derivatives are described. Their synthesis starts either from a CoCO₅⁺ salt, or directly from Co₂ (CO)₈ and a Ag⁺ salt. Stability and solubility of these complexes was achieved by using the weakly coordinating anions (WCAs) [Al(OR^F )₄ ]^- and [F{Al(OR^F )₃ }₂ ]^- {R^F =C(CF₃ )₃ } and the solvent ortho-difluorobenzene (o-DFB). The magnetic properties of Co(bz)₂⁺ were measured and compared in the condensed and gas phases. The weakly bound Co(o-dfb)₂⁺ salts are of particular interest for the preparation of further Co^I salts, for example, the structurally characterized low-coordinate 12 valence electron Co(P^t Bu₃ )₂⁺ and Co(NHC)₂⁺ salts.

Site-Selective Dissociation upon Sulfur L-Edge X-ray Absorption in a Gas-Phase Protonated Peptide

Site-selective dissociation induced by core photoexcitation of biomolecules is of key importance for the understanding of radiation damage processes and dynamics and for its promising use as "chemical scissors" in various applications. However, identifying products of site-selective dissociation in large molecules is challenging at the carbon, nitrogen, and oxygen edges because of the high recurrence of these atoms and related chemical groups. In this paper, we present the observation of site-selective dissociation at the sulfur L-edge in the gas-phase peptide methionine enkephalin, which contains only a single sulfur atom. Near-edge X-ray absorption mass spectrometry has revealed that the resonant S 2p → σ*_C-S excitation of the sulfur contained in the methionine side chain leads to site-selective dissociation, which is not the case after core ionization above the sulfur L-edge. The prospects of such results for the study of charge dynamics in biomolecular systems are discussed.

The carbon and oxygen K-edge NEXAFS spectra of CO+

We present and analyze high resolution near edge X-ray absorption fine structure (NEXAFS) spectra of CO⁺ at the carbon and oxygen K-edges.

CD20-targeted measles virus shows high oncolytic specificity in clinical samples from lymphoma patients independent of prior rituximab therapy

New therapeutic modalities for B-cell non-Hodgkin's lymphomas (B-NHL) are needed, especially for relapsing and aggressive subtypes. Toward this end, we previously generated a fully CD20-targeted and armed measles virus, and tested its efficacy in a xenograft model of mantle cell lymphoma (MCL). Here, we quantify its spread in peripheral blood mononuclear cells and/or tissue of patients with different histological subtypes of B-NHL, including splenic marginal zone lymphoma (SMZL). CD20-targeted MV efficiently infects lymphoma cells from SMZL and MCL while sparing most cells in the CD20-negative population, in contrast to the parental vaccine-lineage MV, which infects CD20-positive and CD20-negative cells equally. Rituximab therapy (4-8 months before relapse) did not interfere with the infectivity and specificity of MV(green)H(blind)antiCD20 in patient lymphoma samples. Thus, CD20-targeted oncolytic virotherapy is likely to be effective after previous antiCD20 therapy.

Endothelin-1 and endothelin receptors in porcine saphenous vein-carotid artery grafts

The regional distribution of endothelin-1 (ET-1) and its receptor subtypes (ETA and ETB) in porcine saphenous vein into carotid artery interposition grafts was studied 1 month after surgery and compared to ungrafted saphenous vein and carotid artery. ET-1 immunoreactivity was identified by immunohistochemistry and ET receptor subtypes were studied using in vitro autoradiography. In vein grafts, there was a higher density of ETA compared to ETB receptor binding in both the tunica media and the neointima. ETA binding to the tunica media of ungrafted saphenous vein was greater than that in the carotid artery or vein grafts, but greater in the vein graft compared to the carotid artery. Immunoreactive ET-1 was located in endothelial cells and throughout the neointima of the vein graft. Dense ETA and ETB binding was also associated with adventitial microvessels in the graft, and ETB binding was also identified to neutrophils, which accumulated at the subendothelium and within the adventitia. ETA receptors may play a role in vein graft thickening at the medial and neointimal vascular smooth-muscle cell level, whereas ETB receptors may play a role in microangiogenesis. The high levels of ETA receptors in the tunica media of ungrafted saphenous vein, relative to the carotid artery and vein graft, may also render this conduit susceptible to neointimal formation. These data indicate that studies of the effect of ET receptor antagonists on the pathobiology of vein graft disease are warranted.

Iron L3-edge energy shifts for the full range of possible 3d occupations within the same oxidation state of iron halides

Oxidation states are integer in number but dⁿ configurations of transition metal centers vary continuously in polar bonds. We quantify the shifts of the iron L₃ excitation energy, within the same formal oxidation state, in a systematic L-edge X-ray absorption spectroscopy study of diatomic gas-phase iron(II) halide cations, [FeX]⁺,where X = F, Cl, Br, I. These shifts correlate with the electronegativity of the halogen, and are attributed exclusively to a fractional increase in population of 3d-derived orbitals along the series as supported by charge transfer multiplet simulations and density functional theory calculations. We extract an excitation energy shift of 420 meV ± 60 meV spanning the full range of possible 3d occupations between the most ionic bond in [FeF]⁺ and covalently bonded [FeI]⁺.

Breaking inversion symmetry by protonation: experimental and theoretical NEXAFS study of the diazynium ion, N2H. Phys Chem Chem Phys 2021;23:17166-17176. [PMID: 34346432 DOI: 10.1039/d1cp02002a]

As an example of symmetry breaking in NEXAFS spectra of protonated species we present a high resolution NEXAFS spectrum of protonated dinitrogen, the diazynium ion N₂H⁺. By ab initio calculations we show that the spectrum consists of a superposition of two nitrogen 1s absorption spectra, each including a π* band, and a nitrogen 1s to H⁺ charge transfer band followed by a weak irregular progression of high energy excitations. Calculations also show that, as an effect of symmetry breaking by protonation, the π* transitions are separated by 0.23 eV, only slightly exceeding the difference in the corresponding dark (symmetry forbidden) and bright (symmetry allowed) core excitations of neutral N₂. By DFT and calculations and vibrational analysis, the complex π* excitation band of N₂H⁺ is understood as due to the superposition of the significantly different vibrational progressions of excitations from terminal and central nitrogen atoms, both leading to bent final state geometries. We also show computationally that the electronic structure of the charge transfer excitation smoothly depends on the nitrogen-proton distance and that there is a clear extension of the spectra going from infinity to close nitrogen-proton distance where fine structures show some, although not fully detailed, similarities. An interesting feature of partial localization of the nitrogen core orbitals, with a strong, non-monotonous, variation with nitrogen-proton distance could be highlighted. Specific effects could be unraveled when comparing molecular cation NEXAFS spectra, as represented by recently recorded spectra of N₂⁺ and CO⁺, and spectra of protonated molecules as represented here by the N₂H⁺ ion. Both types containing rich physical effects not represented in NEXAFS of neutral molecules because of the positive charge, whereas protonation also breaks the symmetry. The effect of the protonation on dinitrogen can be separated in charge, which extends the high-energy part of the spectrum, and symmetry-breaking, which is most clearly seen in the low-energy π* transition.