Abstract: The Hayabusa2 spacecraft made two landings on the asteroid (162173) Ryugu in 2019, during which it collected samples of the surface material. Those samples were delivered to Earth in December 2020. The colors, shapes, and morphologies of the returned samples are consistent with those observed on Ryugu by Hayabusa2, indicating that they are representative of the asteroid. Laboratory analysis of the samples can determine the chemical composition of Ryugu and provide information on its formation and history. RATIONALE We used laboratory analysis to inform the following questions: (i) What are the elemental abundances of Ryugu? (ii) What are the isotopic compositions of Ryugu? (iii) Does Ryugu consist of primary materials produced in the disk from which the Solar System formed or of secondary materials produced in the asteroid or on a parent asteroid? (iv) When were Ryugu’s constituent materials formed? (v) What, if any, relationship does Ryugu have with meteorites? RESULTS We quantified the abundances of 66 elements in the Ryugu samples: H, Li, Be, C, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Te, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Tl, Pb, Bi, Th, and U. There is a slight variation in chemical compositions between samples from the first and second touchdown sites, but the variations could be due to heterogeneity among the samples that were analyzed. The Cr-Ti isotopes and abundance of volatile elements are similar to those of carbonaceous meteorites in the CI (Ivuna-like) chondrite group. The Ryugu samples consist of the minerals magnetite, breunnerite, dolomite, and pyrrhotite as grains embedded in a matrix composed of serpentine and saponite. This mineral assemblage and the texture are also similar to those of CI meteorites. Anhydrous silicates are almost absent, which indicates extensive liquid water–rock reactions (aqueous alteration) in the material. We conclude that the samples mainly consist of secondary materials that were formed by aqueous alteration in a parent body, from which Ryugu later formed. The oxygen isotopes in the bulk Ryugu samples are also similar to those in CI chondrites. We used oxygen isotope thermometry to determine the temperature at which the dolomite and magnetite precipitated from an aqueous solution, which we found to be 37° ± 10°C. The 53 Mn- 53 Cr isotopes date the aqueous alteration at 5.2 − 0.7 + 0.8 million (statistical) or 5.2 − 2.1 + 1.6 million (systematic) years after the birth of the Solar System. Phyllosilicate minerals are the main host of water in the Ryugu samples. The amount of structural water in Ryugu is similar to that in CI chondrites, but interlayer water is largely absent in Ryugu, which suggests a loss of interlayer water to space. The abundance of structural water and results from dehydration experiments indicate that the Ryugu samples remained below ~100°C from the time of aqueous alteration until the present. We ascribe the removal of interlayer water to a combination of impact heating, solar heating, solar wind irradiation, and long-term exposure to the ultrahigh vacuum of space. The loss of interlayer water from phyllosilicates could be responsible for the comet-like activity of some carbonaceous asteroids and the ejection of solid material from the surface of asteroid Bennu. CONCLUSION The Ryugu samples are most similar to CI chondrite meteorites but are more chemically pristine. The chemical composition of the Ryugu samples is a closer match to the Sun’s photosphere than to the composition of any other natural samples studied in laboratories. CI chondrites appear to have been modified on Earth or during atmospheric entry. Such modification of CI chondrites could have included the alteration of the structures of organics and phyllosilicates, the adsorption of terrestrial water, and the formation of sulfates and ferrihydrites. Those issues do not affect the Ryugu samples. Those modifications might have changed the albedo, porosity, and density of the CI chondrites, causing the observed differences between CI meteorites, Hayabusa2 measurements of Ryugu’s surface, and the Ryugu samples returned to Earth. Representative petrography of a Ryugu sample, designated C0002-C1001. Colors indicate elemental abundances determined from x-ray spectroscopy. Lines of iron, sulfur, and calcium are shown as red, green, and blue (RGB) color channels in that order. Combinations of these elements are assigned to specific minerals, as indicated in the legend. All visible minerals were formed by aqueous alteration on Ryugu’s parent body.

Abstract: We used complementary deoxyribonucleic acid expression microarrays to assess the effects of radiotherapy on gene expression in glioblastoma multiforme. We hypothesized that postradiation recurrent tumors may demonstrate alterations in gene expression from the primary tumor specimen. METHODS Patients were diagnosed with glioblastoma multiforme at resection of the initial tumor, and they received 60 Gy of fractionated radiotherapy before recurrence. Ribonucleic acid samples from both the primary and the postradiation recurrent tumor in each patient were screened and compared using complementary deoxyribonucleic acid expression arrays and Northern blot analysis. RESULTS Messenger ribonucleic acid levels of growth factors participating in paracrine loops, such as vascular endothelial growth factor and platelet-derived growth factor receptor β, were decreased in postradiation recurrent tumors as compared with primary tumors in three of four patients. However, messenger ribonucleic acid levels of growth factors involved in autocrine loops, such as epidermal growth factor receptor, platelet-derived growth factor α, platelet-derived growth factor A, and basic fibroblast growth factor, were decreased in two of four, two of four, three of four, and three of four patients' recurrent tumors, respectively. Microvessel counts demonstrated that blood vessel growth was decreased significantly in postradiation recurrent tumor specimens. CONCLUSION After radiotherapy of glioblastoma multiforme, levels of paracrine-acting growth factors are diminished in correspondence with the reduction in vascular density. In contrast, growth factors that participate in autocrine loops demonstrate elevated levels of gene expression. These results suggest that maintenance of autocrine loops may be important in tumor regrowth after radiotherapy.

Abstract: Background: Activities of nonhematopoietic cells (NHCs) reportedly underlie lymphomagenesis. In follicular lymphoma (FL), mesenchymal stromal cells (SCs) including follicular dendritic cells (FDCs) have been shown to facilitate FL expansion. However, comprehensive understanding of lymphoma NHC activities have been hampered by indefinite NHC heterogeneity even in normal human lymph node (LN). Indeed, human LN blood endothelial cells (BECs) and non-endothelial stromal cells (NESCs) have not been analyzed at single-cell resolution. Here, we aimed to construct a single-cell atlas of NHCs in human LN applicable to lymphoma researches. We also sought to reveal the landscape of stromal remodeling in lymphomas, particularly in FL, to advance understanding of stromal contributions in lymphomagenesis. Methods: We prospectively performed single-cell RNA sequencing of NHCs ( & gt;100,000 cells) extracted from 27 human samples including metastasis-free LN (MFLN; n=9), nodal FL (n=10), peripheral T-cell lymphoma (PTCL; n=5), and diffuse large B-cell lymphoma transformed from FL (tDLBCL; n=3). Data from MFLN samples were used for the construction of NHC atlas. Immunofluorescence (IF) staining was performed to investigate the existence and topological localizations of each NHC subcluster in the LN. Using the NHC atlas, we performed comprehensive comparative analysis with FL NHCs by differentially-expressed gene (DEG) and intercellular ligand-receptor analyses. We also investigated the prognostic impact of putative stroma-derived biomarkers using deposited microarray data of FL patients. Finally, we examined the applicability of the atlas to NHCs from other lymphoma subtypes by analyzing PTCL and tDLBCL NHCs. Data analysis was performed through multiple pipelines including Seurat, Monocle3, and CellphoneDB. Results: Graph-based clustering analysis revealed that the transcriptional features of NHC subpopulations in MFLN are detectable in FL NHCs. Unsupervised sub-clustering analysis of BECs, lymphatic endothelial cells (LECs), and NESCs revealed 10, 8, and 12 subclusters, respectively, including some lacking mouse counterpart. IF staining successfully identified each NHC subcluster and its localization in the LN. In FL NHCs, the proportion of arterial BEC subclusters markedly increased relative to MFLN, while the proportion of LECs decreased. In FL NESCs, the proportion of marginal reticular cells (MRCs) as well as FDCs greatly increased. DEG analysis revealed that the greatest changes in gene expression occurs in NESC subclusters, particularly in MRCs, T-zone reticular cells (TRCs), pericytes, and FDCs. Notably, in some NESC subclusters, we observed marked upregulation of genes relevant to solid cancers but previously not described in lymphomas (e.g. POSTN, EGFL6, and FAP). Combined interactome and DEG analysis revealed 60 FL-specific interactions between NHC subclusters and malignant B cells. For example, interactions mediated through stroma-derived CD70 were enhanced at medullary SC subclusters and SCs at LN capsule adventitia. Additionally, the CCR7-CCL19 interaction and interactions via B-cell activating factor (BAFF) were unexpectedly upregulated at non-TRC SC and medullary SC subclusters, respectively. Also, the CXCL13-CXCR5 axis was highly activated in MRCs, collectively indicating that non-FDC SCs vigorously participate in FL cell expansion and/or infiltration into extra-follicular lesions. Some intercellular interactions were functionally validated by in vitro binding assays. Based on this dataset, we identified putative stroma-derived biomarkers linked to unfavorable prognosis in FL patients including TDO2, encoding immune-modulators, and LY6H and LOX, tip cell markers. We finally confirmed that NHC subclusters identified in our atlas were also detectable in NHCs of more aggressive lymphoma subtypes including PTCL and tDLBCL. Notably, we found that extra-follicular SCs had further differentiated into follicular SCs in tDLBCL, likely representing a terminal form of stromal remodeling in FL. Conclusion: We constructed a comprehensive single-cell atlas of NHCs in human LN highly applicable to lymphoma NHC researches and revealed a total of 30 NHC subclusters. Our study largely updates NHC taxonomy in LNs and provides a rich resource and deeper insights into lymphoma biology, a contribution that should advance lymphoma management and therapy. Figure 1 Figure 1. Disclosures Usuki: Otsuka Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Novartis Pharma K.K.: Research Funding, Speakers Bureau; Ono Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Janssen Pharmaceutical K.K.: Research Funding; Celgene K.K.: Research Funding, Speakers Bureau; Takeda Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Nippon-Boehringer-Ingelheim Co., Ltd.: Research Funding; Mundipharma K.K.: Research Funding; Amgen-Astellas Biopharma K.K.: Research Funding; Nippon-Shinyaku Co., Ltd.: Research Funding, Speakers Bureau; Kyowa-Kirin Co., Ltd.: Research Funding, Speakers Bureau; Pfizer Japan Inc.: Research Funding, Speakers Bureau; Alexion Pharmaceuticals, Inc.: Research Funding, Speakers Bureau; Eisai Co., Ltd.: Speakers Bureau; MSD K.K.: Research Funding, Speakers Bureau; PharmaEssentia Japan KK: Research Funding, Speakers Bureau; Yakult Honsha Co., Ltd.: Research Funding, Speakers Bureau; Daiichi Sankyo Co., Ltd.: Research Funding, Speakers Bureau; Sumitomo-Dainippon Pharma Co., Ltd.: Research Funding; SymBio Pharmaceuticals Ltd.: Research Funding, Speakers Bureau; Gilead Sciences, Inc.: Research Funding; Bristol-Myers-Squibb K.K.: Research Funding, Speakers Bureau; Apellis Pharmaceuticals, Inc.: Research Funding; AbbVie GK: Research Funding, Speakers Bureau; Astellas Pharma Inc.: Research Funding, Speakers Bureau; Incyte Biosciences Japan G.K.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Sanofi K.K.: Speakers Bureau; Amgen K.K.: Research Funding.

Abstract: The Hayabusa2 spacecraft retrieved surface and subsurface samples from the carbonaceous near-Earth asteroid (162173) Ryugu, which was expected to be enriched in volatile species. The samples were collected from two locations, one undisturbed surface and the other including material excavated by an artificial impact. Unlike meteorites, these samples have experienced minimal alteration by Earth’s atmosphere. Ryugu is thought to have formed from material ejected (by an impact) from a parent body, which had experienced aqueous alteration (reactions with liquid water) ~4.56 billion years (Gyr) ago. Ryugu’s orbit later migrated from the main asteroid belt to become a near-Earth asteroid. RATIONALE Noble gases and nitrogen isotopes in Ryugu grains are inherited from Ryugu’s parent body and potentially provide information about the source of Earth’s volatile elements. Noble gas isotopes can also be used to assess the orbital evolution and recent surface activities of Ryugu. We pelletized ~0.8-mm-diameter Ryugu grains and investigated their mineralogy before carrying out isotope measurements. We measured the concentrations and isotopic compositions of noble gases and nitrogen, extracted by stepped heating, with mass spectrometers. RESULTS The mineralogy of the Ryugu grains is similar to Ivuna-type carbonaceous (CI) chondrite meteorites. Fine-grained hydrous silicates (phyllosilicates), produced through aqueous alteration of primary minerals, compose the major fraction of the samples. This is consistent with infrared spectroscopic observations of the asteroid. Iron oxide, iron sulfides, and carbonates are also found within the matrix. Noble gas isotopes are dominated by primordially trapped gases. Their abundances are mostly similar to the highest found in a CI chondrite, with some grains having several times higher concentrations than the highest CI value. Isotopic compositions and concentrations of nitrogen vary between the Ryugu grains, with divergence from the CI chondrite composition. The nitrogen concentrations in four Ryugu grains are one-half to one-third the CI values, and the 15 N/ 14 N ratio is also lower. The Ryugu grains with compositions farthest from the CI values are similar to the composition of a dehydrated CI chondrite. Only two surface samples, out of the 16 Ryugu grains measured, have clear signs of noble gases derived from solar wind (SW). Their abundances correspond to SW exposure durations of ≳3500 and ≳250 years at the current orbit, whereas most of the grains were exposed for ≳1 to ≳50 years. Cosmic ray–produced 21 Ne concentrations vary, with no systematic difference between the sample collection sites. The estimated cosmic ray exposure (CRE) ages for the surface and subsurface samples are 5.3 ± 0.9 and 5.2 ± 0.8 million years (Myr), assuming irradiations at 2 to 5 g cm −2 and 150 g cm −2 , respectively. This is consistent with the expected surface residence time under near-Earth impact rates. We infer that Ryugu’s orbit migrated from the main asteroid belt to the near-Earth region ~5 Myr ago. About 30% of cosmogenic 21 Ne, corresponding to a CRE age of ~1 Myr, was released in gas-extraction steps at 100°C, indicating that the Ryugu samples have not experienced heating above 100°C within the past 1 Myr. Previous studies have suggested that Ryugu experienced an orbital excursion much closer to the Sun. If this is the case, this excursion must have occurred ≳1 Myr ago. CONCLUSION The mineralogical and noble gas measurements show that the Ryugu samples are similar to CI chondrites. The nitrogen data indicate a heterogeneous distribution of nitrogen-carrying materials with different compositions, one of which has been lost from Ryugu grains to varying degrees. The CRE age of ~5 Myr and the implanted SW are records of the recent irradiation at the current near-Earth orbit of Ryugu. Inferred formation and history of Ryugu. Ryugu’s parent body formed in the early Solar System, incorporating primordial noble gases and nitrogen, followed by aqueous alteration ~4.56 Gyr ago. Ryugu formed from the accumulation of fragments of the parent body ejected by an impact, at an unknown date. Ryugu migrated to its current near-Earth orbit ~5 Myr ago. Ryugu might have experienced another change in orbit, bringing it closer to the Sun (“Path A”), or remained in the same near-Earth orbit (“Path B”).

Abstract: Organic compounds in asteroids and comets contain information about the early history of the Solar System. They could also have delivered organic material to early Earth. The Hayabusa2 spacecraft visited the carbonaceous asteroid Ryugu and collected samples of its surface materials, which were brought to Earth in December 2020. RATIONALE We investigated the macromolecular organic matter in the Ryugu samples, measuring its elemental, isotopic, and functional group compositions along with its small-scale structures and morphologies. Analytical methods used included spectro-microscopies, electron microscopy, and isotopic microscopy. We examined intact Ryugu grains and insoluble carbonaceous residues isolated by acid treatment of the Ryugu samples. RESULTS Organic matter is abundant in the Ryugu grains, distributed as submicrometer-sized organic grains and as organic matter dispersed in matrix. The Ryugu organic matter consists of aromatic carbons, aliphatic carbons, ketones, and carboxyls. The functional group compositions are consistent with those of insoluble organic matter (IOM) from primitive carbonaceous CI (Ivuna-type) and CM (Mighei-type) chondritic meteorites. Those meteorites experienced aqueous alteration (reactions with liquid water) on their parent bodies, which implies that the Ryugu organic material was also modified by aqueous alteration on the asteroid parent body. The functional group distributions of the Ryugu organic matter vary on submicrometer scales in ways that relate to the morphologies: nanoparticulate and/or nanoglobular regions are aromatic-rich, whereas organic matter associated with Mg-rich phyllosilicate matrix and carbonates is IOM-like or occurs as diffuse carbon. The observed macromolecular diversity provides further evidence that the organics were modified by aqueous alteration on Ryugu’s parent body. The diffuse carbon is similar to clay-bound organic matter that occurs in CI chondrites and the ungrouped C2-type meteorite Tagish Lake. No graphite-like material was found, which indicates that the Ryugu organic matter was not subjected to heating events on the parent body. The bulk hydrogen and nitrogen isotopic ratios of the Ryugu grains are between the bulk values of CI chondrites and the IOM in CI chondrites. Some carbonaceous grains showed extreme deuterium (D) and/or nitrogen-15 ( 15 N) enrichments or depletions. These indicate an origin in the interstellar medium or presolar nebula. The bulk hydrogen isotopic ratios of insoluble carbonaceous residues from the Ryugu samples are lower than those in CI and CM chondrites. The range of D enrichments are consistent with the ranges of CI, CM, and Tagish Lake chondrites. The nitrogen isotopic ratios of the IOM from Ryugu samples were close to those in CI chondrites. CONCLUSION The organic matter in Ryugu probably consists of primordial materials that formed during (or before) the early stages of the Solar System’s formation, which were later modified by heterogeneous aqueous alteration on Ryugu’s parent body asteroid. Although the surface of Ryugu is exposed to solar wind, impacts, and heating by sunlight, the macromolecular organics in the surface grains of Ryugu are similar in their chemical, isotopic, and morphological compositions to those seen in primitive carbonaceous chondrites. The properties of Ryugu’s organic matter could explain the low albedo of the asteroid’s surface. Chemical evolution of macromolecular organic matter in samples of asteroid Ryugu. Organic matter formed in the interstellar medium or in the outer region of the protoplanetary disk that formed the Solar System. It was then incorporated into a planetesimal—Ryugu’s parent body—where it experienced varying degrees of reactions with liquid water. An impact ejected material from the parent body, which reassembled to form Ryugu. Samples were brought to Earth by Hayabusa2. CREDIT: HIROSHIMA UNIVERSITY, JAXA, UNIVERSITY OF TOKYO, KOCHI UNIVERSITY, RIKKYO UNIVERSITY, NAGOYA UNIVERSITY, CHIBA INSTITUTE OF TECHNOLOGY, MEIJI UNIVERSITY, UNIVERSITY OF AIZU, AIST