Distinct skeletal stem cell types orchestrate long bone skeletogenesis
Ambrosi, TH;Sinha, R;Steininger, HM;Hoover, MY;Murphy, MP;Koepke, LS;Wang, Y;Lu, WJ;Morri, M;Neff, NF;Weissman, IL;Longaker, MT;Chan, CK;
PMID: 34280086 | DOI: 10.7554/eLife.66063
Skeletal stem and progenitor cell populations are crucial for bone physiology. Characterization of these cell types remains restricted to heterogenous bulk populations with limited information on whether they are unique or overlap with previously characterized cell types. Here we show, through comprehensive functional and single-cell transcriptomic analyses, that postnatal long bones of mice contain at least two types of bone progenitors with bona fide skeletal stem cell (SSC) characteristics. An early osteochondral SSC (ocSSC) facilitates long bone growth and repair, while a second type, a perivascular SSC (pvSSC), co-emerges with long bone marrow and contributes to shape the hematopoietic stem cell niche and regenerative demand. We establish that pvSSCs, but not ocSSCs, are the origin of bone marrow adipose tissue. Lastly, we also provide insight into residual SSC heterogeneity as well as potential crosstalk between the two spatially distinct cell populations. These findings comprehensively address previously unappreciated shortcomings of SSC research.
Lee, YJ;Kang, SG;Kim, CH;
PMID: 37369491 | DOI: 10.21873/invivo.13236
To determine the expression of long non-coding RNA urothelial cancer-associated 1 (UCA1) by performing array-based quantitative polymerase chain reaction (PCR) and to identify the clinicopathological significance of UCA1 expression in prostate cancer using in situ hybridization (ISH) of surgically resected specimens.Array-based quantitative PCR was performed using 10 pairs of fresh malignant (prostate cancer) and normal tissue samples to determine UCA1 expression. Single-color RNA ISH of surgically resected prostate cancer specimens was performed using 70 formalin-fixed, paraffin-embedded tissue specimens to examine the clinicopathological significance of UCA1.Prostate cancer tissues exhibited higher levels of UCA1 expression than paired benign tissues. Furthermore, a correlation between high UCA1 expression and unfavourable clinicopathological characteristics, including advanced pathologic T stage, extraprostatic extension, presence of Gleason pattern 5, and involvement of the resection margins was observed. Notably, increased UCA1 expression significantly correlated with high- or very-high-risk patients, as defined by the 2023 National Comprehensive Cancer Network guidelines.UCA1 could be used as a novel diagnostic and prognostic biomarker for establishing an effective treatment protocol for prostate cancer.
Nat Commun. 2018 Oct 22;9(1):4386.
Liu J, Li Y, Tong J, Gao J, Guo Q, Zhang L, Wang B, Zhao H, Wang H, Jiang E, Kurita R, Nakamura Y, Tanabe O, Engel JD, Bresnick EH, Zhou J, Shi L.
PMID: 30349036 | DOI: 10.1038/s41467-018-06883-x
In addition to serving as a prosthetic group for enzymes and a hemoglobin structural component, heme is a crucial homeostatic regulator of erythroid cell development and function. While lncRNAs modulate diverse physiological and pathological cellular processes, their involvement in heme-dependent mechanisms is largely unexplored. In this study, we elucidated a lncRNA (UCA1)-mediated mechanism that regulates heme metabolism in human erythroid cells. We discovered that UCA1 expression is dynamically regulated during human erythroid maturation, with a maximal expression in proerythroblasts. UCA1 depletion predominantly impairs heme biosynthesis and arrests erythroid differentiation at the proerythroblast stage. Mechanistic analysis revealed that UCA1 physically interacts with the RNA-binding protein PTBP1, and UCA1 functions as an RNA scaffold to recruit PTBP1 to ALAS2 mRNA, which stabilizes ALAS2 mRNA. These results define a lncRNA-mediated posttranscriptional mechanism that provides a new dimension into how the fundamental heme biosynthetic process is regulated as a determinant of erythrocyte development.
Cheng, S;Butrus, S;Tan, L;Xu, R;Sagireddy, S;Trachtenberg, JT;Shekhar, K;Zipursky, SL;
PMID: 35063073 | DOI: 10.1016/j.cell.2021.12.022
The role of postnatal experience in sculpting cortical circuitry, while long appreciated, is poorly understood at the level of cell types. We explore this in the mouse primary visual cortex (V1) using single-nucleus RNA sequencing, visual deprivation, genetics, and functional imaging. We find that vision selectively drives the specification of glutamatergic cell types in upper layers (L) (L2/3/4), while deeper-layer glutamatergic, GABAergic, and non-neuronal cell types are established prior to eye opening. L2/3 cell types form an experience-dependent spatial continuum defined by the graded expression of ∼200 genes, including regulators of cell adhesion and synapse formation. One of these genes, Igsf9b, a vision-dependent gene encoding an inhibitory synaptic cell adhesion molecule, is required for the normal development of binocular responses in L2/3. In summary, vision preferentially regulates the development of upper-layer glutamatergic cell types through the regulation of cell-type-specific gene expression programs.
Oncol Rep. 2018 Nov;40(5):2497-2506.
Lebrun L, Milowich D, Le Mercier M, Allard J, Van Eycke YR, Roumeguere T, Decaestecker C, Salmon I, Rorive S.
PMID: 30226613 | DOI: 10.3892/or.2018.6697
Non‑coding RNAs (ncRNAs) have been shown to serve important roles in carcinogenesis via complex mechanisms, including transcriptional and post‑transcriptional regulation, and chromatin interactions. Urothelial carcinoma‑associated 1 (UCA1), a long ncRNA, was recently shown to have tumorigenic properties in urothelial bladder cancer (UBC), as demonstrated by enhanced proliferation, migration, invasion and therapy resistance of UBC cell lines in vitro. These in vitro findings suggested that UCA1 is associated with aggressive tumor behavior and could have prognostic implications in UBC. The aims of the present study were to therefore to investigate the statistical associations between UCA1 RNA expression and UBC pathological features, patient prognosis and p53 and Ki‑67 expression. Chromogenic in situ hybridization and immunohistochemistry were performed on UBC tissue microarrays to characterize UCA1 RNA, and p53 and Ki‑67 expression in 208 UBC cases, including 145 non‑muscle‑invasive and 63 muscle‑invasive cases. UCA1 was observed in the tumor cells of 166/208 (80%) UBC cases tested. No expression was noted in normal stromal and endothelium cells. Patients with UBC that overexpressed UCA1 (35%) had a significantly higher survival rate (P=0.006) compared with that in patients with UBC that did not overexpress UCA1. This prognostic factor was independent of tumor morphology, concomitant carcinoma in situ, tumor grade and tumor stage. In addition, the absence of UCA1 overexpression was significantly associated with a high Ki‑67 proliferative index (P=0.008) and a p53 'mutated' immunoprofile (strong nuclear expression or complete absence of staining; P=0.003). In conclusion, the present results identified UCA1 as potentially being a novel independent prognostic marker in UBC that was associated with a better patient prognosis and that could serve a pivotal role in bladder cancer carcinogenesis.