Viscoelasticity quantification of cancerous tongue using intraoral optical coherence elastography: a preliminary study.

Quantifying the biomechanical properties of the tongue is significant for early diagnosis of tongue carcinoma. Therefore, an intraoral optical coherence elastography system based on a miniature probe was proposed here to evaluate the viscoelasticity of in vivo tongue for the first time. Results of experiments with Sprague-Dawley rats indicate that considerable elasticity diversity occurred between cancerous and normal tongues, and the corresponding ratio of their Young's modulus was evaluated to be 3.74. It is also found that, viscosity in diseased tissue is smaller than that in normal tissue. Additionally, healthy, transitional and cancerous regions in the cancerous tongue can be distinguished easily by calculating viscoelasticity characteristics. Based on this preliminary attempt, our method with advantages of noninvasive, high-resolution, high-sensitivity and real-time detection and convenient operation may have good potential to become a useful tool for tongue carcinoma assessment after further optimization.

Exploring Central and Bridge Symptoms in Patients with Lung Cancer: A Network Analysis.

OBJECTIVES: This study aimed to identify symptom clusters in lung cancer patients undergoing chemotherapy and the central and bridge symptoms within each symptom cluster. METHODS: In this cross-sectional study, 1,255 patients with lung cancer were recruited through convenience sampling at Nanfang Hospital. Patient symptom burden was assessed using the M.D. Anderson Symptom Inventory (MDASI) and the Lung Cancer module of the MDASI (MDASI-LC). Symptom clusters were identified using the Walktrap algorithm, and central and bridge symptoms in the symptom clusters were identified by network analysis. RESULTS: The patients included 818 (65.18%) males and 437 (34.82%) females with a mean age of 56.56 ± 11.78 years. Four symptom clusters were identified: fatigue, gastrointestinal, psychoneurological and respiratory. Their central symptoms were fatigue, vomiting, distress and hemoptysis, respectively, and their bridge symptoms were pain, vomiting, dry mouth and shortness of breath. CONCLUSIONS: Lung cancer symptoms show certain strong correlations with each other, resulting in symptom clusters. Central symptoms may influence other symptoms within a symptom cluster, and bridge symptoms might impact the density of the symptom network. This study identified central and bridge symptoms in lung cancer patients undergoing chemotherapy. Targeting these symptoms with interventions for symptom clusters could make symptom management more precise and effective. IMPLICATIONS FOR NURSING PRACTICE: In clinical settings, the burden of symptom clusters may be reduced by intervening against the central symptoms of these symptom clusters. Alternatively, if the objective is to diminish the connections between different symptom clusters and holistically alleviate the overall burden, interventions focused on bridge symptoms may be employed.

Percutaneous versus traditional open approaches for the treatment of thoracolumbar fractures in patients without neurologic deficits: a meta-analysis of 35 cohort studies.

At present, percutaneous surgery is widely used to treat thoracolumbar fractures. However, the actual safety, feasibility, and effectiveness of percutaneous surgery are not clear. Through systematic review and meta-analysis, we compared the efficacies of percutaneous pedicle screw fixation and open pedicle screw fixation in the treatment of thoracolumbar fractures without nerve root symptoms. We systematically searched the PubMed, Embase, and Cochrane libraries for articles published on or before June 2023. All results were evaluated by standard methods recommended for meta-analysis, continuous data were expressed by standard mean differences (SMDs), and binary variables were analyzed by odds ratios (ORs) and 95% confidence intervals (95% CIs). We also explored the main sources of heterogeneity and the stability of the results through sensitivity analysis, Begg's funnel plots, and Egger's test. Thirty-five cohort studies with a total of 3039 patients were included. The study found that patients who undergo percutaneous approaches have less intraoperative blood loss (IBL), shorter length of hospital stay (LOS), shorter operation time, and shorter incision. Moreover, percutaneous approaches had more advantages in terms of visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, and infection rates. However, there was no significant difference in anterior vertebral body height (AVB), Cobb angle (CA), or screw errors between the two groups. In the long run, the clinical and surgical results of the percutaneous approach are better than those of the open approach, but the radiological results of both operations do not seem to show an advantage for any specific approach. Because of publication bias and heterogeneity, our findings must be interpreted with caution. However, this paper will provide some support for clinicians to choose suitable surgical methods for the treatment of thoracolumbar fractures.

Differential Characteristics of Fatigue-Pain-Sleep Disturbance-Depression Symptom Cluster and Influencing Factors of Patients With Advanced Cancer During Treatment: A Latent Class Analysis.

BACKGROUND: Patients with advanced cancer may experience symptom clusters during treatment (eg, fatigue, pain, sleep disturbance, depression). Understanding the characteristics and factors associated with symptom cluster classes among this patient population is essential for effective symptom management. OBJECTIVE: The aims of this study were to identify symptom cluster (fatigue-pain-sleep disturbance-depression) classes and explore influencing factors in patients with advanced cancer during the treatment. METHODS: A cross-sectional survey was conducted in an oncology department of a tertiary hospital in China from September 2020 to March 2021. Cancer patients (stage III/IV) 18 years or older completed the questionnaires on pain, fatigue, sleep disturbance, depression, physical activity, and exercise self-efficacy. Latent class analysis and multinomial logistic regression were used. RESULTS: Three hundred sixty-five patients who were male (65.2%) and younger than 60 years (59.5%) completed questionnaires. Three symptom cluster classes were identified: class 1 ("low symptom burden" class), class 2 ("fatigue-insomnia" class), and class 3 ("high symptom burden" class), with a percentage of 54.5%, 38.6%, and 6.8%, respectively. The quality-of-life score, introversion/extroversion, economic burden, Karnofsky Performance Status, albumin level, and exercise self-efficacy were significantly different among the 3 classes (P < .05). CONCLUSION: Patients with advanced cancer were classified into 3 distinct classes, with class 1 having the best function. Results from this study reveal that Karnofsky Performance Status, albumin level, and exercise self-efficacy were significant factors for the latent classes of symptom cluster. IMPLICATIONS FOR PRACTICE: Exercise self-efficacy is important for personalized interventions and improving symptom management efficiency.

Two-dimensional elastic distribution imaging of the sclera using acoustic radiation force optical coherence elastography.

The scleral elasticity is closely related with many ocular diseases, but the relevant research is still insufficient. Here, we utilized optical coherence elastography to carefully study biomechanical properties of the sclera at different positions and under different intraocular pressures. Meanwhile, elastic wave velocity and Young's modulus of each position were obtained using a phase velocity algorithm. Accordingly, the two-dimensional elasticity distribution image was achieved by mapping the Young's modulus values to the corresponding structure based on the relationship between the position and its Young's modulus. Therefore, elastic information in regions-of-interest can be read and compared directly from the scleral structure, indicating that our method may be a very useful tool to evaluate the elasticity of sclera and provide intuitive and reliable proof for diagnosis and research.

Three new cadinene-type sesquiterpenoids from the aerial parts of Ageratina adenophora.

Three new cadinene sesquiterpenoids 1-3, were isolated from the aerial sections of Ageratina adenophora using various chromatographic techniques. Their structures were characterised by comprehensive spectroscopic investigations (including 1D, 2D-NMR and HRMS), and single crystal X-ray diffraction. The cytotoxic activity of new compounds 1-3 were evaluated by testing in vitro tumour growth inhibitory rate against five human tumour cell lines, HL-60, A-549, SMMC-7721, MDA-MB-231, and SW480.

Unusual 5/5 fused bicyclosesquiterpenoids from Eupatorium adenophorum.

The chemical analysis on the aerial sections of Eupatorium adenophorum Spreng. resulted in the identification of four unprecedented 5/5 fused bicyclosesquiterpenoids, eupatorid A (1), and its analogues named eupatorester A-C (2-4) using various chromatographic techniques. Their structures were unambiguously confirmed by detailed spectroscopic investigations (including 1D, 2D-NMR and HRMS), and single crystal X-ray diffraction. The anti-inflammatory activities, in vitro tumor growth inhibitory activities and antibacterial activities of these compounds were evaluated.

The high burden of symptoms associated with cognitive impairment in lung cancer patients: A latent class analysis.

Objective: To explore the association between the pain-fatigue-sleep disturbance-depression symptom cluster (SC) and cancer-related cognitive impairment (CRCI) in patients having lung cancer and to identify other factors influencing CRCI. Methods: A cross-sectional study was conducted to investigate 378 patients having lung cancer in China from October 2021 to July 2022. The perceived cognitive impairment scale and the general anxiety disorder-7 were used to assess patients' cognitive impairment and anxiety, respectively. The pain-fatigue-sleep disturbance-depression SC was assessed with the brief fatigue inventory, the brief pain inventory, the Patient Health Questionnaire-9, and the Athens Insomnia Scale. Latent class analysis by Mplus.7.4 was used to identify latent classes of the SC. We adjusted for covariates in the multivariable logistic regression model to examine the relationship between the pain-fatigue-sleep disturbance-depression SC and CRCI. Results: Among patients having lung cancer, two SC classes were identified: high and low symptom burden groups. In the crude model, compared to the low symptom burden group, the high symptom group had greater odds of developing CRCI (odds ratio: 10.065, 95% confidence interval: 4.138-24.478). After adjusting for covariates, in model 1, the high symptom group still had greater odds of developing CRCI (odds ratio: 5.531, 95% confidence interval: 2.133-14.336). Additionally, a diagnosis of over 6 months, anxiety, leisure activity, and a high platelet-to-lymphocyte ratio were found to be influencing factors of CRCI (all P â€‹< â€‹0.05). Conclusions: Our study revealed that a high symptom burden is a significant risk factor for CRCI, which may provide a new perspective for managing CRCI in lung patients having cancer.

UBC9 deficiency enhances immunostimulatory macrophage activation and subsequent antitumor T cell response in prostate cancer.

The role of tumor-associated macrophages (TAMs), along with the regulatory mechanisms underlying distinct macrophage activation states, remains poorly understood in prostate cancer (PCa). Herein, we report that PCa growth in mice with macrophage-specific Ubc9 deficiency is substantially suppressed compared with that in wild-type littermates, an effect partially ascribed to the augmented CD8+ T cell response. Biochemical and molecular analyses revealed that signal transducer and activator of transcription 4 (STAT4) is a crucial UBC9-mediated SUMOylation target, with lysine residue 350 (K350) as the major modification site. Site-directed mutation of STAT4 (K350R) enhanced its nuclear translocation and stability, thereby facilitating the proinflammatory activation of macrophages. Importantly, administration of the UBC9 inhibitor 2-D08 promoted the antitumor effect of TAMs and increased the expression of PD-1 on CD8+ T cells, supporting a synergistic antitumor efficacy once it combined with the immune checkpoint blockade therapy. Together, our results demonstrate that ablation of UBC9 could reverse the immunosuppressive phenotype of TAMs by promoting STAT4-mediated macrophage activation and macrophage-CD8+ T cell crosstalk, which provides valuable insights to halt the pathogenic process of tumorigenesis.

Tophaceous gouty arthritis with spondylolysis: a case report.

Spinal gout is a rare occurrence, and the combination of gout with lumbar spondylolysis has not been reported. We present a unique case involving a 29-year-old male who complained of low back pain for 1 month. Computed tomography and magnetic resonance imaging revealed articular subchondral erosions and a mass in the left L5-S1 facet joints. Initially treated for a spinal infection, the patient subsequently underwent lumbar spinal canal decompression and fusion, achieving complete relief. Postoperative pathology confirmed the spinal lesions to be tophaceous gout. Dual-energy CT or biopsy can assist in confirming the diagnosis. This report discusses another rare case of tophaceous gouty arthritis with spondylolysis to be added to the literature.

Risk factor analysis and nomogram construction for predicting suicidal ideation in patients with cancer.

BACKGROUND: Suicidal ideation in cancer patients is a critical challenge. At present, few studies focus on factors associated with suicidal ideation, and predictive models are still lacking. This study aimed at investigating the risk factors for suicidal ideation among cancer patients, and developed a predictive nomogram to screen high risk cancer patients for early prevention and intervention. METHODS: A questionnaire survey was conducted among cancer patients between May 2021 and January 2022. The factors associated with suicidal ideation were used to construct a multivariate logistic regression model, which was visualized as a predictive nomogram to evaluate the risk of suicidal ideation. Areas under the curve, calibration plot, decision curve analysis, and internal and external validation were used to validate the discrimination, calibration and clinical usefulness of the model. RESULTS: A total of 820 patients with cancer were recruited for this study and 213 (25.98%) developed suicidal ideation. Levels of demoralization, depression and cancer staging, marital status, residence, medical financial burden, and living condition were influence factors for suicidal ideation. Comparing nomogram with Self-rating Idea of Suicide Scale (SIOSS), the nomogram had a satisfactory discrimination ability with an AUC of 0.859 (95% CI: 0.827-0.890) and 0.818 (95% CI: 0.764-0.873) in the training and validation sets, respectively. The calibration plot and decision curve analysis revealed that this nomogram was in good fitness and could be beneficial in clinical applications. CONCLUSIONS: Suicidal ideation is common in cancer patients. Levels of demoralization, depression and cancer staging were independent predictors of suicidal ideation. The nomogram is an effective and simple tool for predictive suicidal ideation in cancer patients.

SUMOylation of PDPK1 Is required to maintain glycolysis-dependent CD4 T-cell homeostasis.

The immune system is finely tuned to fight against infections, eradicate neoplasms, and prevent autoimmunity. Protein posttranslational modification (PTM) constitutes a molecular layer of regulation to guarantee the proper intensity of immune response. Herein, we report that UBC9-mediated protein SUMOylation plays an essential role in peripheral CD4 T-cell proliferation, but without a perceptible impact on T-cell polarization. Both conventional T-cell (Tcon) and regulatory T-cell (Treg) maintenance are differentially affected, which was likely caused by a shared deficit in cell glycolytic metabolism. Mechanistically, PDPK1 (3-phosphoinositide-dependent protein-kinase 1) was identified as a novel SUMOylation substrate, which occurred predominantly at lysine 299 (K299) located within the protein-kinase domain. Loss of PDPK1 SUMOylation impeded its autophosphorylation at serine 241 (S241), thereby leading to hypoactivation of downstream mTORC1 signaling coupled with incompetence of cell proliferation. Altogether, our results revealed a novel regulatory mechanism in peripheral CD4 T-cell homeostatic proliferation, which involves SUMOylation regulation of PDPK1-mTORC1 signaling-mediated glycolytic process.

The MAPK dual specific phosphatase (DUSP) proteins: A versatile wrestler in T cell functionality.

The functional state of T cells is diverse and under dynamic control for adapting to the changes of microenvironment. Reversible protein phosphorylation represents an important post-translational modification that not only involves in the immediate early response of T cells, but also affects their functionality in the long run. Perturbation of global phosphorylation profile and/or phosphorylation of specific signaling nodes result in aberrant T cell activity. Dual specific phosphatases (DUSPs), which target MAPKs and beyond, have increasingly been emerged as a versatile regulator in T cell biology. Herein in this mini review, we sought to summarize and discuss the impact of DUSP proteins on the regulation of effector T cell activity, T cell polarization, regulatory T cell development and T cell senescence/exhaustion. Given the distinctive engagement of each DUSP member under various disease settings such as chronic infection, autoimmune disorders, cancer and age-related diseases, DUSP proteins likely hold the promise to become a druggable target other than the existing therapeutics that are predominantly by manipulating protein kinase activity.

N6-Methyladenosine RNA Modification in Inflammation: Roles, Mechanisms, and Applications.

N6-methyladenosine (m6A) is the most prevalent internal mRNA modification. m6A can be installed by the methyltransferase complex and removed by demethylases, which are involved in regulating post-transcriptional expression of target genes. RNA methylation is linked to various inflammatory states, including autoimmunity, infection, metabolic disease, cancer, neurodegenerative diseases, heart diseases, and bone diseases. However, systematic knowledge of the relationship between m6A modification and inflammation in human diseases remains unclear. In this review, we will discuss the association between m6A modification and inflammatory response in diseases, especially the role, mechanisms, and potential clinical application of m6A as a biomarker and therapeutic target for inflammatory diseases.

Targeted Inhibition of FTO Demethylase Protects Mice Against LPS-Induced Septic Shock by Suppressing NLRP3 Inflammasome.

Sepsis refers to the systemic inflammatory response syndrome caused by infection. It is a major clinical problem and cause of death for patients in intensive care units worldwide. The Fat mass and obesity-related protein (FTO) is the primary N6-methyladenosine demethylase. However, the role of FTO in the pathogenesis of inflammatory diseases remains unclear. We herein show that nanoparticle-mediated Fto-siRNA delivery or FTO inhibitor entacapone administration dramatically inhibited macrophage activation, reduced the tissue damage and improved survival in a mouse model of LPS-induced endotoxic shock. Importantly, ablation of FTO could inhibit NLRP3 inflammasome through FoxO1/NF-κB signaling in macrophages. In conclusion, FTO is involved in inflammatory response of LPS-induced septic shock and inhibition of FTO is promising for the treatment of septic shock.

Chondrocyte ferroptosis contribute to the progression of osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a complex process comprised of mechanical load, inflammation, and metabolic factors. It is still unknown that if chondrocytes undergo ferroptosis during OA and if ferroptosis contribute to the progression of OA. MATERIALS AND METHODS: In our study, we use Interleukin-1 Beta (IL-1ß) to simulate inflammation and ferric ammonium citrate (FAC) to simulate the iron overload in vitro. Also, we used the surgery-induced destabilized medial meniscus (DMM) mouse model to induce OA in vivo. We verify ferroptosis by its definition that defined by the Nomenclature Committee on Cell Death with both in vitro and in vivo model. RESULTS: We observed that both IL-1ß and FAC induced reactive oxygen species (ROS), and lipid ROS accumulation and ferroptosis related protein expression changes in chondrocytes. Ferrostatin-1, a ferroptosis specific inhibitor, attenuated the cytotoxicity, ROS and lipid-ROS accumulation and ferroptosis related protein expression changes induced by IL-1ß and FAC and facilitated the activation of Nrf2 antioxidant system. Moreover, erastin, the most classic inducer of ferroptosis, promoted matrix metalloproteinase 13 (MMP13) expression while inhibited type II collagen (collagen II) expression in chondrocytes. At last, we proved that intraarticular injection of ferrostatin-1 rescued the collagen II expression and attenuated the cartilage degradation and OA progression in mice OA model. CONCLUSIONS: In summary, our study firstly proved that chondrocytes underwent ferroptosis under inflammation and iron overload condition. Induction of ferroptosis caused increased MMP13 expression and decreased collagen II expression in chondrocytes. Furthermore, inhibition of ferroptosis, by intraarticular injection of ferrostatin-1, in our case, seems to be a novel and promising option for the prevention of OA. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The translation potential of this article is that we first indicated that chondrocyte ferroptosis contribute to the progression of osteoarthritis which provides a novel strategy in the prevention of OA.

The role of hydrogen sulphide signalling in macrophage activation.

Hydrogen sulphide (H2 S) is the latest identified small gaseous mediator enabled by its lipophilic nature to freely permeate the biological membranes. Initially, H2 S was recognized by its roles in neuronal activity and vascular relaxation, which makes it an important molecule involved in paracrine signalling pathways. Recently, the immune regulatory function of gasotransmitters, H2 S in particular, is increasingly being appreciated. Endogenous H2 S level has been linked to macrophage activation, polarization and inflammasome formation. Mechanistically, H2 S-induced protein S-sulphydration suppresses several inflammatory pathways including NF-κB and JNK signalling. Moreover, H2 S serves as a potent cellular redox regulator to modulate epigenetic alterations and to promote mitochondrial biogenesis in macrophages. Here in this review, we intend to summarize the recent advancements of H2 S studies in macrophages, and to discuss with focus on the therapeutic potential of H2 S donors by targeting macrophages. The feasibility of H2 S signalling component as a macrophage biomarker under disease conditions would be also discussed.

Hyperoside ameliorates the progression of osteoarthritis: An in vitro and in vivo study.

BACKGROUND: Osteoarthritis (OA) is a common degenerative joint disease. The pathogenesis of OA is closely related to inflammatory responses and apoptosis of chondrocytes. Hyperoside (Hyp), a natural flavonoid compound, exerts multiple bioactivities in various diseases. PURPOSE: Our study aims to investigate the anti-arthritic effects of Hyp and delineate the potential mechanism at the cellular level. METHODS: Murine chondrocytes were stimulated with interleukin-1ß (IL-1ß) with or without Hyp treatment. CCK-8 assay was used to evaluate the cytotoxic effect of Hyp. DCFH-DA was used to detect intracellular ROS. Annexin V-FITC/PI method was applied to examine apoptosis of chondrocytes. The anti-arthritic effects of Hyp and related mechanisms were investigated by examining and analyzing relative markers through quantitative PCR, western blot analysis and immunofluorescent staining. C57BL/6 mice were performed the destabilized medial meniscus (DMM) surgery to establish OA model and then injected intraperitoneally with Hyp (20 mg/kg)) for 4 or 8 weeks. Finally, mice were sacrificed and knee joints were collected for histological observation and analysis. RESULTS: Hyp inhibited IL-1ß-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Additionally, Hyp attenuated IL-1ß-induced destruction of the extracellular matrix (ECM) by downregulating the expression of MMPs and ADAMTS5, and meanwhile upregulating the expression of collagen II, aggrecan, and SOX9. Also, Hyp pretreatment reduced IL-1ß-induced overproduction of ROS and apoptosis of chondrocytes. Mechanistically, Hypexerted anti-inflammatory effects by partly suppressing the PI3K/AKT/NF-κB and the MAPK signaling pathways, enhancing the Nrf2/HO-1 to limit the activation of NF-κB. Moreover, Hyp played an anti-apoptotic effect via the Nrf2/ROS/BAX/Bcl-xlaxis. In vivo, cartilage degradation was attenuated with a lower OARSI score in Hyp-treated group compared to the DMM group. CONCLUSION: Our study demonstrated that anti-arthritic effects of Hyp in vitro and in vivo, indicating Hyp might serve as a potential agent for the treatment of OA.

Loss of ubiquitin-conjugating enzyme E2 (Ubc9) in macrophages exacerbates multiple low-dose streptozotocin-induced diabetes by attenuating M2 macrophage polarization.

Type 1 diabetes (T1D) is characterized by the selective autoimmune destruction of the islet ß cells, and macrophages play a significant role in this process. Small ubiquitin-like modification (SUMOylation) is an important posttranslational modification involved in T1D pathogenesis, but its function in macrophages remains unexplored. We presently developed and used macrophage-specific ubiquitin-conjugating enzyme E2 (Ubc9) knockout (LyzM-Cre-Ubc9fl/fl, KO) mice to address the impact of SUMOylation on macrophage function in a T1D model. We observed that blocking Ubc9 in macrophages exacerbated multiple-low dose streptozotocin (MLD-STZ)-induced diabetes. Specifically, after STZ treatment, blood glucose levels were consistently elevated in the KO mice. The KO mice exhibited a higher diabetes incidence than WT controls (85% vs. 55%, P < 0.01) along with a higher insulitis severity. The loss of Ubc9 impaired macrophage energy metabolism and attenuated macrophage M2 program, thereby enhancing T cell activation. Pancreas-resident macrophages, rather than migrant macrophages, played a predominant role in MLD-STZ-induced diabetes. Mechanistically, Ubc9-mediated SUMOylation of interferon regulator factor 4 (IRF4) enhanced its nuclear localization and stability, thereby transcribing IL-4 and arginase 1 (Arg1) to promote the macrophage M2 program. Ubc9-mediated SUMOylation modulates T1D risk at least in part by regulating macrophage function. Modulation of disturbed SUMOylation process in macrophages, either through cell adoptive transfer or targeted drug-delivery, could help to establish a tolerant pancreatic microenvironment and promote inflammation resolution in early insulitis stage, thus hindering T1D progression.

Ubc9 deficiency selectively impairs the functionality of common lymphoid progenitors (CLPs) during bone marrow hematopoiesis.

Hematopoietic development occurs in the bone marrow, and this process begins with hematopoietic stem cells (HSCs). Ubc9 is a unique E2-conjugating enzyme required for SUMOylation, an evolutionarily conserved post-translational modification system. We herein show that a conditional Ubc9 deletion in the hematopoietic system caused decreased thymus weight and reduced lymphocyte to myeloid cell ratio. Importantly, Ubc9 deletion in the hematopoietic system only selectively impaired the development of common lymphoid progenitors (CLPs) in the bone marrow and perturbed their potential to differentiate into lymphocytes, thereby decreasing the number of T/B cells in the periphery. Ubc9 was found to be required for CLP viability, and therefore, Ubc9 deficiency rendered CLPs to undergo apoptosis and attenuated their proliferation. Thus, Ubc9 plays a critical role in the regulation of CLP function during hematopoietic development in the bone marrow.