UHRF1P contributes to IL-17A-mediated systemic lupus erythematosus via UHRF1-MAP4K3 axis.

Inflammatory T cells contribute to the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). Analysis of the T-cell transcriptomics data of two independent SLE patient cohorts by three machine learning models revealed the pseudogene UHRF1P as a novel SLE biomarker. The pseudogene-encoded UHRF1P protein was overexpressed in peripheral blood T cells of SLE patients. The UHRF1P protein lacks the amino-terminus of its parental UHRF1 protein, resulting in missing the proteasome-binding ubiquitin-like (Ubl) domain of UHRF1. T-cell-specific UHRF1P transgenic mice manifested the induction of IL-17A and autoimmune inflammation. Mechanistically, UHFR1P prevented UHRF1-induced Lys48-linked ubiquitination and degradation of MAP4K3 (GLK), which is a kinase known to induce IL-17A. Consistently, IL-17A induction and autoimmune phenotypes of UHRF1P transgenic mice were obliterated by MAP4K3 knockout. Collectively, UHRF1P overexpression in T cells inhibits the E3 ligase function of its parental UHRF1 and induces autoimmune diseases.

Weight regain, but not weight loss exacerbates hepatic fibrosis during multiple weight cycling events in male mice.

PURPOSE: Weight cycling is a phenomenon characterized by fluctuating body weight that is commonly observed in individuals employing intentional weight loss methods. Despite its prevalence, the impact of weight cycling on health remains equivocal. The current investigation aimed to examine the effects of weight cycling on liver health. METHODS: The weight cycling model was established by switching the feeding method of mice between ad libitum (AL) and restricted intake (DR or 60% of AL) of the breeding diet to cause weight gain and weight loss, respectively. The weight cycling model comprised two and a half cycles, with one group terminating the experience during the weight-gain period (S-AL) and the other during the weight-loss period (S-DR). Liver tissue was collected to investigate morphology alterations, apoptosis, lipid metabolism, and mitochondrial homeostasis. RESULTS: The results demonstrated that the termination point of weight cycling affected body weight and hepatic steatosis. All parameters examined in the S-DR mice exhibited a comparable trend to those observed in the DR mice. Notably, S-AL mice showed a significant increase in lipid metabolism-related proteins in the liver compared to AL-fed mice, along with reduced lipid droplets. Moreover, hepatic apoptosis and fibrosis were exacerbated in the S-AL mice compared to AL mice, whereas mitochondrial fusion, biogenesis, and mitophagy were decreased in the S-AL mice. CONCLUSION: Weight cycling ending in weight gain exacerbated hepatic fibrosis, potentially by inducing apoptosis or disrupting mitochondrial homeostasis. Conversely, weight cycling ending in weight loss demonstrated beneficial effects on hepatic health.

DUSP8 induces TGF-ß-stimulated IL-9 transcription and Th9-mediated allergic inflammation by promoting nuclear export of Pur-α.

Dual-specificity phosphatase 8 (DUSP8) is a MAPK phosphatase that dephosphorylates and inactivates the kinase JNK. DUSP8 is highly expressed in T cells; however, the in vivo role of DUSP8 in T cells remains unclear. Using T cell-specific Dusp8 conditional KO (T-Dusp8 cKO) mice, mass spectrometry analysis, ChIP-Seq, and immune analysis, we found that DUSP8 interacted with Pur-α, stimulated interleukin-9 (IL-9) gene expression, and promoted Th9 differentiation. Mechanistically, DUSP8 dephosphorylated the transcriptional repressor Pur-α upon TGF-ß signaling, leading to the nuclear export of Pur-α and subsequent IL-9 transcriptional activation. Furthermore, Il-9 mRNA levels were induced in Pur-α-deficient T cells. In addition, T-Dusp8-cKO mice displayed reduction of IL-9 and Th9-mediated immune responses in the allergic asthma model. Reduction of Il-9 mRNA levels in T cells and allergic responses of T-Dusp8-cKO mice was reversed by Pur-α knockout. Remarkably, DUSP8 protein levels and the DUSP8-Pur-α interaction were indeed increased in the cytoplasm of T cells from people with asthma and patients with atopic dermatitis. Collectively, DUSP8 induces TGF-ß-stimulated IL-9 transcription and Th9-induced allergic responses by inhibiting the nuclear translocation of the transcriptional repressor Pur-α. DUSP8 may be a T-cell biomarker and therapeutic target for asthma and atopic dermatitis.

Early-onset caloric restriction alleviates ageing-associated steatohepatitis in male mice via restoring mitochondrial homeostasis.

Non-alcoholic fatty liver disease is associated with ageing, and impaired mitochondrial homeostasis is the main cause for hepatic ageing. Caloric restriction (CR) is a promising therapeutic approach for fatty liver. The purpose of the present study was to investigate the possibility of early-onset CR in decelerating the progression of ageing-related steatohepatitis. The putative mechanism associated with mitochondria was further determined. C57BL/6 male mice at 8 weeks of age were randomly assigned to one of three treatments: Young-AL (AL, ad libitum), Aged-AL, or Aged-CR (60% intake of AL). Mice were sacrificed when they were 7 months old (Young) or 20 months old (Aged). Aged-AL mice displayed the greatest body weight, liver weight, and liver relative weight among treatments. Steatosis, lipid peroxidation, inflammation, and fibrosis coexisted in the aged liver. Mega mitochondria with short, randomly organized crista were noticed in the aged liver. The CR ameliorated these unfavourable outcomes. The level of hepatic ATP decreased with ageing, but this was reversed by CR. Ageing caused a decrease in mitochondrial-related protein expressions of respiratory chain complexes (NDUFB8 and SDHB) and fission (DRP1), but an increase in proteins related to mitochondrial biogenesis (TFAM), and fusion (MFN2). CR reversed the expression of these proteins in the aged liver. Both Aged-CR and Young-AL revealed a comparable pattern of protein expression. To summarize, this study demonstrated the potential of early-onset CR in preventing ageing-associated steatohepatitis, and maintaining mitochondrial functions may contribute to CR's protection during hepatic ageing.

SARS-CoV-2 spike protein enhances MAP4K3/GLK-induced ACE2 stability in COVID-19.

ACE2 on epithelial cells is the SARS-CoV-2 entry receptor. Single-cell RNA-sequencing data derived from two COVID-19 cohorts revealed that MAP4K3/GLK-positive epithelial cells were increased in patients. SARS-CoV-2-induced GLK overexpression in epithelial cells was correlated with COVID-19 severity and vesicle secretion. GLK overexpression induced the epithelial cell-derived exosomes containing ACE2; the GLK-induced exosomes transported ACE2 proteins to recipient cells, facilitating pseudovirus infection. Consistently, ACE2 proteins were increased in the serum exosomes from another COVID-19 cohort. Remarkably, SARS-CoV-2 spike protein-stimulated GLK, and GLK stabilized ACE2 in epithelial cells. Mechanistically, GLK phosphorylated ACE2 at two serine residues (Ser776, Ser783), leading to the dissociation of ACE2 from its E3 ligase UBR4. Reduction in UBR4-induced Lys48-linked ubiquitination at three lysine residues (Lys26, Lys112, Lys114) of ACE2 prevented its degradation. Furthermore, SARS-CoV-2 pseudovirus or live virus infection in humanized ACE2 mice induced GLK and ACE2 protein levels, and ACE2-containing exosomes. Collectively, ACE2 stabilization by SARS-CoV-2-induced MAP4K3/GLK may contribute to the pathogenesis of COVID-19.

Genomic sequencing and functional analyses identify MAP4K3/GLK germline and somatic variants associated with systemic lupus erythematosus.

OBJECTIVES: MAP4K3 (GLK) overexpression in T cells induces interleukin (IL)-17A production and autoimmune responses. GLK overexpressing T-cell population is correlated with severity of human systemic lupus erythematosus (SLE); however, it is unclear how GLK is upregulated in patients with SLE. METHODS: We enrolled 181 patients with SLE and 250 individuals without SLE (93 healthy controls and 157 family members of patients with SLE) in two independent cohorts from different hospitals/cities. Genomic DNAs of peripheral blood mononuclear cells were subjected to next-generation sequencing to identify GLK gene variants. The functional consequences of the identified GLK germline or somatic variants were investigated using site-directed mutagenesis and cell transfection, followed by reporter assays, mass spectrometry, immunoblotting, coimmunoprecipitation, and in situ proximity ligation assays. RESULTS: We identified 58 patients with SLE from Cohort #1 and #2 with higher frequencies of a somatic variant (chr2:39 477 124 A>G) in GLK 3'-untranslated region (UTR); these patients with SLE showed increased serum anti-double-stranded DNA levels and decreased serum C3/C4 levels. This somatic variant in 3'-UTR enhanced GLK mRNA levels in T cells. In addition, we identified five patients with SLE with GLK (A410T) germline variant in Cohort #1 and #2, as well as two other patients with SLE with GLK (K650R) germline variant in Cohort #1. Another GLK germline variant, A579T, was also detected in one patient with SLE from Cohort #2. Both GLK (A410T) and GLK (K650R) mutants inhibited GLK ubiquitination induced by the novel E3 ligase makorin ring-finger protein 4 (MKRN4), leading to GLK protein stabilisation. CONCLUSIONS: Multiple GLK germline and somatic variants cause GLK induction by increasing mRNA or protein stability in patients with SLE.

More than causing (epi)genomic instability: emerging physiological implications of transposable element modulation.

Transposable elements (TEs) initially attracted attention because they comprise a major portion of the genomic sequences in plants and animals. TEs may jump around the genome and disrupt both coding genes as well as regulatory sequences to cause disease. Host cells have therefore evolved various epigenetic and functional RNA-mediated mechanisms to mitigate the disruption of genomic integrity by TEs. TE associated sequences therefore acquire the tendencies of attracting various epigenetic modifiers to induce epigenetic alterations that may spread to the neighboring genes. In addition to posting threats for (epi)genome integrity, emerging evidence suggested the physiological importance of endogenous TEs either as cis-acting control elements for controlling gene regulation or as TE-containing functional transcripts that modulate the transcriptome of the host cells. Recent advances in long-reads sequence analysis technologies, bioinformatics and genetic editing tools have enabled the profiling, precise annotation and functional characterization of TEs despite their challenging repetitive nature. The importance of specific TEs in preimplantation embryonic development, germ cell differentiation and meiosis, cell fate determination and in driving species specific differences in mammals will be discussed.

Transcriptome Analysis of Dnmt3l Knock-Out Mice Derived Multipotent Mesenchymal Stem/Stromal Cells During Osteogenic Differentiation.

Multipotent mesenchymal stem/stromal cells (MSCs) exhibit great potential for cell-based therapy. Proper epigenomic signatures in MSCs are important for the maintenance and the subsequent differentiation potential. The DNA methyltransferase 3-like (DNMT3L) that was mainly expressed in the embryonic stem (ES) cells and the developing germ cells plays an important role in shaping the epigenetic landscape. Here, we report the reduced colony forming ability and impaired in vitro osteogenesis in Dnmt3l-knockout-mice-derived MSCs (Dnmt3l KO MSCs). By comparing the transcriptome between undifferentiated Dnmt3l KO MSCs and the MSCs from the wild-type littermates, some of the differentially regulated genes (DEGs) were found to be associated with bone-morphology-related phenotypes. On the third day of osteogenic induction, differentiating Dnmt3l KO MSCs were enriched for genes associated with nucleosome structure, peptide binding and extracellular matrix modulation. Differentially expressed transposable elements in many subfamilies reflected the change of corresponding regional epigenomic signatures. Interestingly, DNMT3L protein is not expressed in cultured MSCs. Therefore, the observed defects in Dnmt3l KO MSCs are unlikely a direct effect from missing DNMT3L in this cell type; instead, we hypothesized them as an outcome of the pre-deposited epigenetic signatures from the DNMT3L-expressing progenitors. We observed that 24 out of the 107 upregulated DEGs in Dnmt3l KO MSCs were hypermethylated in their gene bodies of DNMT3L knock-down ES cells. Among these 24 genes, some were associated with skeletal development or homeostasis. However, we did not observe reduced bone development, or reduced bone density through aging in vivo. The stronger phenotype in vitro suggested the involvement of potential spreading and amplification of the pre-deposited epigenetic defects over passages, and the contribution of oxidative stress during in vitro culture. We demonstrated that transient deficiency of epigenetic co-factor in ES cells or progenitor cells caused compromised property in differentiating cells much later. In order to facilitate safer practice in cell-based therapy, we suggest more in-depth examination shall be implemented for cells before transplantation, even on the epigenetic level, to avoid long-term risk afterward.

MAP4K3/GLK Promotes Lung Cancer Metastasis by Phosphorylating and Activating IQGAP1.

Overexpression of the serine/threonine kinase GLK/MAP4K3 in human lung cancer is associated with poor prognosis and recurrence, however, the role of GLK in cancer recurrence remains unclear. Here, we report that transgenic GLK promotes tumor metastasis and cell migration through the scaffold protein IQ motif-containing GTPase-activating protein 1(IQGAP1). GLK transgenic mice displayed enhanced distant metastasis. IQGAP1 was identified as a GLK-interacting protein; two proline-rich regions of GLK and the WW domain of IQGAP1 mediated this interaction. GLK and IQGAP1 colocalized at the leading edge including filopodia and lamellipodia of migrating cells. GLK directly phosphorylated IQGAP1 at Ser-480 enhancing Cdc42 activation and subsequent cell migration. GLK-induced cell migration and lung cancer metastasis were abolished by IQGAP1 depletion. Consistently, human NSCLC patient tissues displayed increased phospho-IQGAP1, which correlated with poor survival. Collectively, GLK promotes lung cancer metastasis by binding to, phosphorylating, and activating IQGAP1. SIGNIFICANCE: These findings show the critical role of the GLK-IQGAP cascade in cell migration and tumor metastasis, suggesting it as a potential biomarker and therapeutic target for lung cancer recurrence.

[Project to Increase the Usage Rate of iCKD Application Mobile Healthcare on Chronic Kidney Disease Patients].

BACKGROUND & PROBLEMS: In recent years, improved mobile capacities and mobile-device computing capabilities as well as a maturing mobile-communications infrastructure have combined to promote the development and widespread use of mobile healthcare applications. Mobile healthcare supports the self-management of chronic diseases, enhances healthcare quality, and reduces medical costs. Due to the low rate of iCKD usage in our hospital, we set up a project team that was tasked to improve the rate of iCKD usage among chronic disease patients. PURPOSE: To improve the iCKD usage rate from the current 5.8% to 9.3%. RESOLUTIONS: Questionnaire-based survey results indicated that the main reasons for the low iCKD usage rate in our hospital were: negative attitudes toward iCKD as a helpful tool in disease management, lack of awareness of the importance of using iCKD, unfamiliarity with how to operate smartphone applications, low numbers of iCKD physician referrals for patients, and slow Internet speeds. The improvement strategy included providing instructions on iCKD use, organizing a practical learning program, designing and printing a mobile healthcare referral form, and holding related events. RESULTS: The rate of iCKD usage increased to 21.3% after the intervention. CONCLUSIONS: The project team successfully increased the iCKD usage rate by getting more patients involved in mobile healthcare, which is expected to have a positive impact on the success of patient self-management.

Spatially and temporally optimized video stabilization.

Properly handling parallax is important for video stabilization. Existing methods that achieve the aim require either 3D reconstruction or long feature trajectories to enforce the subspace or epipolar geometry constraints. In this paper, we present a robust and efficient technique that works on general videos. It achieves high-quality camera motion on videos where 3D reconstruction is difficult or long feature trajectories are not available. We represent each trajectory as a Bézier curve and maintain the spatial relations between trajectories by preserving the original offsets of neighboring curves. Our technique formulates stabilization as a spatial-temporal optimization problem that finds smooth feature trajectories and avoids visual distortion. The Bézier representation enables strong smoothness of each feature trajectory and reduces the number of variables in the optimization problem. We also stabilize videos in a streaming fashion to achieve scalability. The experiments show that our technique achieves high-quality camera motion on a variety of challenging videos that are difficult for existing methods.