Subtle Structural Differences Affect the Inhibitory Potency of RGD-Containing Cyclic Peptide Inhibitors Targeting SPSB Proteins.

The SPRY domain-containing SOCS box proteins SPSB1, SPSB2, and SPSB4 utilize their SPRY/B30.2 domain to interact with a short region in the N-terminus of inducible nitric oxide synthase (iNOS), and recruit an E3 ubiquitin ligase complex to polyubiquitinate iNOS, resulting in the proteasomal degradation of iNOS. Inhibitors that can disrupt the endogenous SPSB-iNOS interactions could be used to augment cellular NO production, and may have antimicrobial and anticancer activities. We previously reported the rational design of a cyclic peptide inhibitor, cR8, cyclo(RGDINNNV), which bound to SPSB2 with moderate affinity. We, therefore, sought to develop SPSB inhibitors with higher affinity. Here, we show that cyclic peptides cR7, cyclo(RGDINNN), and cR9, cyclo(RGDINNNVE), have ~6.5-fold and ~2-fold, respectively, higher SPSB2-bindng affinities than cR8. We determined high-resolution crystal structures of the SPSB2-cR7 and SPSB2-cR9 complexes, which enabled a good understanding of the structure-activity relationships for these cyclic peptide inhibitors. Moreover, we show that these cyclic peptides displace full-length iNOS from SPSB2, SPSB1, and SPSB4, and that their inhibitory potencies correlate well with their SPSB2-binding affinities. The strongest inhibition was observed for cR7 against all three iNOS-binding SPSB proteins.

WDFY4 polymorphisms in Chinese patients with anti-MDA5 dermatomyositis is associated with rapid progressive interstitial lung disease.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 antibody positive dermatomyositis (MDA5+DM), is susceptible to development of rapidly progressive interstitial lung disease (RPILD), which has been predominantly reported in East Asia. A Japanese genome-wide study has identified a WDFY4 variant rs7919656 linkage. We sought to evaluate this genetic marker and exploit its possible clinical relevance in Chinese MDA5+DM. METHODS: We genotyped and compared the minor allele A frequency of WDFY4 rs7919656 in patients with MDA5+DM (n = 254) including 190 clinically amyopathic dermatomyositis (CADM), MDA5-DM (n = 53), anti-synthetases syndrome (ASyS, n = 72) and healthy controls (n = 192). Association of the WDFY4 variant with clinical phenotype was evaluated using logistic regression. RESULTS: Although the minor allele A frequencies of WDFY4 rs7919656 in MDA5+DM and CADM were comparable to that in healthy controls, we observed a significant correlation between the WDFY4 variant (GA+AA genotype) and the incidence of RPILD in MDA5+DM (OR: 2.11; 95% CI: 1.21, 3.69; P = 0.007). Moreover, this variant was an independent risk factor for RPILD in multivariate analysis (OR: 4.98; 95% CI: 1.59, 17.19; P = 0.008), along with other well-recognized risk factors, i.e. forced vital capacity % predicted, diffusing capacity for carbon monoxide % predicted, serum ferritin and prednisolone exposure. In addition, this variant was associated with higher expression of WDFY4 in PBMCs of MDA5+DM, especially those with RPILD. WDFY4 overexpression was also observed in lung biopsy of MDA5+DM-RPILD bearing the variant genotype. CONCLUSION: We found that the WDFY4 variant was associated with an increased risk of RPILD, not with disease susceptibility in Chinese MDA5+DM.

One-year renal outcome in lupus nephritis patients with acute kidney injury: a nomogram model.

OBJECTIVE: To develop a short-term renal outcome prediction model for acute kidney injury (AKI) in patients with LN. METHODS: Two lupus AKI cohorts from two independent centres during 2013-2019 were included: a derivation cohort from a rheumatology centre and a validation cohort from a nephrology centre. Clinical characteristics and renal histologic features were obtained. The outcome measurement was the recovery of kidney function within 12 months. Lasso regression was used for feature selection. Prediction models with or without pathology were built and a nomogram was plotted. Model evaluation including calibration curve and decision curve analysis was performed. RESULTS: A total of 130 patients were included in the derivation cohort and 96 patients in the validation cohort, of which 82 and 73 patients received a renal biopsy, respectively. The prognostic nomogram model without pathology included determinants of SLE duration, days from AKI onset to treatment and baseline creatinine level [C-index 0.85 (95% CI 0.78, 0.91) and 0.79 (95% CI 0.70, 0.88) for the two cohorts]. A combination of histologic tubulointerstitial (TI) fibrosis in the nomogram gave an incremental predictive performance (C-index 0.93 vs 0.85; P = 0.039) in the derivation cohort but failed to improve the performance in the validation cohort (C-index 0.81 vs 0.79; P = 0.78). Decision curve analysis suggested clinical benefit of the prediction models. CONCLUSION: The predictive nomogram models might facilitate more accurate management for lupus patients with AKI.

Attaining treat-to-target endpoints with metformin in lupus patients: a pooled analysis.

OBJECTIVES: Low disease activity status and remission are crucial treat-to-target (T2T) endpoints in systemic lupus erythematosus (SLE). To evaluate the efficacy of metformin add-on in attaining T2T among Chinese patients with mild-to-moderate lupus, a post-hoc analysis combining our previous two randomised trials was carried out. METHODS: Data from the open-labeled proof-of-concept trial (ChiCTR-TRC-12002419) and placebo-controlled trial (NCT02741960) were integrated together. Disease flares were compared between patients attaining T2T or not at baseline. The efficacy of metformin versus placebo/nil add-on to standard therapy in SLE patients who did not meet the T2T criteria at baseline was evaluated in terms of attaining T2T at 12-month follow-up. RESULTS: Of 253 SLE patients, 43.8% (n=89) attained T2T at baseline. During the 12 months, 15 patients flared in the T2T group, which was significantly lower than that in the non-T2T group (16.9% vs. 36.0%, p=0.001). For 164 patients who did not meet the T2T criteria at entry, 59.0% and 43.6% of the 78 patients taking metformin in this population attained the lupus low disease activity status (LLDAS) and remission endpoints at last visit, respectively, as compared to 37.2% and 24.4% of the 86 patients in the placebo/nil group (LLDAS p=0.008; remission p=0.013). Over time, metformin helped patients achieving T2T earlier and maintain longer T2T duration over placebo/nil (LLDAS duration: 44.9% vs. 26.4%, p=0.002; remission duration:19.1% vs. 10.7%, p=0.014). CONCLUSIONS: This post-hoc analysis suggested that metformin might be an adjuvant therapy in achieving treat-to-target in SLE patients.

Forced vital capacity predicts the survival of interstitial lung disease in anti-MDA5 positive dermatomyositis: a multi-centre cohort study.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 (MDA5) positive DM is a life-threatening disease often complicated with rapidly progressive interstitial lung disease (ILD). This study aimed to establish and validate a clinical prediction model for 6-month all-cause mortality in Chinese patients with anti-MDA5 positive DM-ILD. METHODS: We conducted a retrospective observational study using a single-centre derivation cohort and a multicentre validation cohort. Hospitalized DM patients with positive anti-MDA5 antibody and ILD course ≤3 months on admission were included. Patients' baseline characteristics were described and compared between the deceased and survivors by univariable Cox regression. Optimal cut-off values were defined by the 'survminer' R package for significant continuous variables. Independent prognostic factors were determined by the final multivariable Cox regression model chosen by backward stepwise algorithm, which could be reproduced in both cohorts. The Kaplan-Meier survival analyses based on the derived predictor were conducted. RESULTS: A total of 184 and 81 eligible patients were included with a cumulative 40.8 and 40.7% 6-month mortality in the derivation and validation cohorts, respectively. Based on multivariable Cox regression, the prognostic factor at baseline was identified and validated as three-category forced vital capacity (FVC)%: FVC% ≥50%, FVC% <50%, unable to perform. This significantly distinguishes three risk stages with mortalities of 15.3, 46.8, 97.4% in the derivation cohort, and 14.9, 58.3, 86.4 in the validation cohort, respectively (all P <0.05). CONCLUSION: The validated FVC%-based categorical predictor in anti-MDA5 positive DM-ILD is helpful for risk stratification in clinical practice and might facilitate cohort enrichment for future trials.

Structural basis for the regulation of inducible nitric oxide synthase by the SPRY domain-containing SOCS box protein SPSB2, an E3 ubiquitin ligase.

Relatively high concentration of nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) in response to a variety of stimuli is a source of reactive nitrogen species, an important weapon of host innate immune defense. The SPRY domain-containing SOCS box protein 2 (SPSB2) is an E3 ubiquitin ligase that regulates the lifetime of iNOS. SPSB2 interacts with the N-terminal region of iNOS via a binding site on the SPRY domain of SPSB2, and recruits an E3 ubiquitin ligase complex to polyubiquitinate iNOS, leading to its proteasomal degradation. Although critical residues for the SPSB2-iNOS interaction have been identified, structural basis for the interaction remains to be explicitly determined. In this study, we have determined a crystal structure of the N-terminal region of iNOS in complex with the SPRY domain of SPSB2 at 1.24 Å resolution. We have resolved the roles of some flanking residues, whose contribution to the SPSB2-iNOS interaction was structurally unclear previously. Furthermore, we have evaluated the effects of SPSB2 inhibitors on NO production using transient transfection and cell-penetrating peptide approaches, and found that such inhibitors can elevate NO production in RAW264.7 macrophages. These results thus provide a useful basis for the development of potent SPSB2 inhibitors as well as recruiting ligands for proteolysis targeting chimera (PROTAC) design.

Crystal structure of the SPRY domain-containing protein 7 reveals unique structural features.

The SPRY/B30.2 domain is one of the most abundant protein domains found in eukaryotes. Vast majority of the SPRY domain-containing proteins are multi-domain proteins. The SPRY domain-containing protein 7 (SPRY7, also named C13orf1, and named chronic lymphocytic leukemia deletion region gene 6 protein, CCLD6, encoded by the spryd7 gene) is the smallest SPRY domain protein in human that does not contain other accessory domains. Here we have determined the crystal structure of human SPRY7 at a resolution of 1.62 Å and found that SPRY7 has some unique structural features that are not present in other previously reported SRPY domain structures. Overall, SPRY7 may represent an evolutionary early version of the SPRY domain, and subsequent loop insertions and expansions, residue substitutions, as well as domain combinations have rendered the SPRY domain versatile binding specificities and broad biological functions. These results serve as a useful basis for a profound characterization of the molecular interactions of SPRY7.

Crystal structure of SPSB2 in complex with a rational designed RGD-containing cyclic peptide inhibitor of SPSB2-iNOS interaction.

SPRY domain-containing SOCS box protein 2 (SPSB2) is a negative regulator of inducible nitric oxide synthase (iNOS) that modulates the lifetime of iNOS and thus the levels of nitric oxide (NO) production. Inhibitors that can disrupt the endogenous SPSB2-iNOS interaction and augment NO production have potential as novel antimicrobial and anticancer drugs. In this study, we have designed a cyclic peptide (cR8), containing an RGD motif and the SPSB2 binding motif (DINNNV). ITC and chemical shift perturbation showed that cR8 binds to the iNOS binding site on SPSB2 with a Kd of 671 nM, and saturation transfer difference NMR showed that cR8 binds to αvß3 integrin-expressing cells. Moreover, we determined the crystal structure of SPSB2 in complex with cR8, at a resolution of 1.34 Å. cR8 forms extensive hydrogen bonding with SPSB2 residues, but loss of an intramolecular hydrogen bond that is present in SPSB2-bound iNOS peptide may destabilize the bound conformation of cR8 and lead to a gentle reduction in SPSB2 binding affinity. These results serve as a useful basis for designing site-directed SPSB2 inhibitors in the future.

Correction: nBu4NI-Mediated oxidation of methyl ketones to α-ketoamides: using ammonium, primary and secondary amine-salt as an amine moiety.

Correction for 'nBu4NI-Mediated oxidation of methyl ketones to α-ketoamides: using ammonium, primary and secondary amine-salt as an amine moiety' by Dan Wang et al., Org. Biomol. Chem., 2017, 15, 3427-3434.

nBu4NI-Mediated oxidation of methyl ketones to α-ketoamides: using ammonium, primary and secondary amine-salt as an amine moiety.

Presented here is the first example of synthesizing an array of primary-, secondary-, and tertiary-α-ketoamides with a non-metal catalyst nBu4NI from methyl ketones and inexpensive readily available amine/ammonium salts; the reactions proceeded smoothly under mild conditions, TBHP was used as an oxidant and the corresponding α-ketoamides were afforded in moderate to excellent yields.

The investigation of ion association characteristics in lanthanum sulfate solution by the density functional theory and molecular dynamics simulations.

The ion association behavior in aqueous lanthanum sulfate solutions was investigated using density functional theory (DFT). The structures and properties of [La(SO4)m·(H2O)n](3-2m) clusters, where m = 1 to 3 and n = 1 to 9, were examined at the PBE0/6-311+G(d, p) level. The results show that Lanthanum sulfate hydrated clusters exist in the aqueous solution's microscopic state of contact ion pairs (CIP). [La(SO4)(H2O)n]+ and [La(SO4)2·(H2O)n]-, and [La(SO4)3·(H2O)n]3- clusters approximately reach the saturation of the first water shell at n = 7 and 6 and 3. [La(SO4)2·(H2O)6]- and [La(SO4)3·(H2O)3]3- clusters have lower binding energy than [LaSO4·(H2O)n]+. This indicates that lanthanum sulfate tends to aggregate in an aqueous solution. Compared to the gas-phase cluster structures, the distance of R(La-O)H2O expands in the PCM solvent model, while R(La-O)SO4 contracts. The hydration energy of LaSO4·(H2O)7, La(SO4)2·(H2O)6, and La(SO4)3·(H2O)3 were -76.5, -54.1 and -332.0 kcal/mol, respectively. The molecular dynamics simulation results show that La is more inclined to coordinate with sulfate's oxygen than water's oxygen, and the coordination number of water around La3+ is 6.075. These results are consistent with the calculated results by DFT.

Cardiovascular risk factors and complications in patients with systemic lupus erythematosus with and without nephritis: a systematic review and meta-analysis.

INTRODUCTION: It remains unclear how the presence of renal involvement will affect the cardiovascular (CV) risk factors and complications in patients with SLE. METHODS: We conducted a systematic review and meta-analysis using PubMed, EMBASE, MEDLINE and Scopus to identify studies published between 1947 and 2022 that evaluate the CV risk factors and complications in patients with SLE with or without lupus nephritis (LN). RESULTS: 58 studies were evaluated, with 22 two-arm studies (n=8675) included in two-arm meta-analysis and 45 studies (n=385 315) included in proportional meta-analysis. Patients with SLE with LN showed significantly higher risk of hypertension (HT) (OR=4.93, 95% CI=3.17 to 7.65, p<0.00001, I2=56%), hyperlipidaemia (OR=11.03, 95% CI=4.20 to 28.95, p<0.00001, I2=0%) and diabetes mellitus (DM) (OR=1.88, 95% CI=1.09 to 3.25, p=0.02, I2=32%) compared with those without LN. Patients with LN showed numerically higher prevalence of myocardial infarction (OR=1.35, 95% CI=0.53 to 3.45, p=0.52, I2=78%) and cerebrovascular accident (OR=1.64, 95% CI=0.79 to 3.39, p=0.27, I2=23%) than general patients with SLE. The incidence rates of CV mortality are also increased in patients with SLE with LN compared with those without LN (11.7/1000 patient-years vs 3.6/1000 patient-years). CONCLUSION: Patients with SLE with LN show increased risk of CV risk factors including DM, HT and hyperlipidaemia. Early identification and optimal control of these CV risk factors may reduce the risk of CV disease and other non-CV complications. PROSPERO REGISTRATION NUMBER: CRD42022314682.

Magnesium promotes vascularization and osseointegration in diabetic states.

Diabetes has long been considered a risk factor in implant therapy and impaired wound healing in soft and hard oral tissues. Magnesium has been proved to promote bone healing under normal conditions. Here, we elucidate the mechanism by which Mg2+ promotes angiogenesis and osseointegration in diabetic status. We generated a diabetic mice model and demonstrated the alveolar bone healing was compromised, with significantly decreased angiogenesis. We then developed Mg-coating implants with hydrothermal synthesis. These implants successfully improved the vascularization and osseointegration in diabetic status. Mechanically, Mg2+ promoted the degradation of Kelch-like ECH-associated protein 1 (Keap1) and the nucleation of nuclear factor erythroid 2-related factor 2 (Nrf2) by up-regulating the expression of sestrin 2 (SESN2) in endothelial cells, thus reducing the elevated levels of oxidative stress in mitochondria and relieving endothelial cell dysfunction under hyperglycemia. Altogether, our data suggested that Mg2+ promoted angiogenesis and osseointegration in diabetic mice by regulating endothelial mitochondrial metabolism.

Early infiltrating NKT lymphocytes attenuate bone regeneration through secretion of CXCL2.

Trauma rapidly mobilizes the immune response of surrounding tissues and activates regeneration program. Manipulating immune response to promote tissue regeneration shows a broad application prospect. However, the understanding of bone healing dynamics at cellular level remains limited. Here, we characterize the landscape of immune cells after alveolar bone injury and reveal a pivotal role of infiltrating natural killer T (NKT) cells. We observe a rapid increase in NKT cells after injury, which inhibit osteogenic differentiation of mesenchymal stem cells (MSCs) and impair alveolar bone healing. Cxcl2 is up-regulated in NKT cells after injury. Systemic administration of CXCL2-neutralizing antibody or genetic deletion of Cxcl2 improves the bone healing process. In addition, we fabricate a gelatin-based porous hydrogel to deliver NK1.1 depletion antibody, which successfully promotes alveolar bone healing. In summary, our study highlights the importance of NKT cells in the early stage of bone healing and provides a potential therapeutic strategy for accelerating bone regeneration.

METTL3 regulates cartilage development and homeostasis by affecting Lats1 mRNA stability in an m6A-YTHDF2-dependent manner.

Cartilage maintains the structure and function of joints, with disturbances leading to potential osteoarthritis. N6-methyladenosine (m6A), the most widespread post-transcriptional modification in eukaryotes, plays a crucial role in regulating biological processes. While current research has indicated that m6A affects the progression of osteoarthritis, its function in the development and homeostasis of articular cartilage remains unclear. Here we report that Mettl3 deficiency in chondrocytes leads to mandibular condylar cartilage morphological alterations, early temporomandibular joint osteoarthritis, and diminished adaptive response to abnormal mechanical stimuli. Mechanistically, METTL3 modulates Lats1 mRNA methylation and facilitates its degradation in an m6A-YTHDF2-dependent manner, which subsequently influences the degradation and nuclear translocation of YAP1. Intervention with the Hippo pathway inhibitor XMU-MP-1 alleviates condylar abnormality caused by Mettl3 knockout. Our findings demonstrate the role of METTL3 in cartilage development and homeostasis, offering insights into potential treatment strategies for osteoarthritis.

Relationship between the evaluation of agricultural scientific and technological innovation capacity and the influencing factors of green agriculture.

China has limited arable land area, and its output value is increased with enhanced agricultural inputs such as machinery, irrigation, fertilizers, and pesticides. However, this mode is accompanied by an increase in agricultural carbon emissions. With the aim to further examine the driving effect of scientific and technological innovation on economic growth and green agriculture, this study uses the Solow growth model coupled with the Cobb-Douglas production function and vector autoregressive models. Then, the agricultural scientific and technological innovation capacity in Guangdong Province during 2006-2020 is evaluated by using the contribution rate of agricultural scientific and technological progress (ASTP) as the assessment index. In addition, the carbon footprints of green agricultural indexes such as machinery, irrigation, fertilizers, and pesticides are measured to analyze the relationship between green agriculture and agricultural scientific and technological innovation capacity. Results demonstrate the gradual increase in the contribution rate of ASTP in Guangdong Province. During the 11th, 12th, and 13th Five-Year Plan periods, the rates were 65.09%, 65.94%, and 70.40%, respectively, indicating that the agricultural scientific and technological innovation ability constantly improved. Among the indexes of green agriculture, the carbon footprints of machinery have a significant impact on agricultural scientific and technological innovation, which is quickly transformed into machinery. Such innovation requires the driving force of science and technology itself, which have relatively significant and rapid effects. On the basis of the results, corresponding policy suggestions are proposed: increasing investments in scientific and technological innovation in the agricultural field, vigorously developing new energy-saving and emission reduction products and processes for fertilizers, and increasing the research and promotion of agricultural machinery. The proposed method provides good prospects for the development of agricultural production towards mechanization, intelligence, efficiency, and greenness.

Analysis of microRNA-199a-3p expression in CD4+ T cells of systemic lupus erythematosus.

OBJECTIVES: Accumulating evidence have suggested microRNAs (miRNAs) play important roles in the pathogenesis of systemic lupus erythematosus (SLE). Here we aimed to explore aberrant expression of miRNAs in CD4+ T cells from SLE patients and their potential function in SLE pathogenesis. METHODS: First, next-generation sequencing was performed on CD4+ T cells from four SLE patients and three healthy controls (HCs). Candidate miRNAs were then validated in CD4+ T cells from 97 patients with SLE, 16 patients with rheumatoid arthritis, and 12 HCs using qRT-PCR. Then the relationship between the candidate miRNA and clinical characteristics was analyzed. Bioinformatics analysis and validation of the target genes of the candidate miRNA were performed. RESULTS: A total of 66 upregulated miRNAs and 70 downregulated miRNAs were found between SLE and normal CD4+ T cells samples. miR-199a-3p was identified significant upregulation in the CD4+ T cells of lupus patients. High expression of miR-199a-3p was correlated with several clinical characteristics including low C3 level, positive anti-dsDNA antibody, high ESR level, active lupus nephritis, and active disease activity. When distinguishing active LN from non-LN or active lupus from stable lupus, the AUCs of miR-199a-3p were 0.68 and 0.70, respectively. And the expression of miR-199a-3p, involved in JAK-STAT signaling pathway, was negatively correlated with the STAM expression in CD4+ T cells of SLE. CONCLUSION: Our study suggested a novel and promising role of miR-199a-3p in CD4+ T cells for SLE. Further studies are needed to precisely determine the function of miR-199a-3p in this disease. Key Points • Aberrant expression of miRNAs in CD4+ T cells and their potential function in SLE pathogenesis remained unclear. • miR-199a-3p in CD4+ T cells plays a novel role in the pathogenesis of SLE and serves as a potential target for SLE.

Two clusters of systemic lupus erythematosus patients with muscle involvement in a Chinese cohort.

OBJECTIVES: This study aimed to depict the clinical features, including myositis specific or associated antibody (MSA/MAA) profile of systemic lupus erythematosus (SLE) patients with muscle involvement in a Chinese cohort. METHODS: We retrospectively studied a cohort of 1696 SLE inpatients and screened for concurrent myositis features from January 2013 to June 2021. Propensity score matching was applied to enroll controls without myositis features from our cohort. Demographic, clinical and laboratory variables were collected. MSA/MAA panels containing 16 autoantibodies (TIF1-γ, MDA5, NXP2, Mi-2α/ß, SAE1, Jo-1, PL-7, PL-12, EJ, OJ, SRP, HMGCR, cN-1A, PM-Scl75/100, Ku and Ro52) were tested by line-blotting assay. Binary logistic regression and K-means clustering were applied. RESULTS: Forty-one of 1696 (2.42%) SLE patients in our SLE inpatient cohort showed features of myositis. Binary logistic regression revealed that new-onset SLE (odds ratio [OR] = 4.77, 95% CI = 1.10-20.57), interstitial lung disease (ILD) (OR = 10.07, 95% CI = 1.65-61.51), positive anti-U1RNP antibody (OR = 4.38, 95% CI = 1.08-17.75), and Raynaud's phenomenon (OR = 7.94, 95% CI = 1.41-44.69) were associated with muscle involvement. Except for anti-Ro52 (50%), anti-Ku antibody (38.2%) was the next frequently detected MSA/MAA in the panel, followed by anti-NXP2 antibody (11.8%). It was noteworthy that multiple MSA/MAAs (≥2, excluding anti-Ro52) coexisted in 9 patients. Patients with myositis features were clustered into 2 subgroups. Cluster 1 was characterized by anti-Ku or anti-Ro52 with high SLE Disease Activity Index, whereas cluster 2 presented with anti-U1RNP, Raynaud's phenomenon and pulmonary arterial hypertension resembling mixed connective tissue disease. CONCLUSION: In our Chinese SLE inpatient cohort, muscle involvement was infrequent. Nevertheless, distinct features in these SLE patients deserve further study.

Four trajectories of 24-hour urine protein levels in real-world lupus nephritis cohorts.

OBJECTIVES: A 24-hour urine protein (24hUP) is a key measurement in the management of lupus nephritis (LN); however, trajectories of 24hUP in LN is poorly defined. METHODS: Two LN cohorts that underwent renal biopsies at Renji Hospital were included. Patients received standard of care in a real-world setting and 24hUP data were collected over time. Trajectory patterns of 24hUP were determined using the latent class mixed modelling (LCMM). Baseline characters were compared among trajectories and multinomial logistic regression was used to determine independent risk factors. Optimal combinations of variables were identified for model construction and user-friendly nomograms were developed. RESULTS: The derivation cohort composed of 194 patients with LN with 1479 study visits and a median follow-up of 17.5 (12.2-21.7) months. Four trajectories of 24hUP were identified, that is, Rapid Responders, Good Responders, Suboptimal Responders and Non-Responders, with the KDIGO renal complete remission rates (time to complete remission, months) of 84.2% (4.19), 79.6% (7.94), 40.4% (not applicable) and 9.8% (not applicable), respectively (p<0.001). The 'Rapid Responders' distinguish itself from other trajectories and a nomogram, composed of age, systemic lupus erythematosus duration, albumin and 24hUP yielded C-indices >0.85. Another nomogram to predict 'Good Responders' yielded C-indices of 0.73~0.78, which composed of gender, new-onset LN, glomerulosclerosis and partial remission within 6 months. When applied to the validation cohort with 117 patients and 500 study visits, nomograms effectively sorted out 'Rapid Responders' and 'Good Responders'. CONCLUSION: Four trajectories of LN shed some light to guide the management of LN and further clinical trials design.

Schwann Cells Contribute to Alveolar Bone Regeneration by Promoting Cell Proliferation.

The plasticity of Schwann cells (SCs) following nerve injury is a critical feature in the regeneration of peripheral nerves as well as surrounding tissues. Here, we show a pivotal role of Schwann cell-derived cells in alveolar bone regeneration through the specific ablation of proteolipid protein 1 (Plp)-expressing cells and the transplantation of teased nerve fibers and associated cells. With inducible Plp specific genetic tracing, we observe that Plp+ cells migrate into wounded alveolar defect and dedifferentiate into repair SCs. Notably, these cells barely transdifferentiate into osteogenic cell lineage in both SCs tracing model and transplant model, but secret factors to enhance the proliferation of alveolar skeletal stem cells (aSSCs). As to the mechanism, this effect is associated with the upregulation of extracellular matrix (ECM) receptors and receptor tyrosine kinases (RTKs) signaling and the downstream extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway and the phosphoinositide 3-kinase-protein kinase B (PI3K-Akt) pathway. Collectively, our data demonstrate that SCs dedifferentiate after neighboring alveolar bone injury and contribute to bone regeneration mainly by a paracrine function. © 2022 American Society for Bone and Mineral Research (ASBMR).