Potential regulatory role of the Nrf2/HMGB1/TLR4/NF-κB signaling pathway in lupus nephritis.

OBJECTIVES: Systemic lupus erythematosus is an autoimmune disease that involves multiple organ systems. One of its major complications, lupus nephritis (LN), is associated with a high mortality rate, and children-onset LN have a more severe course and worse prognosis than adults. Oxidative stress and inflammatory responses are involved in LN development and pathogenesis. Thus, this study aimed to explore the role of signaling regulation of the Nrf2/HMGB1/TLR/NF-κB pathway in LN pathogenesis and unravel the expression of TLR4+CXCR4+ plasma cells subset (PCs) in LN. METHODS: C57BL/6 and MRL/lpr mice were divided into four groups: control, model, vector control, and Nrf2 overexpression groups. The vector control and Nrf2 overexpression groups were injected with adenoviral vectors into the kidney in situ. Pathological changes in kidney tissues were observed by hematoxylin-eosin staining. The expression of Nrf2, HMGB1, TLR4, NF-κB, and downstream inflammatory factors in kidney samples was analyzed by quantitative polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay. The ratios of TLR4+CXCR4+ PC subsets in the blood and kidneys of mice were determined by flow cytometry. RESULTS: In MRL/lpr mice, Nrf2 was downregulated while HMGB1/TLR4/NF-κB pathway proteins were upregulated. Nrf2 overexpression decreased the expression of HMGB1, TLR4, NF-κB, and its downstream inflammatory cytokines (IL-1ß and TNFα). These cytokines were negatively correlated with an increase in Nrf2 content. PC and TLR4 + CXCR4 + PCs in the blood and kidney samples were significantly increased in MRL/lpr mice; however, they were decreased upon Nrf2 overexpression. CONCLUSION: This study showed severe kidney injury in an LN mouse model and an increased ratio of TLR4 + CXCR4 + PCs. Furthermore, we observed that Nrf2 regulates LN immune response through the Nrf2/HMGB1/TLR4/NF-κB pathway, which can be considered an important target for LN treatment. The clinical value of the findings of our study requires further investigation.

Han family with essential tremor caused by the P421L variant of the TENM4 gene in China.

BACKGROUND: Essential tremor (ET) is an autosomal dominant inheritance disorder. Mutations in fusion sarcoma (FUS), mitochondrial serine peptidase 2 (HTRA2), teneurin transmembrane protein 4 (TENM4), sortilin1 (SORT1), SCN11A, and notch2N-terminal-like (NOTCH2NLC) genes are associated with familial ET. METHODS: A proband with ET was tested using whole-exome sequencing and repeat-primed polymerase chain reaction. Subsequently, the family members were screened for the suspected mutation, and the results were verified using Sanger sequencing. The relationship between pedigree and phenotype was also analyzed, and structural and functional changes in the variants were predicted using bioinformatics analysis. RESULTS: In a family with ET, the proband (III4) and the proband's father (II1), grandfather (I1), uncle (II2), and cousin (III5) all presented with involuntary tremors of both upper limbs. The responsible mutation was identified as TENM4 c.1262C > T (p.P421L), which showed genetic co-segregation in the family survey. AlphaFold predicted a change in the spatial position of TENM4 after the P421L mutation, which may have affected its stability. AlphaFold also predicted P421L to be a deleterious variation, which would lead to lower degrees of freedom of the TENM4 protein, thereby affecting the protein's structure and stability. According to the bioinformatics analysis, TENM4 (p.P421L) may reduce the signal reaching the nucleus by affecting the expression of TENM4 messenger RNA (mRNA), thereby impairing the normal oligodendrocyte differentiation process and leading to impaired myelination. CONCLUSION: This study revealed that the TENM4 (p.P421L) pathogenic missense variation was responsible for ET in the proband.

Splenic Artery Embolization and Splenectomy for Spontaneous Rupture of Splenic Hemangioma and Its Imaging Features.

Background: Spontaneous splenic rupture (SSR) is a rare, often life-threatening, acute abdominal injury that requires immediate diagnosis and early treatment. SSR is mainly treated surgically or conservatively. A few cases of interventional embolization for SSRs have been reported. Case Presentation: A 30-year-old male patient complaining mainly of left upper abdominal pain underwent emergency abdominal computed tomography (CT) and showed enlargement of the spleen with a massive mixed-density shadow approximately 10.0 × 8.0 × 12.5 cm in size. The boundary was unclear and showed obvious progressive enhancement. Considering the intrasplenic tumor lesions with rupture and hemorrhage, the possibility of vascular tumors was high, with intraperitoneal blood and fluid accumulation. Digital subtraction angiography of the splenic arteriography and embolization of the ruptured splenic artery branches were performed. Postoperative hemoglobin progressively decreased, inflammatory indicators, such as white blood cell counts, procalcitonin (PCT), and C-reactive protein (CRP) were significantly increased, and 2 days after embolization, the patient developed severe hypoxemia, shock, pulmonary edema, and acute respiratory distress syndrome. CT re-examination 9 days after embolization showed reduced lesion absorption. After stabilization of the condition, splenectomy was performed, and postoperative platelet count increase, anticoagulant improvement, and discharge were observed. Postoperative pathological examination revealed extensive hemorrhage and necrosis, vascular tissue with abnormal hyperplasia in the surrounding area, vascular tissue in the bleeding area and outer wall (elastic fiber staining +), and local myofibroblast hyperplasia. Immunohistochemistry showed actin (SM +) and Ki67 (10% +). Conclusion: SSR caused by splenic hemangioma is rare, and the choice between surgical treatment or splenic artery embolization remains dependent on the patient's hemodynamic stability and imaging findings.

A Primary Extraskeletal Osteosarcoma of the Spleen: Rare Case Report.

Extraskeletal osteosarcoma is a rare malignant soft-tissue sarcoma that is difficult to diagnose. Surgery is a common treatment, although chemotherapy and radiotherapy are also used. Patients at risk of bleeding can undergo embolization combined with resection. The occurrence of primary splenic extraskeletal osteosarcoma in humans does not seem to have been reported in the literature. A 50-year-old woman who complained of pain in the left upper abdomen for 1 day was initially diagnosed with "splenic hemangioma with a high possibility of rupture and bleeding" and urgently underwent digital subtraction angiography, combined with splenic arteriography and embolization. Abdominal pain worsened 2 days postoperatively, with a hemoglobin level of 106.0 g/L. Consequently, emergency laparotomy combined with splenectomy was performed. The clinical and imaging features, pathological diagnosis, and embolization treatment of this case were analyzed retrospectively. CT of the upper abdomen revealed splenomegaly, an irregular low-density shadow in the spleen, and a flake-like calcification in the lateral margin of the left kidney. Nuclear MRI of the upper abdomen showed splenomegaly and a mass (approximately 8.4 cm × 5.7 cm × 6.3 cm) below the spleen with clear boundaries-this exhibited an uneven signal, which was slightly low in T1-weighted imaging (T1WI) and slightly high in T2-weighted imaging (T2WI). Several small cystic lesions or cystic cavities were observed in the mass, which exhibited a longer T2 signal. During the enhanced scan, the signal of the lesion showed progressive enhancement, and the enhancement range increased in the delayed phase scan, as well as a hematoma below the spleen capsule and calcification below the lesion (nodular T1WI/T2WI hypointense, approximately 3.3 cm × 3.6 cm). Postoperative biopsy pathology showed splenic soft tissue tumor: at low magnification, the multinucleated giant cells were scattered; at medium magnification, osteoclast-like multinucleated giant cells were observed; and at high magnification, lace- or grid-like tumor osteogenesis was detected. Immunohistochemistry showed that the expression of CD31, CD34, F8, s-100, desmin, SMA, and CD99 was negative, whereas the expression of ß-catenin, BCL-2, SATB-2, and P16 was positive. CD68 and MDM-2 showed low expression, while 50% of the cells were positive for Ki-67 expression. No abnormal concentration of radioactivity was found on the bone scan with 99mTc-MDP after the operation, further ruling out the occurrence of other bone tumors. The patient was diagnosed with primary extraskeletal osteosarcoma. It is necessary for multidisciplinary teams to diagnose malignant extraskeletal osteosarcomas.