Fluoxetine partially alleviates inflammation in the kidney of socially stressed male C57 BL/6 mice.

Stress-related illnesses are linked to the onset and progression of renal diseases and depressive disorders. To investigate stress-induced changes in the renal transcriptome associated with the development of depressive behaviors, we generated here a chronic social defeat stress (CSDS) model of C57 BL/6 male mice and then performed RNA sequencing of the kidneys to obtain an inflammation-related transcriptome. Administration of the antidepressant drug fluoxetine (10 mg·kg-1 ·day-1 ) during CSDS induction could partially alleviate renal inflammation and reverse CSDS-induced depression-like behaviors. Moreover, fluoxetine also modulated gene expression of stress-related hormone receptors, including prolactin and melanin-concentrating hormone. These results suggest that CSDS can induce gene expression changes associated with inflammation in the kidney of C57 BL/6 male mice, and this inflammation can be treated effectively by fluoxetine.

Identification of hematopoietic stem cells residing in the meninges of adult mice at steady state.

Steady-state extramedullary hematopoiesis during adulthood is an emerging field of great interest. The meninges contain both innate and adaptive immune cells, which provide immunosurveillance of the central nervous system (CNS). Hematopoietic progenitors that give rise to meningeal immune cells remain elusive. Here, we report that steady-state meninges of adult mice host hematopoietic stem cells (HSCs), as defined by long-term, efficient, multi-lineage reconstitution and self-renewal capacity in the meninges, blood, spleen, and bone marrow of sublethally irradiated adult recipients. HSCs lodge in the meninges after birth with local expression of pro-hematopoietic niche factors. Meningeal HSCs are locally maintained in homeostasis and get replenished from the blood only when the resident pool is reduced. With a tissue-specific expression profile, meningeal HSCs can provide the CNS with a constant supply of leukocytes more adapted to local microenvironment.

Single-cell RNA-seq recognized the initiator of epithelial ovarian cancer recurrence.

Epithelial ovarian cancers (EOCs) are sensitive to chemotherapy but will ultimately relapse and develop drug resistance. The origin of EOC recurrence has been elusive due to intra-tumor heterogeneity. Here we performed single-cell RNA sequencing (scRNA-seq) in 13,369 cells from primary, untreated peritoneal metastasis, and relapse tumors. We used time-resolved analysis to chart the developmental sequence of cells from the metastatic tumors, then traced the earliest replanting cells back to the primary tumors. We discovered seven distinct subpopulations in primary tumors where the CYR61+ "stress" subpopulation was identified as the relapse-initiators. Furthermore, a subpopulation of RGS5+ cancer-associated fibroblasts (CAFs) was found to strongly support tumor metastasis. The combined CYR61/RGS5 expression scores significantly correlated with the relapse-free-survival of EOC patients and can be used as predictors of EOC recurrence. Our study provides insights into the mechanism of EOC recurrence and presents CYR61+ relapse-initiating cells as potential therapeutic targets to prevent EOC relapse.

Single-cell EMT-related transcriptional analysis revealed intra-cluster heterogeneity of tumor cell clusters in epithelial ovarian cancer ascites.

Malignant ascites of epithelial ovarian cancer is a metastatic tumor microenvironment in which large amounts of disseminated single cells (DSCs) and disseminated tumor cell clusters (DTCCs) are commonly observed. The tumor cell clusters are known to be more aggressive than individual tumor cells in cancer metastasis; however, little is known about the mechanism. Applying single-cell epithelial-to-mesenchymal transition (EMT)-related transcriptional analysis in 120 DSCs and 195 intra-cluster cells from 27 DTCCs, we demonstrated that DTCCs were heterogeneous cellular units comprised of epithelial tumor cells, leukocytes, and cancer-associated fibroblasts (CAFs). Through the analysis of intra-DTCC heterogeneity, we identified that CAFs induced EMT of tumor cells via TGFß signaling within the DTCC microenvironment. The activation of EMT program, in particular the upregulation of ZEB2, enabled the acquisition of additional chemoresistance and metastasis abilities of the intra-DTCC tumor cells, which resulted in the aggressiveness of DTCCs.

A 90-day toxicology study of meat from genetically modified sheep overexpressing TLR4 in Sprague-Dawley rats.

Genetic modification offers alternative strategies to traditional animal breeding. However, the food safety of genetically modified (GM) animals has attracted increasing levels of concern. In this study, we produced GM sheep overexpressing TLR4, and the transgene-positive offsprings (F1) were confirmed using the polymerase chain reaction (PCR) and Southern blot. The expression of TLR4 was 2.5-fold compared with that of the wild-type (WT) sheep samples. During the 90-day safety study, Sprague-Dawley rats were fed with three different dietary concentrations (3.75%, 7.5%, and 15% wt/wt) of GM sheep meat, WT sheep meat or a commercial diet (CD). Blood samples from the rats were collected and analyzed for hematological and biochemical parameters, and then compared with hematological and biochemical reference ranges. Despite a few significant differences among the three groups in some parameters, all other values remained within the normal reference intervals and thus were not considered to be affected by the treatment. No adverse diet-related differences in body weights or relative organ weights were observed. Furthermore, no differences were observed in the gross necropsy findings or microscopic pathology of the rats whose diets contained the GM sheep meat compared with rats whose diets contained the WT sheep meat. Therefore, the present 90-day rat feeding study suggested that the meat of GM sheep overexpressing TLR4 had no adverse effect on Sprague-Dawley rats in comparison with WT sheep meat. These results provide valuable information regarding the safety assessment of meat derived from GM animals.