A potent Henipavirus cross-neutralizing antibody reveals a dynamic fusion-triggering pattern of the G-tetramer.

The Hendra and Nipah viruses (HNVs) are highly pathogenic pathogens without approved interventions for human use. In addition, the interaction pattern between the attachment (G) and fusion (F) glycoproteins required for virus entry remains unclear. Here, we isolate a panel of Macaca-derived G-specific antibodies that cross-neutralize HNVs via multiple mechanisms. The most potent antibody, 1E5, confers adequate protection against the Nipah virus challenge in female hamsters. Crystallography demonstrates that 1E5 has a highly similar binding pattern to the receptor. In cryo-electron microscopy studies, the tendency of 1E5 to bind to the upper or lower heads results in two distinct quaternary structures of G. Furthermore, we identify the extended outer loop ß1S2-ß1S3 of G and two pockets on the apical region of fusion (F) glycoprotein as the essential sites for G-F interactions. This work highlights promising drug candidates against HNVs and contributes deeper insights into the viruses.

Adverse independent prognostic effect of initial lung cancer on female patients with second primary breast cancer: a propensity score-matched study based on the SEER database.

OBJECTIVE: To investigate the prognostic impact of initial lung cancer (LC) on second primary breast cancer after LC (LC-BC) and further develop a nomogram for predicting the survival of patients. METHODS: All patients diagnosed with LC-BC and first primary BC (BC-1) during 2000-2017 were collected from Surveillance, Epidemiology, and End Results database. Pathological features, treatment strategies and survival outcomes were compared between LC-BC and BC-1 before and after propensity score matching (PSM). Cox regression analysis was performed to identify the prognostic factors associated with LC in patients with LC-BC. Additionally, least absolute shrinkage and selection operator regression analysis was used to select clinical characteristics for nomogram construction, which were subsequently evaluated using the concordance index (C-index), calibration curve and decision curve analysis (DCA). RESULTS: 827 429 patients with BC-1 and 1445 patients with LC-BC were included in the analysis. Before and after PSM, patients with BC-1 had a better prognosis than individuals with LC-BC in terms of both overall survival (OS) and breast cancer-specific survival (BCSS). Furthermore, characteristics such as more regional lymph node dissection, earlier stage and the lack of chemotherapy and radiation for LC were found to have a stronger predictive influence on LC-BC. The C-index values (OS, 0.748; BCSS, 0.818), calibration curves and DCA consistently demonstrated excellent predictive accuracy of the nomogram. CONCLUSION: In conclusion, patients with LC-BC have a poorer prognosis than those with BC-1, and LC traits can assist clinicians estimate survival of patients with LC-BC more accurately.

Deep learning-based activity recognition and fine motor identification using 2D skeletons of cynomolgus monkeys.

Video-based action recognition is becoming a vital tool in clinical research and neuroscientific study for disorder detection and prediction. However, action recognition currently used in non-human primate (NHP) research relies heavily on intense manual labor and lacks standardized assessment. In this work, we established two standard benchmark datasets of NHPs in the laboratory: MonkeyinLab (MiL), which includes 13 categories of actions and postures, and MiL2D, which includes sequences of two-dimensional (2D) skeleton features. Furthermore, based on recent methodological advances in deep learning and skeleton visualization, we introduced the MonkeyMonitorKit (MonKit) toolbox for automatic action recognition, posture estimation, and identification of fine motor activity in monkeys. Using the datasets and MonKit, we evaluated the daily behaviors of wild-type cynomolgus monkeys within their home cages and experimental environments and compared these observations with the behaviors exhibited by cynomolgus monkeys possessing mutations in the MECP2 gene as a disease model of Rett syndrome (RTT). MonKit was used to assess motor function, stereotyped behaviors, and depressive phenotypes, with the outcomes compared with human manual detection. MonKit established consistent criteria for identifying behavior in NHPs with high accuracy and efficiency, thus providing a novel and comprehensive tool for assessing phenotypic behavior in monkeys.

EDIL3 and VEGF Synergistically Affect Angiogenesis in Endothelial Cells.

Background: Angiogenesis is one of the histologically predominant characteristics of psoriasis. Vascular endothelial growth factor (VEGF) and epidermal growth factor-like repeats and discoidin I-like domains 3 (EDIL3) have critical effects on angiogenesis. Both these proteins are vital proangiogenic factors in tumor occurrence and progression; however, the relationship between EDIL3 and VEGF with psoriasis remains unclear. Objective: We aimed to elucidate the role of EDIL3 and VEGF and the involved mechanisms in psoriasis-associated angiogenesis. Methods: EDIL3 and VEGF expression in cutaneous tissue was determined by immunohistochemical assay. The effects of EDIL3 on VEGF, VEGFR2, and the growth, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were analyzed by Western blotting assay, cell counting kit-8 assay, Transwell assay, and Matrigel tube formation assay. Results: EDIL3 and VEGF levels in psoriatic lesions significantly increased as compared to those in normal individuals and showed a positive relationship with the Psoriasis Area and Severity Index. The downregulation of EDIL3 decreased VEGF and VEGFR2 expression in HUVECs. Moreover, the decreased expression of EDIL3 and VEGF reduced the growth, invasion, and tube formation abilities of HUVECs, while EDIL3 resistance to VEGF and VEGFR2 was restored by using the EDIL3 recombinant protein. Conclusion: These results suggest that psoriasis is also characterized by EDIL3 and VEGF-mediated angiogenesis. Thus, EDIL3 and VEGF could serve as novel targets for treating psoriasis.

Cryo-EM structure of the plant nitrate transporter AtCLCa reveals characteristics of the anion-binding site and the ATP-binding pocket.

Nitrate is one of the major nitrogen sources for most plants. Chloride channel (CLC) proteins mediate the transport and vacuole storage of nitrate in plants, but the structural basis of nitrate transport by plant CLC proteins remains unknown. Here, we solved the cryo-EM structure of ATP-bound Arabidopsis thaliana CLCa (AtCLCa) at 2.8 Å resolution. Structural comparison between nitrate-selective AtCLCa and chloride-selective CLC-7 reveals key differences in the central anion-binding site. We observed that the central nitrate is shifted by ∼1.4 Å from chloride, which is likely caused by a weaker interaction between the anion and Pro160; the side chains of aromatic residues around the central binding site are rearranged to accommodate the larger nitrate. Additionally, we identified the ATP-binding pocket of AtCLCa to be located between the cytosolic cystathionine ß-synthase domains and the N-terminus. The N-terminus may mediate the ATP inhibition of AtCLCa by interacting with both ATP and the pore-forming transmembrane helix. Together, our studies provide insights into the nitrate selectivity and ATP regulation of plant CLCs.

EDIL3 influenced the αvß3-FAK/MEK/ERK axis of endothelial cells in psoriasis.

One of the earliest events in the development of psoriatic lesion is a vascular network expansion. The abnormal vascular network is associated with increased endothelial cells (ECs) survival, proliferation, adhesion, migration, angiogenesis and permeability in psoriatic lesion. Our previous study demonstrated that epidermal growth factor-like repeats and discoidin I-like domains 3 (EDIL3) derived from psoriatic dermal mesenchymal stem cells (DMSCs) promoted cell-cell adhesion, migration and angiogenesis of ECs, but the molecular mechanism of upstream or downstream has not been explored. So, this study aimed to explore the association between EDIL3 derived from DMSCs (DMSCs-derived EDIL3) and psoriasis-associated angiogenesis. We injected recombinant EDIL3 protein to mouse model of psoriasis to confirm the roles of EDIL3 in psoriasis. Besides, we employed both short-interference RNA (si-RNA) and lentiviral vectors to explore the molecular mechanism of EDIL3 promoting angiogenesis in psoriasis. In vivo, this research found that after injected recombination EDIL3 protein, the epidermis thickness and microvessel density were both elevated. EDIL3 accelerated the process of psoriasis in the IMQ-induced psoriasis-like mouse model. Additionally, we confirmed that in vitro DMSCs-derived EDIL3 is involved in the tube formation of ECs via αvß3-FAK/MEK/ERK signal pathway. This suggested that DMSCs-derived EDIL3 and αvß3-FAK/MEK/ERK signal pathway in ECs play an important role in the pathogenesis of psoriasis. And the modification of DMSCs, EDIL3 and αvß3-FAK/MEK/ERK signal pathway will provide a valuable therapeutic target to control the angiogenesis in psoriasis.

Normal mesenchymal stem cells can improve the abnormal function of T cells in psoriasis via upregulating transforming growth factor-ß receptor.

Psoriasis, a chronic inflammatory skin disease, is a refractory disorder. Previous studies have shown that the imbalance of the T-helper (Th)17/regulatory T cells (Treg) results in the immune imbalance of T cells in psoriatic patients, and that mesenchymal stem cells display an immunosuppressive role by promoting the differentiation of T cells into Treg, leading to a reduction in the proportion of Th17/Treg. Utility of mesenchymal stem cells is becoming a new approach for the treatment of immune disorders. Following co-culture of dermal mesenchymal stromal cells (DMSC) and CD3+ T cells with or without transforming growth factor (TGF)-ß receptor inhibitor, the biological function and relative signal pathway of CD3+ T cells were assessed by flow cytometry, transwell, real-time polymerase chain reaction and western blotting, respectively. Normal DMSC were more potent than psoriatic DMSC in inhibition of CD3+ T-cell proliferation, and stimulation of CD3+ T-cell apoptosis than psoriasis DMSC. Moreover, normal DMSC decreased the ratio of Th17/Treg, while enhancing the immunosuppressive effect of Tregs on effector T cells. However, TGF-ß receptor (TGF-ßR) inhibitor attenuated the effect of normal DMSC on CD3+ T cells and Th17/Treg ratio. Additionally, the normal DMSC were more potent than the psoriatic DMSC in increasing TGF-ß receptors and activation of TGF-ß/SMAD pathway in psoriatic CD3+ T cells. In conclusion, normal DMSC can partially improve the biological function and immunosuppressive ability of psoriatic CD3+ T cells, possibly via upregulating the TGF-ß receptors.

Cryo-EM, Protein Engineering, and Simulation Enable the Development of Peptide Therapeutics against Acute Myeloid Leukemia.

Cryogenic electron microscopy (cryo-EM) has emerged as a viable structural tool for molecular therapeutics development against human diseases. However, it remains a challenge to determine structures of proteins that are flexible and smaller than 30 kDa. The 11 kDa KIX domain of CREB-binding protein (CBP), a potential therapeutic target for acute myeloid leukemia and other cancers, is a protein which has defied structure-based inhibitor design. Here, we develop an experimental approach to overcome the size limitation by engineering a protein double-shell to sandwich the KIX domain between apoferritin as the inner shell and maltose-binding protein as the outer shell. To assist homogeneous orientations of the target, disulfide bonds are introduced at the target-apoferritin interface, resulting in a cryo-EM structure at 2.6 Å resolution. We used molecular dynamics simulations to design peptides that block the interaction of the KIX domain of CBP with the intrinsically disordered pKID domain of CREB. The double-shell design allows for fluorescence polarization assays confirming the binding between the KIX domain in the double-shell and these interacting peptides. Further cryo-EM analysis reveals a helix-helix interaction between a single KIX helix and the best peptide, providing a possible strategy for developments of next-generation inhibitors.

MiR-155 inhibits TP53INP1 expression leading to enhanced glycolysis of psoriatic mesenchymal stem cells.

BACKGROUND: Psoriasis is a systemic disease with multiple associated comorbidities, including metabolic syndrome. Studies suggest that chronic inflammation is a central link between psoriasis and metabolic abnormalities. MiR-155 is a well-known microRNA that plays an important regulatory role in inflammation. Studies from our group and others have demonstrated an upregulation of miR-155 in psoriasis. OBJECTIVES: Here, we investigated whether miR-155 regulates glycolysis of psoriasis and the underlying mechanisms. METHODS: Human dermal-derived mesenchymal stem cells (MSC) were treated with miR-155 mimic or inhibitor, followed by assessments of cells proliferation, metabolism and inflammatory response. Target gene prediction and GO/Pathway analysis were used to screen the putative targets involved in the pathways of metabolism, and verified by dual-luciferase reporter assay. To determine whether TP53INP1/p53 signaling pathway is involved in miR-155-mediated regulation of glycolysis, changes in glycolysis were assessed in psoriatic MSC (PM) with either overexpression or knockdown of TP53INP1, or activation/inhibition of p53 signaling pathway. RESULTS: Our results showed that miR-155 promoted proliferation, migration, inflammatory response and metabolite levels of MSC, while inhibiting apoptosis. In comparison to the MSC from normal subjects, the glycolysis levels were increased in PM. GO and KEGG analyses indicated that TP53INP1 was miR-155 target gene with negative regulation of cellular metabolic process. Moreover, miR-155 promoted glycolysis of PM by negative regulation of TP53INP1/p53 signaling pathway. CONCLUSIONS: MiR-155 could promote glycolysis via targeting of TP53INP1 in PM. These findings suggest a pathogenic role of miR-155 in metabolic abnormalities in psoriasis.

Role of psoriatic keratinocytes in the metabolic reprogramming of dermal mesenchymal stem cells.

BACKGROUND: Psoriasis is an immune-mediated inflammatory skin disease, featured by epidermal hyperproliferation. Psoriasis exhibits metabolic abnormalities, which can further aggravate the condition of psoriasis. The present study aimed to investigate the role of psoriatic keratinocytes (KCs) in the metabolic reprogramming of dermal mesenchymal stem cells (DMSCs). METHODS: Dermal mesenchymal stem cells were cocultured with primary KCs either from psoriatic lesions or from normal subjects using Transwell plate. Glycolysis and mitochondrial metabolism of DMSCs were detected by Seahorse Metabolic Analyzer. Expression levels of proteins were analyzed by Western blotting. DMSCs proliferation was assessed using 5-ethynyl-2'-deoxyuridine assay and Cell Counting Kit-8. RESULTS: In comparison with normal KCs, coculture of psoriatic KCs with DMSCs dramatically increased glycolytic and mitochondrial metabolism, and expression levels of stem cell factor, epidermal growth factor, glucose transporter 1, and c-Myc. Moreover, psoriatic KCs were more potent than normal KCs in the stimulation of DMSC proliferation. CONCLUSIONS: In conclusion, psoriatic KCs display a higher potency in metabolic reprogramming and stimulation of DMSC proliferation, possibly contributing to the pathogenesis of psoriasis. However, whether the intervention of metabolic reprogramming of DMSCs can alleviate psoriasis remains to be determined.

Dermal Mesenchymal Stem Cells from Psoriatic Lesions Stimulate HaCaT Cell Proliferation, Differentiation, and Migration via Activating the PI3K/AKT Signaling Pathway.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease characterized by excessive proliferation and abnormal differentiation of keratinocytes. Dermal mesenchymal stem cells (DMSCs) are not only involved in the regeneration of skin tissue, but also can regulate skin microenvironment by secreting cytokines. However, whether and how psoriatic DMSCs regulate proliferation and differentiation of keratinocytes remains unknown. OBJECTIVE: To study the effects of psoriatic DMSCs on the proliferation, differentiation, and migration of keratinocytes and the underlying mechanisms. METHODS: Following co-cultures of HaCaT cells with either psoriatic DMSCs (p-DMSCs) or DMSCs from normal volunteers (n-DMSCs), HaCaT cell proliferation was assessed using CCK-8 and EDU incorporation assay, while scratch assay and transwell assay were used to assess cell migration. qRT-PCR was used to determine expression levels of mRNA for cell proliferation (Ki-67) and differentiation (keratin 5, involucrin, and filaggrin). Western blot was used to measure expression levels of proteins associated with keratinocyte proliferation and differentiation in cultured HaCaT cells treated with or without PI3K inhibitor. ELISA assay was used to measure expression profile of stem cell factor (SCF), epidermal growth factor (EGF), and interleukin-11 (IL-11) within the co-culture supernatants. RESULTS: The results showed that p-DMSCs displayed a higher potency than n-DMSCs in stimulating proliferation, differentiation, and migration of HaCaT cells. Expression levels of PI3K and AKT proteins were markedly increased in HaCaT cells co-cultured with DMSCs versus HaCaT cell culture alone. Moreover, inhibition of the PI3K/AKT signaling pathway reversed the effect of p-DMSCs on proliferation, differentiation, and migration of HaCaT cells. Compared with n-DMSCs, the p-DMSCs showed increased secretion of IL-11, EGF, and SCF. CONCLUSION: p-DMSCs stimulate HaCaT cell proliferation, differentiation and migration via activating the PI3K/AKT signaling pathway, providing a new insight into the pathogenesis of psoriasis.

Fis1 phosphorylation by Met promotes mitochondrial fission and hepatocellular carcinoma metastasis.

Met tyrosine kinase, a receptor for a hepatocyte growth factor (HGF), plays a critical role in tumor growth, metastasis, and drug resistance. Mitochondria are highly dynamic and undergo fission and fusion to maintain a functional mitochondrial network. Dysregulated mitochondrial dynamics are responsible for the progression and metastasis of many cancers. Here, using structured illumination microscopy (SIM) and high spatial and temporal resolution live cell imaging, we identified mitochondrial trafficking of receptor tyrosine kinase Met. The contacts between activated Met kinase and mitochondria formed dramatically, and an intact HGF/Met axis was necessary for dysregulated mitochondrial fission and cancer cell movements. Mechanically, we found that Met directly phosphorylated outer mitochondrial membrane protein Fis1 at Tyr38 (Fis1 pY38). Fis1 pY38 promoted mitochondrial fission by recruiting the mitochondrial fission GTPase dynamin-related protein-1 (Drp1) to mitochondria. Fragmented mitochondria fueled actin filament remodeling and lamellipodia or invadopodia formation to facilitate cell metastasis in hepatocellular carcinoma (HCC) cells both in vitro and in vivo. These findings reveal a novel and noncanonical pathway of Met receptor tyrosine kinase in the regulation of mitochondrial activities, which may provide a therapeutic target for metastatic HCC.

Processive cleavage of substrate at individual proteolytic active sites of the Lon protease complex.

The Lon protease is the prototype of a family of proteolytic machines with adenosine triphosphatase modules built into a substrate degradation chamber. Lon is known to degrade protein substrates in a processive fashion, cutting a protein chain processively into small peptides before commencing cleavages of another protein chain. Here, we present structural and biochemical evidence demonstrating that processive substrate degradation occurs at each of the six proteolytic active sites of Lon, which forms a deep groove that partially encloses the substrate polypeptide chain by accommodating only the unprimed residues and permits processive cleavage in the C-to-N direction. We identify a universally conserved acidic residue at the exit side of the binding groove indispensable for the proteolytic activity. This noncatalytic residue likely promotes processive proteolysis by carboxyl-carboxylate interactions with cleaved intermediates. Together, these results uncover a previously unrecognized mechanism for processive substrate degradation by the Lon protease.

A Novel Systematic Oxidative Stress Score Predicts the Prognosis of Patients with Operable Breast Cancer.

BACKGROUND: Breast cancer was associated with imbalance between oxidation and antioxidation. Local oxidative stress in tumors is closely related to the occurrence and development of breast cancer. However, the relationship between systematic oxidative stress and breast cancer remains unclear. This study is aimed at exploring the prognostic value of systematic oxidative stress in patients with operable breast cancer. METHODS: A total of 1583 operable female breast cancer patients were randomly assigned into the training set and validation set. The relationship between systematic oxidative stress biomarkers and prognosis were analyzed in the training and validation sets. RESULTS: The systematic oxidative stress score (SOS) was established based on five systematic oxidative stress biomarkers including serum creatinine (CRE), serum albumin (ALB), total bilirubin (TBIL), lactate dehydrogenase (LDH), and blood urea nitrogen (BUN). SOS was an independent prognostic factor for operable breast cancer patients. A nomogram based on SOS and clinical characteristics could accurately predict the prognosis of operable breast cancer patients, and the area under the curve (AUC) of the nomogram was 0.823 in the training set and 0.872 in the validation set, which was much higher than the traditional prognostic indicators. CONCLUSIONS: SOS is an independent prognostic indicator for operable breast cancer patients. A prediction model based on SOS could accurately predict the outcome of operable breast cancer patients.

A Novel Pyroptosis-Associated Long Non-coding RNA Signature Predicts Prognosis and Tumor Immune Microenvironment of Patients With Breast Cancer.

Background: Pyroptosis, a kind of programmed cell death characterized by the rupture of cell membranes and the release of inflammatory substances, plays an important role in the occurrence and development of cancer. However, few studies focus on the pyroptosis-associated long non-coding RNAs (lncRNAs) in breast cancer (BC). The prognostic value of pyroptosis-associated lncRNAs and their relationship with tumor microenvironment (TME) in BC remain unclear. The purpose of this study was to explore the prognostic role of pyroptosis-associated lncRNAs and their relationship with TME in BC. Methods: The transcriptome data and clinical data of female BC patients were downloaded from The Cancer Genome Atlas (TCGA) database. A total of 937 patients were randomly assigned to either training set or validation set. A pyroptosis-associated lncRNA signature was constructed in the training set and verified in the validation set. Functional analysis and immune microenvironment analysis related to pyroptosis-associated lncRNAs were performed. A nomogram based on the risk score and clinical characteristics was established. Results: A 9-pyroptosis-associated lncRNA signature was constructed to separate BC patients into two risk groups. High-risk patients had poorer prognosis than low-risk patients. The risk score was proven to be an independent prognostic factor by multivariate Cox regression analysis. Function analysis and immune microenvironment analysis showed that low-risk BC tended to be an immunologically "hot" tumor. A nomogram was constructed with risk score and clinical characteristics. Receiver operating characteristic curve (ROC) analysis demonstrated credible predictive power of the nomogram. The area under time-dependent ROC curve (AUC) reached 0.880 at 1 year, 0.804 at 3 years, and 0.769 at 5 years in the training set, and 0.799 at 1 year, 0.794 at 3 years, and 0.728 at 5 years in the validation set. Conclusion: We identified a novel pyroptosis-associated lncRNA signature that was an independent prognostic indicator for BC patients. Pyroptosis-associated lncRNAs had potential relationship with the immune microenvironment and might be therapeutic targets for BC patients.

Complete three-dimensional structures of the Lon protease translocating a protein substrate.

Lon is an evolutionarily conserved proteolytic machine carrying out a wide spectrum of biological activities by degrading misfolded damaged proteins and specific cellular substrates. Lon contains a large N-terminal domain and forms a hexameric core of fused adenosine triphosphatase and protease domains. Here, we report two complete structures of Lon engaging a substrate, determined by cryo­electron microscopy to 2.4-angstrom resolution. These structures show a multilayered architecture featuring a tensegrity triangle complex, uniquely constructed by six long N-terminal helices. The interlocked helix triangle is assembled on the top of the hexameric core to spread a web of six globular substrate-binding domains. It serves as a multipurpose platform that controls the access of substrates to the AAA+ ring, provides a ruler-based mechanism for substrate selection, and acts as a pulley device to facilitate unfolding of the translocated substrate. This work provides a complete framework for understanding the structural mechanisms of Lon.

Molecular basis for ATPase-powered substrate translocation by the Lon AAA+ protease.

The Lon AAA+ (adenosine triphosphatases associated with diverse cellular activities) protease (LonA) converts ATP-fuelled conformational changes into sufficient mechanical force to drive translocation of a substrate into a hexameric proteolytic chamber. To understand the structural basis for the substrate translocation process, we determined the cryo-electron microscopy (cryo-EM) structure of Meiothermus taiwanensis LonA (MtaLonA) in a substrate-engaged state at 3.6 Å resolution. Our data indicate that substrate interactions are mediated by the dual pore loops of the ATPase domains, organized in spiral staircase arrangement from four consecutive protomers in different ATP-binding and hydrolysis states. However, a closed AAA+ ring is maintained by two disengaged ADP-bound protomers transiting between the lowest and highest position. This structure reveals a processive rotary translocation mechanism mediated by LonA-specific nucleotide-dependent allosteric coordination among the ATPase domains, which is induced by substrate binding.

Cryo-EM and antisense targeting of the 28-kDa frameshift stimulation element from the SARS-CoV-2 RNA genome.

Drug discovery campaigns against COVID-19 are beginning to target the SARS-CoV-2 RNA genome. The highly conserved frameshift stimulation element (FSE), required for balanced expression of viral proteins, is a particularly attractive SARS-CoV-2 RNA target. Here we present a 6.9 Å resolution cryo-EM structure of the FSE (88 nucleotides, ~28 kDa), validated through an RNA nanostructure tagging method. The tertiary structure presents a topologically complex fold in which the 5' end is threaded through a ring formed inside a three-stem pseudoknot. Guided by this structure, we develop antisense oligonucleotides that impair FSE function in frameshifting assays and knock down SARS-CoV-2 virus replication in A549-ACE2 cells at 100 nM concentration.

Immunomodulatory effect of psoriasis-derived dermal mesenchymal stem cells on TH1/TH17 cells.

T cell-mediated inflammation plays an important role in the development of psoriasis. Mesenchymal stem cells (MSCs) are a population of multipotent cells that regulate the T cell-mediated immune response. To investigate the effects of psoriatic dermal mesenchymal stem cells (p-DMSCs) on proliferation, apoptosis and differentiation of T cells. p-DMSCs and normal DMSCs (n-DMSCs) were isolated from psoriatic skin and normal healthy controls, respectively, and co-cultured with activated T cells isolated from healthy volunteers using a Transwell system. Proliferation and apoptosis of T cells were assessed by cell count and flow cytometry, respectively. Expression levels of transcription factors associated with subtypes of T cells and cytokines were measured by qRT-PCR and western blot. Both p-DMSCs and n-DMSCs inhibited T cell proliferation and cytokine production. Similarly, the presence of p-DMSCs and n-DMSCs decreased the expression levels of both T-bet and ROR-γt in T cells. However, n-DMSCs exhibited a stronger inhibitory effect than p-DMSCs on T cell proliferation, cytokine production, and T-bet and ROR-γt expression. These results suggest that the effect of p-DMSCs on T cell function could contribute, at least in part, to the pathogenesis of psoriasis.

Regulation of reversible conformational change, size switching, and immunomodulation of RNA nanocubes.

In biological systems, conformational changes and allosteric modulation play pivotal roles in regulating biological functions, such as the dynamic change of protein molecules, in response to binding or interacting with other factors such as pH, voltage, salt, light, or ligand. RNA can be manipulated and tuned with a level of simplicity that is characteristic of DNA or polymers, while displaying versatility in structure, diversity in function, and adaptability in a configuration similar to proteins. In the past, the work on the investigation of conformational change mainly focused on protein. The induced-fit and conformational capture in RNA have also been explored, such as in the study of riboswitches. Herein, we report the engineering of three-dimensional RNA nanocubes and demonstrated the operation and regulation for its configuration. We demonstrate the operation of reconfigurable RNA nanocubes whose shapes change precisely and reversibly in response to a specific trigger strand. The shape, size, and conformation can be regulated precisely and reversibly in response to the specific triggering signals. The shape and conformational conversion were observed by cryo-EM and gel electrophoresis, respectively. Harnessing the size, shape, conformation, and self-assembly capabilities of the RNA nanocube can provide a new potential use of this technology as nanocarriers for the treatment of various diseases.