Uncovering structural variants associated with body weight and obesity risk in labrador retrievers: a genome-wide study.

Although obesity in the domestic dog (Canis lupus familiaris) is known to decrease well-being and shorten lifespan, the genetic risk variants associated with canine obesity remain largely unknown. In our study, which focused on the obesity-prone Labrador Retriever breed, we conducted a genome-wide analysis to identify structural variants linked to body weight and obesity. Obesity status was based on a 5-point body condition score (BCS) and the obese dog group included all dogs with a BCS of 5, along with dogs with the highest body weight within the BCS 4 group. Data from whole-gene sequencing of fifty dogs, including 28 obese dogs, were bioinformatically analyzed to identify potential structural variants that varied in frequency between obese and healthy dogs. The seven most promising variants were further analyzed by droplet digital PCR in a group of 110 dogs, including 63 obese. Our statistical evidence suggests that common structural mutations in or near six genes, specifically ALPL, KCTD8, SGSM1, SLC12A6, RYR3, and VPS26C, may contribute to the variability observed in body weight and body condition scores among Labrador Retriever dogs. These findings emphasize the need for additional research to validate the associations and explore the specific functions of these genes in relation to canine obesity.

Prognostic biomarker SGSM1 and its correlation with immune infiltration in gliomas.

OBJECTIVE: Glioma was the most common type of intracranial malignant tumor. Even after standard treatment, the recurrence and malignant progression of lower-grade gliomas (LGGs) were almost inevitable. The overall survival (OS) of patients with LGG varied widely, making it critical for prognostic prediction. Small G Protein Signaling Modulator 1 (SGSM1) has hardly been studied in gliomas. Therefore, we aimed to investigate the prognostic role of SGSM1 and its relationship with immune infiltration in LGGs. METHODS: We obtained RNA sequencing data from The Cancer Genome Atlas (TCGA) to analyze SGSM1 expression. Functional enrichment analyses, immune infiltration analyses, immune checkpoint analyses, and clinicopathology analyses were performed. Univariate and multivariate Cox regression analyses were used to identify independent prognostic factors. And nomogram model has been developed. Kaplan-Meier survival analysis and log-rank test were used to estimate the relationship between OS and SGSM1 expression. The survival analyses and Cox regression were validated in datasets from the Chinese Glioma Genome Atlas (CGGA). RESULTS: SGSM1 was significantly down-regulated in LGGs. Functional enrichment analyses revealed SGSM1 was correlated with immune response. Most immune cells and immune checkpoints were negatively correlated with SGSM1 expression. The Kaplan-Meier analyses showed that low SGSM1 expression was associated with a poor outcome in LGG and its subtypes. The Cox regression showed SGSM1 was an independent prognostic factor in patients with LGG (HR = 0.494, 95%CI = 0.311-0.784, P = 0.003). CONCLUSION: SGSM1 was considered to be a new prognostic biomarker for patients with LGG. And our study provided a potential therapeutic target for LGG treatment.

Targeted massively parallel sequencing of candidate regions on chromosome 22q predisposing to multiple schwannomas: An analysis of 51 individuals in a single-center experience.

Constitutional LZTR1 or SMARCB1 pathogenic variants (PVs) have been found in ∼86% of familial and ∼40% of sporadic schwannomatosis cases. Hence, we performed massively parallel sequencing of the entire LZTR1, SMARCB1, and NF2 genomic loci in 35 individuals with schwannomas negative for constitutional first-hit PVs in the LZTR1/SMARCB1/NF2 coding sequences; however, with 22q deletion and/or a different NF2 PV in each tumor, including six cases with only one tumor available. Furthermore, we verified whether any other LZTR1/SMARCB1/NF2 (likely) PVs could be found in 16 cases carrying a SMARCB1 constitutional variant in the 3'-untranslated region (3'-UTR) c.*17C>T, c.*70C>T, or c.*82C>T. As no additional variants were found, functional studies were performed to clarify the effect of these 3'-UTR variants on the transcript. The 3'-UTR variants c.*17C>T and c.*82C>T showed pathogenicity by negatively affecting the SMARCB1 transcript level. Two novel deep intronic SMARCB1 variants, c.500+883T>G and c.500+887G>A, resulting in out-of-frame missplicing of intron 4, were identified in two unrelated individuals. Further resequencing of the entire repeat-masked genomics sequences of chromosome 22q in individuals negative for PVs in the SMARCB1/LZTR1/NF2 coding- and noncoding regions revealed five potential schwannomatosis-predisposing candidate genes, that is, MYO18B, NEFH, SGSM1, SGSM3, and SBF1, pending further verification.

Small G protein signalling modulator 2 (SGSM2) is involved in oestrogen receptor-positive breast cancer metastasis through enhancement of migratory cell adhesion via interaction with E-cadherin.

The function of small G protein signalling modulators (SGSM1/2/3) in cancer remains unknown. Our findings demonstrated that SGSM2 is a plasma membrane protein that strongly interacted with E-cadherin/ß-catenin. SGSM2 downregulation enhanced the phosphorylation of focal adhesion kinase (FAK; Y576/577), decreased the expression of epithelial markers such as E-cadherin, ß-catenin, and Paxillin, and increased the expression of Snail and Twist-1, which reduced cell adhesion and promoted cancer cell migration. Oestrogen and fibronectin treatment was found to promote the colocalization of SGSM2 at the leading edge with phospho-FAK (Y397). The BioGRID database showed that SGSM2 potentially interacts with cytoskeleton remodelling and cell-cell junction proteins. These evidences suggest that SGSM2 plays a role in modulating cell adhesion and cytoskeleton dynamics during cancer migration.

Evaluation of 4-bp insertion/deletion polymorphism within the 3'UTR of SGSM3 in bladder cancer using mismatch PCR-RFLP method: A preliminary report.

The small G protein signaling modulator 3 (SGSM3) has been shown to be associated with small G-protein-coupled receptor signaling. There is little data regarding the impact of SGSM3 polymorphisms on cancer risk. In the present study, we aimed to evaluate the impact of 4-bp insertion/deletion (rs56228771) polymorphism in the 3'UTR of SGSM3 and susceptibility to bladder cancer in a sample of the Iranian population. This case-control study included 143 pathologically confirmed bladder cancer patients and 144 healthy subjects. The SGSM3 4-bp ins/del (rs56228771) variant was determined by mismatch PCR-RFLP. The findings showed that ins/del genotype and ins allele of SGSM3 4-bp ins/del polymorphism significantly increased the risk of bladder cancer (OR = 3.11, 95%CI = 1.70-5.71, P < 0.0001 and OR = 2.11, 95%CI = 1.27-3.52, P = 0.004, respectively). Our findings support an association between 4-bp ins/del polymorphism in the 3'UTR of SGSM3 and the risk of bladder cancer in an Iranian population. Additional studies with larger sample sizes and diverse ethnicities are warranted to establish if such an association exists in general.

Protective effects of kenpaullone on cardiomyocytes following H2O2-induced oxidative stress are attributed to inhibition of connexin 43 degradation by SGSM3.

A previous study showed that small G protein signaling modulator 3 (SGSM3) was highly correlated with Cx43 in heart functions and that high levels of SGSM3 may induce Cx43 turnover through lysosomal degradation in infarcted rat hearts. Here, we investigated the protective effects of kenpaullone on cardiomyocytes following H2O2-induced oxidative stress mediated by the interaction of SGSM3 with Cx43. We found that the gap junction protein Cx43 was significantly down-regulated in an H2O2 concentration-dependent manner, whereas expression of SGSM3 was up-regulated upon H2O2 exposure in H9c2 cells. The effect of kenpaullone pretreatment on H2O2-induced cytotoxicity was evaluated in H9c2 cells. H2O2 markedly increased the release of lactate dehydrogenase (LDH), while kenpaullone pretreatment suppressed LDH release in H9c2 cells. Moreover, kenpaullone pretreatment significantly reduced ROS fluorescence intensity and significantly down-regulated the level of apoptosis-activating genes (cleaved caspase-3, cleaved caspase-9 and cytochrome C), autophagy markers (LC3A/B), and the Cx43-interacting partner SGSM3. These results suggest that kenpaullone plays a role in protecting cardiomyocytes from oxidative stress and that the turnover of Cx43 through SGSM3-induced lysosomal degradation underlies the anti-apoptotic effect of kenpaullone.

Interaction of small G protein signaling modulator 3 with connexin 43 contributes to myocardial infarction in rat hearts.

Connexin 43 (Cx43), a ubiquitous connexin expressed in the heart and skin, is associated with a variety of hereditary conditions. Therefore, the characterization of Cx43-interacting proteins and their dynamics is important to understand not only the molecular mechanisms underlying pathological malfunction of gap junction-mediated intercellular communication but also to identify novel and unanticipated biological functions of Cx43. In the present study, we observed potential targets of Cx43 to determine new molecular functions in cardio-protection. MALDI-TOF mass spectrometry analysis of Cx43 co-immunoprecipitated proteins showed that Cx43 interacts with several proteins related to metabolism. In GeneMANIA network analysis, SGSM3, which has not been previously associated with Cx43, was highly correlated with Cx43 in heart functions, and high levels of SGSM3 appeared to induce the turnover of Cx43 through lysosomal degradation in myocardial infarcted rat hearts. Moreover, we confirmed that lysosomal degradation of Cx43 is dependent upon the interaction between SGSM3 and Cx43 in H9c2 cardiomyocytes. The functional importance of the interaction between SGSM3 and Cx43 was confirmed by results showing that Cx43 expression was enhanced by SGSM3 siRNA knockdown in H9c2 cells. In summary, the results of this study elucidate the molecular mechanisms in which Cx43 with SGSM3 is degraded in myocardial infarcted rat hearts, which may contribute to the establishment of new therapeutic targets to modulate cardiac function in physiological and pathological conditions.

Genetic variants of ESR1 and SGSM3 are associated with the susceptibility of breast cancer in the Chinese population.

BACKGROUND: The objective of this study was to investigate whether the genetic polymorphism rs12665607 of ESR1, rs10995190 of ZNF365, rs3817198 of LSP1 and rs17001868 of SGSM3/MKL1 are associated with the development of breast cancer (BC) in the Chinese women. METHODS: The 4 SNPs were genotyped for 453 female BC patients and 750 controls. The differences of genotype and allele distributions between patients and controls were evaluated using the Chi-square test. The comparison of SGSM3 expression in the tumor and the adjacent normal breast tissues was carried out by the Student's t test. One-way ANOVA test was used to analyze the relationship between genotypes of rs17001868 and the tissue expression of SGSM3. RESULTS: Patients were found to have significantly higher allele T of rs12665607 and allele C of rs17001868 than that of the controls (35.2 % vs. 29.6 %, p = 0.004 for rs12665607; 23.1 % vs. 19.1 %, p = 0.02 for rs17001868). The OR values were 1.29 for rs12665607 and 1.27 for rs17001868, respectively. The mean expression level of SGSM3 was significantly lower in BC tumors than in the adjacent normal tissues (0.0082 ± 0.0038 vs. 0.0134 ± 0.0078; p < 0.001). Patients with genotype CC were found to have a remarkably lower SGSM3 expression in the tumors than those with genotype AA (p = 0.007). CONCLUSIONS: ESR1 gene and the SGSM3 gene are associated with the risk of BC in Chinese population. Besides, rs17001868 may be a putative functional variant that can affect the expression of SGSM3 in patients with BC. With the OR ranging from 1.27 to 1.29, variants of these 2 genes can only explain limited variance of BC. Further investigations into the functional role of the susceptible genes would be helpful to clarify the etiology of BC.

γ-Secretase modulators reduce endogenous amyloid ß42 levels in human neural progenitor cells without altering neuronal differentiation.

Soluble γ-secretase modulators (SGSMs) selectively decrease toxic amyloid ß (Aß) peptides (Aß42). However, their effect on the physiologic functions of γ-secretase has not been tested in human model systems. γ-Secretase regulates fate determination of neural progenitor cells. Thus, we studied the impact of SGSMs on the neuronal differentiation of ReNcell VM (ReN) human neural progenitor cells (hNPCs). Quantitative PCR analysis showed that treatment of neurosphere-like ReN cell aggregate cultures with γ-secretase inhibitors (GSIs), but not SGSMs, induced a 2- to 4-fold increase in the expression of the neuronal markers Tuj1 and doublecortin. GSI treatment also induced neuronal marker protein expression, as shown by Western blot analysis. In the same conditions, SGSM treatment selectively reduced endogenous Aß42 levels by ∼80%. Mechanistically, we found that Notch target gene expressions were selectively inhibited by a GSI, not by SGSM treatment. We can assert, for the first time, that SGSMs do not affect the neuronal differentiation of hNPCs while selectively decreasing endogenous Aß42 levels in the same conditions. Our results suggest that our hNPC differentiation system can serve as a useful model to test the impact of GSIs and SGSMs on both endogenous Aß levels and γ-secretase physiologic functions including endogenous Notch signaling.