Septins belong to a family of polymerizing GTP-binding proteins that are required for many cellular functions, such as membrane compartmentalization, vesicular trafficking, mitosis, and cytoskeletal remodeling. One family member, septin12, is expressed specifically in the testis. In this study, we found septin12 expressed in multiple subcellular compartments during terminal differentiation of mouse germ cells. In humans, the testicular tissues of men with either hypospermatogenesis or maturation arrest had lower levels of SEPTIN12 transcripts than normal men. In addition, increased numbers of spermatozoa with abnormal head, neck, and tail morphologies lacked SEPT12 immunostaining signals, as compared with normal spermatozoa. To elucidate the role of septin12, we generated 129 embryonic stem cells containing a septin12 mutant allele with a deletion in the exons that encode the N-terminal GTP-binding domain. Most chimeras derived from the targeted embryonic stem cells were infertile, and the few fertile chimeras only produced offspring with a C57BL/6 background. Semen analysis of the infertile chimeras showed a decreased sperm count, decreased sperm motility, and spermatozoa with defects involving all subcellular compartments. The testicular phenotypes included maturation arrest of germ cells at the spermatid stage, sloughing of round spermatids, and increased apoptosis of germ cells. Electron microscopic examination of spermatozoa showed misshapen nuclei, disorganized mitochondria, and broken acrosomes. Our data indicate that Septin12 expression levels are critical for mammalian spermiogenesis.

IMPORTANCEThe use of proton pump inhibitors (PPIs) in children has increased substantially in recent years, concurrently with emerging concerns that these drugs may increase the risk of asthma. Whether PPI use in the broad pediatric population is associated with increased risk of asthma is not known.OBJECTIVE To investigate the association between PPI use and risk of asthma in children.

IMPORTANCE Proton pump inhibitor (PPI) use has been linked to increased risk of fracture in adults. Despite a trend in prescription of PPIs in children, there is scarce evidence regarding this safety concern in pediatric patients. OBJECTIVE To evaluate the association between PPI use and risk of fracture in children. DESIGN This nationwide register-based cohort study included data from Sweden from July 2006 to December 2016. Children younger than 18 years who initiated PPI use were matched on propensity score and age with those who did not initiate PPI use. EXPOSURE Initiation of PPI use. MAIN OUTCOMES AND MEASURESCox regression was adopted to estimate hazard ratios (HRs) for a first fracture of any type and 5 subtypes of fracture, with follow-up for up to 5 years. To address potential residual confounding, high-dimensional propensity score matching and a direct comparison with histamine-2 receptor antagonists were performed.RESULTS There were a total of 115 933 pairs of children included. During a mean (SD) of 2.2 (1.6) years of follow-up, 5354 and 4568 cases of any fracture occurred among those who initiated PPIs vs those who did not, respectively (20.2 vs 18.3 events per 1000 person-years; hazard ratio [HR], 1.11 [95% CI, 1.06-1.15]). Use of PPIs was associated with increased risk of upper-limb fracture (HR, 1.08 [95% CI, 1.03-1.13]), lower-limb fracture (HR, 1.19 [95% CI, 1.10-1.29]), and other fractures (HR, 1.51 [95% CI, 1.16-1.97]) but not head fracture (HR, 0.93 [95% CI, 0.76-1.13]) or spine fracture (HR, 1.31 [95% CI,). The HRs for fracture according to cumulative duration of PPI use were 1.08 (95% CI, 1.03-1.13) for 30 days or less, 1.14 (95% CI, 1.09-1.20) for 31 to 364 days, and 1.34 (95% CI, 1.13-1.58) for 365 days or more. The association was consistent in most sensitivity analyses, including high-dimensional propensity score matching (HR, 1.10 [95% CI, 1.06-1.15]), although the analysis of PPI vs histamine-2 receptor antagonist did not reach statistical significance (HR, 1.06 [95% CI, 0.97-1.15]). CONCLUSIONS AND RELEVANCEIn this large pediatric cohort, PPI use was associated with a small but significant increased risk of any fracture. Risk of fracture should be taken into account when weighing the benefits and risks of PPI treatment in children.

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Oxidative stress is the main factor responsible for the induction of diabetic renal fibrosis. Thus, improving the state of oxidative stress can effectively prevent the further deterioration of diabetic nephropathy (DN). Previous research has shown that formononetin (FMN), a flavonoid with significant antioxidant activity and Sirt1 activation effect, can improve diabetic renal fibrosis. However, the exact mechanisms underlying the effect of FMN on diabetic renal fibrosis have yet to be elucidated. In this study, we carried out in vivo experiments in a db/db (diabetic) mouse model and demonstrated that FMN activated the nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway and improved oxidative stress by increasing levels of sirtuin-1 (Sirt1) protein level in renal tissue. We also found that this process reversed the up-regulation of fibronectin (FN) and intercellular adhesion molecule 1 (ICAM-1) and led to an improvement in renal insufficiency. In vitro results further showed that FMN significantly reversed the upregulation of FN and ICAM-1 in glomerular mesangial cells (GMCs) exposed to high glucose. FMN also promoted the expression of Nrf2 and widened its nuclear distribution. Thus, our data indicated that FMN inhibited hyperglycemia-induced superoxide overproduction by activating the Nrf2/ARE signaling pathway. We also found that FMN up-regulated the expression of Sirt1 and that Sirt1 deficiency could block the activation of the Nrf2/ARE signaling pathway in GMCs induced by high glucose. Finally, we found that Sirt1 deficiency could reverse the down-regulation of FN and ICAM-1 induced by FMN. Collectively, our data demonstrated that FMN up-regulated the expression of Sirt1 to activate the Nrf2/ARE signaling pathway, improved oxidative stress in DN to prevent the progression of renal fibrosis. Therefore, FMN probably represents an efficient therapeutic option of patients with DN.

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