[Genetic analysis of three cases of acephalic spermatozoa syndrome caused by SUN5 mutation and the outcome of assisted reproductive technology].

To explore the genetic causes of 3 male infertility patients with acephalospermia and the outcome of assisted reproductive technology. Clinical diagnosis, sperm morphology examination, sperm transmission electron microscopy examination were performed on 3 patients, and the whole exome sequencing technology was used for screening, Sanger sequencing verification, mutation pathogenicity analysis, and protein sequence homology comparison. Assisted reproductive technology was implemented to assist pregnancy treatment. The 3 patients were all sporadic infertile men, aged 25, 42 and 26 years, and there was no obvious abnormality in the general physical examination. Male external genitalia developed normally, bilateral testicles were normal in volume, and bilateral epididymis and spermatic vein were palpated without nodules, cysts, and tenderness. Repeated semen analysis showed that a large number of immature sperm could be seen, and they had the ability to move. The SUN5 gene of the 3 male infertile patients was a case of homozygous missense mutation c.7C>T (p.Arg3Trp), a case of compound heterozygous missense mutation c.1067G>A (p.Arg356His) and nonsense mutation c.216G>A (p.Trp72*) and a case of homozygous missense mutation c.1043A>T (p.Asn348Ile), of which c.7C>T (p.Arg3Trp) and c.1067G>A (p.Arg356His) were new variants that had not been reported. SIFT, Mutation Taster and PolyPhen-2 software function prediction results were all harmful, the nonsense mutation c.216G>A (p.Trp72*) led to the premature termination of peptide chain synthesis which might have a greater impact on protein function. The homology regions in the protein sequence homology alignment were all highly conserved.The 3 male patients and their spouses obtained 4 biological offspring through intracytoplasmic sperm injection, all of which were boys, and one of them was a twin.Three male infertile patients might be caused by SUN5 gene mutations. Such patients could obtain their biological offspring through assisted reproductive technology. It was still necessary to pay attention to the genetic risk of ASS, it was recommended that both men and women conduct genetic counseling and screening at the same time. In clinical diagnosis, whole exome sequencing technology could be used to perform auxiliary examinations to determine the treatment plan and assisted reproductive methods as soon as possible to reduce the burden on the family and society. The newly discovered mutation sites of SUN5 gene provided clues and directions for elucidating the pathogenic mechanism, and at the same time expanded the pathogenic mutation spectrum of ASS.

Beneficial effects of low-level laser irradiation on senile osteoporosis in rats.

OBJECTIVE: To investigate the effect of low-level laser irradiation (LLLI) on bone mineral density (BMD), bone structures, bone biomechanical properties and bone metabolism in senile osteoporosis, and to explore a relatively more secure and effective way to prevent and treat osteoporosis. MATERIALS AND METHODS: Sprague-Dawley (SD) male rats at different age stages (4 months old, 12 months old and 20 months old) were selected and randomly divided into six groups. The rats in the treatment group were treated with LLLI for 12 weeks, and then the microstructure of bones was analyzed by micro-computed tomography (micro-CT) scanning. The biomechanical indexes of the femur were detected by the three-point bending test. Levels of the blood calcium (Ca)2+, blood phosphorus (P)3+, urine Ca, urine P and urine creatinine (CREA) were detected using an automatic biochemical analyzer. The contents of serum osteocalcin (OCN) and bone alkaline phosphatase (BAP) were measured by enzyme-linked immunosorbent assay (ELISA). The bone formation rate (BFR) was analyzed by double fluorescent labeling with calcein and tetracycline. Hematoxylin and eosin (HE) staining and toluidine blue staining were used to analyze the number of bone marrow osteoblasts and adipocytes. RESULTS: Micro-CT results showed that compared with those in the young group, the bone mineral density (BMD) in the old group was significantly decreased, and the trabecular microstructure was seriously damaged. LLLI could significantly enhance the BMD and improve the damage to the trabecular microstructure; the three-point bending test revealed that LLLI could significantly improve the biomechanical properties and enhance the mechanical strength of the femur in the old group; the biochemical analysis showed that LLLI could significantly reduce Ca and P losses and elevate the levels of serum BAP and OCN; the bone histomorphology analysis results indicated that LLLI could increase BFR and mineral apposition rate (MAR), increase the number of osteoblasts and decrease the number of adipocytes in the bone marrow in the old group. CONCLUSIONS: LLLI can effectively improve osteoporosis, increase BMD, improve bone structure and improve bone biomechanical properties in old rats; at the same time, it increases the levels of serum BAP and OCN and the number of osteoblasts in the bone marrow, suggesting that the osteogenesis function of osteoblasts is enhanced.

Mechanism for the isotype dependence of antibody-mediated toxicity in Cryptococcus neoformans-infected mice.

Ab-based therapies have undergone a renaissance in recent years, but infusion-related reactions are a significant clinical problem. Administration of certain mAbs to Swiss Webster mice infected with Cryptococcus neoformans can result in acute lethal toxicity (ALT) characterized by cardiovascular collapse. The ability of a mAb to produce ALT is isotype dependent and occurs with IgG1 but not IgG3. To investigate this phenomenon, we measured spleen and liver cytokine responses and platelet-activating factor (PAF) content in mice given C. neoformans glucuronoxylomannan (GXM) followed by specific Ab of IgG1 or IgG3 isotype. We found no evidence to suggest that the differences in IgG1 and IgG3 toxicity were due to differences in chemokine or cytokine response. In contrast, liver and spleen tissue PAF content was significantly greater in mice IgG1. Furthermore, our results show differences in the response to IgG1- and IgG3-GXM complexes regarding: 1) macrophage-inflammatory protein-1alpha and monocyte chemoattractant protein-1 regulation, 2) splenic and hepatic PAF content, and 3) hepatic PAF content in infected mice. IgG1-associated ALT appears to be the result of greater production of PAF in response to IgG1-GXM complex formation. The results are consistent with the view that IgG1 and IgG3 interact with different Fc receptors. Our findings strongly suggest that the mechanism for Ab-mediated ALT is different from the cytokine release syndrome described after administration of other therapeutic mAbs.

The role of xanthine oxidase in platelet activating factor induced intestinal injury in the rat.

BACKGROUND: Xanthine oxidase (XO) is an important source of reactive oxygen species in the small intestine. AIMS: To examine the interaction of platelet activating factor (PAF), XO, and neutrophils in mediating intestinal injury in rats. METHODS: Two doses of PAF were used to induce either reversible hypotension, or irreversible shock with intestinal necrosis. The activities of XO, and its precursor xanthine dehydrogenase (XD), in both the whole intestinal tissue and epithelial cells, were measured. XO was localised by histochemical staining. RESULTS: PAF dose dependently induced an increase in XO activity, predominantly in the ileal epithelium, without altering the total activity of XD+XO. Most of the XD to XO conversion was via proteolysis. PAF induced XO activation and intestinal injury were prevented by prior neutrophil depletion. PAF induced XO activation is probably not due to reperfusion, as XO activation preceded the recovery of mesenteric flow. Allopurinol pretreatment substantially inhibited intestinal neutrophil sequestration induced by high dose (but not low dose) PAF. CONCLUSIONS: PAF rapidly activates intestinal XO through proteolytic XD-XO conversion, predominantly in the ileal epithelium. This effect is mediated by neutrophils. XO activation promotes PAF induced polymorphonuclear leucocyte sequestration in the intestine.

Intestinal NF-kappaB is activated, mainly as p50 homodimers, by platelet-activating factor.

NF-kappaB, a transcription factor, upregulates gene transcription of many inflammatory mediators. Here, we examined the activity of NF-kappaB in the rat small intestine, and how it may be affected by platelet-activating factor (PAF), an important mediator for intestinal injury and inflammation. Ileal nuclear extracts from sham-operated and PAF (1.5 microg/kg)-injected rats were prepared for the assessment of NF-kappaB DNA-binding activity, and the identification of NF-kappaB subunits. The experiment was also performed on neutrophil-depleted rats to examine whether the PAF effect is neutrophil-dependent. Cellular NF-kappaB was localized by immunohistochemistry. We found that: (a) NF-kappaB is constitutively active in rat small intestine; (b) PAF at a dose below that causing shock and bowel necrosis enhances DNA-binding activity of NF-kappaB within 30 min after injection; activated NF-kappaB contains predominantly p50 subunits; (c) immunohistochemistry showed that PAF induced translocation of p50 into the nucleus of cells of the lamina propria, as well as of the epithelium; and (d) the effect of PAF is abrogated by neutrophil depletion, suggesting a role of neutrophils in NF-kappaB activation. Our study suggests that NF-kappaB is weakly active constitutively in the intestine, and inflammatory stimuli such as PAF activate NF-kappaB and enhance its DNA-binding activity in the intestine, which contains predominantly p50 subunits.