Tex46 knockout male mice are sterile secondary to sperm head malformations and failure to penetrate through the zona pellucida

Each year, infertility affects 15% of couples worldwide, with 50% of cases attributed to men. It is assumed that sperm head shape is important for sperm-zona pellucida (ZP) penetration but research has yet to elucidate why. We generated testis expressed 46 (Tex46) knockout mice to investigate the essential roles of TEX46 in mammalian reproduction. We used RT-PCR to demonstrate that Tex46 was expressed exclusively in the male reproductive tract in mice and humans. We created Tex46-/- mice using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system and analyzed their fertility. Tex46 null spermatozoa underwent further evaluation using computer-assisted sperm analysis, light microscopy, and ultrastructural microscopy. We used immunoblot analysis to elucidate relationships between TEX46 and other acrosome biogenesis-related proteins. Mouse and human TEX46 are testis-enriched and encode a transmembrane protein which is conserved from amphibians to mammals. Loss of the mouse TEX46 protein causes male sterility primarily due to abnormal sperm head formation and secondary effects on sperm motility. Tex46 null spermatozoa morphologically lack the typical hooked sperm head appearance and fail to penetrate through the ZP. Electron microscopy of the testicular germ cells reveals malformation of the acrosomal cap, with misshapen sperm head tips and the appearance of a gap between the acrosome head and the nucleus. TEX46 is essential for sperm head formation, sperm penetration through the ZP, and male fertility in mice, and is a putative contraceptive target in men.

PABPN1L is required for maternal mRNA degradation after meiosis resumption

Poly(A)-binding proteins (PABPs) play roles in mRNA maturation, translational activity, and decay. The functions of PABPs, especially PABPN1 and PABPC1, in somatic cells have been well-studied. However, little is known about the roles of PABPs in oocytes because of the unique mechanisms of mRNA metabolism in oocytes. This study focused on PABPN1L and generated Pabpn1l knockout (KO) mice using the CRISPR/Cas9 system. After mating tests, we found that Pabpn1l KO females were infertile due to the failure of the embryos to develop to the 4-cell stage. RNA-seq analysis revealed aberrant mRNA persistence in Pabpn1l KO-MII oocytes, which indicates impaired mRNA degradation during the germinal vesicle (GV) to MII transition. We also revealed that the exogenous expression of Pabpn1l mRNA in KO-GV oocytes recovered defects of embryonic development. PABPN1L is partly indispensable for female fertility in mice, owing to its necessity for embryonic development, which is supported by mRNA degradation during GV to MII maturation.

Organoleptic characteristics and compositional profile of meat of growing Japanese quail fed different levels of poultry byproducts compost

The poultry industry generates a lot of waste, including dead birds, manure, and poultry litter. Poultry waste should never be disposed of improperly because it can seriously harm the environment. The waste can be recycled as a feedstock for use in poultry feed by composting the litter and deceased birds. The compositional profile and organoleptic properties of the meat of growing Japanese quail were examined over the course of a 4-week trial to ascertain the effect of adding compost to the diet. In a completely randomized design (CRD), 1200 newly hatched quail chicks (Coturnix coturnix japonica) were divided into five treatment groups (diets with 0, 2.5, 5, 7.5, and 10% compost), each consisting of 40 birds with six replicates. The addition of compost to the diet had no noticeable effects on the organoleptic qualities of appearance, color, aroma, taste, texture, juiciness, tenderness, and acceptability (P>0.05). The compositional profile characteristics for chicks given compost at any level compared to chicks fed the control diet showed no differences (P>0.05). These findings suggest that the sensory characteristics and compositional profile of growing meat quails can be maintained when fed diets including up to 10% compost.

Assessing effect of feeding poultry byproducts compost on organoleptic characteristics and compositional profile of meat of broiler chickens

Large amounts of waste, including dead birds, manure, and poultry litter, are produced by the poultry industry. Poultry waste should be disposed of properly to avoid major pollution and health risks. Composting litter and dead birds could be an option to recycle the waste and use in poultry feed. A study was conducted to investigate the effects of feeding composted poultry waste on the organoleptic qualities and compositional profile of the meat of broiler chickens. A total of 300 day-old broiler chicks (500-Cobb) were randomly allocated to five treatment groups replicated six times with 10 birds each, under a completely randomized design (CRD). Five iso-caloric and iso-nitrogenous diets including composted poultry byproducts at concentrations of 0, 2.5, 5, 7.5, and 10% were fed ad libitum to the birds from day 0 to day 35. The sensory grading and meat composition profile of 500 Cobb broiler chickens were tested at 35 days of age. The findings showed that there were no variations in the sensory profiles of the meat from birds given various diets (P>0.05). Although the results were somewhat lower for the chicks fed compost-containing diets than for the control group, this difference was deemed to be insignificant (P>0.05). Similarly, there were no variations in the compositional profile values of the meat between meat from birds fed various diets (P>0.05). These findings imply that broiler chickens may be raised on diets containing up to 10% poultry byproduct compost without any negative impacts on the meat's sensory quality or composition. Additionally, using compost into broiler diets may help to lower the cost of feed.

PDCL2 is essential for sperm acrosome formation and male fertility in mice

BACKGROUND

Each year, infertility affects 15% of couples worldwide, with 50% of cases attributed to men. Globozoospermia is an uncommon cause of male factor infertility, characterized by defects in sperm acrosome formation, leading to round-headed spermatozoa.

OBJECTIVE

We generated Pdcl2 knockout mice to investigate the essential roles of PDCL2 in mammalian reproduction.

MATERIALS AND METHODS

We used reverse transcription-polymerase chain reaction to demonstrate that PDCL2 was expressed exclusively in the male reproductive tract in mice and humans. We created Pdcl2 knockout mice using the CRISPR-Cas9 system and analyzed their fertility. Pdcl2 null spermatozoa underwent further evaluation using computer-assisted sperm analysis, light microscopy, and ultrastructural microscopy. We used immunoblot analysis and immunofluorescence to elucidate relationships between PDCL2 and other acrosomal proteins.

RESULTS

The PDC family is highly conserved in eukaryotes. Mouse and human PDCL2 are testis enriched and localized to the testicular endoplasmic reticulum. Loss of the protein causes sterility because of abnormal acrosome biogenesis during spermiogenesis and immotility. Furthermore, Pdcl2 null spermatozoa have rounded heads, similar to globozoospermia in humans. Observation of the knockout testis shows a lack of acrosomal cap formation, aberrant localization of mitochondria in the sperm head, and misshapen nuclei.

CONCLUSION

PDCL2 is essential for sperm acrosome development and male fertility in mice and is a putative contraceptive target in men.

Rectal Melanoma: Rare Cancer with Grave Prognosis

Malignant melanoma of the rectum is an exceedingly rare type of cancer with an aggressive presentation, comprising up to 4% of all anorectal cancers. Presentation of this cancer tends to occur in individuals in their late 80s, with nonspecific symptoms such as anal pain or rectal bleeding. Diagnosing rectal melanoma, especially in early stages, is difficult due to its amelanotic presentation and lack of pigmentation, which results in poor remission rates and prognosis. Furthermore, surgical treatment is difficult as these types of malignant melanomas tend to spread along submucosal planes; thus, complete resections are impractical, especially if caught later. In this case report, we present the radiological and pathological features as seen in a 76-year-old man diagnosed with rectal melanoma. Based on his presentation of a heterogeneous bulky anorectal mass with extensive local invasion, initial impressions were colorectal carcinoma. However, surgical pathology found the mass to be a c-KIT+ melanoma, with positive SOX10, Melan-A, HMB-45, and CD117 biomarkers. While the patient was treated with imatinib, the melanoma was too widespread and aggressive, leading to progression and ultimately death.

Multi-layer PDMS films having antifouling property for biomedical applications

Poly(dimethylsiloxane) (PDMS) elastomer is now a well-known material for packaging implantable biomedical micro-devices owing to unique bulk properties such as biocompatibility, low toxicity, excellent rheological properties, good flexibility, and mechanical stability. Despite the desirable bulk characteristics, PDMS is generally regarded as a high-flux material for oxygen and water vapor to penetrate compared with other polymeric barrier materials, which is related to the defect-induced penetration through the packaging coating prepared by the traditional deposition techniques. Besides, its hydrophobic nature causes serious fouling problems and limits the practical application of PDMS-based devices. In this work, the performance of silicone thin films as a packaging layer was improved by the fabrication of the roller-casted multiple thin layers to minimize a defect-induced failure. To confer hydrophilicity and cell fouling resistance, high-density and well-defined poly(oligo(ethylene glycol) methacrylate) (POEGMA) brushes were tethered via the surface-initiated atom transfer radical polymerization (SI-ATRP) technique on the roller-casted multiple thin PDMS layers. The characteristics of fabricated substrates were determined by static water contact angle measurement, X-ray photoelectron spectroscopy, and attenuated total reflection-Fourier transform infrared spectroscopy. In vitro cell behavior of POEGMA-grafted PDMS substrates was evaluated to examine cell-fouling resistance.

Interconnected porous nanofibrous gelatin scaffolds prepared via a combined thermally induced phase separation/particulate leaching method

To mimic the fibrous architecture of collagen, the nanofibrous gelatin scaffolds are fabricated employing a thermally induced phase separation (TIPS) technique. The influences of processing parameters, including polymer concentration and solvent mixture composition on the scaffold microstructure are investigated. However, using the TIPS technique, a limited pore size range is generally obtained. To yield the well-interconnected macroporous structures with equiaxed pores and nanofibrous architectures, the TIPS technique is combined with particulate leaching. The macroporous structure of produced scaffolds duplicates the predefined three-dimensional template structure. The homogenous macrostructure with well-interconnected equiaxed pores and no particular orientation is created. Modulating the size and shape of microspheres has precise control over porosity, pore size, and interconnection of the matrix. Because of the well-interconnected macroporous nanofibrous structure, the useful applications of these scaffolds in the tissue engineering field are expected.

CRISPR/Cas9-based genome editing in mice uncovers 13 testis- or epididymis-enriched genes individually dispensable for male reproduction†

Developing a safe and effective male contraceptive remains a challenge in the field of medical science. Molecules that selectively target the male reproductive tract and whose targets are indispensable for male reproductive function serve among the best candidates for a novel non-hormonal male contraceptive method. To determine the function of these genes in vivo, mutant mice carrying disrupted testis- or epididymis-enriched genes were generated by zygote microinjection or electroporation of the CRISPR/Cas9 components. Male fecundity was determined by consecutively pairing knockout males with wild-type females and comparing the fecundity of wild-type controls. Phenotypic analyses of testis appearance and weight, testis and epididymis histology, and sperm movement were further carried out to examine any potential spermatogenic or sperm maturation defect in mutant males. In this study, we uncovered 13 testis- or epididymis-enriched evolutionarily conserved genes that are individually dispensable for male fertility in mice. Owing to their dispensable nature, it is not feasible to use these targets for the development of a male contraceptive.

CRISPR/Cas9-Mediated Genome Editing Reveals Oosp Family Genes are Dispensable for Female Fertility in Mice

There are over 200 genes that are predicted to be solely expressed in the oocyte and ovary, and thousands more that have expression patterns in the female reproductive tract. Unfortunately, many of their physiological functions, such as their roles in oogenesis or fertilization, have yet to be elucidated. Previous knockout (KO) mice studies have proven that many of the genes that were once thought to be essential for fertility are dispensable in vivo. Therefore, it is extremely important to confirm the roles of all genes before spending immense time studying them in vitro. To do this, our laboratory analyzes the functions of ovary and oocyte-enriched genes in vivo through generating CRISPR/Cas9 KO mice and examining their fertility. In this study, we have knocked out three Oosp family genes (Oosp1, Oosp2, and Oosp3) that have expression patterns linked to the female reproductive system and found that the triple KO (TKO) mutant mice generated exhibited decreased prolificacy but were not infertile; thus, these genes may potentially be dispensable for fertility. We also generated Cd160 and Egfl6 KO mice and found these genes are individually dispensable for female fertility. KO mice with no phenotypic data are seldom published, but we believe that this information must be shared to prevent unnecessary experimentation by other laboratories.

Type 1 diabetes genetic risk score discriminates between monogenic and Type 1 diabetes in children diagnosed at the age of <5 years in the Iranian population

AIM

To examine the extent to which discriminatory testing using antibodies and Type 1 diabetes genetic risk score, validated in European populations, is applicable in a non-European population.

METHODS

We recruited 127 unrelated children with diabetes diagnosed between 9 months and 5 years from two centres in Iran. All children underwent targeted next-generation sequencing of 35 monogenic diabetes genes. We measured three islet autoantibodies (islet antigen 2, glutamic acid decarboxylase and zinc transporter 8) and generated a Type 1 diabetes genetic risk score in all children.

RESULTS

We identified six children with monogenic diabetes, including four novel mutations: homozygous mutations in WFS1 (n=3), SLC19A2 and SLC29A3, and a heterozygous mutation in GCK. All clinical features were similar in children with monogenic diabetes (n=6) and in the rest of the cohort (n=121). The Type 1 diabetes genetic risk score discriminated children with monogenic from Type 1 diabetes [area under the receiver-operating characteristic curve 0.90 (95% CI 0.83-0.97)]. All children with monogenic diabetes were autoantibody-negative. In children with no mutation, 59 were positive to glutamic acid decarboxylase, 39 to islet antigen 2 and 31 to zinc transporter 8. Measuring zinc transporter 8 increased the number of autoantibody-positive individuals by eight.

CONCLUSIONS

The present study provides the first evidence that Type 1 diabetes genetic risk score can be used to distinguish monogenic from Type 1 diabetes in an Iranian population with a large number of consanguineous unions. This test can be used to identify children with a higher probability of having monogenic diabetes who could then undergo genetic testing. Identification of these individuals would reduce the cost of treatment and improve the management of their clinical course.

Relationship between surrogate estimates and direct measurement of insulin resistance in women with polycystic ovary syndrome

PURPOSE

To evaluate the relationship between surrogate estimates of insulin resistance and a direct measurement of insulin-mediated glucose uptake women with and without PCOS.

METHODS

Retrospective cohort study of 75 PCOS and 118 controls. Fasting plasma glucose and insulin concentrations, insulin resistance as determined by the insulin suppression test, calculation of multiple surrogate estimates of insulin resistance, total and free testosterone concentrations, and correlations between the direct measure and surrogate estimates of insulin resistance were evaluated.

RESULT(S)

Surrogate markers of insulin resistance were correlated to a variable, but statistically significant degree with the direct measure of insulin resistance in control population and the women with PCOS. There was no correlation between the surrogate estimates of insulin resistance and total or free plasma testosterone concentrations.

CONCLUSION(S)

The surrogate estimates of insulin resistance evaluated were significantly related to a direct measure of insulin resistance, and this was true of both the control population and women with PCOS. The magnitude of the relationship between the surrogate estimates and the direct measurement was comparable and not significantly altered by androgen levels. Fasting plasma insulin concentration seems to be at least as accurate as any other surrogate estimate, and is by far the simplest.

In situ probing of switchable nanomechanical properties of responsive high-density polymer brushes on poly(dimethylsiloxane): An AFM nanoindentation approach

Nanomechanical characteristics of end grafted polymer brushes were studied by AFM based, colloidal probe nanoindentation measurements. A high-density polymer brush of poly(2-hydroxyethyl methacrylate) (PHEMA) was precisely prepared on the surface of a flexible poly(dimethylsiloxane) (PDMS) substrate oxidized in ultraviolet/ozone (UVO). Exposure times less than 10min resulted in laterally homogeneous oxidized surfaces, characterized by a SiO_x thickness ∼35nm and an increased modulus up to 9MPa, as shown by AFM nanoindentation measurements. We have demonstrated that a high surface density of up to ∼0.63chains/nm² of the well-defined PHEMA brushes can be grown from the surface of oxidized PDMS by surface-initiated atom transfer radical polymerization (SI-ATRP) from trimethoxysilane derivatives mixed-SAM. The reversible nanomechanical changes of PHEMA layer between extended (hydrated state) and collapsed (dehydrated state) chain upon immersing in selective and non-selective solvents were investigated by in situ AFM nanoindentation analysis in liquid environments. The elastic modulus derived from force-indentation curves obtained for swollen PHEMA grafted chains in water was estimated to be equal 2.7±0.2MPa, which is almost two orders of magnitude smaller than the modulus of dry PHEMA brush. Additionally, under cyclohexane immersion, the modulus of the PHEMA layer decreased by one order of magnitude, indicating a more compact chain packing at the PDMS surface.

Dietary weight loss in insulin-resistant non-obese humans: Metabolic benefits and relationship to adipose cell size

BACKGROUND AND AIMS

Overweight and obesity increase risk for diabetes and cardiovascular disease, largely through development of insulin resistance. Benefits of dietary weight loss are documented for obese individuals with insulin resistance. Similar benefits have not been shown in overweight individuals. We sought to quantify whether dietary weight loss improves metabolic risk profile in overweight insulin-resistant individuals, and evaluated potential mediators between weight loss and metabolic response.

METHODS AND RESULTS

Healthy volunteers with BMI 25-29.9 kg/m2 underwent detailed metabolic phenotyping including insulin-mediated-glucose disposal, fasting/daylong glucose, insulin, triglycerides, FFA, and cholesterol. Subcutaneous fat biopsies were performed for measurement of adipose cell size. After 14 weeks of hypocaloric diet and 2 weeks of weight maintenance, cardiometabolic measures and biopsies were repeated. Changes in weight, % body fat, waist circumference, adipose cell size and FFA were evaluated as predictors of change in insulin resistance. Weight loss (4.3 kg) yielded significant improvements in insulin resistance and all cardiovascular risk markers except glucose, HDL-C, and LDL-C. Improvement in insulin sensitivity was greater among those with <2 vs >2 cardiovascular risk factors at baseline. Decrease in adipose cell size and waist circumference, but not weight or body fat, independently predicted improvement in insulin resistance.

CONCLUSIONS

Weight loss yields metabolic health benefits in insulin-resistant overweight adults, even in the absence of classic cardiovascular risk factors. Weight loss-related improvement in insulin sensitivity may be mediated through changes in adipose cell size and/or central distribution of body fat. The insulin-resistant subgroup of overweight individuals should be identified and targeted for dietary weight loss.

CLINICAL TRIALS IDENTIFIER

NCT00186459.

RSPH6A is required for sperm flagellum formation and male fertility in mice

The flagellum is an evolutionarily conserved appendage used for sensing and locomotion. Its backbone is the axoneme and a component of the axoneme is the radial spoke (RS), a protein complex implicated in flagellar motility regulation. Numerous diseases occur if the axoneme is improperly formed, such as primary ciliary dyskinesia (PCD) and infertility. Radial spoke head 6 homolog A (RSPH6A) is an ortholog of Chlamydomonas RSP6 in the RS head and is evolutionarily conserved. While some RS head proteins have been linked to PCD, little is known about RSPH6A. Here, we show that mouse RSPH6A is testis-enriched and localized in the flagellum. Rsph6a knockout (KO) male mice are infertile as a result of their short immotile spermatozoa. Observation of the KO testis indicates that the axoneme can elongate but is disrupted before accessory structures are formed. Manchette removal is also impaired in the KO testis. Further, RSPH9, another radial spoke protein, disappeared in the Rsph6a KO flagella. These data indicate that RSPH6A is essential for sperm flagellar assembly and male fertility in mice.This article has an associated First Person interview with the first author of the paper.

Revolutionizing male fertility factor research in mice by using the genome editing tool CRISPR/Cas9

Background

Reproductive research is quintessential in understanding not only the cause of infertility, but also for creating family planning tools. The knockout (KO) system approach is conducive to discovering genes that are essential for fertility in mice. However, in vivo research has been limited due to its high cost and length of time needed to establish KO mice.

Methods

The mechanisms behind the CRISPR/Cas9 system and its application in investigating male fertility in mice are described by using original and review articles.

Results

The CRISPR/CAS9 SYSTEM has enabled researchers to rapidly, efficiently, and inexpensively produce genetically modified mice to study male fertility. Several genes have been highlighted that were found to be indispensable for male fertility by using the CRISPR/Cas9 system, as well as more complicated gene manipulation techniques, such as point mutations, tag insertions, and double knockouts, which have become easier with this new technology.

Conclusion

In order to increase efficiency and usage, new methods of CRISPR/Cas9 integration are being developed, such as electroporation and applying the system to embryonic stem cells. The hidden mysteries of male fertility will be unraveled with the help of this new technology.

EFFECTS OF VARIOUS TREATMENTS ON SILICONE RUBBER SURFACE

Hydroxy groups were generated on a poly(dimethylsiloxane) (PDMS) surface using different methods. Attempts were made to prepare a homogeneous film on the PDMS surface and eliminate microwrinkles from the surface. Because the hydroxylation process changes the chemical composition of the PDMS surface, resulting in a cracked surface, selecting the best method for surface treatment with minimized surface microwrinkles and cracks was attempted. The results obtained from scanning electron microscopy showed that using the pulsed ultraviolet-ozone (UVO) radiation method with a controlled duration time, ozone treatment, continuous UVO treatment using a glass filter, and water media in UVO treatment was more effective than other methods evaluated in this study to prevent microwrinkles. The results obtained from contact angle measurements and attenuated total reflectance Fourier transform infrared spectroscopy revealed that the UVO treatment in the presence of a water medium created more hydroxy groups compared with other methods.

Self-assembling nano mixed-brushes having co-continuous surface morphology by melt growing single crystals and comparison with solution patterned leopard-skin surface morphology

The behavior of melt-grown mixed-brushes was studied and compared with the behavior of the corresponding solution-grown matrix-dispersed mixed-brushes.

Effect of liraglutide administration and a calorie-restricted diet on lipoprotein profile in overweight/obese persons with prediabetes

BACKGROUND AND AIMS

To evaluate the effects of 14 weeks of liraglutide plus modest caloric restriction on lipid/lipoprotein metabolism in overweight/obese persons with prediabetes.

METHODS AND RESULTS

Volunteers with prediabetes followed a calorie-restricted diet (-500 Kcal/day) plus liraglutide (n = 23) or placebo (n = 27) for 14 weeks. The groups were similar in age (58 ± 7 vs. 58 ± 8 years) and body mass index (31.9 ± 2.8 vs. 31.9 ± 3.5 kg/m(2)). A comprehensive lipid/lipoprotein profile was obtained before and after intervention using vertical auto profile (VAP). Weight loss was greater in the liraglutide group than in the placebo group (6.9 vs. 3.3 kg, p < 0.001), as was the fall in fasting plasma glucose concentration (9.9 mg/dL vs. 0.3 mg/dL, p < 0.001). VAP analysis revealed multiple improvements in lipid/lipoprotein metabolism in liraglutide-treated compared with placebo-treated volunteers, including decreases in concentrations of total cholesterol, low-density lipoprotein cholesterol and several of its subclasses, triglyceride, and non-high-density cholesterol. The liraglutide-treated group also had a significant shift away from small, dense low-density lipoprotein-particles, as well as decreases in apolipoprotein B concentration and ratio of apolipoprotein B/apolipoprotein A-1. There were no significant changes in the lipoprotein profile in the placebo-treated group.

CONCLUSION

Treatment with liraglutide plus modest calorie restriction led to enhanced weight loss, a decrease in fasting plasma glucose concentration, and improvement in multiple aspects of lipid/lipoprotein metabolism associated with increased cardiovascular disease (CVD) risk. The significant clinical benefit associated with liraglutide-assisted weight loss in a group at high risk for CVD - obese/overweight individuals with prediabetes - as seen in our pilot study, suggests that this approach deserves further study.

A novel approach to prepare polymer mixed-brushes via single crystal surface patterning

Single crystals having matrix-dispersed surface morphologies were prepared and characterized.

Microstructure and characteristic properties of gelatin/chitosan scaffold prepared by a combined freeze-drying/leaching method

A combined freeze-drying and particulate leaching method for scaffold synthesis showed an improvement in the horizontal microstructure of the gelatin/chitosan scaffolds. Type and concentration of the cross-linking agent, freezing temperature, concentration of the polymeric solution and gelatin/chitosan weight ratio were the variables affecting the scaffold properties. Assessment of the tensile properties of the scaffolds revealed that for a scaffold with 50% chitosan, glutaraldehyde, as a cross-linking agent, created much tighter polymeric network compared to N,N-(3-dimethylaminopropyl)-N'-ethyl carbodiimide (EDC). However, in the case of gelatin scaffolds, EDC was identified as the stronger cross-linker. Compressive behavior of the scaffolds satisfied formulations obtained from the theoretical modeling of the low-density, elastomeric foams. The investigation of the scaffold degradation indicated that the increase in the mechanical strength of the scaffolds would not always reduce their degradation rate.