Activation of lipophagy ameliorates cadmium-induced neural tube defects via reducing low density lipoprotein cholesterol levels in mouse placentas.

Neural tube defects (NTDs) represent a prevalent and severe category of congenital anomalies in humans. Cadmium (Cd) is an environmental teratogen known to cause fetal NTDs. However, its underlying mechanisms remain elusive. This study aims to investigate the therapeutic potential of lipophagy in the treatment of NTDs, providing valuable insights for future strategies targeting lipophagy activation as a means to mitigate NTDs.We successfully modeled NTDs by Cd exposure during pregnancy. RNA sequencing was employed to investigate the transcriptomic alterations and functional enrichment of differentially expressed genes in NTD placental tissues. Subsequently, pharmacological/genetic (Atg5-/- placentas) experiments confirmed that inducing placental lipophagy can alleviate Cd induced-NTDs. We found that Cd exposure caused NTDs. Further analyzed transcriptomic data from the placentas with NTDs which revealed significant downregulation of low-density lipoprotein receptor associated protein 1(Lrp1) gene expression responsible for positive regulation of low-density lipoprotein cholesterol (LDL-C) transport. Correspondingly, there was an increase in maternal serum/placenta/amniotic fluid LDL-C content. Subsequently, we have discovered that Cd exposure activated placental lipophagy. Pharmacological/genetic (Atg5-/- placentas) experiments confirmed that inducing placental lipophagy can alleviate Cd induced-NTDs. Furthermore, our findings demonstrate that activation of placental lipophagy effectively counteracts the Cd-induced elevation in LDL-C levels. Lipophagy serves to mitigate Cd-induced NTDs by reducing LDL-C levels within mouse placentas.

m6A-methylated Lonp1 drives mitochondrial proteostasis stress to induce testicular pyroptosis upon environmental cadmium exposure.

Cadmium (Cd) is a widely distributed typical environmental pollutant and one of the most toxic heavy metals. It is well-known that environmental Cd causes testicular damage by inducing classic types of cell death such as cell apoptosis and necrosis. However, as a new type of cell death, the role and mechanism of pyroptosis in Cd-induced testicular injury remain unclear. In the current study, we used environmental Cd to generate a murine model with testicular injury and AIM2-dependent pyroptosis. Based on the model, we found that increased cytoplasmic mitochondrial DNA (mtDNA), activated mitochondrial proteostasis stress occurred in Cd-exposed testes. We used ethidium bromide to generate mtDNA-deficient testicular germ cells and further confirmed that increased cytoplasmic mtDNA promoted AIM2-dependent pyroptosis in Cd-exposed cells. Uracil-DNA glycosylase UNG1 overexpression indicated that environmental Cd blocked UNG-dependent repairment of damaged mtDNA to drive the process in which mtDNA releases to cytoplasm in the cells. Interestingly, we found that environmental Cd activated mitochondrial proteostasis stress by up-regulating protein expression of LONP1 in testes. Testicular specific LONP1-knockdown significantly reversed Cd-induced UNG1 protein degradation and AIM2-dependent pyroptosis in mouse testes. In addition, environmental Cd significantly enhanced the m6A modification of Lonp1 mRNA and its stability in testicular germ cells. Knockdown of IGF2BP1, a reader of m6A modification, reversed Cd-induced upregulation of LONP1 protein expression and pyroptosis activation in testicular germ cells. Collectively, environmental Cd induces m6A modification of Lonp1 mRNA to activate mitochondrial proteostasis stress, increase cytoplasmic mtDNA content, and trigger AIM2-dependent pyroptosis in mouse testes. These findings suggest that mitochondrial proteostasis stress is a potential target for the prevention of testicular injury.

NBR1-dependent autophagy activation protects against environmental cadmium-evoked placental trophoblast senescence.

Cadmium (Cd), a well-established developmental toxicant, accumulates in the placentae and disrupts its structure and function. Population study found adverse pregnancy outcomes caused by environmental Cd exposure associated with cell senescence. However, the role of autophagy activation in Cd-induced placental cell senescence and its reciprocal mechanisms are unknown. In this study, we employed animal experiments, cell culture, and case-control study to investigate the above mentioned. We have demonstrated that exposure to Cd during gestation induces placental senescence and activates autophagy. Pharmacological and genetic interventions further exacerbated placental senescence induced by Cd through the suppression of autophagy. Conversely, activation of autophagy ameliorated Cd-induced placental senescence. Knockdown of NBR1 exacerbated senescence in human placental trophoblast cells. Further investigations revealed that NBR1 facilitated the degradation of p21 via LC3B. Our case-control study has demonstrated a positive correlation between placental senescence and autophagy activation in all-cause fetal growth restriction (FGR). These findings offer a novel perspective for mitigating placental aging and placental-origin developmental diseases induced by environmental toxicants.

Environmental cadmium inhibits testicular testosterone synthesis via Parkin-dependent MFN1 degradation.

Low testosterone (T) levels are associated with many common diseases, such as obesity, male infertility, depression, and cardiovascular disease. It is well known that environmental cadmium (Cd) exposure can induce T decline, but the exact mechanism remains unclear. We established a murine model in which Cd exposure induced testicular T decline. Based on the model, we found Cd caused mitochondrial fusion disorder and Parkin mitochondrial translocation in mouse testes. MFN1 overexpression confirmed that MFN1-dependent mitochondrial fusion disorder mediated the Cd-induced T synthesis suppression in Leydig cells. Further data confirmed Cd induced the decrease of MFN1 protein by increasing ubiquitin degradation. Testicular specific Parkin knockdown confirmed Cd induced the ubiquitin-dependent degradation of MFN1 protein through promoting Parkin mitochondrial translocation in mouse testes. Expectedly, testicular specific Parkin knockdown also mitigated testicular T decline. Mito-TEMPO, a targeted inhibitor for mitochondrial reactive oxygen species (mtROS), alleviated Cd-caused Parkin mitochondrial translocation and mitochondrial fusion disorder. As above, Parkin mitochondrial translocation induced mitochondrial fusion disorder and the following T synthesis repression in Cd-exposed Leydig cells. Collectively, our study elucidates a novel mechanism through which Cd induces T decline and provides a new treatment strategy for patients with androgen disorders.

Maternal prednisone exposure during pregnancy elevates susceptibility to osteoporosis in female offspring: The role of mitophagy/FNDC5 alteration in skeletal muscle.

Maternal exposure to glucocorticoids has been associated with adverse outcomes in offspring. However, the consequences and mechanisms of gestational exposure to prednisone on susceptibility to osteoporosis in the offspring remain unclear. Here, we found that gestational prednisone exposure enhanced susceptibility to osteoporosis in adult mouse offspring. In a further exploration of myogenic mechanisms, results showed that gestational prednisone exposure down-regulated FNDC5/irisin protein expression and activation of OPTN-dependent mitophagy in skeletal muscle of adult offspring. Additional experiments elucidated that activated mitophagy significantly inhibited the expression of FNDC5/irisin in skeletal muscle cells. Likewise, we observed delayed fetal bone development, downregulated FNDC5/irisin expression, and activated mitophagy in fetal skeletal muscle upon gestational prednisone exposure. In addition, an elevated total m6A level was observed in fetal skeletal muscle after gestational prednisone exposure. Finally, gestational supplementation with S-adenosylhomocysteine (SAH), an inhibitor of m6A activity, attenuated mitophagy and restored FNDC5/irisin expression in fetal skeletal muscle, which in turn reversed fetal bone development. Overall, these data indicate that gestational prednisone exposure increases m6A modification, activates mitophagy, and decreases FNDC5/irisin expression in skeletal muscle, thus elevating osteoporosis susceptibility in adult offspring. Our results provide a new perspective on the earlier prevention and treatment of fetal-derived osteoporosis.

Multigenerational paternal obesity enhances the susceptibility to male subfertility in offspring via Wt1 N6-methyladenosine modification.

There is strong evidence that obesity is a risk factor for poor semen quality. However, the effects of multigenerational paternal obesity on the susceptibility to cadmium (a reproductive toxicant)-induced spermatogenesis disorders in offspring remain unknown. Here, we show that, in mice, spermatogenesis and retinoic acid levels become progressively lower as the number of generations exposed to a high-fat diet increase. Furthermore, exposing several generations of mice to a high fat diet results in a decrease in the expression of Wt1, a transcription factor upstream of the enzymes that synthesize retinoic acid. These effects can be rescued by injecting adeno-associated virus 9-Wt1 into the mouse testes of the offspring. Additionally, multigenerational paternal high-fat diet progressively increases METTL3 and Wt1 N6-methyladenosine levels in the testes of offspring mice. Mechanistically, treating the fathers with STM2457, a METTL3 inhibitor, restores obesity-reduced sperm count, and decreases Wt1 N6-methyladenosine level in the mouse testes of the offspring. A case-controlled study shows that human donors who are overweight or obese exhibit elevated N6-methyladenosine levels in sperm and decreased sperm concentration. Collectively, these results indicate that multigenerational paternal obesity enhances the susceptibility of the offspring to spermatogenesis disorders by increasing METTL3-mediated Wt1 N6-methyladenosine modification.

Bladder neck contracture following transurethral surgery of prostate: a retrospective single-center study.

PURPOSE: Bladder neck contracture (BNC) is a rare but intolerant complication after transurethral surgery of prostate. The present study aims to investigate the incidence and risk factors of BNC in patients diagnosed benign prostate hyperplasia (BPH) and following transurethral resection or enucleation of the prostate (TURP/TUEP). METHODS: This retrospective study included 1008 BPH individuals who underwent transurethral surgery of the prostate between January 2017 and January 2022. Patients' demographics, medical comorbidities, urologic characteristics, perioperative parameters, and the presence of BNC were documented. Univariate and multivariate analyses were conducted to identify the risk factors. RESULTS: A total of 2% (20/1008) BPH patients developed BNC postoperatively and the median occurring time was 5.8 months. Particularly, the incidences of BNC were 4.7% and 1.3% in patients underwent Bipolar-TURP and TUEP respectively. Preoperative urinary tract infection (UTI), elevated PSA, smaller prostate volume (PV), bladder diverticulum (BD), and B-TURP were significantly associated with BNC in the univariate analysis. Further multivariate logistic regression demonstrated preoperative UTI (OR 4.04, 95% CI 2.25 to 17.42, p < 0.001), BD (OR 7.40, 95% CI 1.83 to 31.66, p < 0.001), and B-TURP (OR 3.97, 95% CI 1.55 to 10.18, p = 0.004) as independent risk factors. All BNC patients were treated with transurethral incision of the bladder neck (TUIBN) combined with local multisite injection of betamethasone. During a median follow-up of 35.8 months, 35% (7/20) of BNC patients recurred at a median time of 1.8 months. CONCLUSION: BNC was a low-frequency complication following transurethral surgery of prostate. Preoperative UTI, BD, and B-TURP were likely independent risk factors of BNC. TUIBN combined with local multisite injection of betamethasone may be promising choice for BNC treatment.

Association between the Khorana risk score and all-cause mortality in Japanese patients with gastric and colorectal cancer: A retrospective cohort study.

BACKGROUND: The Khorana risk score (KRS) has poor predictive value for cancer-associated thrombosis in a single tumor type but is associated with early all-cause mortality from cancer. Evidence for the association between KRS and all-cause mortality in Japanese patients with gastric and colorectal cancer is limited. AIM: To investigate whether KRS was independently related to all-cause mortality in Japanese patients with gastric and colorectal cancer after adjusting for other covariates and to shed light on its temporal validity. METHODS: Data from Dryad database were used in this study. Patients in the Gastroenterology Department of Sapporo General Hospital, Sapporo, Japan, were enrolled. The starting and ending dates of the enrollment were January 1, 2008 and January 5, 2015, respectively. The cutoff date for follow-up was May 31, 2016. The independent and dependent (target) variables were the baseline measured using the KRS and final all-cause mortality, respectively. The KRS was categorized into three groups: Low-risk group (= 0 score), intermediate-risk group (1-2 score), and high-risk group (≥ 3 score). RESULTS: Men and patients with Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≥ 2 displayed a higher 2-year risk of death than women and those with ECOG PS 0-1 in the intermediate/high risk group for KRS. The higher the score, the higher the risk of early death; however, the relevance of this independent prediction decreased with longer survival. The overall survival of each patient was recorded via real-world follow-up and retrospective observations, and this study yielded the overall relationship between KRS and all-cause mortality. CONCLUSION: The prechemotherapy baseline of KRS was independently associated with all-cause mortality within 2 years; however, this independent predictive relationship weakened as survival time increased.

Loss of Atg5 in Sertoli cells enhances the susceptibility of cadmium-impaired testicular spermatogenesis in mice.

Cadmium (Cd), one of the most common contaminants in diet and drinking water, impairs testicular germ cell development and spermatogenesis. Autophagy is essential for maintaining Sertoli cell function and Sertoli-germ cell communication. However, the role of Sertoli cell autophagy in Cd-caused spermatogenesis disorder remains unclear. Here, the mice of autophagy-related gene 5 (Atg5) knockouts in Sertoli cells were used to investigate the effect of autophagy deficiency on Cd-impaired spermatogenesis and its underlying mechanisms. Results showed that Sertoli cell-specific knockout of Atg5 exacerbated Cd-reduced sperm count and MVH (a specific marker for testicular germ cells) level in mice. Additionally, Sertoli cell Atg5 deficiency reduced the number of spermatocytes and decreased the level of meiosis-related proteins (SYCP3 and STRA8) in Cd-treated mouse testes. Loss of Atg5 in Sertoli cell exacerbated Cd-reduced the level of retinoic acid (RA) and retinal dehydrogenase (ALDH1A1 and ALDH1A) in mouse testes. Meanwhile, we found that the level of transcription factor WT1 was significantly downregulated in Atg5-/- plus Cd-treated testes. Further experiments showed that Wt1 overexpression restored Cd-decreased the levels of ALDH1A1 in Sertoli cells. Collectively, the above data suggest that knockout of Atg5 in Sertoli cell enhances the susceptibility of Cd-impaired testicular spermatogenesis. These findings provide new insights into autophagy of Sertoli cell preventing environmental toxicants-impaired testicular spermatogenesis.

Sperm Rhoa m6A modification mediates intergenerational transmission of paternally acquired hippocampal neuronal senescence and cognitive deficits after combined exposure to environmental cadmium and high-fat diet in mice.

Little is currently known about the effect and mechanism of combined paternal environmental cadmium (Cd) and high-fat diet (HFD) on offspring cognitive ability. Here, using in vivo model, we found that combined paternal environmental Cd and HFD caused hippocampal neuronal senescence and cognitive deficits in offspring. MeRIP-seq revealed m6A level of Rhoa, a regulatory gene of cellular senescence, was significantly increased in combined environmental Cd and HFD-treated paternal sperm. Interestingly, combined paternal environmental Cd and HFD markedly enhanced Rhoa mRNA, its m6A and reader protein IGF2BP1 in offspring hippocampus. STM2457, the inhibitor of m6A modification, markedly mitigated paternal exposure-caused the elevation of hippocampal Rhoa m6A, neuronal senescence and cognitive deficits in offspring. In vitro experiments, Rhoa siR significantly reversed mouse hippocampal neuronal senescence. Igf2bp1 siR obviously reduced the level and stability of Rhoa in aging mouse hippocampal neuronal cells. In conclusion, combined paternal environmental Cd and HFD induce offspring hippocampal neuronal senescence and cognitive deficits by promoting IGF2BP1-mediated Rhoa stabilization in offspring hippocampus via elevating Rhoa m6A in paternal sperm.

Activation of Atg5-dependent placental lipophagy ameliorates cadmium-induced fetal growth restriction.

Cadmium (Cd), an environmental contaminant, can result in placental non-selective autophagy activation and fetal growth restriction (FGR). However, the role of placental lipophagy, a selective autophagy, in Cd-induced FGR is unclear. This work uses case-control study, animal experiments and cultures of primary human placental trophoblast cells to explore the role of placental lipophagy in Cd-induced FGR. We found association of placental lipophagy and all-cause FGR. Meanwhile, pregnancy Cd exposure induced FGR and placental lipophgay. Inhibition of placental lipophagy by pharmacological and genetic means (Atg5-/- mice) exacerbated Cd-caused FGR. Inversely, activating of placental lipophagy relieved Cd-stimulated FGR. Subsequently, we found that activation of Atg5-dependent lipophagy degrades lipid droplets to produce free cholesterol, and promotes placental progesterone (P4) synthesis. Gestational P4 supplementation significantly reversed Cd-induced FGR. Altogether, activation of Atg5-dependent placental lipophagy ameliorates Cd-induced FGR.

Spongimides A and B, two new alkaloids from the marine sponge Spongia sp.

Two new alkaloids, spongimides A (1) and B (2), along with five known ones (3-7), were isolated from the marine sponge Spongia sp. The structures of 1 and 2 were determined by the spectroscopic methods (UV, IR, MS, and NMR) and X-ray diffraction analysis. Compounds 1, 3, and 4 were the first examples of 2,4-imidazolidinediones isolated from this genus. In addition, the cytotoxic and antibacterial activities of compounds 1 and 2 were also evaluated.

Gestational cadmium exposure disrupts fetal liver development via repressing estrogen biosynthesis in placental trophoblasts.

Cadmium (Cd), commonly found in diet and drinking water, is known to be harmful to the human liver. Nevertheless, the effects and mechanisms of gestational Cd exposure on fetal liver development remain unclear. Here, we reported that gestational Cd (150 mg/L) exposure obviously downregulated the expression of critical proteins including PCNA, Ki67 and VEGF-A in proliferation and angiogenesis in fetal livers, and lowered the estradiol concentration in fetal livers and placentae. Maternal estradiol supplement alleviated aforesaid impairments in fetal livers. Our data showed that the levels of pivotal estrogen synthases, such as CYP17A1 and 17ß-HSD, was markedly decreased in Cd-stimulated placentae but not fetal livers. Ground on ovariectomy (OVX), we found that maternal ovarian-derived estradiol had no major effects on Cd-impaired development in fetal liver. In addition, Cd exposure activated placental PERK signaling, and inhibited PERK activity could up-regulated the expressions of CYP17A1 and 17ß-HSD in placental trophoblasts. Collectively, gestational Cd exposure inhibited placenta-derived estrogen synthesis via activating PERK signaling, and therefore impaired fetal liver development. This study suggests a protective role for placenta-derived estradiol in fetal liver dysplasia shaped by toxicants, and provides a theoretical basis for toxicants to impede fetal liver development by disrupting the placenta-fetal-liver axis.

New and effective method to develop primary hepatocytes from liver cancer patients.

Liver cancer (LC) is one of the most common malignant tumors worldwide. Since the mechanism of LC pathogenesis and metastasis cannot be carried out directly on the human body, it is particularly important to establish human liver cancer cell lines for research in vitro. In this study, tissue block adherence method combined with cell clumps digestion method was used to establish primary human hepatocytes (PHHs) with a successful rate of 60% (45/75). Short tandem repeat (STR) analysis proved the cells were derived from its paired tissues. These cells from hepatocellular carcinoma (HCC) expressed NTCP and secreted ALB and AAT as detected by western blot, and expressed hepatocyte-specific membrane protein ASGR1 as detected by flow cytometry. Liver cancer biomarkers like CK7 in ICC (intrahepatic cholangiocarcinoma), AFP, and GPC3 in HCC expressed of different degree as detected by immunohistochemical analysis. These cells displayed typical liver cancer cell morphological characteristics and can passage stably. In conclusion, we developed an effective method to establish PHHs. Further studies are necessary to study if these cells maintaining other liver function and reproduce the physiology of the tumors and how these cells behavior in the drug development.

DNA methylation and single-nucleotide polymorphisms in DDX58 are associated with hand, foot and mouth disease caused by enterovirus 71.

BACKGROUND: This research aimed to explore the association between the RIG-I-like receptor (RIG-I and MDA5 encoded by DDX58 and IFIH1, respectively) pathways and the risk or severity of hand, foot, and mouth disease caused by enterovirus 71 (EV71-HFMD). In this context, we explored the influence of gene methylation and polymorphism on EV71-HFMD. METHODOLOGY/PRINCIPAL FINDINGS: 60 healthy controls and 120 EV71-HFMD patients, including 60 mild EV71-HFMD and 60 severe EV71-HFMD patients, were enrolled. First, MiSeq was performed to explore the methylation of CpG islands in the DDX58 and IFIH1 promoter regions. Then, DDX58 and IFIH1 expression were detected in PBMCs using RT-qPCR. Finally, imLDR was used to detect DDX58 and IFIH1 single-nucleotide polymorphism (SNP) genotypes. Severe EV71-HFMD patients exhibited higher DDX58 promoter methylation levels than healthy controls and mild EV71-HFMD patients. DDX58 promoter methylation was significantly associated with severe HFMD, sex, vomiting, high fever, neutrophil abundance, and lymphocyte abundance. DDX58 expression levels were significantly lower in mild patients than in healthy controls and lower in severe patients than in mild patients. Binary logistic regression analysis revealed statistically significant differences in the genotype frequencies of DDX58 rs3739674 between the mild and severe groups. GeneMANIA revealed that 19 proteins displayed correlations with DDX58, including DHX58, HERC5, MAVS, RAI14, WRNIP1 and ISG15, and 19 proteins displayed correlations with IFIH1, including TKFC, IDE, MAVS, DHX58, NLRC5, TSPAN6, USP3 and DDX58. CONCLUSIONS/SIGNIFICANCE: DDX58 expression and promoter methylation were associated with EV71 infection progression, especially in severe EV71-HFMD patients. The effect of DDX58 in EV71-HFMD is worth further attention.

Effect of autoinduction and food on the pharmacokinetics of furmonertinib and its active metabolite characterized by a population pharmacokinetic model.

Furmonertinib (AST2818) is a novel third-generation irreversible EGFR TKI and recently has been approved in China for the treatment of non-small cell lung cancer (NSCLC) with EGFR-sensitizing and T790M resistance mutations. In the current study, we developed a semi-mechanistic population pharmacokinetic model to characterize the nonstationary pharmacokinetics (PK) of the furmonertinib and its active metabolite AST5902 simultaneously. The PK data of furmonertinib and AST5902 were obtained from 38 NSCLC patients and 16 healthy volunteers receiving 20-240 mg furmonertinib in three clinical trials. A nonlinear mixed-effects modeling approach was used to describe the PK data. The absorption process of furmonertinib was described by a transit compartment model. The disposition of both furmonertinib and AST5902 was described by a two-compartment model. An indirect response model accounted for the autoinduction of furmonertinib metabolism mediated by CYP3A4. The model-based simulation suggested that furmonertinib clearance was increased in one cycle of treatment (orally once daily for 21 days) compared to baseline, ranging from 1.1 to 1.8 fold corresponding to the dose range of 20-240 mg. The concentration of furmonertinib was decreased over time whereas that of AST5902 was increased. Interestingly, the concentration of the total active compounds (furmonertinib and AST5902) appeared to be stable. The food intake, serum alkaline phosphatase and body weight were identified as statistically significant covariates. The mechanism of food effect on PK was investigated, where the food intake might increase the bioavailability of furmonertinib via increasing the splanchnic blood flow. Overall, a population PK model was successfully developed to characterize the nonstationary PK of furmonertinib and AST5902 simultaneously. The concentrations of total active compounds were less affected by the autoinduction of furmonertinib metabolism.

Gestational cadmium exposure impairs placental angiogenesis via activating GC/GR signaling.

Gestational exposure to environmental Cd caused placental angiogenesis impairment and fetal growth restriction (FGR). However, its mechanism remained unclear. This study was to investigate the effects of Cd exposure during pregnancy on placental angiogenesis and its mechanism. Pregnant mice were exposed to CdCl2 (4.5 mg/kg) on gestational day (GD) 8 with or without melatonin (MT) (5.0 mg/kg), an anti-endoplasmic reticulum stress agent, from GD7 to GD15. Human primary placental trophoblasts and JEG-3 cells were stimulated using CdCl2 (20 µM) after MT (1 mM) preprocessing. We firstly found MT treatment obviously mitigated environmental Cd-induced placental angiogenesis disorder and reduction of the VEGF-A level. Mechanistically, MT reversed environmental Cd-downregulated the protein expression of VEGF-A via inhibiting glucocorticoid receptor (GR) activation. Notably, our data showed MT treatment antagonized Cd-activated GC/GR signaling via blocking PERK signaling and thereby upregulated VEGF-A and 11ß-HSD2 protein expression. Based upon the population case-control study, the levels of VEGF-A and 11ß-HSD2 protein in small-for-gestational-age placentae were significantly reduced when compared to appropriate-for-gestational-age placentae. Overall, environmental Cd exposure during gestation impaired placental angiogenesis via PERK-regulated GC/GR signaling in placental trophoblasts. Our findings will provide a basis for prevention and treatment of placental impairments and fetal growth restriction caused by environment toxicants in future.

New Reticular Chemistry of the Rod Secondary Building Unit: Synthesis, Structure, and Natural Gas Storage of a Series of Three-Way Rod Amide-Functionalized Metal-Organic Frameworks.

Reticular chemistry and methane storage materials have been predominately focused on finite metal-cluster-based metal-organic frameworks (MOFs). In contrast, MOFs constructed from infinite rod secondary building units (SBUs), i.e., rod MOFs, are less developed, and the existing ones are typically built from simple one-way helical, zigzag, or (mixed)polyhedron SBUs. Herein, inspired by a recent unveiled structure of Zn6(H2O)3(BTP)4 and by means of an amide-functionalized preliminary single tricarboxylate, a subsequent mixed tricarboxylate, and dicarboxylate linkers, an intricate three-way rod MOF and the next three isoreticular three-way rod MOFs have been successfully realized, namely, 3W-ROD-1 and 3W-ROD-2-X (X = -OH, -F, and -CH3), respectively. The structural analyses disclosed that the four compounds were constructed from unprecedented three-way invariant nonintersecting trigonal rod-packing SBUs cross-linked via the noncovalent-interaction-driven self-assembly of pseudo hexacarboxylates with the original tricarboxylate or different functional ditopic linkers, resulting in cage-like pore geometries accessible via ultramicroporous apertures concomitant with the complex topology transitivity, namely, 18 42 and 18 44. Sorption studies show that the apparent surface areas of these materials are among the most highly porous materials for rod MOFs. Due to the presence of favorable pocket sites created by X, ketone, and proximal amide groups as revealed by Monte Carlo molecular dynamics (MCMD) computational calculations, the MOFs exhibit impressive methane storage working capacities, outperforming the well-known rod Ni-MOF-74 and representing the highest values among rigid rod MOFs.

Two bone blocks sandwich technique for horizontal reconstruction of severely atrophic alveolar ridge in anterior maxilla: A case report.

BACKGROUND: Severe horizontal bone deficiency of the maxillary anterior region is considered a major challenge in reconstruction and successful implant placement. Various approaches have been developed to augment bone volume. Of these approaches, onlay bone graft, alveolar bone splitting, and guided bone regeneration have been suggested. CASE SUMMARY: A 22-year-old female patient, with no previous medical history, presented to the Department of Oral Implantology, Wuhan University due to a missing right maxillary incisor. The X-ray results showed severe horizontal bone deficiency, with an available bone width of 3.1-4.0 mm. The two bone blocks sandwich technique was performed to augment the bone volume. After 6 months healing, X-ray results showed that the newly formed alveolar ridge dimension increased to 4.7-9.5 mm horizontally. Implant insertion surgery was performed and all-ceramic restorations were fabricated. The implant was stable at the 1-year follow-up visit after restoration, and the X-ray showed a stable bone level around the dental implant. The scores for the pink esthetic score and white esthetic score were 12 and 8, respectively, and the patient was satisfied with the esthetic outcome. CONCLUSION: The two bone blocks sandwich technique may be an alternative treatment option in augmenting severe horizontal bone deficiency of the anterior maxilla.