Regulation of retinoic acid synthetic enzymes by WT1 and HDAC inhibitors in 293 cells

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.

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.

Mitochondria and immunity in chronic fatigue syndrome

It is widely accepted that the pathophysiology and treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) could be considerably improved. The heterogeneity of ME/CFS and the confusion over its classification have undoubtedly contributed to this, although this would seem a consequence of the complexity of the array of ME/CFS presentations and high levels of diverse comorbidities. This article reviews the biological underpinnings of ME/CFS presentations, including the interacting roles of the gut microbiome/permeability, endogenous opioidergic system, immune cell mitochondria, autonomic nervous system, microRNA-155, viral infection/re-awakening and leptin as well as melatonin and the circadian rhythm. This details not only relevant pathophysiological processes and treatment options, but also highlights future research directions. Due to the complexity of interacting systems in ME/CFS pathophysiology, clarification as to its biological underpinnings is likely to considerably contribute to the understanding and treatment of other complex and poorly managed conditions, including fibromyalgia, depression, migraine, and dementia. The gut and immune cell mitochondria are proposed to be two important hubs that interact with the circadian rhythm in driving ME/CFS pathophysiology.

Loss of ARID1A induces a stemness gene ALDH1A1 expression with histone acetylation in the malignant subtype of cholangiocarcinoma

Genomic analyses have recently discovered the malignant subtype of human intrahepatic cholangiocarcinoma (ICC) characterized by frequent mutations of chromatin remodeling gene ARID1A; however, the biological and molecular functions still remain obscure. We here examined the clinical and biological significances of ARID1A deficiency in human ICC. Immunohistochemical analysis demonstrated that the loss of ARID1A was an independent prognostic factor for overall survival of ICC patients (P = 0.023). We established ARID1A-knockout (KO) cells by using the CRISPR/Cas9 system from two human cholangiocarcinoma cell lines. ARID1A-KO cells exhibited significantly enhanced migration, invasion, and sphere formation activity. Microarray analysis revealed that ALDH1A1, a stemness gene, was the most significantly elevated genes in ARID1A-KO cells. In addition, ALDH enzymatic activity as a hallmark of cancer stem cells was markedly high in the KO cells. ARID1A and histone deacetylase 1 were directly recruited to the ALDH1A1 promoter region in cholangiocarcinoma cells with undetectable ALDH1A1 expression by chromatin immunoprecipitation assay. The histone H3K27 acetylation level at the ALDH1A1 promoter region was increased in cells when ARID1A was disrupted (P < 0.01). Clinically, inverse correlation between ARID1A and ALDH1A1 expression was also identified in primary ICC (P = 0.018), and ARID1A-negative and ALDH1A1-positve ICCs showed worse prognosis than only ARID1A-negative cases (P = 0.002). In conclusion, ARID1A may function as a tumor suppressor in ICC through transcriptional downregulation of ALDH1A1 expression with decreasing histone H3K27 acetylation. Our studies provide the basis for the development of new epigenetic approaches to ARID1A-negative ICC. Immunohistochemical loss of ARID1A is an independent prognostic factor in intrahepatic cholangiocarcinoma patients. ARID1A recruits HDAC1 to the promoter region of ALDH1A1, a stemness gene, and epigenetically suppresses ALDH1A1 expression with decreasing histone H3K27 acetylation in cholangiocarcinoma cells.

How Microbial Food Fermentation Supports a Tolerant Gut

The gastrointestinal tract harbors a complex resident microbial ecosystem, comprising over 500 species, spanning commensals, mutualist, opportunistic, and professional pathogens thriving on undigested food components originating from the diet and endogenous secretions. Despite this high concentration of food and bacterial antigens, a healthy gut has a near absent level of inflammation, a status called intestinal immune homeostasis. This immune homeostasis is built and maintained in the presence, and interestingly, with cooperation of the microbiota. The microbiota ferments undigested food components into a wide variety of metabolites, some of which interact with the intestinal immune system. In particular short-chain fatty acids, aryl hydrocarbon receptor ligands, and bile acid metabolites have been involved in the induction of intestinal immune homeostasis. The production of these metabolites is influenced by the microbial load and community structure, as well as the availability of substrates and the gut environment which are directly or indirectly modulated by food intake. In this manuscript, the factors that influence the production of these metabolites and their interaction with the immune cells that play key roles in maintaining intestinal immune homeostasis in the healthy gut are reviewed.

Integrating Autism Spectrum Disorder Pathophysiology: Mitochondria, Vitamin A, CD38, Oxytocin, Serotonin and Melatonergic Alterations in the Placenta and Gut

BACKGROUND

A diverse array of data has been associated with autism spectrum disorder (ASD), reflecting the complexity of its pathophysiology as well as its heterogeneity. Two important hubs have emerged, the placenta/prenatal period and the postnatal gut, with alterations in mitochondria functioning crucial in both.

METHODS

Factors acting to regulate mitochondria functioning in ASD across development are reviewed in this article.

RESULTS

Decreased vitamin A, and its retinoic acid metabolites, lead to a decrease in CD38 and associated changes that underpin a wide array of data on the biological underpinnings of ASD, including decreased oxytocin, with relevance both prenatally and in the gut. Decreased sirtuins, poly-ADP ribose polymerase-driven decreases in nicotinamide adenine dinucleotide (NAD+), hyperserotonemia, decreased monoamine oxidase, alterations in 14-3-3 proteins, microRNA alterations, dysregulated aryl hydrocarbon receptor activity, suboptimal mitochondria functioning, and decreases in the melatonergic pathways are intimately linked to this. Many of the above processes may be modulating, or mediated by, alterations in mitochondria functioning. Other bodies of data associated with ASD may also be incorporated within these basic processes, including how ASD risk factors such as maternal obesity and preeclampsia, as well as more general prenatal stressors, modulate the likelihood of offspring ASD.

CONCLUSION

Such a mitochondria-focussed integrated model of the pathophysiology of ASD has important preventative and treatment implications.

Inhibition of GSK3 Represses the Expression of Retinoic Acid Synthetic Enzyme ALDH1A2 via Wnt/β-Catenin Signaling in WiT49 Cells

Organogenesis, including renal development, requires an appropriate retinoic acid concentration, which is established by differential expression of aldehyde dehydrogenase 1 family member A2 (ALDH1A2) and cytochrome P450 family 26 subfamily A/B/C member 1 (CYP26A1/B1/C1). In the fetal kidney, ALDH1A2 expresses in the developing stroma and renal vesicle and its derivatives but does not present in the ureteric bud. It remains unclear what may contribute to this expression pattern. Here we show that the glycogen synthase kinase 3 alpha/beta (GSK3A/B) inhibitor CHIR99021 significantly represses ALDH1A2 expression in WiT49, which is a Wilms’ tumor cell line that exhibits “triphasic” differential potential and is used as a fetal kidney cell model. CHIR99021 fails to suppress ALDH1A2 as β-catenin is inhibited, suggesting that the downregulation of ALDH1A2 by CHIR99021 is through Wnt/β-catenin signaling. Ectopic expression of mouse Wnt1, Wnt3a, Wnt4, and Wnt9b represses ALDH1A2 expression in WiT49 cells. Using immunohistochemistry, we show an inverse correlation of Aldh1a2 expression with β-catenin in rat E18.5 kidney. ChIP demonstrated that β-catenin is recruited to the ALDH1A2 promoter, the conserved intron1G, and another site within intron 1 of ALDH1A2. Using a luciferase assay, we further show that the ALDH1A2 promoter and the intron1G element are involved in the repression of ALDH1A2 expression by CHIR99021. Our work demonstrates that ALDH1A2 expression can be directly repressed by the Wnt/β-catenin signaling in fetal kidney cells, suggesting that Wnt/β-catenin may play a role in maintaining the expression pattern of ALDH1A2 in the fetal kidney, thus controlling the availability and localization of retinoic acid and regulating aspects of kidney development.

Endometriosis Pathoetiology and Pathophysiology: Roles of Vitamin A, Estrogen, Immunity, Adipocytes, Gut Microbiome and Melatonergic Pathway on Mitochondria Regulation

Endometriosis is a common, often painful, condition that has significant implications for a woman’s fertility. Classically, endometriosis has been conceptualized as a local estrogen-mediated uterine condition driven by retrograde menstruation. However, recent work suggests that endometriosis may be a systemic condition modulated, if not driven, by prenatal processes. Although a diverse array of factors have been associated with endometriosis pathophysiology, recent data indicate that the low body mass index and decreased adipogenesis may be indicative of an early developmental etiology with alterations in metabolic function crucial to endometriosis pathoetiology.

The present article reviews the data on the pathoetiology and pathophysiology of endometriosis, suggesting key roles for alterations in mitochondria functioning across a number of cell types and body systems, including the immune system and gut microbiome. These changes are importantly regulated by decreases in vitamin A and its retinoic acid metabolites as well as increases in mitochondria estrogen receptor-beta and the N-acetylserotonin/melatonin ratio across development. This has treatment and future research implications for this still poorly managed condition, as well as for the association of endometriosis with a number of cancers.