Does over-expression of transforming growth factor-beta account for the increased morbidity in African-Americans?: Possible clinical study and therapeutic implications

Genetic and Epidemiological Similarities, and Differences Between Postoperative Intraperitoneal Adhesion Development and Other Benign Fibro-proliferative Disorders

Intraperitoneal adhesions complicate over half of abdominal-pelvic surgeries with immediate, short, and long-term sequelae of major healthcare concern. The pathogenesis of adhesion development is similar to the pathogenesis of wound healing in all tissues, which if unchecked result in production of fibrotic conditions. Given the similarities, we explore the published literature to highlight the similarities in the pathogenesis of intra-abdominal adhesion development (IPAD) and other fibrotic diseases such as keloids, endometriosis, uterine fibroids, bronchopulmonary dysplasia, and pulmonary, intraperitoneal, and retroperitoneal fibrosis. Following a literature search using PubMed database for all relevant English language articles up to November 2020, we reviewed relevant articles addressing the genetic and epidemiological similarities and differences in the pathogenesis and pathobiology of fibrotic diseases. We found genetic and epidemiological similarities and differences between the pathobiology of postoperative IPAD and other diseases that involve altered fibroblast-derived cells. We also found several genes and single nucleotide polymorphisms that are up- or downregulated and whose products directly or indirectly increase the propensity for postoperative adhesion development and other fibrotic diseases. An understanding of the similarities in pathophysiology of adhesion development and other fibrotic diseases contributes to a greater understanding of IPAD and these disease processes. At a very fundamental level, blocking changes in the expression or function of genes necessary for the transformation of normal to altered fibroblasts may curtail adhesion formation and other fibrotic disease since this is a prerequisite for their development. Similarly, applying measures to induce apoptosis of altered fibroblast may do the same; however, apoptosis should be at a desired level to simultaneously ameliorate development of fibrotic diseases while allowing for normal healing. Scientists may use such information to develop pharmacologic interventions for those most at risk for developing these fibrotic conditions.

Migraines and keloids: a 15-year Taiwan claim database analysis

Background

Fibroproliferative lesions with intractable pruritus, pain and hyperesthesia that cause uncontrolled scar growth are known as keloids. Migraines are common upsetting headache disorders characterised by frequent recurrence and attacks aggravated by physical activity. Both keloids and migraines can cause physical exhaustion and discomfort in patients; they have similar pathophysiological pathways, that is, the transforming growth factor-β1 gene and neurogenic inflammation.

Objective

To investigate subsequent development of migraines in patients with keloids.

Methods

Data were retrieved from the Taiwan National Health Insurance Research Database. The keloids group included patients aged 20 years and older with a recent diagnosis of keloids(n=9864). The non-keloids group included patients without keloids matched for gender and age at 1–4 ratio (n=39 456). Migraine risk between groups was measured by Cox proportional hazards regression models. Incidence rates and hazard ratios were calculated.

Results

During the study period, 103 keloids patients and 323 non-keloids patients developed migraines. The keloids patients had a 2.29-fold greater risk of developing migraines compared with the non-keloids group after adjustment for covariates (1.81 vs 0.55 per 1000 person-years, respectively). In the keloids group, female or patients younger than 50 years were prone to developing migraines.

Conclusion

The higher tendency to develop migraines in the keloids group in comparison with the non-keloids group suggests that keloids could be a predisposing risk factor for migraine development in adults. Keloids patients who complain of headaches should be examined for migraines.

Outcomes of Ex-PRESS and Trabeculectomy in a Glaucoma Population of African Origin: One Year Results

Aim

To compare the efficacy and safety of Ex-PRESS glaucoma filtration surgery to trabeculectomy in African origin patients.

Materials and methods

A retrospective chart review was performed on 56 African American patients undergoing Ex-PRESS glaucoma shunt (E) or trabeculectomy (T) between 2004 and 2012. Data collected included intraocular pressure (IOP) and glaucoma medication use at baseline and postoperative week 1, Month (M) 1, M3, M6, M12. Postoperative interventions including laser suture lysis (LSL) and 5FU injections were analyzed. Complete and qualified success rate, and eyes failing and requiring more surgery were determined. Means, SD, chi-square, and Student’s t-test were performed.

Results

A total of 56 subjects (E 28, T 28) were included in the analysis. There was a statistically significant reduction (p < 0.05) in IOP and number of glaucoma medications at all time points compared to baseline for both groups. Extent of IOP reduction between groups was not statistically significant at any time point, except postoperative week 1. Mean number of glaucoma medications between groups was not significant, except at 3 months (lower in EXP group). The cumulative number of postoperative interventions within 3 months (LSL and 5-FU) was significantly greater for the TRAB than EXP (3.89 ± 2.4 vs 2.36 ± 2.2, p = 0.007). Success rates were comparable between both groups (Table 2).

Conclusion

Our study is unique in patients of African origin showing statistical significance in the requirement of less postoperative 5-FU injections during the first 3 months following surgery in the Ex-PRESS group vs the trabeculectomy group. The Ex-PRESS shunt was as effective as trabeculectomy in reducing IOP and use of glaucoma medications up to 1 year.

Clinical significance

The possible benefit of this article is to help guiding ophthalmologists to select the type of glaucoma filtration surgery to undergo in an African American patient with glaucoma.

How to cite this article

Bustros YD, Fechtner R, Khouri AS. Outcomes of Ex-PRESS and Trabeculectomy in a Glaucoma Population of African Origin: One Year Results. J Curr Glaucoma Pract 2017;11(2):42-47.

Ethnic differences in heterotopic ossification following total hip arthroplasty

Aims

We aimed to assess the influence of ethnicity on the incidence of heterotopic ossification (HO) after total hip arthroplasty (THA).

Patients and Methods

We studied the six-month post-operative anteroposterior radiographs of 1449 consecutive primary THAs (1324 patients) and retrospectively graded them for the presence of HO, using the Brooker Classification.

Results

Based on multivariate analysis, African-American ethnicity was an independent risk factor for HO formation following THA with an adjusted odds ratio (OR) of 2.6 (95% confidence interval (CI) 1.3 to 5.2, p = 0.007) for severe HO and 1.9 (95% CI 1.3 to 2.7, p < 0.001) for any grade of HO.

Conclusion

Given the increased risk of HO formation, particularly high grade HO, and the potentially poorer outcomes associated with HO, it is important to consider using prophylaxis against HO in patients of African-American ethnicity undergoing THA. Take home message: African Americans are at an increased risk for developing heterotopic ossification and thus may benefit from HO prophylaxis. Cite this article: Bone Joint J 2016;98-B:761–6.

Pleiotropic Effects of Immune Responses Explain Variation in the Prevalence of Fibroproliferative Diseases

Many diseases are differentially distributed among human populations. Differential selection on genetic variants in ancestral environments that coincidentally predispose to disease can be an underlying cause of these unequal prevalence patterns. Selected genes may be pleiotropic, affecting multiple phenotypes and resulting in more than one disease or trait. Patterns of pleiotropy may be helpful in understanding the underlying causes of an array of conditions in a population. For example, several fibroproliferative diseases are more prevalent and severe in populations of sub-Saharan ancestry. We propose that this disparity is due to selection for an enhanced Th2 response that confers resistance to helminthic infections, and concurrently increases susceptibility to fibrosis due to the profibrotic action of Th2 cytokines. Many studies on selection of Th2-related genes for host resistance to helminths have been reported, but the pleiotropic impact of this selection on the distribution of fibrotic disorders has not been explicitly investigated. We discuss the disproportionate occurrence of fibroproliferative diseases in individuals of African ancestry and provide evidence that adaptation of the immune system has shaped the genetic structure of these human populations in ways that alter the distribution of multiple fibroproliferative diseases.

Transforming growth factor-β signaling induced during prostate cancer cell death and neuroendocrine differentiation is mediated by bone marrow stromal cells

INTRODUCTION

Prostate cancer that has metastasized to bone undergoes critical interactions with bone marrow stromal cells (BMSCs), ultimately promoting tumor survival. Previous studies have shown that BMSCs secrete factors that promote prostate cancer apoptosis or neuroendocrine differentiation. Because of the significance of transforming growth factor-β (TGF-β) family cytokines in cytostasis and bone metastasis, the role of TGF-β signaling in the context of prostate cancer-BMSC interactions was investigated.

METHODS

The role of TGF-β family signaling in BMSC-induced apoptosis of lineage-related prostate cancer cells was investigated in live/dead assays. SMAD phosphorylation or activity during apoptosis and neuroendocrine differentiation was investigated using immunofluorescence, Western blotting, and luciferase reporter assays, along with the ALK-4, -5, -7 kinase inhibitor, SB-431542.

RESULTS

Treatment of castration-resistant prostate cancer cells with SB-431542 resulted in significant reduction of apoptosis mediated by HS-5 BMSCs, supporting the involvement of TGF-β/SMAD signaling during this event. Interestingly, however, pre-treatment of BMSCs with TGF-β1 (5 ng/mL) yielded a conditioned medium that elicited a marked reduction in prostate cancer death. Phosphorylated-SMAD2 (P-SMAD2) was activated in BMSC-triggered transdifferentiated prostate cancer cells, as demonstrated through immunoblotting and luciferase reporter assays. However, SB-431542 did not restore androgen receptor and prostate specific antigen levels down-regulated by BMSC-secreted factors. Prostate cancer cells induced to undergo neuroendocrine differentiation in a BMSC-independent mechanism also showed elevated levels of P-SMAD2.

DISCUSSION

Collectively, our findings indicate that: (1) TGF-β family cytokines or regulated factors secreted from BMSCs are involved in prostate cancer apoptosis; (2) TGF-β signaling in prostate cancer cells is induced during neuroendocrine differentiation; and (3) TGF-β1 stimulation of BMSCs alters paracrine signaling to create a permissive environment for prostate cancer survival, suggesting a mechanism for prostate cancer-mediated colonization of bone.

CONCLUSIONS

TGF-β signaling resulting in activation of SMAD2 in prostate cancer may be an indicator of cellular stress in the presence of toxic paracrine factors released from the bone marrow stroma, ultimately fostering prostate cancer colonization of bone.

Blood pressure homeostasis is maintained by a P311-TGF-β axis

P311 is an 8-kDa intracellular protein that is highly conserved across species and is expressed in the nervous system as well as in vascular and visceral smooth muscle cells. P311-null (P311-/-) mice display learning and memory defects, but alterations in their vasculature have not been previously described. Here we report that P311-/- mice are markedly hypotensive with accompanying defects in vascular tone and VSMC contractility. Functional abnormalities in P311-/- mice resulted from decreased total and active levels of TGF-β1, TGF-β2, and TGF-β3 that arise as a specific consequence of decreased translation. Vascular hypofunctionality was fully rescued in vitro and in vivo by exogenous TGF-β1-TGF-β3. Conversely, P311-transgenic (P311(TG)) mice had elevated levels of TGF-β1-TGF-β3 and subsequent hypertension. Consistent with findings attained in mouse models, arteries recovered from hypertensive human patients displayed increased P311 expression. Thus, we identified P311 as the first protein known to modulate TGF-β translation and the first pan-regulator of TGF-β expression under steady-state conditions. Together, our findings point to P311 as a critical blood pressure regulator and establish a potential link between P311 expression and the development of hypertensive disease.

Racial and ethnic differences in the pathogenesis and clinical manifestations of uterine leiomyoma

Uterine leiomyomas are the most common benign gynecologic condition. The prevalence is three times more common among women of African ethnicity. Disparity in this disease is evidenced by earlier age of onset, greater severity of symptoms, and different response to treatment. Although the pathogenesis of disease development is not completely known, growing evidence focuses on investigating the molecular mechanisms in disease development and the influence of ethnicity. Variation in the expression levels or function of estrogen and progesterone receptors, polymorphism of genes involved in estrogen synthesis and/or metabolism (COMT, CYP17), retinoic acid nuclear receptors (retinoid acid receptor-α, retinoid X receptor-α), and aberrant expression of micro-RNAs (miRNAs) are some of the molecular mechanisms that may be involved. Nutritional factors, such as vitamin D deficiency, might also contribute to the higher incidence in dark skinned populations who are also commonly suffer from hypovitaminosis D. Culture and environmental difference might have a role in disease development. Further analysis and better understanding of these mechanisms will provide insight into the molecular basis of racial disparities in leiomyoma formation and will help to develop new innovations in leiomyoma treatment.

Keloids and non-diabetic kidney disease: similarities and the APOL1-MYH9 haplotype as a possible genetic link

Keloids and non-diabetic kidney disease are both fibrotic processes that disproportionately affect persons of African descent. Despite similarities in these conditions, the authors identified no studies to date investigating a shared genetic etiology. MYH9 and APOL1 are in linkage disequilibrium and have both been associated with non-diabetic kidney disease. MYH9 codes for a non-muscle myosin that is involved in cell adhesion and locomotion and is known to be overexpressed in keloids. Variations in APOL1 confer resistance to subspecies of Trypanosoma brucei, which may explain why otherwise deleterious genetic alterations in this haplotype could have gained prominence. We feel that the pathophysiological and epidemiological overlap between keloids and non-diabetic kidney disease support a common genetic origin and further investigation into keloids and the MYH9-APOL1 haplotype and keloids is warranted. Furthermore, we feel this haplotype might offer insight into thrombosis, stroke and other conditions that disproportionately affect persons of African descent.

Uterine fibroids and current clinical challenges

Uterine fibroids (UF) are the most common gynecological tumors in premenopausal women. Hysterectomy remains the major and definitive therapeutic option. Minimally invasive surgical techniques for performing hysterectomy have many advantages over laparotomy. Current drug therapies for UF remain unsatisfactory. Unquestionably, continued investigation of novel agents is necessary. The currently used drugs for UF treatment which exclusively modulate a single target, typically either the estrogen or progesterone signaling pathways, are limited in their therapeutic effects. By contrast, multi-target drugs which simultaneously modulate multiple critical hubs in the network of the signaling pathways underlying UF pathogenesis should achieve robust and durable therapeutic effects.

Racial differences between blacks and whites with systemic sclerosis

PURPOSE OF REVIEW

Racial disparities appear to exist in the susceptibility and severity of systemic sclerosis (SSc, scleroderma) and are responsible for a greater health burden in blacks as compared with whites. Disparities in socioeconomic status and access to healthcare do not sufficiently explain the observed differences in prevalence and mortality. It is important to determine whether there might be a biologic basis for the racial disparities observed in SSc.

RECENT FINDINGS

We present data to suggest that the increased susceptibility and severity of SSc in blacks may result in part from an imbalance of profibrotic and antifibrotic factors. Racial differences in the expression of transforming growth factor-β1 (TGF-β1) and caveolin-1, as well as differences in the expression of hepatocyte growth factor and PPAR-γ, have been demonstrated in blacks with SSc, as well as in normal black individuals. A genetic predisposition to fibrosis may account for much of the racial disparities between black and white patients with SSc.

SUMMARY

A better understanding of the biologic basis for the racial disparities observed in SSc may lead to improved therapies, along with the recognition that different therapies may need to be adapted for different groups of patients.

Comparison of characteristics of fibroids in African American and white women undergoing premenopausal hysterectomy

OBJECTIVE

To compare pathologic characteristics and epidemiologic risk factors for uterine fibroids in African American and white women undergoing hysterectomy.

DESIGN

Cross-sectional analysis of women undergoing premenopausal hysterectomy.

SETTING

Two university-associated hospitals in North Carolina.

PATIENT(S)

African American (n = 225) and white women (n = 135) with fibroid diagnosis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Data were obtained from an in-person interview and abstracted from operative and pathologic reports. Analysis of variance and multiple linear regression models were used to identify characteristics associated with higher uterine weight, greater number of fibroids, and size of the largest fibroid.

RESULT(S)

African American women had substantially more fibroids (9.9 vs. 4.5) with a concomitant higher mean uterine weight (477 vs. 267 g). Although African American women had a higher prevalence of established risk factors for fibroids, such as high body mass index (BMI) and hypertension, these factors were not associated with larger uteri or more numerous fibroids. In multiple linear regression models, the only factors statistically significantly associated with higher uterine weight, larger fibroids, and more numerous fibroids were race and nulligravidity.

CONCLUSION(S)

The presentation of fibroids as measured by uterine size or number of fibroids is more severe in African American women compared with white women. The differences in presentation cannot be explained by racial differences in the prevalence of known risk factors. Additional research is needed on environmental and genetic factors that may increase the risk for fibroids.

Are uterine leiomyoma a consequence of a chronically inflammatory immune system?

The cumulative incidence of uterine leiomyoma at age 50 is ≈ 70% in White women and >80% in Black women. Although risk factor research is limited, increasing age, and being premenopausal, nulliparous or Black are risk factors for leiomyomas. Black women tend to have larger leiomyomas and be younger at diagnosis. Surprisingly little is known about the etiology or pathogenesis of uterine leiomyomas. Women with diagnosed uterine leiomyomas have higher healthcare costs - more than 2.5 times that of women without a diagnosis. In the United States, leiomyomas are the leading indication for hysterectomy. The proposed hypothesis is that leiomyomas are caused in part by a systemic immune milieu that is chronically inflammatory - one that predominates in T helper 17 (Th17) cytokines. Inflammation can be problematic if it is not well regulated. Should an inflammatory imbalance be demonstrated to be associated with leiomyoma development and growth, this would provide an avenue for development of preventative treatments (e.g., focus on anti-inflammatory pathways), which would substantially reduce the morbidity costs of these tumors and reduce a known health disparity.